JP4748050B2 - Sealed thrust ball bearing - Google Patents

Description

  The present invention relates to a sealed thrust ball bearing used for, for example, a strut suspension device of a vehicle.

  For example, in a strut suspension device for a vehicle, a sealed thrust ball bearing is used between an upper mount and a lower mount (see, for example, Patent Documents 1 and 3). A rubber sealing material is provided to prevent foreign matter from entering the bearing and leakage of grease filled in the bearing, and separation of the bearing is prevented using the sealing material (for example, (See Patent Documents 1 to 3.)

  As a structure for preventing the separation of such bearings (the first race and the second race, the inner race and the outer race), in Patent Document 1, the second seal lip bonded to the outer peripheral surface of the outer diameter side cylindrical flange of the first race is used as the first seal lip. It is press-contacted to the inner peripheral surface of the cylindrical flange of the two races. In Patent Document 2, a holding groove is formed on the outer peripheral surface of the inner wall of the first race, and the second elastomer sealing lip of the second race is formed in the holding groove. In Patent Document 3, a cylindrical metal core on which the outer elastic sealing material is baked is press-fitted into the inner surface of the cylindrical portion of the second race, and the lip of the outer sealing material is bent outside the first race. It is in pressure contact with the outer surface of the part.

JP 2002-227861 A (FIG. 1-2) Japanese Examined Patent Publication No. 63-58290 (Fig. 3) Japanese Utility Model Publication No. 5-40328 (FIG. 1)

  In the conventional bearing separation preventing structure as described above, in the configuration of Patent Document 1, as described above, the bearing separation is prevented only by the restoring force due to the elastic deformation of the seal lip that contacts in the radial direction. In order to ensure the above, it is necessary to increase the restoring force. Therefore, since the frictional resistance increases, the rotational torque of the bearing increases. Moreover, in the structure of patent document 2, since it is necessary to process the said holding groove in the outer peripheral surface of the inner side wall of a 1st race, manufacturing cost rises. Furthermore, in the configuration of Patent Document 3, a cylindrical cored bar baked with an elastic sealing material is required, and the number of parts and assembly man-hours increase, resulting in an increase in manufacturing cost.

  Therefore, in view of the above-described situation, the present invention intends to solve a sealed type capable of reliably preventing separation while suppressing an increase in rotational torque of the bearing and suppressing an increase in manufacturing cost. A thrust ball bearing is provided.

In order to solve the above problems, the sealed thrust ball bearing according to the present invention includes a pair of annular races facing each other in the axial direction, and a plurality of balls arranged so as to roll between the facing surfaces of these races, A sealed-type thrust ball bearing comprising an inner elastic seal material and an outer elastic seal material that seal between the inner peripheral portions and between the outer peripheral portions of the pair of races, wherein the elastic seal material includes an elastic body is obtained by integrally covering the race, at least one of the inner elastic seal member and the outer elastic seal member, Rutotomoni comprises a lip extending toward the contact face of the race of the seal member and another member, the The seal is provided with a cylindrical base connected to the end of the cylindrical portion of the race integrated with the seal material, and the lip is elastically deformed in the assembly direction when the pair of races are assembled close to the axial direction. After When the assembly is completed, the pressure contact surface is inclined so as to be elastically deformed by reversing in the direction opposite to the direction of the elastic deformation, and when the assembly is completed, the restoring force of the elastic deformation of the lip is inclined. It acts on the pressure contact surface.

  Here, it is preferable that the inclined pressure contact surface is an outer peripheral surface of a curved portion serving as a track portion of the ball, and a lip extending inward of the outer elastic sealing material is pressed into the curved outer peripheral surface.

According to the sealed thrust ball bearing of the present invention, a pair of annular races facing each other in the axial direction, a plurality of balls arranged so as to roll between opposing surfaces of these races, and the pair of races A sealed-type thrust ball bearing comprising an inner elastic seal member and an outer elastic seal member for sealing between inner peripheral portions and between outer peripheral portions, wherein the elastic seal member covers an elastic body on the race. is obtained by integrating, integral at least one of the inner elastic seal member and the outer elastic seal member, Rutotomoni comprises a lip extending toward the contact face of the race of the seal member and another member, and the seal member The seal is provided with a cylindrical base connected to the end of the cylindrical portion of the race, and the lip is elastically deformed in the assembly direction when the pair of races are assembled close to the axial direction, and then assembled. Upon completion The pressure contact surface is inclined so as to be elastically deformed by reversing the direction of the elastic deformation, and when the assembly is completed, the restoring force of the elastic deformation of the lip acts on the inclined pressure contact surface. Therefore, at the time of assembly work for assembling a pair of races in the axial direction, for example, the lip of the elastic seal material integrated with the races by vulcanization adhesion is deformed after being deformed in the assembly direction as described above. The assembling work is completed in a state in which it is reversed and elastically deformed in the opposite direction. In this state, the lip is pressed against the inclined pressure contact surface and the bearing is reliably prevented from being separated, so that it is not necessary to increase the restoring force of the elastic deformation of the lip. Therefore, the rotational torque of the bearing does not increase unlike the configuration as in Patent Document 1. Moreover, since the number of parts and the number of assembly steps do not increase, an increase in manufacturing cost can be suppressed for a configuration such as Patent Document 1, and for a configuration such as Patent Document 2 or 3. Manufacturing cost can be reduced. That is, it is possible to obtain a sealed thrust ball bearing that can reliably prevent separation while suppressing an increase in rotational torque of the bearing and can suppress an increase in manufacturing cost.

  Further, the inclined press contact surface is an outer peripheral surface of a curved portion used as a track portion of the ball, and the effect is obtained when the lip extending inward of the outer elastic seal material is pressed into the curved outer peripheral surface. In addition, since the inclined press contact surface is not newly formed, for example, it is manufactured by sheet metal pressing of a steel plate, and the outer peripheral surface of the curved portion that is always provided to form the raceway portion is used as the press contact surface. Manufacturing cost can be reduced.

  Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments shown in the accompanying drawings, and includes all the embodiments that satisfy the requirements described in the claims. It is a waste. In this specification, the direction in which the second race is assembled to the first race (inner ring) (the direction of the arrow in FIG. 2) is the assembling direction, upward, and upward, and the opposite side is downward and downward. And

  FIG. 1 is a longitudinal side view showing a configuration of a sealed thrust ball bearing according to an embodiment of the present invention, FIG. 1 (a) is a view showing the entire bearing, and FIG. 1 (b) is an enlarged view of a main part. . FIG. 2 is a schematic view showing the state of elastic deformation of the main lip of the first race (inner ring) during assembly work for assembling a pair of races in the axial direction, and FIG. 2 (a) to FIG. 2 (e). Assembling proceeds in order, and FIG. 2 (e) shows an assembled state.

  As shown in FIG. 1, the sealed thrust ball bearing includes, for example, an annular first race (inner ring) 1 and second race (outer ring) 2 which are manufactured by sheet metal pressing of steel plates, and are opposed to each other in the axial direction. A plurality of steel balls 3,..., An inner peripheral portion of the pair of races 1 and 2, which are arranged so as to roll between the opposing surfaces of the upper and lower races 1 and 2, and are held by a synthetic resin cage 4 The inner elastic sealing material 5 and the outer elastic sealing material 6 made of an elastic body such as synthetic rubber, and the lubrication sealed between the first race 1 and the second race 2 are sealed between each other and between the outer peripheral portions. It consists of grease, which is an agent. The example shown in FIG. 1 is a structure used for a strut suspension of an automobile, and a spring seat 7 serving as a spring receiving portion is disposed below the second race 2.

  As shown in FIG. 1 (b), the curved portion 1A of the first race 1 and the curved portion 2A of the second race 2 are used as the track portions of the balls 3,. An inner elastic seal 5 is provided at the lower end of the portion 1B, and an outer elastic seal 6 is provided at the lower end of the outer cylindrical portion 1C that extends downward on the outer side of the first race 1. Here, the inner elastic seal 5 and the outer elastic seal 6 are integrated with the first race 1 by covering the first race 1 (metal inner ring) with an elastic body such as synthetic rubber by vulcanization adhesion. The tip portion has a lip structure. As the synthetic rubber, nitrile rubber (NBR), acrylic rubber (ACM), fluorine rubber (FPA) or the like is used.

  The second race 2 is formed with an outer cylindrical portion 2C that is connected to the curved portion 2A on the outer side and extends upward, and an inner cylindrical portion 2B that extends downward on the inner side. The inner cylindrical portion 2B is a spring. The lower surface of the horizontal portion that is press-fitted into the inner diameter side of the cylindrical portion 7A that extends downward on the inner side of the seat 7 and is connected to the upper end portion of the inner cylindrical portion 2B from the lower portion of the curved portion 2A of the second race 2 is It contacts the upper surface of the flange portion 7B extending outward from the upper end portion of the cylindrical portion 7A. In this way, a unit is formed as a sealed thrust ball bearing with the spring seat 7. Further, the spring seat 7 is formed with a flange portion 7C that is stepped down from the flange portion 7B and extends outward, and an inclined portion 7D that connects the flange portions 7B and 7C.

  In the sealed thrust ball bearing in the assembled state as shown in FIG. 1, the inner elastic seal 5 extending obliquely outwardly from the lower end portion of the inner cylindrical portion 1 </ b> B of the first race 1 is formed on the second race 2. Since the inner peripheral surface of the inner cylindrical portion 2B is pressed against the inner peripheral surface, the inner peripheral portions of the pair of races 1 and 2 are sealed. The outer elastic seal 6 provided at the lower end portion of the outer cylindrical portion 1C of the first race 1 has a main lip 6A extending inward and pressed against the outer peripheral surface of the curved portion 2A of the second race 2, and substantially downward The lip 6A, 6B seals the outer peripheral portions of the pair of races 1, 2 with each other. Here, the main lip 6A has a function of preventing leakage of grease filled in the bearing and preventing separation of the bearing, and the dust lip 6B has a function of preventing entry of foreign matter such as muddy water from the outside.

  Next, elastic deformation of the main lip 6A at the time of assembling work for assembling the pair of races 1 and 2 in the axial direction will be described. In a state where the first race 1 and the second race 2 are separated from each other in the axial direction, the main lip 6A is in a free state (a state in which it is not elastically deformed) as shown in FIG. From this free state, when the second race 2 is brought closer to the upper side (the assembling direction, the direction of the arrow in the figure) than the first race 1, the main lip 6A is pushed up by the edge of the outer cylindrical portion 2C of the second race 2 As shown in FIGS. 2A to 2D, the main lip 6A is greatly elastically deformed in the assembling direction. In this state, the restoring force due to the elastic deformation of the main lip 6A acts downward (in the direction opposite to the assembling direction). Since the cylindrical portion that is the base portion of the main lip 6A is elastically deformed outward, the second race 2 can be easily moved in the assembly direction even when the main lip 6A is largely elastically deformed.

  2D, the elastically deformed main lip 6A is in contact with the outer peripheral surface of the outer cylindrical portion 2C of the second race 2. When the second race 2 is further brought closer to the assembly direction with respect to the first race 1, the track portion of the balls 3,... (See FIG. 1) is formed below the outer cylindrical portion 2C of the second race 2. Since the curved portion 2A is formed, the main lip 6A contacts the outer peripheral surface of the curved portion 2A. Therefore, when the second race 2 is further moved in the assembling direction, the outer peripheral surface of the curved portion 2A is inclined so that the diameter decreases as it goes downward (the direction opposite to the assembling direction). The elastic deformation of the main lip 6A is gradually reduced, and the main lip 6A that has been elastically deformed in the assembling direction is elastically deformed by reversing the direction of the elastic deformation by the restoring force (see FIG. 2E). )

  Then, in the state where the assembly work for assembling the pair of races 1 and 2 shown in FIG. 2E in the axial direction is completed, the main lip 6A is pressed against the outer peripheral surface of the curved portion 2A inclined as described above. Therefore, it is not necessary to increase the restoring force of the elastic deformation of the main lip 6A in order to prevent the bearing from being separated. Therefore, the rotational torque of the bearing does not increase due to the frictional resistance due to the restoring force. Further, the number of parts does not increase, and furthermore, if the work for assembling the first race 1 and the second race 2 in the axial direction is performed, the state shown in FIG. There is nothing at all. Therefore, it is possible to obtain a sealed thrust ball bearing that can reliably prevent separation while suppressing an increase in rotational torque of the bearing and can suppress an increase in manufacturing cost. In addition, without forming a new inclined pressure contact surface (surface on which the main lip 6A is pressed) formed to reverse the elastic deformation direction of the main lip 6A as described above, for example, a sheet metal plate Since the outer peripheral surface of the curved portion 2A that is manufactured by press working and is always provided to form the track portion is the inclined press contact surface, the manufacturing cost can be reduced.

  In the above description, an example has been shown in which the outer elastic sealing material 6 attached to the first race (inner ring) 1 that seals between the outer peripheral portions of the pair of races 1 and 2 is provided with a bearing separation preventing function. However, it is sufficient that at least one of the inner elastic sealing material and the outer elastic sealing material has a bearing separation preventing function. Further, in the structure in which the seal is attached to the second race (outer ring), the seal may be provided with a function of preventing the bearing from being separated. That is, at least one of the inner elastic sealing material and the outer elastic sealing material is a seal having a lip extending toward the pressure contact surface of the race separate from the sealing material, and the pair of races are assembled close to each other in the axial direction. In this case, after the lip is elastically deformed in the assembly direction, the pressure contact surface is inclined so as to be elastically deformed by reversing the direction of the elastic deformation when the assembly is completed, and when the assembly is completed, What is necessary is just to comprise so that the restoring force of the elastic deformation of a lip may act on the said inclined press-contact surface.

It is a vertical side view which shows the structure of the sealed thrust ball bearing which concerns on embodiment of this invention, (a) is a figure which shows the whole bearing, (b) is a principal part enlarged view. It is the schematic which shows the mode of the elastic deformation of the main lip of the 1st race (inner ring) at the time of the assembly work which assembles a pair of races in an axial direction, and assembly progresses in order of (a) to (e). ) Indicates an assembled state.

Explanation of symbols

1 First race (inner ring)
1A curved portion 1B inner cylindrical portion 1C outer cylindrical portion 2 second race (outer ring)
2A curved portion 2B inner cylindrical portion 2C outer cylindrical portion 3 ball 4 cage 5 inner elastic seal 6 outer elastic seal 6A main lip 6B dust lip 7 spring seat 7A cylindrical portion 7B, 7C flange portion 7D inclined portion

Claims (2)

A pair of annular races facing each other in the axial direction, a plurality of balls arranged so as to be able to roll between opposing surfaces of these races, and a gap between inner and outer circumferences of the pair of races are sealed. A sealed thrust ball bearing comprising an inner elastic sealing material and an outer elastic sealing material,
The elastic sealing material is formed by covering and integrating an elastic body with the race,
Wherein at least one of the inner elastic seal member and the outer elastic seal member, Rutotomoni comprises a lip extending toward the contact face of the race of the seal member and another member, the cylindrical portion of the race which is integral with the sealing member The seal is provided with a cylindrical base connected to the end, and when the pair of races are assembled close to each other in the axial direction, the lip is elastically deformed in the assembling direction, and the direction of elastic deformation when the assembling is completed. The sealing surface is formed by inclining the pressure contact surface so as to be elastically deformed by being reversed in the reverse direction, and further, when the assembly is completed, the restoring force of the elastic deformation of the lip is applied to the inclined pressure contact surface. Thrust ball bearing.
2. The inclined press contact surface is an outer peripheral surface of a curved portion serving as a track portion of the ball, and a lip extending inward of the outer elastic seal material is pressed into the curved outer peripheral surface. Sealed thrust ball bearing.

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