JP2004076757A - Ball bearing and ball bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ball bearing to be incorporated in a power steering device, e.g., preventing the occurrence of a gap in the axial direction when fixing the ball bearing to a housing. <P>SOLUTION: The ball bearing 41 comprises a rotary ring 41a, a fixed ring 41b opposed to the rotary ring 41a in the radial direction, and a plurality of balls 41c rollingly held between the rotary ring 41a and the fixed ring 41b in the radial direction. The fixed ring 41b has a rolling groove 61 recessed in contact with the balls 41c at two points apart therefrom in the axial direction. The fixed ring 41b is formed with its axial width changeable with the elastically compressed deformation of the fixed ring 41b. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a ball bearing and a ball bearing device used for, for example, supporting an operation shaft of a power steering device.
[0002]
[Prior art]
As a ball bearing, for example, as shown in FIG. 9, a ball bearing used for supporting a steering operation shaft 73 of a power steering device 70 on a housing 72 is known. In this case, a gap is formed between the ball bearing 71 and the end surface 72a of the housing 72 in the axial direction of the steering operation shaft 73.
[0003]
That is, while the inner ring 71a of the ball bearing 71 is press-fitted into the steering operation shaft 73 and securely fixed, the outer ring 71b is relatively loosely fitted in the housing. There was a gap between 71b and the end surface 72a of the housing 72.
[0004]
This is because the power steering device is relatively loosely assembled since it can withstand practical use even if the operation shaft support accuracy is not high.
[0005]
[Problems to be solved by the invention]
However, since there is a gap between the ball bearing and the housing in the axial direction, the steering operation shaft 73 has low stability such that the steering operation shaft 73 moves in the axial direction. Therefore, there is a possibility that the driver may feel an operation sensation that the steering wheel is slightly rattled.
[0006]
In order to suppress such rattling, for example, it is conceivable that a gap is minimized by interposing a shim 78 or the like in a gap between the housing and the fixed ring of the bearing device. It was not enough to eliminate the gap so as to prevent rattling.
[0007]
SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and solves the problem of, for example, fixing a ball bearing to a housing or the like so that a gap does not occur in an axial direction in a ball bearing incorporated in a power steering device or the like. The challenge is to try.
[0008]
[Means for Solving the Problems]
(1) A ball bearing according to the present invention is provided with a rotating wheel, a fixed wheel radially opposed to the rotating wheel, and radially interposed between the rotating wheel and the fixed wheel so as to roll freely. A ball bearing including a plurality of balls, wherein the fixed ring has a recess formed with rolling grooves that contact the ball at two points separated in the axial direction, and the fixed ring has The width in the axial direction is configured to be changeable by elastic compression of the fixed wheel.
[0009]
According to the ball bearing according to the present invention, the fixed ring has a recess formed with a rolling groove for allowing each ball as a rolling element to be rolled, and the fixed ring has an axial direction. The width of the fixed ring is deformable due to the elastic deformation of the fixed ring, so even in the case where the fixed ring is mounted in a casing or the like where the ball bearing is mounted, even if the width in the axial direction is relatively large. If the fixed ring is configured to be relatively wide in advance in the axial direction of the mounting portion, the fixed ring can be compressed and deformed in the axial direction to be mounted on the mounting portion.
[0010]
In addition, in the mounted state, both ends in the axial direction of the fixed wheel are pressed against the fixed wheel receiving portion in the axial direction at the fixed wheel mounting portion by the elastic biasing force toward the wide side of the fixed wheel, respectively. Fixed without rattling.
[0011]
In the ball bearing according to the present invention, preferably, the fixed ring has an M-shaped one-half cross-sectional shape by continuously connecting annular portions along the radial direction to both axial end portions of the rolling groove. It is configured.
[0012]
In this case, the annular portions at both axial ends of the fixed wheel abut against the fixed wheel receiving portion, and the fixed wheel is fixedly held in the fixed wheel receiving portion.
[0013]
In the ball bearing according to the present invention, preferably, the fixed ring is formed by press-forming an annular plate.
[0014]
In this case, since the fixed wheel is manufactured by press molding, which is a simple manufacturing method, the cost can be reduced.
[0015]
(2) The ball bearing device according to the present invention includes a rotating wheel, a fixed wheel radially opposed to the rotating wheel, and a radially interposed roller between the rotating wheel and the fixed wheel. A ball bearing device provided with a ball bearing including a plurality of balls to be formed, wherein the fixed ring has a recess formed with a rolling groove that contacts the ball at two points separated in the axial direction. In addition, the fixed wheel is configured such that its axial width is freely changeable by elastic compression of the fixed wheel, and is provided with a fixed wheel receiving portion that regulates the position of the fixed wheel on both axial sides.
[0016]
Here, the ball bearing device refers to a device in which a ball bearing is used as a bearing.
[0017]
ADVANTAGE OF THE INVENTION According to the ball bearing device which concerns on this invention, while a fixed wheel is mounted and hold | maintained in the state restrict | regulated by the fixed wheel receiving part, the fixed wheel is hold | maintained in the mounting part in the state deformed by compression in the axial direction. Therefore, the fixed wheel and the fixed wheel receiving portion are closely contacted with no gap in the axial direction.
[0018]
As a result, the fixed wheel does not rattle in the axial direction. For example, in the case of a ball bearing device that supports a steering operation shaft of a power steering device, it is preferable that the user does not feel unjust rattling. The steering operation can be performed with a simple operation feeling.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
The details of the present invention will be described based on an embodiment shown in the drawings. 1 to 4 show a ball bearing device and the like according to an embodiment of the present invention. FIG. 1 is a sectional view showing a power steering device having the ball bearing device. FIG. 2 is an enlarged view of a main part in FIG. FIG. 3 is a further enlarged view of FIG. 2, and FIG. 4 is a partially cutaway perspective view of the outer race of the ball bearing device of FIG.
[0020]
The hydraulic power steering device 1 shown in FIG. 1 includes an input shaft 2 connected to a steering wheel (not shown), and an output shaft 4 connected to the input shaft 2 via a torsion bar 3.
[0021]
The torsion bar 3 is connected to the input shaft 2 via a pin 5 and to the output shaft 4 via a serration 6.
[0022]
Thus, the input shaft 2 and the output shaft 4 relatively rotate elastically in accordance with the steering torque. A pinion 7 is integrally formed on the outer periphery of the output shaft 4 so as to rotate together with the output shaft 4, and a rack 8 meshing with the pinion 7 is connected to wheels (not shown).
[0023]
When the rotation of the input shaft 2 due to the steering is transmitted through the torsion bar 3, the output shaft 4 rotates together with the pinion 7, and the rack 8 moves in the vehicle width direction. The movement of the rack 8 changes the steering angle of the wheels.
[0024]
The support yoke 16 supporting the rack 8 is pressed against the rack 8 by the elasticity of the spring 17.
[0025]
A hydraulic cylinder 12 is provided as a hydraulic actuator for generating a steering assist force. The hydraulic cylinder 12 includes a cylinder tube formed by a pinion housing 21 that covers the pinion 7 and the rack 8, a piston 13 formed integrally with the rack 8, and a pair of oil chambers 14 and 15 partitioned by the piston 13. Prepare.
[0026]
At a position away from the pinion 7 in the axial direction, a rotary hydraulic control valve 11 is provided around the output shaft 4.
[0027]
The hydraulic control valve 11 is covered by a valve housing 22 connected to a pinion housing 21, and rotates together with the output shaft 4, that is, a cylindrical first valve member 24 connected to rotate in conjunction with the output shaft 4. And a second valve member 25 integrally provided on the outer periphery of the input shaft 2 covered by the first valve member 24.
[0028]
The first valve member 24 rotates relative to the valve housing 22 about the axis of the output shaft 4 by rotation of the output shaft 4.
[0029]
The two valve members 24 and 25 rotate relative to each other due to the elastic relative rotation of the input and output shafts 2 and 4 according to the steering torque.
[0030]
An inter-valve oil passage 27 is provided between the two valve members 24 and 25, and the pump P and the oil chambers 14 and 15 of the hydraulic cylinder 12 are provided in the inter-valve oil passage 27 with ports 22 a and 22 b provided in the valve housing 22. The first valve member 22 and the first valve member 24 are individually connected via oil passages 24a, 24b, and 24c.
[0031]
The tank T is connected to the inter-valve oil passage 27 via a port 22d provided in the valve housing 22, oil passages 2a and 2b formed in the input shaft 2, and between the input shaft 2 and the torsion bar 3. You.
[0032]
Along the cylindrical surface concentric with the outer peripheral surface of the first valve member 24 and opposed through a minute gap, the minute gap is sealed by a seal ring 26 between the ports 22a, 22b, 22c and 22d. I have.
[0033]
In the inter-valve oil passage 27, a throttle whose opening changes according to the relative rotation amount of the two valve members 24 and 25 can control the oil pressure of the pressure oil discharged from the pump P according to the relative rotation amount. Is provided.
[0034]
The pressure oil is supplied to one of the two oil chambers 14 and 15 of the hydraulic cylinder 12 according to the steering direction, and is returned to the tank T via the hydraulic control valve 11 from the other.
[0035]
As a result, the hydraulic cylinder 12 operates in accordance with the hydraulic pressure controlled by the hydraulic control valve 11, thereby generating a steering assist force acting on the rack 8. A well-known hydraulic control valve 11 can be used.
[0036]
The input shaft 2 is supported by a ball bearing 31 provided in the valve housing 22 and a bush 32 fitted in a recess formed at an end of the output shaft 4.
[0037]
The hydraulic control valve 11 is arranged between the bearing 31 and the bush 32. An oil seal 33 that seals between the outer periphery of the input shaft 2 and the inner periphery of the valve housing 22 is provided between the ball bearing 31 and the other end of the valve housing 22.
[0038]
The output shaft 4 is supported by a ball bearing (ball bearing) 41 provided in the valve housing 22 and the pinion housing 21 between the pinion 7 and the hydraulic control valve 11, and is more distant from the hydraulic control valve 11 than the pinion 7. The other side is supported by a needle bearing 49. The ball bearing 41 is externally fitted with the inner race 41a pressed into the output shaft 4, while the outer race 41b is loosely fitted to both housings 21 and 22.
[0039]
As shown in FIGS. 1 and 2, a deep groove type inner ring 41 a as a rotating wheel of the ball bearing 41 includes an inner ring receiving portion 42 formed by a step formed on the outer periphery of the output shaft 4, and an outer periphery of the output shaft 4. Is fixed to the output shaft 4 by being sandwiched by the retaining ring 43 fitted to the output shaft 4. The inner race 41a may be of a deep groove type in which the ball 41c makes one point contact, or may be one in which the ball 41c makes two point contact in the axial direction.
[0040]
The end surface of the valve housing 22 has a valve-side receiving portion 45 that receives the valve-side end surface of the outer ring 41b as a fixed ring via the shim 28. The valve-side receiving portion 45 has a surface substantially orthogonal to the rotation axis of the output shaft 4. Note that the shim 28 may not be provided. The valve side receiving portion 45 and the shim 28 constitute an outer ring receiving portion as a fixed wheel receiving portion. Here, the shim 28 is an annular plate made of metal.
[0041]
The position of the pinion-side end surface of the outer ring 41 b is restricted by the pinion-side receiving portion 44 of the pinion housing 21. The pinion-side receiving portion 44 has a surface substantially orthogonal to the rotation axis of the output shaft 4.
[0042]
The pinion housing 21 and the valve housing 22 have outwardly protruding flanges 21b and 22e, and a bolt 55 inserted into one flange portion 22e is screwed into a female screw formed on the other flange portion 21b. Both housings 21 and 22 are connected. Due to the connection between the pinion housing 21 and the valve housing 22, the outer ring 41b and the shim 28 are sandwiched between the receiving portions 44 and 45 as fixed wheel receiving portions. The spigot portion 22f of the valve housing 22 is fitted inside the pinion housing 21 so that the housings are not displaced in the radial direction. An O-ring mounting groove is formed on the outer periphery of the spigot portion 22f, and an O-ring is mounted in the groove. In the spigot portion 22f in which the pinion housing 21 and the valve housing 22 are fitted, an O-ring is formed. The ring seals the fitting.
[0043]
An oil seal 51 that seals between the outer circumference of the output shaft 4 and the inner circumference of the valve housing 22 is disposed between the hydraulic control valve 11 and the ball bearing 41. The oil seal 51 is positioned by being disposed between a step formed on the inner periphery of the valve housing 22 and the ball bearing 41.
[0044]
Next, the characteristic configuration of the present invention will be described. As shown in FIG. 4, the outer ring 41b is plastically deformed into a M-shaped cross-section by pressing a band-shaped sheet metal, and the deformed band-shaped member is bent into a ring shape. It is manufactured by joining its both ends by welding. As the outer ring 41b, for example, a steel plate material such as JIS SPCC, JIS SPCD, JIS SPCE, JIS SPB, and JIS SPB2 is used.
[0045]
In the outer race 41b, an annular rolling groove 61 in which a plurality of balls 41c as rolling elements disposed in the circumferential direction while being sandwiched between the inner race 41b is slidably contacted with the outer race 41b. In other words, it is recessed radially outward when viewed from the ball 41c side. Both axial side surfaces of the rolling groove 61 are inclined surfaces such that the distance between them increases in the axial direction toward the inside in the radial direction.
[0046]
Each ball 41c is in one-point contact with each side surface of the rolling groove 61 in the axial direction. That is, each ball 41c is in rolling contact with the rolling groove 61 at two points (two locations) in the axial direction.
[0047]
Annular portions 62, 62 extending in the radial direction are connected to both ends in the axial direction of the rolling groove 61 of the outer ring 41b. The outer ring 41b is elastically deformable so that the axial width can be changed by a compressive force received in the axial direction. That is, the relative spacing in the axial direction between the annular portions 62, 62 on both sides in the axial direction and both axial side portions of the rolling groove 61 (may be regarded as a relative angle between the surfaces), and the rolling groove 61. The relative angle between the bottom portion of the shaft and the axial side portions of the rolling groove 61 can be changed by elastic deformation.
[0048]
The outer ring 41b is provided in a state where its axial position is regulated by a valve-side receiving portion 45 that is an end surface of the valve housing 22 and a pinion-side receiving portion 44 that is an end surface facing the outer ring 41b of the pinion housing 21. More specifically, the annular portion 62 of the outer ring 41b on the pinion housing 21 side contacts the pinion side receiving portion 44, and the annular portion 62 of the outer ring 41b on the valve housing 22 side contacts the shim 28 on the valve housing 22. I have. When the shim 28 is not provided, the annular portion 62 is in direct contact with the valve-side receiving portion 45. When the outer ring 41b is not mounted in such a manner, its axial width is set to be larger than the interval between the annular elastic member 46 and the valve housing 22 facing each other. Therefore, when the valve housing 22 is connected to the pinion housing 21, the outer ring 41 b is sandwiched in a state where the outer ring 41 b is pressed by the pinion housing 21 and the valve housing 22. The outer ring 41b is mounted in a state where there is no gap between them. Further, as shown in FIG. 3, in such a mounted state, the outer peripheral edges of the annular portions 62, 62 of the outer race 41 b are in contact with the inner peripheral surface of the pinion housing 21. The contact position corresponds to the outer diameter position of the outer ring 41b. The bottom portion 63 of the rolling groove 61 changes its radial position in accordance with the expansion and contraction of the outer ring 41b in the axial direction, and the outer peripheral edge of each of the annular portions 62 is formed inside the pinion housing 21. Even in the state of contact with the peripheral surface, the bottom 63 does not always contact the inner peripheral surface of the pinion housing 21. Although the bottom 63 of the rolling groove 61 has a certain width in the axial direction, the bottom 63 may have almost no width in the axial direction.
[0049]
By mounting the outer ring 41b as described above, the ball bearing 41 is provided on the valve housing 22 and the pinion housing 21 without play in the axial direction. Steering operation can be performed without touching.
[0050]
In the present invention, the inner ring may be formed as a fixed ring, and the inner ring may be formed of an elastic member formed by pressing. In this case, the outer ring becomes a rotating wheel.
[0051]
The present invention may have a configuration in which there is no intervening member such as an annular elastic member as a member for restricting the fixed ring in the axial direction at the mounting position of the fixed ring. That is, a configuration in which the fixed wheel directly contacts the fixed wheel receiving portion such as the housing in the axial direction may be employed.
[0052]
According to the present invention, as shown in FIG. 5, when the outer ring is a fixed ring, the annular portions 62, 62, which are M-shaped in cross section and are continuously provided at both ends in the axial direction of the rolling groove 61, are folded back. It may be one that has been pressed in a stack.
[0053]
According to the present invention, as shown in FIG. 6, in the case where the outer ring is a fixed ring, the outer peripheral edges of annular portions 62, 62 which are M-shaped in cross section and are continuously provided at both axial ends of the rolling groove 61. May be provided with cylindrical portions 64, 64 extending along the axial direction, and flanges 65, 65 extending radially inward at the ends of the cylindrical portions 64, 64.
[0054]
According to the present invention, as shown in FIG. 7, in a case where the outer ring 41b is a fixed ring, the outer ring 41b is formed such that the annular portions 64, 64 at both ends in the axial direction of the annular plate made of sheet metal are radially inward. The ball contact portions 65, 65 are formed so as to bend and bend inward in the axial direction. Also in this case, the ball 41c abuts at two points in the axial direction by the two ball abutting portions 65, 65 in the axial direction. Further, when the annular portions 64, 64 are not attached to the cylindrical portion 66 that connects the annular portions 64, 64 in the axial direction, the annular portions 64, 64 are opened slightly wider outward in the axial direction. The position of the pinion-side receiving portion 44 of the pinion housing 21 and the valve-side receiving portion 45 of the valve housing 22 are axially regulated via the shim 28. The portions 64, 64 are elastically compressed in the width direction so that the interval between them becomes narrower. That is, in this case, the relative angle between the two annular portions 64 and 64 with respect to the cylindrical portion 66 is close to 90 degrees.
[0055]
In the present invention, as shown in FIG. 8, in a case where the outer ring 41b is a fixed ring, a pinion-side end surface of the outer ring 41b in the axial direction and a fixed ring for regulating the position of the outer ring 41b of the pinion housing 21 in the axial direction. The shim 46 may be interposed between the pinion-side receiving portion 44 as the receiving portion.
[0056]
【The invention's effect】
According to the present invention, when a ball bearing is mounted on a casing or the like for rotationally supporting the shaft, the ball is fixed to the fixed wheel receiving portion in the axial direction at the fixed wheel mounting portion by an elastic biasing force toward the wide side of the fixed wheel. Since the axial both ends of the wheel are in pressure contact with each other, the fixed ring of the ball bearing is fixed without rattling, and the shaft supported by the ball bearing is unstable in the axial direction. Support can be eliminated.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a power steering device as a ball bearing device provided with a ball bearing according to the present invention. FIG. 2 is an enlarged sectional view showing the vicinity of the ball bearing in FIG. 1. FIG. FIG. 4 is a partially cutaway perspective view showing an outer ring as a fixed ring of the ball bearing in FIG. 1; FIG. 5 is a half sectional view of a modified example of the embodiment of the ball bearing according to the present invention; FIG. 6 is an enlarged sectional view showing the vicinity of one half of a modification of the embodiment of the ball bearing according to the present invention. FIG. 7 is the vicinity of one half of the modification of the embodiment of the ball bearing according to the present invention. FIG. 8 is an enlarged sectional view showing the vicinity of one half of a modification of the embodiment of the ball bearing according to the present invention. FIG. 9 is a ball bearing of a power steering device as a ball bearing device provided with a conventional ball bearing. Enlarged sectional view showing the vicinity [Explanation of reference numerals]
41 Ball bearing 41a Rotating wheel 41b Fixed wheel 41c Ball 44, 45 Fixed wheel receiving portion 61 Rolling groove

Claims (3)

A ball bearing including a rotating wheel, a fixed wheel radially opposed to the rotating wheel, and a plurality of balls rotatably interposed between the rotating wheel and the fixed wheel in a radial direction. So,
The fixed wheel has a recess formed with a rolling groove that contacts the ball at two points separated in the axial direction, and the axial width of the fixed wheel can be changed by elastic compression of the fixed wheel. A ball bearing comprising: The ball bearing according to claim 1,
The ball is characterized in that one half cross-sectional shape is formed in an M-shape by continuously connecting annular portions along the radial direction to both ends of the rolling groove in the axial direction, respectively. bearing. A ball bearing including a rotating wheel, a fixed wheel radially opposed to the rotating wheel, and a plurality of balls radially interposed between the rotating wheel and the fixed wheel so as to roll freely. A ball bearing device provided,
The fixed wheel has a recess formed with a rolling groove that contacts the ball at two points separated in the axial direction, and the axial width of the fixed wheel can be changed by elastic compression of the fixed wheel. Is composed of
A ball bearing device comprising a fixed wheel receiving portion that regulates the position of the fixed wheel on both axial sides.

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