JPH0635653U - Rolling bearing lubricator - Google Patents

Abstract

(57) [Summary] [Purpose] It is applied to bearings for machine tool spindles used for grease lubrication. The lubricant stored in the lubricant reservoir recess can be supplied in small amounts along with the operation, and the capacity of the recess can be increased, so that excellent lubrication durability can be obtained. [Structure] A lubricant reservoir recess 8 is provided on the outer diameter surface of the shaft 1.
The recess 8 is sealed by the inner ring spacer 6, and a lubricant outflow passage 11 is provided which opens from the lubricant reservoir recess 8 to the rolling passage of the rolling element 5. The outflow passage 11 is formed by a fitting contact surface 9 between the inner ring spacer 6 and the shaft 1 and a contact surface 10 between end surfaces of the inner ring spacer 6 and the inner ring 3. On these contact surfaces 9 and 10, minute gaps are formed between the irregularities caused by the surface roughness, and these minute gaps form the flow throttle portion of the lubricant outflow passage 11. The flow rate may be throttled only on one of the contact surfaces 9 and 10.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bearing used for grease lubrication or the like, and more particularly to a rolling bearing lubrication device used for a bearing for a main shaft of a machine tool or the like.

[0002]

[Prior art]

 Grease lubrication is easy to handle and no auxiliary equipment is required, so there is a strong demand for grease lubrication to improve the lubrication life. For grease lubrication, grease is generally used by filling grease inside the bearing, that is, in the gaps between the rolling elements, inner and outer rings, cages, and other components.

In this case, if the amount of grease retained between the members is small, the lubricating life of the bearing may be shortened. It is possible to increase the amount of grease to be filled to some extent.However, if a large amount of grease is filled between the above-mentioned components, the heat generated by the stirring resistance of the grease will increase at the beginning of operation, and excess grease will not be discharged or discharged. There is a problem that the time required for running-in to improve familiarity becomes long. In particular, when used in machine tools, heat generation in bearings affects machining accuracy, so it is necessary to reduce it as much as possible, and improved durability is also desired.

As a solution to such a problem, the applicant of the present invention has proposed a lubricant such as grease to be enclosed in a reservoir provided in the inner ring spacer to prolong the lubricating life of the bearing. (Practical application No. 3-49662, No. 3-77609). In these proposals, a minute gap created by unevenness of the surface roughness of the mating surface or a minute slit formed on the mating surface is used as the lubricant outflow path, and the lubricant from the pool to the rolling surface The flow of water is carried out by utilizing the capillary action due to the minute gaps or slits in the lubricant outflow channel and the centrifugal force due to rotation. Therefore, the effect of reducing the outflow amount is great, and the lubricant can be supplied in very small amounts.

[0005]

However, since the lubricant reservoir space is provided in the inner ring spacer, the lubricant capacity is limited, and it is desired to increase the lubricant reservoir amount to improve the lubricating life.

An object of the present invention is to supply a small amount of the lubricant stored in the lubricant reservoir recess along with the operation, and to increase the capacity of the lubricant reservoir recess, thereby improving lubrication durability. To provide a rolling bearing lubrication device.

[0007]

[Means for Solving the Problems]

 The rolling bearing lubrication device of the present invention has a lubricant reservoir concave portion provided on the outer diameter surface of the shaft. The recess is sealed by an inner ring member composed of an inner ring of the rolling bearing and a member adjacent to the inner ring, and a lubricant outflow passage is provided which opens from the lubricant reservoir recess to the rolling passage of the rolling element. At least a part of the outflow passage is formed by a minute gap between irregularities generated by surface roughness formed on a contact surface between the inner ring member and the shaft or a contact surface between a plurality of members forming the inner ring member.

[0008]

[Action]

 According to this configuration, the amount of lubricant to be retained in advance in the vicinity of the rolling elements inside the bearing is small, and the lubricant is enclosed in the lubricant reservoir concave portion for operation. The lubricant or its components in the lubricant reservoir recess is supplied to the vicinity of the rolling elements by the capillary action due to the minute gaps in the lubricant outflow passage or by the centrifugal force accompanying the rotation of the shaft. In this case, since the lubricant is supplied through the minute gaps between the irregularities caused by the surface roughness, the lubricant has a large throttling effect, and therefore the lubricant is supplied little by little for a long period of time. In addition, since it uses the capillary phenomenon, it is less affected by the number of revolutions compared to the one that uses only the centrifugal force, and a stable supply is performed. Since the lubricant reservoir recess is formed on the shaft, the capacity can be sufficiently increased. Due to these, excellent lubrication durability of the bearing can be obtained.

[0009]

【Example】

 An embodiment of this invention will be described with reference to FIG. A combination angular ball bearing consisting of two angular ball bearings 2 and 2 is installed on the small-diameter shaft portion of the stepped rotary shaft 1. Each of the angular ball bearings 2 and 2 has a rolling element 5 held by a cage (not shown) interposed between an inner ring 3 and an outer ring 4 so that thrust loads can be applied from both sides to each other. It is arranged in the opposite direction. The inner rings 3 and 3 of each angular contact ball bearing 2 are narrow without the non-load side portion, and an inner ring spacer 6 is interposed between the inner rings 3 and 3. An inner ring member 7 is constituted by the inner rings 3 and 3 and the inner ring spacer 6 which is a member adjacent to the inner ring.

The shaft 1 is provided with a lubricant reservoir concave portion 8 having a circumferential groove on the outer diameter surface at a position where it is sealed by the inner ring spacer 6, and the lubricant is sealed therein. By the fitting contact surface 9 between the inner ring spacer 6 and the shaft 1 and the contact surface 10 between the inner ring spacer 6 and the end surface of the inner ring 3, the lubrication that opens from the lubricant reservoir recess 8 to the rolling path of the rolling element 5 An outflow channel 11 for the agent is formed.

The inner ring spacer 6 is tightly fitted to the shaft 1 to the extent of an interference fit or a stop fit, but the contact surfaces 9 and 10 have unevenness due to the surface roughness R _{MAX of} 0.2 to 10 μm for finishing. Therefore, a minute gap is formed, and the lubricant outflow passage 11 is formed in this minute gap.

As the lubricant to be filled in the lubricant reservoir recess 8, in addition to general semi-solid or solid grease, liquid grease, plastic grease, oil-containing resin, woven cloth or felt containing lubricating oil is used. , Porous materials can be used. Plastic grease is a composition in which a mixture of a resin such as ultra-high molecular weight polyethylene or ultra-high molecular weight polyolefin and grease is heated and melted and then solidified by cooling, and one in which oil gradually exudes was developed. ing. In addition, a small amount of lubricant such as grease is applied to the raceways of the inner ring 3 and the outer ring 4.

According to this structure, the lubricant or its components enclosed in the lubricant reservoir recess 8 is exuded from the minute gaps between the contact surfaces 9 and 10 by the capillary action and the centrifugal force caused by the rotation of the shaft 1. It is taken out and supplied to the rolling path of the rolling element 5 to lubricate the raceway surfaces 3a, 4a. When the sealing lubricant is a semi-solid grease, the grease base oil mainly separates from the thickener and flows out.

Since the lubricant outflow passage 11 formed by the contact surfaces 9 and 10 is a minute gap formed between the unevenness caused by the surface roughness, the throttling effect is large, and the lubricant in the lubricant reservoir recess 8 is large. Alternatively, the components thereof flow out in small amounts over a long period of time. Further, since the lubricant reservoir recess 8 is formed in the shaft 1, the capacity can be increased as compared with the case where it is formed in the inner ring spacer 6 or the like. For these reasons, it is possible to obtain extremely excellent lubrication durability. Moreover, because the capillary phenomenon is used for the outflow from the lubricant outflow passage 11, the outflow is stable. Since the lubrication durability is improved in this way, the amount of lubricant applied to the raceway surfaces 3a, 4a in advance can be reduced to prevent heat generation due to stirring resistance and shorten the required running-in time.

FIG. 2 shows another embodiment. In this example, a single row angular contact ball bearing 2 is installed adjacent to the stepped portion on the medium diameter shaft portion 1a of the stepped rotary shaft 1, and a small diameter shaft portion 1b formed continuously from the medium diameter shaft portion 1a. A lubricant reservoir recess 8'is formed on the outer periphery of the. The angular contact ball bearing 2 has the same structure as the one bearing 2 shown in FIG. On the outer periphery of the lubricant reservoir recess 8 ', an inner ring spacer 6 which is fitted to the medium diameter shaft portion 1a and is adjacent to the inner ring 3 extends, and a nut 14 screwed to the male screw portion 1c of the small diameter shaft portion 1b is mounted. It contacts the end face of the inner ring spacer 6.

The inner ring spacer 6 and the nut 14 seal the lubricant reservoir recess 8 ′. The nut 14 is a width pressing member that presses the width surface of the inner ring 3 via the inner ring spacer 6. In this embodiment, the inner ring 3 and the inner ring spacer 6 and the nut 14, which are the inner ring adjacent members, serve as the inner ring. The member 7'is constructed. A retaining ring may be used instead of the nut 14. The lubricant outflow passage 11 has the same surface roughness due to the contact surface 9 between the inner ring spacer 6 and the shaft 1 and the contact surface 10 between the inner ring spacer 6 and the end surfaces of the inner ring 3 as in the above-described embodiment. It is formed with a minute gap. The contact portion between the spacer 6 and the nut 14 other than the lubricant outflow passage 11 may form a sealing means for preventing outflow. Also in the case of such a configuration, the effect of improving the lubricating life and the like can be obtained as in the above-described embodiment.

In each of the above-mentioned embodiments, the lubricant reservoir spaces 8 and 8'are formed in an annular shape, but the lubricant reservoir spaces 8 and 8'may be formed by being divided into a plurality of portions in the circumferential direction. good. Further, the lubricant reservoir spaces 8 and 8'may be formed in the shaft 1 within the width in which the inner ring 3 is fitted. Further, in each of the above-mentioned embodiments, the flow restricting portion formed by the minute gap is formed by the contact surfaces 9 and 10 on both the inner diameter surface and the end surface of the inner ring spacer 6, but only one of the contact surfaces 9 and 10 is formed. You may make it obtain a diaphragm effect. Further, the contact surfaces 9 and 10 on which the throttling effect is obtained may be provided with a fine axial groove or a group of fine grooves in a slanting lattice shape to increase the flow rate to some extent. Furthermore, the present invention can be applied not only to double-row angular contact ball bearings, but also to single-row angular contact ball bearings and other rolling bearings in general.

[0018]

[Effect of device]

 In the rolling bearing lubrication device of the present invention, the lubricant reservoir recess is provided on the outer diameter surface of the shaft, and the lubricant outflow passage with a minute gap formed between the contact surfaces due to the unevenness of the surface roughness is provided. The lubricant or its components enclosed in the agent reservoir recesses are supplied little by little to the rolling elements due to the centrifugal force caused by the capillary phenomenon and the rotation of the shaft. Moreover, since the lubricant reservoir recess is formed on the shaft, the capacity can be sufficiently increased. These provide excellent lubrication durability. Therefore, the amount of lubricant sealed near the rolling elements can be reduced to reduce the initial heat generation and shorten the required running-in time.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a sectional view of another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Shaft, 2 ... Angular ball bearing, 3 ... Inner ring, 5 ... Rolling element, 6 ... Inner ring spacer, 7 ... Inner ring member, 8, 8 '... Lubricant reservoir recess, 9, 10 ... Contact surface, 11 ... Lubrication Agent outflow channel, 14
…nut

Claims (1)

[Scope of utility model registration request] 1. A lubricant reservoir recess is provided on an outer diameter surface of a shaft, and the recess is sealed by an inner ring member composed of an inner ring of a rolling bearing and a member adjacent to the inner ring, and a rolling path of a rolling element from the lubricant reservoir recess. An outflow passage for the lubricant to be opened is provided, and at least a part of this outflow passage is generated by the surface roughness formed on the contact surface between the inner ring member and the shaft or the contact surface between a plurality of components forming the inner ring member. Rolling bearing lubrication device formed by minute gaps between irregularities.