JP2010216651A - Roller bearing and rotating shaft cooling structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a roller bearing and rotating shaft cooling structure which can execute good lubrication and cooling under high temperature and high speed rotating conditions by adjusting a supply amount of lubricant which is supplied to the bearing or the rotating shaft corresponding to the rotating speed and the temperature. <P>SOLUTION: The roller bearing 10 is under-race lubricated and an oil amount adjustment mechanism 20, which allows the supply amount of lubricant (to be supplied) to the inside of the roller bearing 10 to be adjusted according to the rotating speed, is provided with an inner race 13. Moreover, either the rotating speed sensitive valve 70 or the temperature sensitive valve 80 is arranged to the oil passage 46, 49, 55, 56, 57 which are prepared in the rotating shaft 41 and the roller bearing 60, and the lubricant of the quantity corresponding to the rotating speed and temperature of the of rotating shaft 41 is supplied. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rolling bearing and a rotating shaft cooling structure, and more specifically, a rolling bearing incorporated in a gas turbine, a jet engine, a machine tool, a turbocharger of an automobile, and the like and used under high temperature and high speed rotation conditions. And a rotating shaft cooling structure.

  Rolling bearings that are incorporated and used in gas turbines, jet engines, machine tools, automobile turbochargers, and the like support rotating shafts that rotate at high speeds, and therefore require sufficient lubrication and cooling. For the purpose of lubricating and cooling the rolling bearing used under such high-speed rotation conditions, conventionally, the lubricating oil is jetted from the oil supply hole having an opening in the inner ring raceway groove of the inner ring toward the rolling element. So-called under-lace lubrication is employed. Further, there has been proposed one that enables high-speed rotation by actively cooling a rotating shaft that rises in temperature due to high-speed rotation.

  As an apparatus for performing conventional under-lace lubrication, V is provided on the inner ring raceway surface through a lubrication hole from the bottom of an annular groove formed on one axial end face of the inner ring by the action of centrifugal force accompanying the rotation of the inner ring. Lubricant is supplied to the groove, and a stable amount of lubricating oil is directly blown toward the rolling element from the clearance for the lubricating oil formed between the opening of the V-shaped groove and the rolling element for lubrication. A rolling bearing device is known (for example, see Patent Document 1).

  In addition, a lubricating oil injection nozzle that supplies lubricating oil to the inside of the rolling bearing is provided, and a compressed air injection nozzle that injects compressed air toward the gap between the outer ring and the cage is provided, and the supplied lubricating oil is supplied to the outer ring. There is known a bearing lubrication device that prevents and stays on the raceway surface to lubricate and cool a rolling bearing used under high temperature and high speed rotation conditions (see, for example, Patent Document 2).

  Further, a flow rate adjusting means for adjusting the flow rate of the lubricating oil is provided in a passage formed in the rotary shaft so as to communicate with the oil supply hole provided in the inner ring, and the flow rate of the lubricating oil supplied to the inside of the bearing is controlled by the rotary shaft. There is disclosed a lubricating oil flow rate adjusting device that adjusts according to the rotational speed of the oil to achieve a stable supply of lubricating oil (see, for example, Patent Document 3).

  In addition, when the temperature of the inner and outer rings of the bearing that supports the rotating shaft is measured and the temperature of the coolant is independently controlled based on the measured temperature of the bearing, the rotating shaft rotates at a high speed and the bearing generates heat. However, a rotating shaft device of a machine tool that suppresses the preload of the bearing within an appropriate range is known (for example, see Patent Document 4).

  Further, a bearing device is known that includes a temperature sensor that measures the temperature of the bearing that supports the rotating shaft, and supplies lubricating oil in an amount corresponding to the temperature of the bearing to the bearing (see, for example, Patent Document 5). ).

Japanese Patent Laid-Open No. 11-182560 JP 2000-192971 A Japanese Patent No. 3084356 JP 2007-90518 A JP 2008-2591 A

  The rolling bearing device described in Patent Document 1 is configured to stably supply lubricating oil from a gap formed between the opening and the rolling element by the action of centrifugal force accompanying the rotation of the inner ring. However, it does not have a function of adjusting the amount of oil supply with a change in the rotational speed. Therefore, a sufficient amount of lubricating oil is not supplied to the rolling bearing during high-speed rotation and heat is generated, and during low-speed rotation, the amount of lubricating oil supplied is excessive, which is caused by the stirring resistance of the lubricating oil. There was a risk that the bearing torque would increase.

  Further, the bearing lubrication device described in Patent Document 2 prevents the lubricating oil from staying in the outer ring by the action of the centrifugal force accompanying the rotation of the inner ring, and efficiently circulates the lubricating oil to improve the lubrication efficiency and the cooling efficiency. This is an improvement, and the amount of oil supply cannot be adjusted as the rotational speed changes. In addition, there is a problem that ancillary equipment is required outside the bearing.

  Moreover, although the lubricating oil flow control apparatus of the said patent document 3 can adjust the amount of oil supply supplied according to a rotational speed, since the lubricating oil flow control apparatus is arrange | positioned at the rotating shaft. The assembly of the rolling bearing and the lubricating oil flow rate adjustment device is complicated and there is room for improvement.

  Further, the techniques described in Patent Document 4 and Patent Document 5 require additional processing for installing a temperature sensor on the rotating shaft and the housing, and have a problem of lack of mass productivity. Further, in order to extract measurement data from the rotating body to the outside, generally an expensive device such as a slip ring, a telemeter, or a non-contact type measuring device is required, which increases the size and cost. There was a problem.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a rotary shaft and a rolling bearing by a simple mechanism, corresponding to the rotational speed, or depending on the bearing temperature (rotational shaft temperature). An object of the present invention is to provide a rolling bearing and a rotating shaft cooling structure capable of performing satisfactory lubrication and cooling under high temperature and high speed rotation conditions by adjusting the supply amount of lubricating oil supplied to the inside.

The above object of the present invention can be achieved by the following constitution.
(1) An outer ring having an outer ring raceway groove on an inner peripheral surface, an inner ring having an inner ring raceway groove on an outer peripheral surface, and a plurality of rolling elements arranged to be freely rollable between the outer ring raceway groove and the inner ring raceway groove. A rolling bearing that is provided with an under-lace lubrication, and the inner ring includes an oil supply amount adjusting mechanism capable of adjusting a supply amount of lubricating oil supplied to the inside of the rolling bearing according to a rotation speed. .
(2) The oil supply amount adjusting mechanism includes a first oil supply passage provided along the radial direction by communicating an inner ring outer peripheral surface and an inner ring inner peripheral surface provided on an axial side of the inner ring raceway groove, and a first oil supply passage. The second oil supply passage branched from the inner ring raceway groove, the valve body of the needle valve disposed in the first oil supply passage, and the coil that urges the valve body of the needle valve toward the inner peripheral surface of the inner ring A rolling bearing according to (1), comprising a spring.
(3) The rolling bearing according to (2), wherein the second oil supply passage is branched from the first oil supply passage at a position different in the radial direction and includes a plurality of flow passages.
(4) A rotating shaft cooling structure that cools a rotating shaft that is rotatably supported by a rolling bearing with lubricating oil, and is disposed in an oil passage for lubricating oil provided on at least one of the rotating shaft and the rolling bearing. A rotating shaft cooling structure comprising a rotation speed sensitive valve that continuously adjusts the supply amount of lubricating oil according to the rotation speed of the rotating shaft.
(5) A rotating shaft cooling structure that cools a rotating shaft that is rotatably supported by a rolling bearing with lubricating oil, and is disposed in an oil passage for lubricating oil provided on at least one of the rotating shaft and the rolling bearing. A rotating shaft cooling structure comprising a temperature sensitive valve that continuously adjusts the supply amount of lubricating oil in accordance with the temperature of the rotating shaft or rolling bearing.
(6) The rotational speed sensitive valve includes a needle valve and a coil spring that urges the valve body of the needle valve in a direction in which the flow path of the needle valve narrows, and acts on the valve body as the rotary shaft rotates. (4) characterized in that the valve body is moved against the urging force of the coil spring by centrifugal force, and the opening degree of the rotation speed sensitive valve is continuously adjusted according to the rotation speed of the rotation shaft. The rotating shaft cooling structure described.
(7) The temperature sensitive valve is formed of a needle memory and a shape memory alloy that expands when the temperature rises and contracts when the temperature drops. Formed with a first heat-sensitive coil spring that urges in the direction in which the flow path widens, and a shape memory alloy that contracts when the temperature rises and expands when the temperature drops, and passes the valve body through the flow path when the temperature drops A second heat-sensitive coil spring that urges in the direction of narrowing, and expands and contracts the first and second heat-sensitive coil springs according to the temperature of the rolling bearing to increase the opening of the temperature-sensitive valve. The rotating shaft cooling structure according to (5), which is continuously adjusted according to

  According to the rolling bearing of the present invention, the lubrication amount adjusting mechanism provided in the inner ring adjusts the supply amount of the lubricating oil supplied to the rolling bearing according to the rotational speed. Can be efficiently cooled, and good underlace lubrication can be performed even under conditions of high temperature and high speed rotation.

  The oil supply amount adjusting mechanism includes a first oil supply passage that opens to the outer peripheral surface of the inner ring, a second oil supply passage that branches from the first oil supply passage and communicates with the inner ring raceway groove, a needle valve, and a coil speed spring. Therefore, during low-speed rotation, the lubricating oil is supplied mainly to the outer peripheral surface of the inner ring to lubricate the rolling bearing, and the bearing resistance is reduced by suppressing the agitation resistance of the lubricating oil by the rolling elements. Lubricating oil can be supplied to the inner ring raceway groove to sufficiently lubricate the rolling elements and the inner ring raceway groove to prevent poor lubrication and improve the cooling efficiency.

  Furthermore, since the second oil supply passage is branched from the first oil supply passage at a different position in the radial direction and includes a plurality of flow passages, the lubricating oil is supplied to the inner ring raceway groove by changing the flow passage according to the rotational speed. The supply amount of the roller can be precisely and continuously controlled, and the rolling bearing can be lubricated and cooled efficiently.

  Further, according to the rotating shaft cooling structure of the present invention, the rotational speed sensitive valve that continuously adjusts the supply amount of the lubricating oil that cools the rotating shaft according to the rotating speed of the rotating shaft is disposed in the oil passage. Therefore, during low-speed rotation, the amount of lubricating oil supplied is reduced to keep the temperature difference between the rotating shaft and the housing substantially constant, and the amount of lubricating oil supplied is increased as the rotational speed of the rotating shaft is increased. The shaft can be cooled efficiently. Thereby, the stable high-speed rotation of the rotating shaft becomes possible.

  Furthermore, since a temperature-sensitive valve that continuously adjusts the supply amount of the lubricating oil according to the temperature of the rotating shaft or the rolling bearing is disposed in the oil passage, an amount of lubricating oil corresponding to the temperature of the rolling bearing is supplied. It can be supplied to the rolling bearing, and the rolling bearing and the rotating shaft can be efficiently cooled, and good lubrication can be performed even under conditions of high temperature and high speed rotation.

  The rotational speed sensitive valve includes a needle valve and a coil spring that urges the valve body of the needle valve in a direction in which the flow path of the needle valve narrows, and a centrifugal force that acts on the valve body as the rotating shaft rotates. The valve body is moved against the urging force of the coil spring by force, and the opening of the rotational speed sensitive valve is continuously adjusted according to the rotational speed of the rotating shaft. An amount of lubricating oil corresponding to the rotational speed of the shaft can be supplied.

  The temperature-sensitive valve further includes a needle valve and first and second heat-sensitive coil springs formed of a shape memory alloy that expands and contracts depending on the temperature, and the first and second heat-sensitive valves depend on the temperature of the rolling bearing. 2. The thermosensitive coil spring is expanded and contracted, and the opening of the temperature sensitive valve is continuously adjusted according to the temperature of the rolling bearing, so an amount of lubricating oil corresponding to the temperature of the rolling bearing can be applied with a simple mechanism. Can be supplied. As a result, the rotating shaft can be effectively cooled to enable stable high-speed rotation.

It is sectional drawing for demonstrating 1st Embodiment of the rolling bearing which concerns on this invention. It is an expanded sectional view of the periphery of the oil supply amount adjustment mechanism shown in FIG. It is an expanded sectional view for demonstrating an effect | action of the oil supply amount adjustment mechanism at the time of an inner ring stop. It is an expanded sectional view for demonstrating an effect | action of the oil supply amount adjustment mechanism at the time of an inner ring | wheel low speed rotation. It is an expanded sectional view for demonstrating the effect | action of the oil supply amount adjustment mechanism at the time of inner ring | wheel medium speed rotation. It is an expanded sectional view for demonstrating the effect | action of the oil supply amount adjustment mechanism at the time of inner ring high-speed rotation. It is an expanded sectional view for explaining a 2nd embodiment of a rolling bearing concerning the present invention. It is sectional drawing for demonstrating one Embodiment of the rotating shaft cooling structure which concerns on this invention. FIG. 9 is an enlarged cross-sectional view of the rotational speed sensitive valve shown in FIG. 8. It is an expanded sectional view of the temperature sensitive type valve shown in FIG. It is an expanded sectional view of the periphery of a temperature sensitive type valve for explaining a modification of a rotating shaft cooling structure concerning the present invention.

  Hereinafter, embodiments of a rolling bearing and a rotating shaft cooling structure according to the present invention will be described in detail with reference to the drawings.

(First embodiment)
First, with reference to FIGS. 1-6, 1st Embodiment of the rolling bearing which concerns on this invention is described.

  As shown in FIG. 1, the rolling bearing 10 of this embodiment is rotatable by an outer ring 11 having an outer ring raceway groove 12 on an inner peripheral surface, an inner ring 13 having an inner ring raceway groove 14 on an outer peripheral surface, and a cage 15. And a ball 16 which is a plurality of rolling elements that are disposed between the outer ring raceway groove 12 and the inner ring raceway groove 14 while being in contact with the outer ring raceway groove 12 and the inner ring raceway groove 14 at a contact angle α. , Angular ball bearings.

  In the rolling bearing 10, an oil supply amount adjusting mechanism 20 is built in the inner ring 13, and the amount of lubricating oil is adjusted according to the rotation speed and supplied to the inside of the bearing 10. That is, it is a bearing of an under race lubrication system that supplies lubricating oil from the inner ring 13.

  As shown in FIG. 2, the oil supply amount adjusting mechanism 20 is provided along the radial direction by communicating an inner ring outer peripheral surface 21 and an inner ring inner peripheral surface 22 provided on the side in the axial direction of the inner ring raceway groove 14 of the inner ring 13. A first oil supply passage 23, a second oil supply passage 27 that branches from the middle of the first oil supply passage 23 and communicates with the inner ring raceway groove 14, a tapered valve body 30 fitted in the taper hole 24, A coil spring 31 that is disposed between the bottom surface of the tapered hole 24 and the valve body 30 and constantly urges the valve body 30 toward the inner peripheral surface 22 of the inner ring. In the present embodiment, the first oil supply passage 23, the valve body 30, and the coil spring 31 constitute a rotational speed sensitive needle valve.

  The first oil supply passage 23 has a tapered hole 24 whose hole diameter gradually decreases from the inner ring inner peripheral surface 22 side toward the inner ring outer peripheral surface 21 side, and a straight hole 25 that opens to the inner ring outer peripheral surface 21 and communicates with the tapered hole 24. And.

  The second oil supply passage 27 is inclined at an inclination angle β of 15 ° to 75 ° with respect to the first oil supply passage 23, branches from the middle of the tapered hole 24, and opens into the inner ring raceway groove 14. The hole diameter of the second oil supply passage 27 is set to 20 to 80% of the hole diameter of the straight hole 25 of the first oil supply passage 23. Further, the second oil supply passage 27 opens into the inner ring raceway groove 14, and the opening is disposed on the opposite side of the contact point P between the inner ring raceway groove 14 and the ball 16 (see FIG. 1). The oil supply passage 27 has almost no influence on the rigidity of the inner ring 13.

  In addition, although the number of oil supply amount adjustment mechanisms 20 may be one, in order to prevent the change of the gravity center position (bad balance) by installation of the oil supply amount adjustment mechanism 20, it is preferable to provide two or more at equal intervals in the circumferential direction. For the same reason, the valve body 30 is preferably molded from a lightweight material such as light metal or resin.

  The operation of the rolling bearing 10 of this embodiment will be described with reference to FIGS. Note that the lubricating oil is supplied from the lubricating oil supply device to the first oil supply passage 23 from the inner ring inner peripheral surface 22 side through an oil supply hole of a rotating shaft (not shown).

  First, as shown in FIG. 3, when the inner ring 13 is stopped, the valve body 30 is positioned on the inner ring inner peripheral surface 22 side by the spring force of the coil spring 31 because the centrifugal force is not acting. .

  Next, when the inner ring 13 rotates at a low speed, as shown in FIG. 4, the valve body 30 moves radially outward (upward in the figure) by centrifugal force, and the weight of the self-weight and the spring force of the coil spring 31 and the valve It moves to a position where the centrifugal force acting on the body 30 is balanced. Thus, a relatively large annular gap C is formed between the inner surface of the tapered hole 24 and the outer surface of the valve body 30.

  At this time, the lubricating oil supplied from the lubricating oil supply device to the first oil supply passage 23 flows into the space downstream of the valve body 30 through the annular gap C between the tapered hole 24 and the valve body 30, It is supplied to the inner ring outer peripheral surface 21 through the straight hole 25 having a relatively larger hole diameter than the second oil supply passage 27.

  A part of the lubricating oil supplied to the inner ring outer peripheral surface 21 is supplied to the inner ring raceway groove 14 along the inner ring outer peripheral surface 21 to lubricate the inner ring raceway groove 14 and the balls 16. Therefore, excessive lubricating oil is not supplied to the inner ring raceway groove 14, the stirring resistance of the lubricating oil by the balls 16 is suppressed, and the bearing torque can be reduced.

  Next, when the inner ring 13 rotates at a medium speed, as shown in FIG. 5, the centrifugal force acting on the valve body 30 increases according to the rotational speed, and the valve body 30 is subjected to its own weight and the spring force of the coil spring 31. Against this, it moves further outward in the radial direction. As a result, the annular gap C between the tapered hole 24 and the valve body 30 is narrowed, and the overlap between the valve body 30 and the opening of the second oil supply passage 27 on the branch point side is reduced. The amount of lubricating oil supplied to 21 decreases, and the amount of lubricating oil supplied from the second oil supply passage 27 to the inner ring raceway groove 14 increases.

  Next, when the inner ring 13 rotates at a high speed, as shown in FIG. 6, the centrifugal force acting on the valve body 30 is further increased, and the valve body 30 further has a diameter against the own weight and the spring force of the coil spring 31. Move outward in the direction. As a result, the annular gap C between the tapered hole 24 and the valve body 30 is further narrowed, and the overlap between the valve body 30 and the opening of the second oil supply passage 27 on the branch point side is further reduced. The amount of lubricating oil supplied to the outer peripheral surface 21 is minimized, and the lubricating oil is mainly supplied from the second oil supply passage 27 to the inner ring raceway groove 14.

  At this time, the lubricating oil supplied from the straight hole 25 to the outer peripheral surface 21 of the inner ring is blown to the outer ring 11 side by the centrifugal force acting on the lubricating oil, but depending on the rotational speed of the inner ring 13 by the valve body 30. Since the lubricating oil whose supply amount has been adjusted (increased) is supplied from the second oil supply passage 27 to the inner ring raceway groove 14, insufficient lubrication of the inner ring raceway groove 14 and the balls 16 is prevented, and the rolling bearing 10 is efficient. Cooled.

  As described above, according to the rolling bearing 10 of the present embodiment, the oil supply amount adjusting mechanism 20 provided in the inner ring 13 continuously adjusts the supply amount of the lubricating oil supplied to the rolling bearing 10 according to the rotational speed. Therefore, the lubricating oil can be supplied without excess or deficiency according to each rotational speed and can be efficiently cooled.

  The thus configured rolling bearing 10 can be applied to a rotating shaft having a rotational speed of 24,000 rpm or more and a dmn value of 3 million or more, such as a gas turbine, a jet engine, a machine tool, and an automobile turbocharger. Suitable for rolling bearings used under high temperature and high speed rotation conditions.

(Second Embodiment)
Next, a second embodiment of the rolling bearing according to the present invention will be described with reference to FIG. Note that portions that are the same as or equivalent to those of the first embodiment are denoted by the same reference numerals in the drawings, and description thereof is omitted or simplified.

  As shown in FIG. 7, the rolling bearing 10 of the present embodiment includes three flow paths 35, 36, and 37 that constitute the second oil supply path 27. The respective flow paths 35, 36, and 37 are branched from different positions in the radial direction in the first oil supply path 23 (taper hole 24), and open to the inner ring raceway groove 14, respectively. Further, the openings of the flow paths 35, 36, and 37 are all disposed on the opposite side of the contact point P between the inner ring raceway groove 14 and the ball 16 (see FIG. 1).

  In the present embodiment, the flow paths 35, 36, and 37 have a hole diameter d1> hole, where the hole diameter of the flow path 35 is d1, the hole diameter of the flow path 36 is d2, and the hole diameter of the flow path 37 is d3. It is preferable that the diameter d2> the hole diameter d3.

  When the inner ring 13 rotates, the valve body 30 moves upward in the figure against its own weight and the spring force of the coil spring 31 according to the rotational speed. As a result, the annular gap C between the tapered hole 24 and the valve body 30 is narrowed, and the flow paths 35, 36, and 37 through which the valve body 30 has passed are sequentially opened, so that the straight hole 25 supplies the inner ring outer peripheral surface 21. The amount of lubricating oil that is supplied decreases, and the amount of lubricating oil that is supplied to the inner ring raceway groove 14 from the flow paths 35, 36, and 37 increases sequentially.

As described above, according to the rolling bearing 10 of the present embodiment, the second oil supply passage 27 branches from the first oil supply passage 23 at different positions in the radial direction, and the plurality of flow passages 35 having different hole diameters. 36, 37, the flow paths 35, 36, 37 are changed in accordance with the rotational speed, and the supply amount of the lubricating oil supplied to the inner ring raceway groove 14 is precisely and continuously controlled to efficiently roll the bearing. Ten lubrications and coolings can be performed.
About another structure and an effect, it is the same as that of the said 1st Embodiment.

  Next, with reference to FIGS. 8-11, one Embodiment of the rotating shaft cooling structure which concerns on this invention is described.

  As shown in FIG. 8, the rotating shaft cooling structure 40 of the present embodiment includes a rotating shaft 41 that is rotatably supported by a pair of rolling bearings 60, a rotational speed sensitive valve 70, and a temperature sensitive valve 80. And comprising. In FIG. 8, reference numeral 61 denotes an outer ring, 63 denotes an inner ring, 65 denotes a cage, and 66 denotes a ball (rolling element).

  The rotating shaft 41 is a triple-structured shaft including an inner shaft 42, a middle shaft 43 that is externally fitted to the inner shaft 42, and an outer shaft 44 that is externally fitted to the middle shaft 43. Both end portions of the outer shaft 44 are rotatably supported with respect to the housing 90 by a pair of rolling bearings 60.

  An oil supply hole 45 is formed in the inner shaft 42 from one end face in the axial direction. The oil supply hole 45 is formed on the outer periphery of the inner shaft 42 by a first radial oil supply path (oil path) 46 formed in the radial direction. It communicates with the surface. Further, a first oil drain hole 47 is formed in the axial direction from the other end face, and the first oil drain hole 47 is formed in a second radial oil supply path 48 and a third radial direction formed in the radial direction. An oil supply passage (oil passage) 49 communicates with the outer peripheral surface of the inner shaft 42. The third radial direction oil supply passage 49 functions as a branch passage for supplying oil from the first oil drain hole 47 to the rolling bearing 60. The outer peripheral surface opening of the first radial oil supply passage 46 and the outer peripheral surface opening of the second radial oil supply passage 48 communicate with each other through a spiral groove 50 formed on the outer peripheral surface of the inner shaft 42.

  The spiral groove 50 acts as a cooling mechanism that cools the inner shaft 42 and the middle shaft 43, in other words, the rotating shaft 41, with the lubricating oil flowing in the spiral groove 50. The cooling effect of the spiral groove 50 formed in a spiral shape on the outer peripheral surface of the inner shaft 42 is higher than, for example, the cooling effect by the hollow shaft. However, the cooling mechanism is not limited to the spiral groove 50, and any form is possible. Is possible.

  The middle shaft 43 is externally fitted to the inner shaft 42 and is formed in a cylindrical shape to be fitted to the outer shaft 44. From one end surface in the axial direction, the third radial oil supply passage 49 and the middle shaft 43 are An oil supply hole 51 is formed in the axial direction for communicating with a circumferential groove-like oil reservoir 52 formed on the outer peripheral surface of the substantially intermediate portion in the axial direction. In addition, a circumferential groove 53 is formed on the outer peripheral surface of the middle shaft 43 at a position corresponding to each rolling bearing 60. The circumferential groove 53 is formed on the outer peripheral surface of the middle shaft 43 and the inner peripheral surface of the outer shaft 44. The oil reservoir 52 communicates with a gap 54 formed therebetween. The third radial direction oil supply passage 49 communicates the first oil discharge hole 47 of the inner shaft 42 and the oil supply hole 51 of the middle shaft 43.

  The outer shaft 44 includes a radial oil supply passage (oil passage) 55 formed in a radial direction so as to communicate with the inner and outer peripheral surfaces thereof, and the radial oil supply passage 55 rolls with the circumferential groove 53 of the middle shaft 43. A radial oil supply path 56 (oil path) formed in the inner ring 63 of the bearing 60 is communicated. Further, a second oil drain hole (oil passage) 57 communicating with the first oil drain hole 47 of the inner shaft 42 is formed on the end surface of the outer shaft 44.

  In the present embodiment, as shown in FIG. 8, the rotational speed sensitive valve 70 includes the first radial oil supply passage 46 of the inner shaft 42, the radial oil supply passage 55 of the outer shaft 44, and the radial direction of the inner ring 63. The temperature sensitive valve 80 is disposed in the oil supply path 56 and is disposed in the second oil drain hole 57 of the outer shaft 44 and the third radial oil supply path 49 of the inner shaft 42. In addition, the arrangement positions of the rotational speed sensitive valve 70 and the temperature sensitive valve 80 are not limited to the above positions. For example, the rotational speed sensitive valve 70 may be disposed in the third radial oil supply passage 49 of the inner shaft 42, and the temperature sensitive valve 80 may be disposed in the radial oil supply passage 56 of the inner ring 63. Good.

  As shown in FIG. 9, the rotational speed sensitive valve 70 includes a flow path 71 formed integrally with the oil supply path 46, a tapered valve body 74 fitted in the tapered hole 72 of the flow path 71, And a coil spring (a tension coil spring) 75 that is disposed between the bottom surface of the tapered hole 72 and the valve body 74 and constantly urges the valve body 74 toward the bottom surface side of the tapered hole 72. Prepare. The flow path 71 includes a tapered hole 72 whose diameter gradually increases from the inner diameter side toward the outer diameter side, and a straight hole 73 that connects the tapered hole 72 and the inner diameter side flow path (the oil supply hole 45 in the drawing). Composed. The rotational speed sensitive valve 70 is also disposed in the oil supply passages 55 and 56 in the same manner.

  In the rotational speed sensitive valve 70 configured as described above, when the rotational speed sensitive valve 70 rotates with the rotation of the rotating shaft 41, the valve body 74 is moved radially outward (upward in FIG. 9) by centrifugal force. It moves and stops at a position where its own weight and the spring force of the coil spring 75 balance with the centrifugal force acting on the valve element 74. That is, the opening degree of the rotational speed sensitive valve 70 is continuously adjusted according to the rotational speed of the rotary shaft 41, and increases as the rotational speed increases and decreases as the rotational speed decreases. Accordingly, the supply amount of the lubricating oil increases as the rotational speed increases, and decreases as the rotational speed decreases.

  As shown in FIG. 10, the temperature-sensitive valve 80 includes a flow path 81 formed integrally with the oil supply path 49 and a tapered valve body 84 fitted into the tapered hole 82 of the flow path 81. A first heat-sensitive coil spring which is disposed between a needle valve having a tapered hole 82 and a valve body 84 and which is formed of a shape memory alloy that expands when the temperature rises and contracts when the temperature decreases. 85, a second heat-sensitive coil spring 86 which is disposed between the opening side of the tapered hole 82 and the valve body 84 and is formed of a shape memory alloy which contracts when the temperature increases and expands when the temperature decreases. And comprising. The flow path 81 has a tapered hole 82 whose diameter gradually increases from the inner diameter side toward the outer diameter side, and a straight hole 83 that allows the tapered hole 82 and the inner diameter side flow path (the first oil drain hole 47 in the figure) to communicate with each other. And. The temperature sensitive valve 80 is similarly disposed in the second oil drain hole 57, and in this case, the first thermal coil spring 85 and the second thermal coil spring 86 are disposed in reverse. . The first thermal coil spring 85 and the second thermal coil spring 86 may be at least one.

  In the temperature sensitive valve 80 configured as described above, when the rotary shaft 41 rotates at a high speed and the temperature of the rotary shaft 41 rises due to heat generated by the rolling bearing 60, the temperature of the temperature sensitive valve 80 also rises. As a result, the first thermal coil spring 85 expands and the second thermal coil spring 86 contracts, so that the valve body 84 is a spring between the first thermal coil spring 85 and the second thermal coil spring 86. Move to a position where the force balances and stop. That is, the opening degree of the temperature sensitive valve 80 is continuously adjusted according to the temperature of the temperature sensitive valve 80, in other words, the temperature of the rotating shaft 41, and increases as the temperature rises. It becomes smaller as it falls. Therefore, the supply amount of the lubricating oil increases as the temperature increases, and decreases as the temperature decreases. Further, in the temperature sensitive valve 80 disposed in the second oil drain hole 57, since the first heat sensitive coil spring 85 and the second heat sensitive coil spring 86 are disposed in reverse, the operation thereof is the above-described oil supply. The operation of the temperature sensitive valve 80 disposed in the path 49 is reversed.

  Below, an effect | action of the rotating shaft cooling structure 40 of this embodiment is demonstrated. The lubricating oil is supplied from a lubricating oil supply device (not shown) to the oil supply hole 45 of the inner shaft 42, and the lubricating oil that has not been used for lubricating the rolling bearing 60 is the first drain oil hole 47 of the inner shaft 42 and It is assumed that the oil is returned from the second oil drain hole 57 of the outer shaft 44 to the lubricating oil supply device.

  When the rotational speed of the rotating shaft 41 is low, the temperature of the rotating shaft 41 is low, and the rotational speed sensitive valve 70 mainly acts rather than the temperature sensitive valve 80. That is, during low speed rotation, the centrifugal force acting on the valve element 74 of the rotation speed sensitive valve 70 is small, and the opening degree of the rotation speed sensitive valve 70 is small. Thereby, the flow rate of the lubricating oil supplied to the oil supply hole 45 is reduced by the rotational speed sensitive valve 70, and a small amount of lubricating oil is supplied to the spiral groove 50 from the first radial oil supply path 46. Therefore, the cooling effect of the rotating shaft 41 (inner shaft 42) by the lubricating oil is not great. On the other hand, since the heat generated by the rolling bearing 60 during low-speed rotation is small, the temperature of the rotating shaft 41 is thereby maintained substantially constant.

  At this time, since the temperature of the rotating shaft 41 is low, the opening degree of the temperature sensitive valve 80 disposed in the third radial oil supply passage 49 is small, and the lubrication supplied from the spiral groove 50 to the first oil discharge hole 47 is performed. A part of the oil is supplied to the rolling bearing 60 via the temperature sensitive valve 80, and most of the remaining oil is supplied to the lubricating oil supply device via the temperature sensitive valve 80 disposed in the second oil drain hole 57. Will be returned. Thus, by supplying a small amount of lubricating oil to the rolling bearing 60, the rolling bearing 60 can be appropriately cooled, and the agitation resistance of the lubricating oil can be suppressed to reduce the bearing torque.

  On the other hand, when the rotary shaft 41 rotates at a high speed, the heat generation of the rolling bearing 60 increases, and the temperature of the rotary shaft 41 rises. Therefore, the opening degree of the temperature sensitive valve 80 disposed in the third radial oil supply passage 49 is increased. Increases with temperature. Further, since the centrifugal force acting on the valve element 74 of the rotational speed sensitive valve 70 increases, the opening degree of the rotational speed sensitive valve 70 increases in accordance with the rotational speed. Accordingly, the flow rate of the lubricating oil supplied from the first radial oil supply passage 46 to the spiral groove 50 via the rotational speed sensitive valve 70 increases, and the inner shaft 42 (rotating shaft 41) is effectively cooled.

  Further, the lubricating oil supplied from the spiral groove 50 through the second radial oil supply passage 48 to the first oil discharge hole 47 passes through the temperature sensitive valve 80 whose opening degree increases as the temperature of the rotary shaft 41 increases. Accordingly, a relatively large amount of lubricating oil (an amount corresponding to the temperature of the rotating shaft 41) is supplied to the oil supply hole 51, and the lubricating oil supplied to the oil supply hole 51 includes an oil reservoir 52, a gap 54, and a circumferential groove. 53, the radial oil supply passage 55, and the radial oil supply passage 56 are supplied to the rolling bearing 60. The flow rate of the lubricating oil supplied to the rolling bearing 60 is also adjusted by a rotational speed sensitive valve 70 disposed in the radial oil supply passage 55 of the outer shaft 44 and the radial oil supply passage 56 of the inner ring 63. .

  Accordingly, the rolling bearing 60 is properly lubricated and cooled, and the reduction of the bearing gap that occurs when the temperature of the inner ring 63 becomes higher than the temperature of the housing 90 is suppressed to a minimum, so that the preload of the rolling bearing 60 is reduced. Can be maintained within an appropriate range.

  As a modification of the present embodiment, as shown in FIG. 11, a temperature sensitive valve 80 may be disposed in the radial oil supply passage 56 of the inner ring 63 instead of the rotational speed sensitive valve 70. .

  In this modification, the temperature-sensitive valve 80 branches from a first flow path 81 formed integrally with the radial oil supply path 56 of the inner ring 63 and an intermediate portion of the first flow path 81 as shown in FIG. A needle valve having a second flow path 87 that opens into the inner ring raceway groove 64 and a tapered valve body 84 fitted in the tapered hole 82 of the first flow path 81, and the bottom surface of the tapered hole 82. A first heat-sensitive coil spring 85 formed of a shape memory alloy that is disposed between the valve body 84 and expands when the temperature rises and contracts when the temperature decreases, and the opening side of the tapered hole 82. And a second heat-sensitive coil spring 86 formed of a shape memory alloy which is disposed between the valve body 84 and contracts when the temperature rises and expands when the temperature falls. The first flow path 81 communicates with an inner diameter side flow path (radial direction oil supply path 55 in the figure), a tapered hole 82 whose diameter gradually decreases from the inner diameter side toward the outer diameter side, and the tapered hole 82 and the inner ring outer periphery. A straight hole 83 communicating with the surface 63a.

  In the rotating shaft cooling structure 40 configured in this way, a large load acts on one of the pair of rolling bearings 60, or the amount of lubricating oil supplied to one of the rolling bearings 60 is small. When the operating conditions of the rolling bearing 60 are different, the temperature of the rolling bearing 60 is different. In such a case, the temperature sensitive valve 80 on the higher temperature side increases the opening of the valve and supplies a large amount of lubricating oil to lubricate and cool the rolling bearing 60. On the other hand, the temperature-sensitive valve 80 on the lower temperature side reduces the opening of the valve to reduce the supply amount of the lubricating oil. As a result, the temperature difference between the pair of rolling bearings 60 is eliminated and good lubrication is performed.

  As described above, according to the rotating shaft cooling structure 40 of the present embodiment, the rotating shaft 41 used under high-temperature and high-speed rotating conditions such as machine tools, gas turbines, jet engines, and automobile turbochargers, in particular. , The supply amount of the lubricating oil is continuously adjusted as the rotational speed of the rotating shaft 41 increases, so that the rotating shaft 41 is effectively cooled and the rolling bearing 60 is lubricated. Further, as the temperature of the rotating shaft 41 rises, the supply amount of the lubricating oil can be continuously adjusted to cool the rolling bearing 60, and the preload of the rolling bearing 60 can be suppressed to an appropriate range.

In addition, this invention is not limited to what was illustrated to the said embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.
For example, in the above-described embodiment, the oil supply amount adjusting mechanism 20 has been described as a structure including the valve body 30 and the coil spring 31. However, the structure is not limited thereto, and the supply amount of the lubricating oil is set according to the rotation speed. Anything can be used as long as it can be adjusted.

  In the above embodiment, the valve body 74 and the coil spring (tensile coil spring) 75 constitute the rotational speed sensitive valve 70, and the valve body 84 and the first shape memory alloy that expands and contracts depending on the temperature. The temperature-sensitive valve 80 is configured by the second heat-sensitive coil springs 85 and 86. However, the present invention is not limited to this, and the flow rate and flow path of the lubricating oil can be continuously switched depending on the rotation speed or temperature. For example, an electromagnetic valve, a shape memory alloy valve, or the like can be used.

10 Rolling bearings (angular ball bearings)
11 outer ring 12 outer ring raceway groove 13 inner ring 14 inner ring raceway groove 16 ball (rolling element)
DESCRIPTION OF SYMBOLS 20 Oil supply amount adjustment mechanism 21 Inner ring outer peripheral surface 22 Inner ring inner peripheral surface 23 1st oil supply path 27 2nd oil supply path 30 Valve body 31 Coil spring 35, 36, 37 Flow path d1, d2, d3 Hole diameter 40 Rotating shaft cooling structure 41 Rotating shaft 42 Inner shaft 43 Middle shaft 44 Outer shaft 46 First radial oil supply passage (oil passage)
48 Second radial oil supply passage 49 Third radial oil supply passage (oil passage)
50 Spiral groove 55 Radial direction oil supply passage (oil passage)
56 Radial oil supply passage (oil passage)
57 Second oil drain hole (oil passage)
60 Rolling bearing 70 Rotational speed sensitive valve 71 Flow path 74 Valve body 75 Coil spring (Tension coil spring)
80 Temperature-sensitive valve 81 Flow path 84 Valve body 85 First thermal coil spring 86 Second thermal coil spring

Claims (7)

An outer ring having an outer ring raceway groove on an inner peripheral surface, an inner ring having an inner ring raceway groove on an outer peripheral surface, and a plurality of rolling elements arranged to be freely rollable between the outer ring raceway groove and the inner ring raceway groove. A rolling bearing that is lubricated under race,
The rolling bearing according to claim 1, wherein the inner ring includes an oil supply amount adjusting mechanism capable of adjusting a supply amount of lubricating oil supplied to the inside of the rolling bearing according to a rotation speed.   The oil supply amount adjusting mechanism includes a first oil supply passage provided along a radial direction by communicating an inner ring outer peripheral surface and an inner ring inner peripheral surface provided on an axial side of the inner ring raceway groove, and the first oil supply passage. A second oil supply path branched from the inner ring raceway groove, a valve body of a needle valve disposed in the first oil supply path, and a valve body of the needle valve facing the inner peripheral surface of the inner ring The rolling bearing according to claim 1, further comprising a coil spring that biases.   The rolling bearing according to claim 2, wherein the second oil supply passage is branched from the first oil supply passage at a position that is different in a radial direction, and includes a plurality of flow passages. A rotating shaft cooling structure that cools a rotating shaft that is rotatably supported by a rolling bearing with lubricating oil,
A rotational speed sensitive valve that is disposed in an oil passage of the lubricating oil provided in at least one of the rotating shaft and the rolling bearing and continuously adjusts the supply amount of the lubricating oil according to the rotational speed of the rotating shaft. A rotating shaft cooling structure comprising: A rotating shaft cooling structure that cools a rotating shaft that is rotatably supported by a rolling bearing with lubricating oil,
A temperature sensitive sensor that is disposed in an oil passage of the lubricating oil provided in at least one of the rotating shaft and the rolling bearing and continuously adjusts the supply amount of the lubricating oil according to the temperature of the rotating shaft or the rolling bearing. A rotary shaft cooling structure comprising a type valve. The rotational speed sensitive valve includes a needle valve,
A coil spring that biases the valve body of the needle valve in a direction in which the flow path of the needle valve narrows,
The valve body is moved against the urging force of the coil spring by the centrifugal force acting on the valve body with the rotation of the rotary shaft, and the opening degree of the rotational speed sensitive valve is set to the rotational speed of the rotary shaft. The rotating shaft cooling structure according to claim 4, wherein the rotating shaft cooling structure is continuously adjusted according to the above. The temperature sensitive valve includes a needle valve,
A first shape memory alloy that expands when the temperature rises and contracts when the temperature falls, and biases the valve body of the needle valve in a direction in which the flow path of the needle valve widens when the temperature rises. A thermal coil spring;
A second heat-sensitive coil spring that is formed of a shape memory alloy that contracts when the temperature rises and expands when the temperature drops, and biases the valve body in a direction in which the flow path narrows when the temperature drops; With
The first and second thermal coil springs are expanded and contracted according to the temperature of the rolling bearing, and the opening degree of the temperature sensitive valve is continuously adjusted according to the temperature of the rolling bearing. Item 6. The rotating shaft cooling structure according to Item 5.

Images