JP2010175023A - Bearing for steering column - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing for a steering column, enabling to generate a stable and great rotating torque while suppressing an increase in the rotating torque at starting. <P>SOLUTION: A friction mechanism 12 includes an annular friction ring 14 arranged between an outer ring 9 and an inner ring 10 and fixed to the inner ring 10, and a circular C-ring (a spring ring) 15 internally fitted to the friction ring 14. The friction ring 14 is internally fitted to the outer ring 9 with clearance fit. With the C-ring 15 fitted to the friction ring 14, the friction ring 14 is elastically energized outwardly in the radial direction. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a steering column bearing used in a steering apparatus for a vehicle such as an automobile.

In a steering apparatus for an automobile, a steering shaft is rotatably supported by a steering column via a steering column bearing.
FIG. 7 is a cross-sectional view of a main part of a conventional steering column bearing 101.
The steering column bearing 101 is provided between an outer ring 109 fitted and fixed to a cylinder 108 as a cylindrical body of the steering column 106, an inner ring 110 fitted on the steering shaft 103, and the outer ring 109 and the inner ring 110. And a plurality of interposed balls (rolling elements) 111. An annular spring-loaded seal member 112 that seals between the inner ring 110 and the outer ring 109 is disposed on both sides of the plurality of balls 111.

  The spring-sealed seal member 112 includes a metal annular body 115 disposed so as to surround the outer periphery of the inner ring 110 and an annular seal 113 formed integrally with the annular body 115. The seal 113 has a lip portion 116 that comes into contact with the inner peripheral surface, and is formed using a rubber material. A ring-shaped spring member 114 is fitted on the outer periphery of the lip 116. The spring member 114 elastically biases the seal 113 inward in the radial direction. Therefore, the seal 113 is pressed against the inner ring 110 while being in sliding contact with the inner peripheral surface of the inner ring 110 over a wide area. As a result, a frictional force is generated between the inner ring 110 and the seal 113.

  In addition, in order to increase the rotational torque of the steering, a structure in which the rotating member is elastically pressed toward the fixing member fixed to the steering shaft in the axial direction (see, for example, Patent Document 1), or a cylinder of the steering column A spherical plain bearing structure (see, for example, Patent Document 2) in which the outer ring (inner ring) of the bearing is slid with respect to the outer ring fitted inside is sometimes used. The structure which provided is adopted.

JP 2006-161983 A JP 2006-336683 A

  However, in the configuration in which the spring-loaded seal member is disposed between the inner ring and the outer ring, the frictional force between the seal and the inner ring at the time of activation may be significantly increased. In addition, when the rubber seal adheres to the inner ring, the frictional force at the time of activation between the seal and the inner ring may be further increased. Therefore, there arises a problem that the rotational torque at the time of starting is remarkably increased until the assist from the power steering device is entered.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a steering column bearing capable of generating a rotational torque having a stable magnitude and suppressing an increase in rotational torque during startup.

  In order to achieve the above object, an invention according to claim 1 includes an outer ring (9) fitted and fixed to a cylindrical body (8) of a steering column (6), and a steering shaft inserted through the cylindrical body. (3) A steering column bearing (7a, 7b) comprising an inner ring (10) fitted and fixed to the outer ring, and a plurality of rolling elements (11) interposed between the inner ring and the outer ring, An annular friction ring (14) having an outer surface (19) opposite to the inner surface of the outer ring and fixed to the inner ring, and fitted into the friction ring, the friction ring being radially outward A steering column bearing comprising a C-shaped spring ring (15) that is elastically biased toward the steering column.

In addition, the alphanumeric characters in parentheses represent corresponding components in the embodiments described later. The same applies hereinafter.
According to this configuration, the C-shaped spring ring elastically biases the friction ring toward the outer side in the radial direction. Therefore, the outer surface of the friction ring is pressed against the inner surface of the outer ring, and a frictional force is generated between the outer ring and the friction ring. Thereby, a stable torque torque can be generated in the steering column bearing.

Further, by appropriately selecting the material of the friction ring, it is possible to relatively reduce the friction force generated at the time of activation between the outer surface of the friction ring and the inner surface of the outer ring. Therefore, an increase in rotational torque at the time of startup can be suppressed.
Further, the friction ring contacts the inner surface of the outer ring. The inner surface of the outer ring has a larger surface area than the outer surface of the inner ring. Therefore, the friction ring and the inner surface of the outer ring can be brought into contact with each other over a wide area.

Furthermore, since the spring ring elastically biases the friction ring toward the outer ring, even if the friction ring is worn due to contact between the outer surface of the friction ring and the inner surface of the outer ring, the spring ring is moved to the outer ring of the friction ring. The pressing state of can be maintained. Thereby, the rotational torque of a stable magnitude | size can be maintained over a long period of time.
The friction ring includes a first cylinder (16) fixed to the outer ring, a second cylinder (17) having the outer surface, and an annular connection plate (18) connecting the first cylinder and the second cylinder. ), The spring ring may be fitted into the second cylinder.

In this case, by increasing the axial length of the second cylinder, the inner surface of the outer ring and the outer surface of the friction ring can be brought into contact with each other over a wide area. For this reason, the frictional force generated between the friction ring and the outer ring can be further increased.
In order to achieve the above object, an invention according to a second aspect of the present invention comprises an outer ring (9) fitted and fixed to a cylinder (8) of a steering column (6), and a steering shaft inserted through the cylinder. (3) A steering column bearing (30) comprising an inner ring (10) fitted and fixed to the outer ring, and a plurality of rolling elements (11) interposed between the inner ring and the outer ring, wherein the inner ring And an annular friction ring (34) fixed to the outer ring, and is fitted on the friction ring so that the friction ring faces inward in the radial direction. A steering column bearing comprising a C-shaped spring ring (35) that is elastically biased.

According to this configuration, the C-shaped spring ring elastically biases the friction ring inward in the radial direction. Therefore, the inner surface of the friction ring is pressed against the outer surface of the inner ring, and a frictional force is generated between the inner ring and the friction ring. Thereby, a stable torque torque can be generated in the steering column bearing.
Further, by appropriately selecting the material of the friction ring, it is possible to relatively reduce the friction force generated at the time of activation between the inner surface of the friction ring and the outer surface of the inner ring. Therefore, an increase in rotational torque at the time of startup can be suppressed.

Further, since the spring ring urges the friction ring toward the inner ring, even if the friction ring is worn out by contact between the inner surface of the friction ring and the outer surface of the inner ring, the friction ring is applied to the inner ring. The pressing state can be maintained. Thereby, the rotational torque of a stable magnitude | size can be maintained over a long period of time.
A third cylinder (36) in which the friction ring is fixed to the outer ring; a fourth cylinder (37) having the inner surface; and an annular connecting plate (38) connecting the third cylinder and the fourth cylinder. The spring ring may be externally fitted to the fourth cylinder.

In this case, by increasing the axial length of the fourth cylinder, the outer surface of the inner ring and the inner surface of the friction ring can be brought into contact with each other over a wide area. For this reason, the frictional force generated between the friction ring and the inner ring can be further increased.
The friction ring may be formed using a resin material.
In this case, an increase in rotational torque at startup can be suppressed.

  It is preferable that the resin material has a relatively small difference between the static friction coefficient and the dynamic friction coefficient. Examples of the resin material include fluorine resins such as PTFE (Polytetrafluoroethylene), POM (Polyacetal), PA (Polyamide), PC (Polycarbonate), and the like. In this case, even if the frictional force (dynamic frictional force) generated between the friction ring and the outer ring (or inner ring) during sliding is large enough to obtain a stable rotational torque, the friction ring and outer ring ( Or it can be set as the magnitude | size which suppressed sufficiently the frictional force (static frictional force) which arises between inner rings | wheels. As a result, it is possible to generate a rotational torque having a stable magnitude during sliding while suppressing an increase in rotational torque during startup.

The friction ring is preferably formed with a plurality of radially extending recesses (22).
According to this configuration, the friction ring has a plurality of recesses. Since each recess extends radially in the radial direction, the friction ring is easily contracted and expanded in the radial direction. For this reason, the entire region of the outer surface (inner surface) of the friction ring can be brought into contact with the inner surface of the outer ring (outer surface of the inner ring) with the spring ring attached to the friction ring. As a result, the friction ring and the outer ring (inner ring) can be brought into contact with each other over a wide area.

  The plurality of recesses may be formed in the connection plate. Each of the recesses may be a radial notch (slit).

1 is a perspective view showing a schematic configuration of a steering device equipped with a steering column bearing according to an embodiment of the present invention. It is sectional drawing seen from the cut surface line II-II shown in FIG. FIG. 2 is an enlarged cross-sectional view of the steering column bearing shown in FIG. 1. FIG. 4 is a view of the friction ring as seen from the arrow IV in FIG. 2. FIG. 4 is a plan view of the C ring shown in FIG. 3. It is principal part sectional drawing of the bearing for steering columns concerning other embodiment of this invention. It is principal part sectional drawing of the conventional steering column bearing.

Embodiments of the present invention will be specifically described below with reference to the drawings.
FIG. 1 is a perspective view showing a schematic configuration of a steering apparatus 1 on which steering column bearings 7a and 7b according to an embodiment of the present invention are mounted.
The steering device 1 includes a steering wheel 2 as a steering member and a turning mechanism (not shown) for turning a steered wheel (not shown). The rotation of the steering wheel 2 is transmitted to the steering mechanism via the steering shaft 3 and the intermediate shaft 4. The steering shaft 3 and the intermediate shaft 4 are connected via a universal joint 5.

  Further, the steering device 1 includes a cylindrical steering column 6 that is fixed to the vehicle body through which the steering shaft 3 is inserted, and a pair of steering column bearings 7a and 7b that support the steering shaft 3 on the steering column 6 (FIG. 1). Then, hatching is shown). Since the steering column bearings 7a and 7b have a common configuration, the configuration of the steering column bearings 7a and 7b will be described by taking the steering column bearing 7a as an example.

2 is a cross-sectional view taken along the section line II-II shown in FIG.
A steering column bearing 7 a is provided between an outer ring 9 fitted and fixed in a cylinder (tubular body) 8 of the steering column 6, an inner ring 10 fitted on the steering shaft 3, and the outer ring 9 and the inner ring 10. A plurality of interposed balls (rolling elements) 11 and a cage (not shown) for holding the plurality of balls 11 are provided. The outer ring 9 and the inner ring 10 are formed using a metal material such as carbon steel. In order to generate a rotational torque of a stable size in the steering column bearing 7a, a frictional force is generated between the outer ring 9 and the inner ring 10 on both sides of the ball 11 with the inner ring 10. A pair of friction mechanisms 12 and 13 are respectively disposed. Since the friction mechanisms 12 and 13 have a common configuration, the configuration of the friction mechanisms 12 and 13 will be described by taking the friction mechanism 12 as an example.

FIG. 3 is an enlarged cross-sectional view of the steering column bearing 7a.
The friction mechanism 12 is disposed between the outer ring 9 and the inner ring 10 and has an annular friction ring 14 fixed to the inner ring 10, and a circular C ring (spring ring) 15 fitted inside the friction ring 14. It has.
An inner peripheral surface of the outer ring 9 is provided with a first cylindrical surface 24 and a second cylindrical surface 25 formed on the side opposite to the ball 11 when viewed from the first cylindrical surface 24 and having a larger diameter than the first cylindrical surface 24. ing. The second cylindrical surface 25 is continuous with the side surface of the outer ring 9. The first cylindrical surface 24 and the second cylindrical surface 25 are connected by a first annular step 28.

  The outer peripheral surface of the inner ring 10 includes a third cylindrical surface 26 and a fourth cylindrical surface 27 that is formed on the opposite side of the ball 11 as viewed from the third cylindrical surface 26 and has a smaller diameter than the third cylindrical surface 26. . The fourth cylindrical surface 27 is continuous with the side surface of the inner ring 10. The third cylindrical surface 26 and the fourth cylindrical surface 27 are connected by a second annular step portion 29. The fourth cylindrical surface 27 of the inner ring 10 faces the second cylindrical surface 25 of the outer ring 9. The friction mechanism 12 is disposed between the second cylindrical surface 25 of the outer ring 9 and the fourth cylindrical surface 27 of the inner ring 10.

  The friction ring 14 is formed using a fluorine resin material such as PTFE (Polytetrafluoroethylene) and has an annular shape. The friction ring 14 has a first cylinder 16 fixed to the inner ring 10, a diameter larger than that of the first cylinder 16, a second cylinder 17 concentric with the first cylinder 16, the first cylinder 16 and the second cylinder 16. It is a member having a U-shaped cross section provided with an annular connecting plate 18 that connects the peripheral edges of the cylinder 17 on the ball 11 side.

  The second cylinder 17 is fitted in the outer ring 9 and has an outer peripheral surface (outer surface) 19 that faces the inner peripheral surface of the outer ring 9. The outer diameter of the second cylinder 17 is set to be slightly smaller than the inner diameter of the outer ring 9. Therefore, the friction ring 14 is fitted into the outer ring 9 by a clearance fit. A C ring 15 is fitted in the second cylinder 17. The friction ring 14 is elastically biased outward by the C ring 15 in the radial direction.

  The second cylinder 17 is provided with an annular protrusion 20 for preventing the C-ring 15 fitted on the second cylinder 17 from dropping off. The annular protrusion 20 is formed so as to protrude radially inward on the peripheral edge (the right edge shown in FIG. 3) on the inner peripheral surface of the second cylinder 17 opposite to the ball 11. An annular opening 21 is formed between the tip edge of the annular protrusion 20 and the peripheral edge (the right edge shown in FIG. 3) on the opposite side of the ball 11 of the first cylinder 16.

4 is a view of the friction ring 14 as viewed from the arrow IV in FIG.
The connecting plate 18 is along a direction orthogonal to the rotation axis C due to the rotation of the steering shaft 3. The connection plate 18 is formed with a plurality of radial notches (recesses) 22 (e.g., eight in FIG. 4). The plurality of notches 22 are arranged at equiangular intervals (for example, 45 ° in FIG. 4).

FIG. 5 is a plan view of the C-ring 15.
The C ring 15 is a C-shape formed using a metal material such as spring steel. The cross-sectional shape of the C-ring 15 is rectangular. The C ring 15 is fitted in the second cylinder 17.
The outer diameter D1 of the C-ring 15 in the unconstrained state is set larger than the first inner diameter D2 (see FIG. 3) of the second cylinder 17 in the unconstrained state. More specifically, the dimension obtained by adding the thickness W1 (see FIG. 3) of the second cylinder 17 to the outer diameter D1 of the C ring 15 is the outer diameter D3 (see FIG. 3; second cylindrical surface 25) of the outer ring 9. The diameter is set to be slightly larger than the diameter. For this reason, the C ring 15 elastically biases the entire area of the second cylinder 17 toward the outside in the radial direction while being fitted in the second cylinder 17.

The friction mechanism 12 is assembled to the steering column bearing 7a as follows.
First, from the side of the steering column bearing 7a, the friction ring 14 is inserted between the inner ring 10 and the outer ring 9 and is pushed in until it abuts on the annular step portions 28 and 29 (until it is received). Thereby, the friction ring 14 is interposed between the fourth cylindrical surface 27 of the inner ring 10 and the second cylindrical surface 25 of the outer ring 9. Then, the first cylinder 16 of the friction ring 14 is fixed to the inner ring 10.

  Next, the C ring 15 is fitted into the second cylinder 17 of the friction ring 14. The C-ring 15 is pressed and contracted inward in the radial direction to reduce the diameter. Then, after the C-ring 15 in the reduced diameter state is passed through the opening 21 and fitted into a region closer to the ball 11 than the annular protrusion 20 between the first cylinder 16 and the second cylinder 17, C The reduced diameter state of the ring 15 is released. As a result, the C ring 15 is restored, and the friction ring 14 elastically biases the inner peripheral surface of the second cylinder 17 of the friction mechanism 12 outward in the radial direction.

  As described above, according to this embodiment, the C-ring 15 elastically biases the friction ring 14 outward in the radial direction. Therefore, the outer peripheral surface 19 of the friction ring 14 is pressed against the inner peripheral surface (second cylindrical surface 25) of the outer ring 9, and a frictional force is generated between the outer ring 9 and the friction ring 14. As a result, a stable rotational torque can be generated in the steering column bearings 7a and 7b.

  Further, the friction ring 14 is formed using a fluorine resin material. The difference between the static friction coefficient and the dynamic friction coefficient is relatively small in the fluorine resin material. Therefore, even if the frictional force (dynamic frictional force) generated during sliding between the friction ring 14 and the outer ring 9 is large enough to obtain a stable rotational torque, it is generated between the friction ring 14 and the outer ring 9 at the time of starting. The friction force (static friction force) can be sufficiently suppressed. As a result, it is possible to generate a rotational torque having a stable magnitude during sliding while suppressing an increase in rotational torque during startup.

Furthermore, by increasing the length of the second cylinder 17 in the axial direction, the inner peripheral surface of the outer ring 9 and the outer peripheral surface 19 of the friction ring 14 can be brought into contact with each other over a wide area. For this reason, the frictional force generated between the friction ring 14 and the outer ring 9 can be further increased.
In addition, since the connection plate 18 of the friction ring 14 is formed with a plurality of notches 22 extending radially in the radial direction, the connection plate 18 of the friction ring 14 is easily contracted and expanded in the radial direction. Therefore, the entire outer peripheral surface 19 of the friction ring 14 can be brought into contact with the inner peripheral surface of the outer ring 9 while the C ring 15 is fitted inside the friction ring 14. Thereby, the inner peripheral surface of the outer ring 9 and the outer peripheral surface 19 of the friction ring 14 can be brought into contact with each other over a wide area, and the frictional force generated between the friction ring 14 and the outer ring 9 can be further increased.

  Furthermore, since the C ring 15 elastically biases the friction ring 14 toward the outer ring 9, the friction ring 14 is worn by contact between the outer peripheral surface of the friction ring 14 and the inner peripheral surface of the outer ring 9. However, the pressing state of the friction ring 14 against the outer ring 9 can be maintained. As a result, a stable rotational torque can be maintained over a long period of time in the steering column bearings 7a and 7b.

FIG. 6 is a cross-sectional view of a main part of a steering column bearing 30 according to another embodiment of the present invention.
In the embodiment of FIG. 6, portions corresponding to those shown in the embodiment shown in FIGS. 1 to 5 are denoted by the same reference numerals as those in FIGS. 1 to 5, and description thereof is omitted.
The steering column bearing 30 shown in FIG. 6 differs from the steering column bearings 7a and 7b shown in FIGS. 1 to 5 in place of the friction mechanisms 12 and 13 that generate a frictional force with the inner ring 10. The friction mechanism 31 that generates a frictional force with the outer ring 9 is employed.

The friction mechanism 31 is disposed between the outer ring 9 and the inner ring 10, and has an annular friction ring 34 fixed to the inner ring 10, and a circular C ring (spring ring) 35 that is externally fitted to the friction ring 34. It has.
The friction ring 34 is formed using a fluorine resin material such as PTFE (Polytetrafluoroethylene) and has an annular shape. The friction ring 34 is formed to have a third cylinder 36 fixed to the outer ring 9, a smaller diameter than the third cylinder 36, a fourth cylinder 37 concentric with the third cylinder 36, and the third cylinder 36 and the fourth cylinder. 37 is a member having a U-shaped cross section provided with an annular connecting plate 38 for connecting the peripheral edges of the balls 11 side.

  The fourth cylinder 37 is fitted on the inner ring 10 and has an inner peripheral surface (inner surface) 39 that faces the outer peripheral surface of the inner ring 10. The inner diameter of the fourth cylinder 37 is set to be slightly larger than the outer diameter of the inner ring 10. Therefore, the friction ring 34 is externally fitted to the inner ring 10 by a clearance fit. A C ring 35 is fitted on the fourth cylinder 37. By fitting the C ring 35 to the friction ring 34, the friction ring 34 is elastically biased outward in the radial direction.

  The fourth cylinder 37 is provided with an annular protrusion 40 for preventing the C-ring 35 fitted on the fourth cylinder 37 from dropping off. The annular protrusion 40 is formed so as to protrude radially inward on the peripheral edge (the right edge shown in FIG. 6) on the inner peripheral surface of the fourth cylinder 37 opposite to the ball 11. An annular opening 41 is formed between the tip edge of the annular protrusion 40 and the peripheral edge (the right edge shown in FIG. 6) of the first cylinder 16 opposite to the ball 11.

The connection plate 38 extends along a direction orthogonal to the rotation axis C due to the rotation of the steering shaft 3, and the connection plate 38 has the same cutout (recess) 22 (see FIG. 4) as the connection plate 18. A notch is formed.
The C ring 35 is a C-shape formed using a metal material such as spring steel. The cross-sectional shape of the C-ring 35 is rectangular. The C ring 35 is fitted on the fourth cylinder 37.

  The inner diameter of the C ring 35 in the unconstrained state is set to be smaller than the outer diameter D5 (the diameter of the fourth cylindrical surface 27) of the fourth cylinder 37 in the unconstrained state. More specifically, the dimension obtained by adding the thickness W2 of the second cylinder 17 to the outer diameter D6 (the diameter of the second cylindrical surface 25) of the inner ring 10 is set to be larger than the inner diameter of the C ring 35. Yes. For this reason, the C ring 35 elastically biases the entire area of the fourth cylinder 37 inward in the radial direction in a state of being fitted on the fourth cylinder 37.

As described above, according to this embodiment, the C-ring 35 elastically biases the friction ring 34 inward in the radial direction. Therefore, the inner peripheral surface 39 of the friction ring 34 is pressed against the outer peripheral surface of the inner ring 10, and a frictional force is generated between the inner ring 10 and the friction ring 34. Thereby, a stable torque can be generated in the steering column bearing 30.
Further, the friction ring 14 is formed using a fluorine resin material. The difference between the static friction coefficient and the dynamic friction coefficient is relatively small in the fluorine resin material. Therefore, even if the frictional force (dynamic frictional force) generated during sliding between the friction ring 14 and the inner ring 10 is large enough to obtain a stable rotational torque, it is generated between the friction ring 14 and the inner ring 10 at the time of starting. The friction force (static friction force) can be sufficiently suppressed. As a result, it is possible to generate a rotational torque having a stable magnitude during sliding while suppressing an increase in rotational torque during startup.

Furthermore, by increasing the axial length of the fourth cylinder 37, the outer peripheral surface of the inner ring 10 and the inner peripheral surface 39 of the friction ring 34 can be brought into contact with each other over a wide area. For this reason, the frictional force generated between the friction ring 14 and the inner ring 10 can be further increased.
Further, since the C ring 35 elastically biases the friction ring 34 toward the inner ring 10, the friction ring 34 is worn due to contact between the inner peripheral surface of the friction ring 34 and the outer peripheral surface of the inner ring 10. However, the pressing state of the friction ring 34 against the outer ring 9 can be maintained. As a result, a stable rotational torque can be maintained over a long period of time in the steering column bearing 30.

While the two embodiments of the present invention have been described above, the present invention can also be implemented in other embodiments.
In each of the above-described embodiments, the friction rings 14 and 34 have been described as members having a U-shaped cross section, but the cross-sectional shape of the friction rings 14 and 34 may be a roll-over H shape that rolls over by 90 °. In this case, the connecting plates 18 and 38 connect the central part of the first cylinder 16 and the central part of the second cylinder 17 (connecting the central part of the third cylinder 36 and the central part of the fourth cylinder 37). ).

Further, for example, the connection plates 18 and 38 of the friction rings 14 and 34 may be provided with elastic deformation portions that can be elastically deformed in the radial direction, and the C rings 15 and 35 may be omitted from the friction mechanisms 12 and 13. . In this case, the number of parts can be reduced by omitting the C-rings 15 and 35. Thereby, cost reduction can be aimed at.
In each of the above-described embodiments, the friction rings 14 and 34 are described as being formed using a fluororesin material. However, a resin material such as POM (Polyacetal), PA (Polyamide), and PC (Polycarbonate) is used. It may be formed.

Alternatively, the outer peripheral surface 19 of the friction ring 14 and the inner peripheral surface 39 of the friction ring 34 may be coated using these resin materials.
In each of the above-described embodiments, the friction mechanisms 12, 13, and 31 are described as being disposed on both sides of the ball 11. However, the friction mechanisms 12, 13, and 31 may be disposed only on one side of the ball 11.

  In each of the above-described embodiments, it has been described that the annular step portions 28 and 29 for receiving the friction mechanisms 12, 13, and 31 are formed on the outer periphery of the inner ring 10 and the inner periphery of the outer ring 9. A stepped portion for receiving may be formed only on one of the outer periphery of the inner ring 10 and the outer ring 9. Further, the outer circumference of the inner ring 10 and the inner circumference of the outer ring 9 may be configured to form a smooth cylindrical surface without forming the annular step portions 28 and 29.

Further, the steering column bearings 7a, 7b, and 30 according to the above-described embodiments can be applied to a steer-by-wire type steering device that can release the mechanical connection between the steering member and the steering mechanism.
In addition, various design changes can be made within the scope of matters described in the claims.

DESCRIPTION OF SYMBOLS 3 ... Steering shaft, 6 ... Steering column, 7a, 7b ... Steering column bearing, 8 ... Cylindrical (cylindrical body), 9 ... Outer ring, 10 ... Inner ring, 11 ... Ball (rolling body), 14 ... Friction ring, 15 ... C ring (spring ring), 16 ... first cylinder, 17 ... second cylinder, 18 ... connecting plate, 19 ... outer peripheral surface (outer surface), 30 ... steering column bearing, 34 ... friction ring, 35 ... C ring (spring) Ring), 36 ... third cylinder, 37 ... fourth cylinder, 38 ... connecting plate, 39 ... inner peripheral surface (inner surface)

Claims (4)

An outer ring that is fitted and fixed to a cylinder of a steering column, an inner ring that is fitted and fixed to a steering shaft that is inserted through the cylinder, and a plurality of rolling elements that are interposed between the inner ring and the outer ring A steering column bearing comprising:
An annular friction ring having an outer surface facing the inner surface of the outer ring and fixed to the inner ring;
A steering column bearing comprising: a C-shaped spring ring that is fitted in the friction ring and elastically biases the friction ring outward in a radial direction. An outer ring that is fitted and fixed to a cylinder of a steering column, an inner ring that is fitted and fixed to a steering shaft that is inserted through the cylinder, and a plurality of rolling elements that are interposed between the inner ring and the outer ring A steering column bearing comprising:
An annular friction ring having an inner surface facing the outer surface of the inner ring and fixed to the outer ring;
A steering column bearing comprising: a C-shaped spring ring that is fitted on the friction ring and elastically biases the friction ring toward a radially inward direction.   The bearing for a steering column according to claim 1 or 2, wherein the friction ring is formed using a resin material. The bearing for a steering column according to any one of claims 1 to 3, wherein the friction ring is formed with a plurality of recesses extending radially.

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