CN221074996U - Oil-containing retainer of space bearing and space bearing - Google Patents

Abstract

The utility model discloses an oil-containing retainer of a space bearing and the space bearing, wherein the retainer is provided with a plurality of oval pockets, the long axis of each oval pocket is arranged along the axial direction of the retainer, and the short axis of each oval pocket is arranged along the circumferential direction of the retainer; and the diameter of the steel ball matched with the retainer is D, the major axis size of the oval pocket is 1.08D-1.2D, and the minor axis size is 1.03D-1.07D. The pockets in the retainer are elliptical pockets, and the high precision and low friction of the bearing can be ensured by limiting the length of the long shaft and the short shaft of the elliptical pockets, and dynamic moment fluctuation caused by high and low temperature of the bearing can be effectively reduced.

Description

Oil-containing retainer of space bearing and space bearing

Technical Field

The utility model relates to the technical field of bearings, in particular to an oil-containing retainer of a space bearing and the space bearing.

Background

The space bearing is generally used in a spacecraft, and the space bearing is usually required to perform running-in tests at normal temperature and high temperature and low temperature due to the fact that the on-orbit height of the spacecraft is higher from the ground and the temperature difference range between the ambient day and night is larger (about-20 ℃ to +60 ℃). The working load of the space bearing is not more than 5% of the rated dynamic load of the bearing, and the technical requirements are low friction, high precision, long service life and high reliability.

The fluctuation of the friction torque of the bearing can influence the control precision of the spacecraft, so that the aerospace bearing has strict requirements on the fluctuation of the friction torque of the bearing. The space bearing is usually lubricated by thin oil once, namely, after the porous polyimide oil-containing retainer is subjected to vacuum oil immersion, the lubricating oil contained in the retainer provides life cycle lubrication for the bearing. The conventional porous polyimide retainer pocket structures are square pockets (namely square pockets) and round pockets, and the lubricating oil circulation transfer mode during bearing operation is mainly retainer-steel ball-ferrule channel-steel ball-retainer, so that the circulation transfer is carried out, and bearing lubrication is maintained.

When the square pocket retainer runs at high temperature of the bearing, the porous polyimide retainer is heated to discharge oil, in the square pocket retainer, the pockets are in point contact with bearing steel balls, the contact area between the steel balls and the retainer is small, the circulation transfer capacity of lubricating oil is weaker, the lubricating oil is easily accumulated in a bearing raceway, and the friction torque fluctuation of the bearing running at high temperature is caused. When the round pocket retainer runs at low temperature of the bearing, the viscosity of lubricating oil is increased due to temperature reduction, hydrodynamic friction force of a contact area of the pocket and the steel ball is increased, and the round pocket retainer contacts with the steel ball to form elliptical contact, so that the contact area and the friction force are both large, and unstable running of the bearing retainer and fluctuation of bearing friction moment are easily caused due to the increase of the friction force between the round pocket and the steel ball at low temperature. The retainers of the two pocket structures have their own disadvantages at high and low temperatures.

Disclosure of utility model

In order to solve the defects in the prior art, the utility model provides the oil-containing retainer for the space bearing and the space bearing, wherein the pocket hole in the retainer is an elliptical pocket hole, and the high precision and low friction of the bearing can be ensured by limiting the length of the long shaft and the short shaft of the elliptical pocket hole, and the dynamic moment fluctuation caused by the high temperature and the low temperature of the bearing can be effectively reduced. The bearing is a space bearing, the guiding mode of the bearing retainer is steel ball and outer ring double guiding, and the outer ring adopts slope-shaped flanges to reduce friction coefficient between the outer ring and the retainer.

In order to achieve the above purpose, the utility model adopts the following specific scheme:

On one hand, the utility model provides an oil-containing retainer for a space bearing, wherein a plurality of oval pockets are arranged on the retainer, the long axis of each oval pocket is arranged along the axial direction of the retainer, and the short axis of each oval pocket is arranged along the circumferential direction of the retainer;

and the diameter of the steel ball matched with the retainer is D, the major axis size of the oval pocket is 1.08D-1.2D, and the minor axis size is 1.03D-1.07D.

Further, the retainer is made of porous polyimide.

Further, the oval pocket is formed by drilling and milling.

Further, the surface roughness Ra of the retainer is less than or equal to 2 mu m.

On the other hand, the utility model provides a space bearing which comprises an inner ring, an outer ring, steel balls and the oil-containing retainer of the space bearing.

Further, both ends of the inner wall of the outer ring are provided with slope-shaped flanges.

Further, the slope angle of the flange is 3 degrees.

Further, the roughness Ra of the flange is less than or equal to 0.1 mu m.

The beneficial effects are that:

1) According to the utility model, the long axis size of the retainer is 1.08D-1.2D, the short axis size is 1.03 Dw-1.07 Dw (wherein D is the diameter of a steel ball matched with the retainer), and experiments prove that the pocket in the size range can effectively guide the bearing to carry and rotate, and the bearing has good high-temperature and low-temperature friction moment stability.

2) In the utility model, the oval pocket on the retainer is provided with the long shaft a and the short shaft b, the long shaft a can reduce the contact area of the steel ball and the normal contact area of the pocket, reduce the contact force and hydrodynamic friction force of the contact area of the oval pocket retainer, and improve the low-temperature running stability of the bearing; meanwhile, the short shaft b can ensure effective guiding of the steel ball, and along with rotation of the steel ball and climbing of lubricating oil on the surface of the steel ball, the lubricating oil in a bearing working area can be effectively and circularly transferred at high temperature, so that the lubricating oil is effectively prevented from accumulating on a roller path.

3) In the utility model, the oval pocket on the retainer is provided with the long shaft a and the short shaft b, so that the guiding performance of the retainer can be effectively maintained, and the guiding performance of the retainer is prevented from being reduced and the running torque is prevented from being fluctuated due to overlarge and undersize guiding gaps.

4) In the utility model, the retainer is made of porous polyimide commonly used for aerospace, the pore radius is recommended to be 0.4-0.9 mu m, the porosity is 13-25%, the radial tensile strength is more than or equal to 14MPa, the surface roughness Ra is less than or equal to 2 mu m, the pocket hole processing mode is drilling and milling, the structure is simple, and the implementation is easy.

5) In the space bearing, the inclined flanges are arranged at the two ends of the inner wall of the outer ring, the inclined angle of each flange is 3 degrees, the roughness Ra is less than or equal to 0.1 mu m, the contact area and friction coefficient between the retainer and the flanges can be effectively reduced by arranging the flanges and controlling the inclined angle and the roughness of the flanges, the stability of the retainer is improved, and the running power consumption of the bearing is reduced.

Drawings

FIG. 1 is a schematic view of the structure of a space bearing according to the present utility model.

Fig. 2 is a cross-sectional view of a cage according to the present utility model.

FIG. 3 is a schematic view of an oval pocket.

The graphic indicia: 1. the device comprises an outer ring, 101, a flange, 2, a retainer, 201, an oval pocket, 3, a steel ball, 4 and an inner ring.

Meaning of each letter in fig. 3: a represents a long axis, b represents a short axis, O represents a center point of the retainer, C represents a center of a left semicircle, D represents a center of a right semicircle, R-pocket radius, and (a-b)/2-pocket center offset distance.

Detailed Description

The technical solutions of the present utility model will be clearly and completely described below in connection with specific embodiments, and it is obvious that the described embodiments are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to fall within the scope of the utility model.

On the one hand, referring to fig. 2, the retainer 2 is provided with a plurality of oval pockets 201, the pocket lintel area of the retainer is a plane, the side walls at two sides of the pockets are in a straight pocket shape, the oval pockets 201 are respectively a long axis a and a short axis b along the axial direction and the circumferential direction of the retainer 2, the long axis a of the oval pockets 201 is 1.08D-1.2D, the short axis b is 1.03D-1.07D, and D is the diameter of a steel ball 3 matched with the retainer 2. The oval pocket 201 of this size can effectively guide the bearing carrier rotation, and the bearing has good high and low temperature friction torque stability.

The retainer 2 is made of porous polyimide, the pore radius is recommended to be 0.4-0.9 mu m, the porosity is 13% -25%, the radial tensile strength is more than or equal to 14MPa, and the surface roughness Ra is less than or equal to 2 mu m.

Referring to fig. 3, when the retainer 2 is processed, firstly, a retainer pocket with a radius R is milled by taking a center point O as a center, and then the milling cutter moves (a-b)/2 respectively on the left side and the right side in the axial direction of the retainer, namely, the center of the left side is C, and the center of the right side is D. The process can ensure that the surface of the transition area of the elliptical pocket 201 is smooth, and has no processing defects such as burrs, bulges and the like. When the bearing runs, the contact area between the steel ball 3 and the retainer 2 is in point contact at the center position O; the contact areas of the steel ball 3 and the oval pocket 201 are in arc contact at the left side and the right side of the center position O.

In another aspect, the present utility model provides a space bearing, please refer to fig. 1, which includes an inner ring 4, an outer ring 1, steel balls 3 and the above-mentioned cage 2. The guiding mode of the bearing retainer 2 is double guiding of the steel ball 3 and the outer ring 1, slope-shaped flanges 101 are arranged at two ends of the inner wall of the outer ring 1, the slope angle alpha of each flange 101 is 3 degrees, the roughness Ra is less than or equal to 0.1 mu m, the contact area and friction coefficient between the retainer 2 and each flange 101 can be effectively reduced by arranging the flanges 101 and controlling the slope angle and the roughness of the flanges 101, the stability of the retainer is improved, and the running power consumption of the bearing is reduced.

When the bearing works, the outer ring 1 rotates, the rotation speed of the retainer 2 is about half of the rotation speed of the outer ring 1, and the contact area and friction between the outer ring 1 and the retainer 2 can be reduced, the power consumption is reduced, and the running stability of the bearing is improved because the outer ring 1 adopts the slope-shaped flange 101. When the bearing works at high temperature, the retainer 2 discharges oil, and the oval pocket 201 can timely and circularly transfer the accumulated lubricating oil in the working area, so that fluctuation of friction torque of the bearing is avoided. When the bearing works at low temperature, the normal contact area of the retainer 2 and the steel ball 3 is in point-surface contact, so that the increase of hydrodynamic friction caused by the increase of viscosity of lubricating oil at low temperature can be effectively relieved, and the running stability of the bearing is improved.

The above description is only of the preferred embodiment of the present utility model, and is not intended to limit the present utility model in any way. All equivalent changes or modifications made according to the essence of the present utility model should be included in the scope of the present utility model.

Claims (8)

1. An oil-containing retainer for a space bearing is characterized in that a plurality of oval pockets (201) are arranged on the retainer (2), the long axis of each oval pocket (201) is arranged along the axial direction of the retainer (2), and the short axis of each oval pocket is arranged along the circumferential direction of the retainer (2);

the diameter of the steel ball (3) matched with the retainer (2) is D, the major axis size of the oval pocket (201) is 1.08D-1.2D, and the minor axis size is 1.03D-1.07D.

2. An oil-impregnated cage for a space bearing according to claim 1, wherein the cage (2) is made of porous polyimide.

3. An oil-impregnated cage for a space bearing according to claim 1, wherein the oval pocket (201) is formed by drilling and milling.

4. An oil-impregnated cage for a space bearing according to claim 1, characterized in that the surface roughness Ra of the cage (2) is less than or equal to 2 μm.

5. A space bearing, characterized by comprising an inner ring (4), an outer ring (1), steel balls (3) and a space bearing oil-containing cage (2) according to any of claims 1-4.

6. A space bearing according to claim 5, characterized in that both ends of the inner wall of the outer ring (1) are provided with ramp-like flanges (101).

7. A space bearing according to claim 6, characterized in that the ramp angle of the flange (101) is 3 °.

8. A space bearing according to claim 6, characterized in that the roughness Ra of the flange (101) is less than or equal to 0.1 μm.