JP2007155061A - Rolling bearing - Google Patents

Abstract

[PROBLEMS] To eliminate the generation of cage noise and reduce the torque fluctuation range in a rolling bearing used in an attitude control device for aircraft and space.
In a ball bearing that supports a rotating body of an aircraft and space attitude control device, the ball bearing is composed of an outer ring 1, an inner ring 2 and a rolling element 3 (ball) only, and a cage is eliminated. And As a result, it is possible to eliminate sliding portions between the guide surface of the cage and the raceway and between the cage pocket surface and the rolling elements 3 (balls).
[Selection] Figure 1

Description

  The present invention relates to an improvement of a rolling bearing used with a so-called small amount of oil lubrication, and is used, for example, in aircraft and space attitude control equipment and electronic / information equipment. The present invention relates to a rolling bearing suitable for a field that requires a small absolute value and fluctuation range of torque.

  Conventionally, flywheels and gyros have been used to control the attitude of aircraft and satellites. As rolling bearings that support flywheels and gyros, for example, combined angular ball bearings with preload are used. ing.

  Especially for flywheel rolling bearings for satellite attitude control and rolling bearings for gyros, in addition to durability in a vacuum environment and low dust generation, it has low torque and minimizes torque fluctuations. And a long life.

  In order to meet these demands, it is required to stably supply lubricating oil while keeping the amount of lubricating oil to a minimum.

  In this type of rolling bearing, a small amount of oil is applied to the raceway surface and rolling elements of the outer inner ring, and the cage is made of a porous material such as phenol resin and impregnated with lubricating oil.

  3A and 3B are a cross-sectional view and a front view of a double-row front combination angular contact ball bearing according to a conventional example.

  4A and 4B are a cross-sectional view and a front view of a single row angular contact ball bearing according to a conventional example.

In FIG. 3 or 4, a ball 3 as a rolling element is interposed between the outer ring 1 and the inner ring 2 so as to roll freely, and the ball 3 is guided and maintained at a predetermined interval by a cage 4. It is configured to be.
JP-A-2005-90657 JP-A-2005-90658

  However, in the above-mentioned rolling bearing, cage noise and torque fluctuation may occur. Patent Documents 1 and 2, etc. introduce a proposal for preventing cage noise and torque fluctuation.

  In other words, a phenolic resin cage is made by molding a phenolic resin on a laminated cotton cloth. Fine holes are formed from the surface to the inside, and a lubricating oil is retained in this part, so that a micro lubrication method is used. Although there are various results in these applications, the phenol resin material itself has a high coefficient of friction, so the interaction of the rolling elements, races, and cage causes the cage noise. Tended to occur.

  The present invention has been made in view of the circumstances as described above, and in a rolling bearing used in an aircraft and space attitude control device used in a trace amount oil lubrication using a phenol cage, An object of the present invention is to provide a rolling bearing that eliminates the occurrence and suppresses the torque fluctuation range.

In order to achieve the above object, a rolling bearing according to the present invention is a rolling bearing in which a rolling element is interposed between an outer ring and an inner ring so as to freely roll.
It is composed of an outer ring, an inner ring, and rolling elements only, and is a full ball type without a cage.

  Preferably, the rolling bearing supports a rotating body of an attitude control device for aircraft and space.

  Moreover, it is preferably loaded in the axial direction with a preload load larger than the radial load.

  Further preferably, the rolling element has a high surface hardness ceramic such as silicon nitride, or steel containing nitrogen or a nitride layer formed on the surface layer.

  According to the present invention, since there is no sliding part between the cage and the raceway surface and between the cage and the rolling element, there is no friction caused by the cage, no cage noise is generated, and torque fluctuation The width of can be kept small.

  In addition, by making full balls, the load capacity of the bearings increases, and in particular for the large vibration load that occurs when launching an artificial satellite, the allowable load for climbing the ball increases. This is advantageous for bearings.

  Hereinafter, a rolling bearing according to an embodiment of the present invention will be described with reference to the drawings.

  1A and 1B are a cross-sectional view and a front view of a double-row front combination angular contact ball bearing according to an embodiment of the present invention.

  2A and 2B are a sectional view and a front view of a single row angular contact ball bearing according to the embodiment of the present invention.

  In FIG. 1 or FIG. 2, it is a double-row front combination angular contact ball bearing or a single-row angular contact ball bearing, and a ball 3 as a rolling element is interposed between the outer ring 1 and the inner ring 2 so as to freely roll. .

  The present embodiment is characterized in that it is composed of only the outer ring 1, the inner ring 2 and the rolling elements 3 (balls) and is a full ball type without a cage. Preferably, the ball bearing supports the rotating body of the aircraft and space attitude control device.

  As described above, in the present embodiment, the ball bearing that supports the rotating body of the aircraft and space attitude control device is configured by only the outer ring 1, the inner ring 2, and the rolling element 3 (ball), and the cage is eliminated. A full ball type rolling bearing.

  As a result, it is possible to eliminate sliding portions between the guide surface of the cage and the raceway, and between the cage pocket surface and the rolling elements 3 (balls).

  In addition, ball bearings are normally loaded in the axial direction with a preload that is much larger than the radial load, so there is almost no change in the contact angle on the circumference of the circle, so there is no difference in rolling element revolution speed. For this reason, the rolling elements 3 (balls) hardly approach or come into contact with each other.

  Furthermore, if the rolling elements 3 (balls) are in contact with each other and there is a concern about torque fluctuation due to rough surfaces of the rolling elements 3 (balls), nitrogen is applied to a ceramic having a high surface hardness, such as silicon nitride, or steel. By using the rolling element 3 (ball) containing or having a nitride layer formed on the surface layer, it is possible to take measures to prevent the rolling element 3 (ball) from being worn.

  Further, the circumferential clearance (Δ) of the rolling element 3 (ball) is> 0.

  From the above, according to the present embodiment, since there are no sliding parts between the cage and the raceway surface and between the cage and the rolling element 3 (ball), there is no friction caused by the cage, and the cage noise. Does not occur, and the width of torque fluctuation can be reduced.

  Also, by making full balls, the load capacity of the bearings increases, and in particular, the allowable load on the rolling elements 3 (balls) for a large vibration load generated when launching an artificial satellite increases. This is advantageous for rolling bearings with cages.

  The following example was performed using the angular ball bearing shown in FIG.1 and FIG.2.

Bearing specifications
・ Bearing type: Front combination angular contact ball bearing (fixed position preload)
・ Main dimensions: inner diameter φ15mm (d1 in FIGS. 1 and 2), outer diameter φ32m (d2 in FIGS. 1 and 2)
・ Rolling element center diameter: φ23.5mm
Ball diameter: φ5.556 mm (d3 in FIGS. 1 and 2)
-Number of balls: 13.

  In addition, this invention is not limited to embodiment mentioned above, A various deformation | transformation is possible.

(A) (b) is sectional drawing and front view of a double row front combination angular contact ball bearing concerning an embodiment of the invention. (A) (b) is sectional drawing and the front view of the single row angular contact ball bearing which concern on embodiment of this invention. (A) and (b) are a sectional view and a front view of a double row front combination angular contact ball bearing according to a conventional example. (A) and (b) are sectional views and front views of a single row angular contact ball bearing according to a conventional example.

Explanation of symbols

1 outer ring 2 inner ring 3 rolling element (ball)
4 Cage

Claims (1)

In rolling bearings that support rotating bodies of aircraft and space attitude control equipment,
Consists only of outer ring, inner ring and rolling elements, and is a full ball type without cage.
The rolling element according to claim 1, wherein the rolling element has a high surface hardness and contains nitrogen in ceramic or steel, or a nitride layer is formed on the surface layer.

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