JP2006322556A - Suspension bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suspension bearing having simple construction for inexpensively producing rotating resistance without impairing travelling stability during straight travel. <P>SOLUTION: On the opposed faces of an inside cylindrical portion 11 and an outside cylindrical portion 12 of an inner ring 1 to a ball storage space K, swollen portions 11a, 12a are formed which are protruded into the ball storage space K. On the opposed faces of an inside cylindrical portion 21 and an outside cylindrical portion 22 of an outer ring 2 to the ball storage space K, swollen portions 21a, 22a are formed which are protruded into the ball storage space K. On a first lip portion 51 of an inside seal 5, an extension portion 51a is formed which has contact with the upper face of the swollen portion 11a to increases friction force. On a second lip portion 52 of the inside seal 5, an extension portion 52a is formed which has contact with the lower face of the swollen portion 21a to increases friction force. On a first lip portion 61 of an outside seal 6, an extension portion 61a is formed which has contact with the upper face of the swollen portion 12a to increases friction force. On a second lip portion 62 of the outside seal 6, an extension portion 62a is formed which has contact with the lower face of the swollen portion 22a to increases friction force. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a suspension bearing, and more particularly to a strut-type suspension bearing.

  In a strut suspension, which is one of vehicle suspension types, a suspension bearing is interposed between an upper end portion of a strut shaft and a vehicle body side support portion. In general, in a vehicle suspension device, a light steering operation is required during steering (when a steering wheel is operated). On the other hand, during straight running (when a steering wheel is neutral), wheel shake caused by road surface unevenness is transmitted to the steering wheel. Driving stability is not required.

  Conventional strut-type suspension bearings have a function of reducing rotational torque (rotational resistance) during steering operation by the relative rotation of a pair of track wheels during steering. However, since the rotational resistance is equal to that during steering even during straight traveling, there is a tendency that traveling stability cannot be maintained. For this reason, variable steering torque structures (for example, variable gear ratio mechanisms using planetary gears and motors) have been incorporated into the steering mechanism itself to obtain rotational resistance during straight travel, but the structure is complicated and costly. There is a problem that becomes high.

  An object of the present invention is to provide a suspension bearing that can obtain a rotational resistance that does not impair running stability during straight running with a simple structure at low cost.

Means for Solving the Problems and Effects of the Invention

In order to solve the above problems, a suspension bearing according to the present invention includes:
A first race ring that is fixed to the upper end portion of the strut shaft and that forms an annular first raceway surface that supports a plurality of rolling elements, and the first race ring that is fixed to a vehicle body side support portion and sandwiches the rolling elements. A suspension bearing having a second race ring forming an annular second raceway surface facing the raceway surface,
An annular seal member is provided for closing the rolling element housing space surrounded by the first and second raceway surfaces and filled with a lubricant;
In the first and / or second race, a protruding portion that protrudes into the rolling element housing space is formed over a predetermined angular range in the circumferential direction,
The seal member is formed with a friction adjusting portion capable of adjusting a frictional force over a predetermined angular range in the circumferential direction when the first and second bearing rings rotate relative to each other, depending on whether or not they contact with the protruding portion. ,
The rotational torque in a specific relative rotational angle range of both races is increased by a frictional force that increases when the friction adjustment portion of the seal member contacts the protruding portion.

In order to solve the above problems, a specific aspect of the suspension bearing according to the present invention is as follows.
A first race ring that is fixed to the upper end portion of the strut shaft and that forms an annular first raceway surface that supports a plurality of rolling elements, and the first race ring that is fixed to a vehicle body side support portion and sandwiches the rolling elements. A suspension bearing having a second race ring forming an annular second raceway surface facing the raceway surface,
An annular cage is disposed in the rolling element housing space surrounded by the first and second raceway surfaces and filled with the lubricant, and the rolling element is disposed in the cage. An annular seal member for closing the accommodation space is fixedly arranged,
In the first and / or second race, a protruding portion that protrudes into the rolling element housing space is formed over a predetermined angular range in the circumferential direction,
The seal member is formed with a friction adjusting portion capable of adjusting a frictional force over a predetermined angular range in the circumferential direction when the first and second bearing rings rotate relative to each other, depending on whether or not they contact with the protruding portion. ,
The rotational torque in a specific relative rotational angle range of both races is increased by a frictional force that increases when the friction adjustment portion of the seal member contacts the protruding portion.

  According to these suspension bearings, the frictional force increases when the friction adjusting portion and the protruding portion of the seal member come into contact (for example, sliding) within a specific relative rotation angle range, and the rotational torque of both race rings is increased. Therefore, during straight running (when the steering wheel is in a neutral position), even if the wheel shakes due to road surface unevenness or the like, it is difficult to transmit to the steering wheel, and running stability is not impaired. Moreover, it is only necessary to form the protrusion and the friction adjustment part without having to incorporate a variable rotational torque structure into the steering mechanism as in the past, so it is easy to achieve a rotational resistance that does not impair running stability during straight running. It can be obtained inexpensively with a simple structure.

  When a seal member having such a friction adjusting portion is fixedly disposed in a cage that holds the mutual spacing of the rolling elements, a simpler and cheaper structure can be obtained. In addition, since it is only necessary to fix the seal member having the friction adjusting portion to the cage that is originally manufactured and assembled with a predetermined accuracy, it is easy to ensure the mounting accuracy of the friction adjusting portion.

  As the suspension bearing of the present invention, a radial bearing such as a radial ball bearing, or a thrust bearing such as a thrust ball bearing or a press-made total ball thrust ball bearing can be used.

  Further, as a lubricant, in order to reduce the viscous resistance that the seal member and the cage receive during steering, for example, a relatively soft grease having a blending degree (grease hardness) of 300 or more based on JIS K2220 (2003) Also recommended are lubricants, polymer lubricants, etc., which have a lower viscosity than grease. In this case, as the lubricating oil, synthetic oil such as poly-α-olefin, diester, perfluoropolyether, synthetic hydrocarbon, ether oil, ester oil, silicon oil, fluorine oil, or mineral oil can be used. As the polymer lubricant, a mixture of the above-described lubricating oil and a thermoplastic resin such as ultrahigh molecular weight polyethylene, polypropylene, polymethylpentene, polyurethane, etc., can be used.

  Further, an extreme pressure additive and / or an anti-wear agent may be added in order to lighten the steering feeling and prevent seizure of the friction surface in the bearing. Examples of these extreme pressure additives and / or antiwear agents include general organometallic complexes such as Mo dithiocarbamate and Zn dithiophosphate, sulfur compounds such as diester sulfide and benzyl sulfide, tricresyl phosphate, and phosphate esters. All extreme pressure additives and anti-wear agents such as phosphorus-based, halogen-based such as alkyl benzene can be used.

  In these suspension bearings, the relative rotation angle range in which the friction adjustment portion contacts the protrusion is determined based on the neutral position of the wheel linked to the strut shaft, and during straight traveling, the friction adjustment portion and the protrusion It is desirable to increase the rotational torque by the contact, and to eliminate or reduce the rotational torque by eliminating the contact between the friction adjusting portion and the protruding portion during steering. This makes it easy to associate the relative rotation angle range that increases the rotational torque of both races with the wheel deflection angle during straight travel based on the neutral position of the wheel, enabling more stable travel during straight travel. become.

  When the frictional force of the seal member (rotational torque of both races) increases based on an increase in the contact area of the seal member and / or an increase in contact surface pressure due to the contact between the friction adjustment portion and the protrusion. By adjusting the contact area and contact surface pressure of the seal member, the frictional force of the seal member (friction adjusting portion) (that is, the rotational torque of both races) can be easily adjusted. For example, the contact area of the seal member in the relative rotation angle range is increased by contact between the friction adjustment portion and the protrusion, or the contact surface pressure of the seal member in the relative rotation angle range is increased by increasing the thickness of the friction adjustment portion. Can be.

  At that time, the protrusions are formed on the first and second race rings, respectively, and the friction adjustment portions are formed on the seal members corresponding to the protrusions, respectively. If the angular ranges are arranged so as to coincide with each other in the circumferential direction, the friction adjusting portion can come into contact with the protruding portion of each raceway ring in synchronization with each other. In this manner, by forming the protrusions on the first and second races, it is possible to easily increase the contact area between the seal member (the friction adjusting portion thereof) and the protrusion in the relative rotation angle range. it can.

Example 1
Next, embodiments of the present invention will be described with reference to examples shown in the drawings. FIG. 1 is a perspective view showing an example of a strut suspension, and FIG. 2 is an enlarged sectional view of a P portion thereof. As shown in FIG. 1, the strut type suspension is mounted on a support member 81 to support a part of the vehicle body, and a strut shaft 83 (suspension part) is incorporated into the strut shaft 83 to absorb vibrations and shocks from the tire side. And a stabilizer support 84 (vehicle body side support portion) fixed to the upper portion of the vehicle body. The strut type suspension is attached to a support member 81 on the vehicle body side and has a role of supporting the entire vehicle body in a floating manner with respect to an axle or the like. Around the support member 81, an axle 93, a hub 90 fixed to the axle 93 and fitted with wheels, a brake disc 91 fixed to the hub 90, and a pad that presses the brake disc 91 with hydraulic pressure are provided inside. A provided caliper body 92 is disposed.

  As shown in FIG. 2, the internal structure of the upper part of the strut suspension includes a coil spring seat 85 that holds the spring seat 82 a of the coil spring 82 and a press-made total ball thrust ball bearing that is held at the upper end of the strut shaft 83. 100 (suspension bearing; hereinafter also simply referred to as a bearing), a bearing housing 89 (vehicle body side support portion) that holds the bearing 100, and a stabilizer support 84 that holds the bearing 100 and the bearing housing 89 so as to surround them. ing. The stabilizer support 84 includes an elastic member 84 a and an outer cylindrical portion 84 b that covers the periphery of the elastic member 84 a and is fixed to the bearing housing 89.

  Then, the annular inner ring 1 (first raceway ring) of the bearing 100 is fitted and fixed to the coil spring seat 85 fixed to the upper end portion of the strut shaft 83, and the ring member 86 (rotation within the elastic member 84 a) is performed by the nut 88. Is movable) and is fixed to the strut shaft 83. On the other hand, the annular outer ring 2 (second race ring) of the bearing 100 is fitted and fixed to the bearing housing 89, and the bearing housing 89 is fixed to the vehicle body side via the stabilizer support 84.

  Next, FIG. 3 is a front sectional view showing an example of a suspension bearing according to the present invention, and FIG. 4 is an enlarged view of a main part thereof. A bearing 100 shown in FIG. 3 supports a plurality of (for example, eight) balls 3 (rolling elements) and forms an annular inner raceway surface 10 (first raceway surface). Ring) and an outer ring 2 (second race ring) made of metal press that forms an annular outer race face 20 that faces the inner race face 10 with the ball 3 interposed therebetween. As described above, the inner ring 1 is fixed to the upper end portion of the strut shaft 83, and the outer ring 2 is fixed to a stabilizer support 84 (bearing housing 89) that is a vehicle body side support portion (see FIG. 2).

  A ball housing space K (rolling member housing space) surrounded by the inner raceway surface 10 and the outer raceway surface 20 is filled with a lubricant L (for example, a blending degree of 300 or more) such as grease. In addition, in the ball housing space K, a metal-made annular cage 4 is disposed in order to keep the balls 3 from each other. In this cage 4, a plurality (eight in this case) of through holes 4 a that hold the balls 3 are formed at equal intervals in the circumferential direction (see FIGS. 5 and 6), and a connecting portion that connects the through holes 4 a. 4b is formed in an umbrella shape inclined obliquely with respect to both raceway surfaces 10 and 20. Further, the cage 4 has an annular inner side that closes (seals) both race rings 1 and 2 (ball housing space K) on the inner and outer circumference sides (that is, on both sides of both raceway surfaces 10 and 20). A seal 5 (seal member) and an annular outer seal 6 (seal member) are fixedly disposed.

  Specifically, as shown in an enlarged view in FIG. 4, the inner seal 5 is in contact with the entire circumference of the ball housing space K facing surface of the inner cylindrical portion 11 of the inner ring 1 to seal the first lip portion 51 (FIG. 6). And a second lip portion 52 (see FIG. 5) that seals in contact with the entire circumference of the ball housing space K facing surface of the inner cylindrical portion 21 of the outer ring 2, and is fixed to the retainer 4 by baking, bonding, or the like. Mounting portion 53. Similarly, the outer seal 6 includes a first lip portion 61 (see FIG. 6) that seals in contact with the entire circumference of the ball housing space K facing surface of the outer cylindrical portion 12 of the inner ring 1, and an inner cylindrical portion 21 of the outer ring 2. It has a second lip portion 52 (see FIG. 5) that contacts and seals the entire circumference of the ball housing space K facing surface, and an attachment portion 63 for fixing to the cage 4 by baking or adhesion.

  The bulging portions 11a and 12a projecting into the ball receiving space K in the form of equally dividing the inner raceway surface 10 in the circumferential direction on the opposing surfaces of the ball receiving space K of the inner cylindrical portion 11 and the outer cylindrical portion 12 of the inner ring 1. (Protrusions) are formed at a plurality of locations (here, two locations) over an angular range θ (for example, 10 °; see FIG. 10) in the circumferential direction. Similarly, the bulging part which protrudes in the ball | bowl accommodation space K in the form which divides | segments the outer raceway surface 20 equally to the circumferential direction in the ball | bowl accommodation space K opposing surface of the inner cylinder part 21 and the outer cylinder part 22 of the outer ring | wheel 2. 21a and 22a (protruding portions) are formed at a plurality of locations (here, two locations) over an angular range θ (for example, 10 °; see FIG. 9) in the circumferential direction.

  The first lip part 51 of the inner seal 5 has an extension part 51a (friction adjustment part) for increasing the frictional force by contacting the upper surface of the bulging part 11a when the inner ring 1 and the outer ring 2 rotate relative to each other. In the form in which the cage 4 is equally divided in the circumferential direction, a plurality of locations (here, 2 locations) are formed over an angular range θ (eg, 10 °; see FIG. 6) in the circumferential direction. Similarly, when the inner ring 1 and the outer ring 2 rotate relative to each other, the second lip portion 52 of the inner seal 5 is brought into contact with the lower surface of the bulging portion 21a to increase the frictional force 52a (friction adjustment). Are formed in a plurality of locations (here, two locations) over the angular range θ (for example, 10 °; see FIG. 5) in the circumferential direction.

  On the other hand, when the inner ring 1 and the outer ring 2 rotate relative to each other, the first lip portion 61 of the outer seal 6 is brought into contact with the upper surface of the bulging portion 12a to increase the frictional force 61a (friction adjusting portion). ) Is formed at a plurality of locations (here, two locations) over an angular range θ (for example, 10 °; see FIG. 6) in the circumferential direction in the form of equally dividing the cage 4 in the circumferential direction. Similarly, when the inner ring 1 and the outer ring 2 rotate relative to each other, the second lip portion 62 of the outer seal 6 is brought into contact with the lower surface of the bulging portion 22a to increase the frictional force 62a (friction adjustment). Are formed in a plurality of locations (here, two locations) over the angular range θ (for example, 10 °; see FIG. 5) in the circumferential direction.

  That is, these extension parts 51a, 52a, 61a, 62a increase the contact area of the inner seal 5 and the outer seal 6 by making contact with the bulging parts 11a, 12a, 21a, 22a, and increase the frictional force.

  Here, the relative rotation angle range in which the extension portions 51a, 52a, 61a, 62a of both seals 5, 6 and the bulging portions 11a, 12a, 21a, 22a of both race rings 1, 2 are in contact with each other is a strut shaft 83 (see FIG. 2), the angle range θ (for example, ± 5 ° with respect to the neutral position C) is set with reference to a neutral position C of a wheel (not shown) linked to the wheel. The combination of a total of four sets of the extension parts 51a, 52a, 61a, 62a and the bulging parts 11a, 12a, 21a, 22a starts contact (sliding) almost simultaneously, and makes contact (sliding) almost simultaneously. Stop.

  Therefore, during straight traveling, as shown in FIG. 7, the relative rotation angle range is increased by the frictional force that increases when the extension portions 51a, 52a, 61a, and 62a come into contact with the bulging portions 11a, 12a, 21a, and 22a. The rotational torque of both race rings 1 and 2 at θ is increased. As a result, both raceways 1 and 2 are less likely to rotate relative to each other, and traveling stability is maintained. On the other hand, at the time of steering, as shown in FIG. 8, the contact between the extension portions 51a, 52a, 61a, 62a and the bulging portions 11a, 12a, 21a, 22a is eliminated by the steering operation. , 2 disappears (or decreases), and the steering operation force is reduced.

  Moreover, since only the extension portions 51a, 52a, 61a, 62a of both seals 5, 6 and the bulging portions 11a, 12a, 21a, 22a of both race rings 1, 2 are formed, the structure is simple and inexpensive. Can be configured. Note that the extension portions 51a, 52a, 61a, and 62a and the bulging portions 11a, 12a, 21a, and 22a may be provided in only one corresponding pair.

(Example 2)
FIG. 11 shows another example of the bearing 100. In the bearing 100 of FIG. 11, both seals 5, 6 are arranged on the entire circumference of the ball housing space K facing surface of the inner cylindrical portions 11, 21 and the outer cylindrical portions 12, 22 of both race rings 1, 2. Specifically, a circumferential angle range θ (for example, the tip of the inner seal 5 (seal member) fixed to the entire circumference of the inner surface of the inner ring portion 11 of the inner ring 1 facing the ball housing space K by baking or bonding. The extended portion 5a (friction adjusting portion) is formed over 10 °. In addition, a circumferential angle range θ (for example, 10 °) is provided at the distal end portion of the outer seal 6 (seal member) fixed to the entire circumference of the ball housing space K facing surface of the outer cylindrical portion 12 of the inner ring 1 by baking or bonding. An extended portion 6a (friction adjusting portion) is formed over the entire area. And these extension parts 5a and 6a are the angular range (theta) of the circumferential direction on the ball storage space K opposing surface of the inner side cylindrical part 21 and the outer side cylindrical part 22 of the outer ring | wheel 2 when both the bearing rings 1 and 2 rotate relatively. (For example, 10 °; see FIG. 9) The bulges 21a and 22a (protruding portions) formed over the respective portions are brought into contact with each other.

  Therefore, during straight running, the rotational torque of both race rings 1 and 2 in the relative rotational angle range θ is increased by the frictional force that increases when the extension portions 5a and 6a come into contact with the bulging portions 21a and 22a. . As a result, both raceways 1 and 2 are less likely to rotate relative to each other, and traveling stability is maintained. On the other hand, at the time of steering, since the contact between the extension portions 5a, 6a and the bulging portions 21a, 22a is canceled by the steering operation, the rotational torque of the both race wheels 1, 2 disappears (or decreases), and the steering operation Power is reduced.

(Example 3)
FIG. 12 shows still another example of the bearing 100. In the bearing 100 of FIG. 12, both seals 5, 6 are arranged on the entire circumference of the ball housing space K facing surface of the inner cylindrical portions 11, 21 and the outer cylindrical portions 12, 22 of both race rings 1, 2. Specifically, the circumferential angle range θ (for example, the tip of the inner seal 5 (seal member) fixed to the entire circumference of the inner surface of the inner cylindrical portion 21 of the outer ring 2 facing the ball housing space K by baking or bonding. The extended portion 5a (friction adjusting portion) is formed over 10 °. Further, an angular range θ (for example, 10 °) in the circumferential direction is formed at the tip of the outer seal 6 (seal member) fixed to the entire circumference of the outer surface of the outer cylindrical portion 22 of the outer cylindrical portion 22 facing the ball housing space K by baking or bonding. An extended portion 6a (friction adjusting portion) is formed over the entire area. And these extension parts 5a and 6a are the angular range (theta) of the circumferential direction on the ball storage space K opposing surface of the inner cylindrical part 1 of the inner ring | wheel 1, and the outer cylindrical part 1 when both the bearing rings 1 and 2 rotate relatively. (For example, 10 °; see FIG. 10) The bulge portions 11a and 12a (protruding portions) formed over the respective portions are brought into contact with each other.

  Therefore, during straight traveling, the rotational torque of both raceways 1 and 2 in the relative rotational angle range θ is increased by the frictional force that increases when the extension portions 5a and 6a come into contact with the bulging portions 11a and 12a. . As a result, both raceways 1 and 2 are less likely to rotate relative to each other, and traveling stability is maintained. On the other hand, at the time of steering, since the contact between the extension portions 5a, 6a and the bulging portions 11a, 12a is canceled by the steering operation, the rotational torque of the both race wheels 1, 2 disappears (or decreases), and the steering operation Power is reduced.

  In the above embodiments, only the case where a press-made full ball thrust ball bearing is used as the suspension bearing has been described. . In addition to increasing the contact area of the seals 5 and 6 as in the embodiment, the frictional force can be increased by increasing the contact surface pressure (contact pressure) due to the thickness change of the seals 5 and 6. it can.

The perspective view which shows an example of a strut type suspension. The expanded sectional view of the P section of FIG. 1 is a front sectional view showing an example of a suspension bearing according to the present invention. The principal part enlarged view of FIG. The top view of the holder | retainer of FIG. The bottom view of the holder | retainer of FIG. AA sectional drawing of FIG. BB sectional drawing of FIG. The bottom view of the outer ring | wheel of FIG. The top view of the inner ring | wheel of FIG. The front sectional view showing other examples of the bearing for suspension concerning the present invention. FIG. 6 is a front sectional view showing still another example of the suspension bearing according to the present invention.

Explanation of symbols

1 Inner ring (first track ring)
10 Inner raceway surface (first raceway surface)
11 inner cylindrical part 11a bulging part (protruding part)
12 outer cylindrical part 12a bulging part (protruding part)
2 Outer ring (second race)
20 Outer raceway surface (second raceway surface)
21 inner cylindrical part 21a bulge part (protrusion part)
22 Outer cylindrical part 22a Swelling part (protruding part)
3 balls (rolling elements)
4 Cage 5 Inner seal (seal member)
51 1st lip part 51a Extension part (friction adjustment part)
52 2nd lip part 52a Extension part (friction adjustment part)
6 Outer seal (seal member)
61 1st lip part 61a Extension part (friction adjustment part)
62 2nd lip part 62a Extension part (friction adjustment part)
83 Strut shaft (suspension part)
84 Stabilizer support (body side support)
89 Bearing housing (body side support)
100 Full ball thrust ball bearings (suspension bearings)
K ball accommodation space (rolling element accommodation space)
L Lubricant

Claims (5)

A first race ring that is fixed to the upper end portion of the strut shaft and that forms an annular first raceway surface that supports a plurality of rolling elements, and the first race ring that is fixed to a vehicle body side support portion and sandwiches the rolling elements. A suspension bearing having a second race ring forming an annular second raceway surface facing the raceway surface,
An annular seal member is provided for closing the rolling element housing space surrounded by the first and second raceway surfaces and filled with a lubricant;
In the first and / or second race, a protruding portion that protrudes into the rolling element housing space is formed over a predetermined angular range in the circumferential direction,
The seal member is formed with a friction adjusting portion capable of adjusting a frictional force over a predetermined angular range in the circumferential direction when the first and second bearing rings rotate relative to each other, depending on whether or not they contact with the protruding portion. ,
A suspension bearing characterized in that a rotational torque in a specific relative rotational angle range of both race rings is increased by a frictional force that increases when a friction adjusting portion of the seal member contacts the protrusion. A first race ring that is fixed to the upper end portion of the strut shaft and that forms an annular first raceway surface that supports a plurality of rolling elements, and the first race ring that is fixed to a vehicle body side support portion and sandwiches the rolling elements. A suspension bearing having a second race ring forming an annular second raceway surface facing the raceway surface,
An annular cage is disposed in the rolling element housing space surrounded by the first and second raceway surfaces and filled with the lubricant, and the rolling element is disposed in the cage. An annular seal member for closing the accommodation space is fixedly arranged,
In the first and / or second race, a protruding portion that protrudes into the rolling element housing space is formed over a predetermined angular range in the circumferential direction,
The seal member is formed with a friction adjusting portion capable of adjusting a frictional force over a predetermined angular range in the circumferential direction when the first and second bearing rings rotate relative to each other, depending on whether or not they contact with the protruding portion. ,
A suspension bearing characterized in that a rotational torque in a specific relative rotational angle range of both race rings is increased by a frictional force that increases when a friction adjusting portion of the seal member contacts the protrusion. The relative rotation angle range in which the friction adjustment portion contacts the protrusion is determined based on a neutral position of a wheel linked to the strut shaft,
During straight traveling, the rotational torque is increased by contact between the friction adjusting portion and the protruding portion, and during steering, the contact between the friction adjusting portion and the protruding portion is eliminated, and the rotational torque disappears or decreases. The suspension bearing according to claim 1 or 2.   The frictional force of the seal member increases based on an increase in a contact area of the seal member and / or an increase in contact surface pressure due to contact between the friction adjustment portion and the protrusion. The suspension bearing according to item. The protrusions are formed on the first and second bearing rings, respectively, and the friction adjustment portions are formed on the seal member corresponding to the protrusions, respectively.
The suspension bearing according to any one of claims 1 to 4, wherein the relative rotation angle ranges of the protrusions formed on the race rings are arranged to coincide with each other in the circumferential direction.

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