JP2013220777A - Bearing structure and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing structure capable of preventing deformation of a bracket, improving productivity and furthermore improving corrosion resistance.SOLUTION: A bearing structure is for supporting a propeller shaft (shaft member) to be capable of freely rotating around a shaft, and includes: a bearing fitted outwardly to the propeller shaft; a vibration control member fitted outwardly to the bearing and having elasticity; a bracket 40 fitted to the vibration control member; and a weight 50 attached to the bracket 40. In this case, the bracket 40 includes a ring bracket 41 fitted outwardly to the vibration control member and an attachment bracket 42 attached to an outer periphery surface 41a of the ring bracket 41 as well as being attached to a vehicle body lower section (outside member). The weight 50 includes an arm 51 held between the attachment bracket 42 and the ring bracket 41 and a weight body 52 supported by the arm 51.

Description

  The present invention relates to a bearing structure that supports a shaft member rotatably around an axis, and a method for manufacturing the same.

  In general, in a rear-wheel drive or four-wheel drive vehicle, power from a transmission mounted on the front of the vehicle is transmitted to the left and right rear wheels via a propeller shaft disposed at the lower part of the vehicle. It is transmitted to a final reduction gear provided between them. When the bending resonance point is set outside the practical range, the propulsion shaft is often divided into two or three in the axial direction, and the number of universal joints and steel pipes increases accordingly. A bearing structure for holding the propulsion shaft toward the vehicle body is disposed near the intermediate universal joint, and the propulsion shaft is rotatably supported by the vehicle body.

The bearing structure includes a bearing that is externally fitted to the propulsion shaft, a vibration isolating member that is externally fitted to the bearing, and a bracket that is externally fitted to the vibration isolating member and attached to the lower portion of the vehicle body.
As such a bearing structure, by attaching an annular weight (mass member) to the bracket via an elastic member (damper part), the natural frequency of the bracket is prevented so that the bracket does not resonate with vibration of the vehicle body or the like. (For example, refer to Patent Document 1).

  As described above, in the configuration in which the annular weight is attached to the bracket via the elastic member, the weight of the bearing structure increases and the manufacturing cost increases. Also, the assembly work of the bearing structure becomes complicated.

  Further, as a conventional bearing structure, plate-like weights are arc welded to both front and rear end portions of the bracket (see, for example, Patent Document 2), or as shown in FIG. 6, the weight 150 is attached to the outer surface 141 of the bracket 140. Some have adjusted the natural frequency of the bracket 140 by welding.

Japanese Patent No. 4434396 JP 2006-062621 A

In the conventional bearing structure shown in FIG. 6, since the weight 150 is thick, the weight 150 is attached to the bracket 140 by plug welding in which a through hole 151 is formed in the weight 150 and the inside of the through hole 151 is filled with a bead. ing.
As described above, when the weight is welded to the bracket, the welding work becomes complicated, and there is a problem that the productivity of the bearing structure decreases. In addition, since the heat input to the bracket is increased, the bracket may be distorted by the heat and the opening may not be a perfect circle, which makes it difficult to press-fit the vibration isolating member into the bracket. Furthermore, since it is difficult for paint to enter the gap between the bracket and the weight, there is a problem that the corrosion resistance of the bearing structure is lowered.

  The present invention solves the above-described problems, can increase the adjustment range of the resonance characteristics of the bracket, can prevent deformation of the bracket, can improve productivity, and further improve corrosion resistance. It is an object of the present invention to provide a bearing structure and a method for manufacturing the same.

  In order to solve the above-mentioned problem, the present invention is a bearing structure that supports a shaft member rotatably around an axis, and has a bearing that is externally fitted to the shaft member, and is externally fitted to the bearing and has elasticity. An anti-vibration member, a bracket fitted on the anti-vibration member, and a weight attached to the bracket are provided. The bracket includes a ring bracket that is externally fitted to the vibration isolation member, and an attachment bracket that is attached to the outer peripheral surface of the ring bracket and is attached to an external member. The weight includes an arm sandwiched between the mounting bracket and the ring bracket, and a weight main body supported by the arm.

  As a manufacturing method of the bearing structure described above, the step of placing the arm on the inner surface of the mounting bracket, and the outer surface of the ring bracket overlaid on the inner surface of the mounting bracket, the ring bracket and the mounting bracket, And sandwiching the arm between the mounting bracket and the ring bracket, and holding the weight on the bracket.

In the bearing structure and the manufacturing method thereof according to the present invention, since it is not necessary to weld the weight to the bracket, the bracket can be prevented from being deformed, the vibration-proof member can be easily press-fitted, and the weight can be easily assembled. Thus, the productivity of the bearing structure can be improved.
Further, since the weight main body is attached to the bracket via the arm, the degree of freedom of the shape of the weight main body can be increased. Therefore, the weight body can be formed into a shape that can be easily processed, the weight of the weight body can be finely adjusted, and the adjustment range of the resonance characteristics of the bracket can be further increased.
Furthermore, since the weight can be attached to the bracket after the weight has been painted, and the gap between the bracket and the weight can be reduced, the corrosion resistance of the bearing structure can be increased.

In the bearing structure described above, the arm may be protruded on both sides of the bracket in the axial direction of the ring bracket, and the weight main body may be attached to both ends of the arm.
Further, a concave groove extending in the axial direction of the ring bracket may be formed on the inner surface of the mounting bracket, and the weight may be positioned with respect to the bracket by fitting the arm into the concave groove.
In these configurations, the stability of the weight with respect to the bracket can be enhanced.

  In the bearing structure described above, a rubber member may be interposed between the arm and the weight main body, and the arm, the weight main body, and the rubber member may be vulcanized and bonded. In this configuration, the arm and the weight main body can be easily joined.

  In the bearing structure and the manufacturing method thereof according to the present invention, the adjustment range of the resonance characteristics of the bracket can be further increased, the bracket can be prevented from being deformed, and the productivity of the bearing structure can be improved. Furthermore, the corrosion resistance of the bearing structure can be enhanced.

It is the whole block diagram which showed the bearing structure and propulsion shaft of this embodiment. It is the plane sectional view showing the bearing structure and propulsion shaft of this embodiment. It is the disassembled perspective view which showed the bracket and weight of this embodiment. It is a front view of the bracket and weight of this embodiment. It is the figure which showed the bracket and weight of this embodiment, and is a perspective view of the state which attached the weight to the attachment bracket. It is the front view which showed the conventional bracket and weight.

Embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
In the present embodiment, a case where the bearing structure of the present invention is used for a propulsion shaft of an automobile will be described as an example.
In the following description, after first explaining the overall configuration of the propulsion shaft, the bearing structure will be described in detail.

  The propulsion shaft 1 (“shaft member” in the claims) shown in FIG. 1 receives power from a transmission (not shown) mounted on the front of the vehicle body and is provided between the left and right rear wheels. It is transmitted to a reduction gear (not shown) and is extended in the front-rear direction of the vehicle.

The propulsion shaft 1 includes a first propulsion shaft 3 near the front of the vehicle, a second propulsion shaft 4 near the rear of the vehicle, and a constant velocity joint 6 that connects the first propulsion shaft 3 and the second propulsion shaft 4. ing. The propulsion shaft 1 has a two-piece structure (two-divided structure) composed of two propulsion shafts 3 and 4.
Further, a substantially intermediate portion in the axial direction of the propulsion shaft 1 is supported by the bearing structure 10 so as to be rotatable about the axis on the vehicle body lower portion V (“external member” in the claims, see FIG. 4).

The first propulsion shaft 3 is a metal hollow tube, the front end portion is connected to a transmission (not shown) via a first joint 5, and the rear end portion is connected to a constant velocity joint 6.
The first joint 5 is a cross shaft joint including a pair of U-shaped yokes 5a and 5b and a cross shaft 5c that couples the yokes 5a and 5b. Both the yokes 5a and 5b are connected to the transmission device. Each is attached to one propulsion shaft 3.

The second propulsion shaft 4 is a metal hollow tube, and a connecting shaft portion 4 a connected to the constant velocity joint 6 protrudes from the front end surface, and the rear end portion is finally decelerated via the second joint 7. Connected to a device (not shown).
The second joint 7 is a cross shaft joint including a pair of U-shaped yokes 7a and 7b and a cross shaft 7c that couples the yokes 7a and 7b, and both the yokes 7a and 7b serve as a final reduction gear. Attached to the second propulsion shaft 4 respectively.

  As shown in FIG. 2, the constant velocity joint 6 is a sliding joint that connects the first propulsion shaft 3 and the second propulsion shaft 4. In the present embodiment, a triport type constant velocity composed of an outer ring member 6a coupled to the first propulsion shaft 3 and a power transmission member 6b (inner ring member) provided on the coupling shaft portion 4a of the second propulsion shaft 4 is provided. A joint 6 is used.

The outer ring member 6a is a bottomed cylindrical metal part, and the rear end portion of the first propulsion shaft 3 is joined to the bottom portion 6c by welding or the like.
The connecting shaft portion 4a is inserted into the rear end opening 6f of the outer ring member 6a, and the gap between the rear end opening 6f and the connecting shaft portion 4a is sealed with a rubber boot 6g.
Three sliding grooves 6d extending in the axial direction are formed at equal intervals in the circumferential direction on the inner peripheral surface of the outer ring member 6a. In each sliding groove 6d, three rollers 6e provided on the power transmission member 6b are slidably assembled.

  The constant velocity joint 6 is configured such that the outer ring member 6a and the power transmission member 6b move relative to each other when the roller 6e slides in the sliding groove 6d in the axial direction. Since the outer peripheral surface of the roller 6e is curved, the roller 6e can smoothly slide in the sliding groove 6d even when the connecting shaft portion 4a is inclined with respect to the outer ring member 6a.

  The bearing structure 10 includes a bearing 20 that is externally fitted to the connecting shaft portion 4 a of the second propulsion shaft 4, a vibration isolation member 30 that is externally fitted to the bearing 20, and a vibration isolation member 30 that is externally fitted to the vehicle body. And a bracket 40 attached to the lower part V (see FIG. 4). Further, the bearing structure 10 includes a weight 50 attached to the lower portion of the bracket 40 as shown in FIG.

  As shown in FIG. 2, the bearing 20 is a radial ball bearing in which a plurality of balls 23 are provided between an inner ring 21 and an outer ring 22. The inner ring 21 is a portion that is fitted on the connecting shaft portion 4a of the propulsion shaft 1, and the propulsion shaft 1 is supported by the bearing 20 so as to be rotatable about the axis.

The vibration isolator 30 includes an inner ring 31 that is externally fitted to the outer ring 22 of the bearing 20, an outer ring 32 that surrounds the inner ring 31 outside the radial direction of the inner ring 31, and an inner ring 31 and an outer ring 32. And a mount 33 interposed therebetween.
The inner ring 31 and the outer ring 32 are cylindrical metal parts, and are arranged double inside and outside in the radial direction at concentric positions.

The mount 33 is a cylindrical rubber part having elasticity. The inner peripheral portion of the mount 33 is joined to the outer peripheral surface of the inner ring 31, and the outer peripheral portion is joined to the inner peripheral surface of the outer ring 32. A bent portion is formed between the inner peripheral portion and the outer peripheral portion of the mount 33.
The mount 33, the inner ring 31 and the outer ring 32 are integrally formed by insert molding.

  In the vibration isolation member 30, the vibration of the inner ring 31 is absorbed by the mount 33, so that the vibration of the inner ring 31 (propulsion shaft 1) is not easily transmitted to the outer ring 32.

A stopper piece 70 that is externally fitted to the connecting shaft portion 4a is disposed in front of the bearing 20. The stopper piece 70 is a cylindrical metal part, and is fixed to the connecting shaft portion 4a by press-fitting.
Since the rear end portion of the stopper piece 70 abuts against the front surface of the inner ring 21 of the bearing 20, the bearing 20 is prevented from coming off. In addition, a flange portion 71 is formed at the front end portion of the stopper piece 70 so as to close the front end opening of the inner ring 31. The flange portion 71 makes it difficult for water or the like to enter the inner ring 31.

  The bracket 40 includes a ring bracket 41 that is externally fitted to the vibration isolation member 30 and a mounting bracket 42 that is attached to the outer peripheral surface 41a of the ring bracket 41 (see FIG. 4). The ring bracket 41 and the mounting bracket 42 are metal parts.

  As shown in FIG. 3, the mounting bracket 42 is formed by bending a flat plate into a substantially U shape, and mounting portions 42 b that are attached to the vehicle body lower portion V (see FIG. 4) are formed at both upper ends. Yes.

  As shown in FIG. 4, the lower half of the outer peripheral surface 41 a of the ring bracket 41 is superimposed on the inner surface 42 f of the mounting bracket 42. The ring bracket 41 and the mounting bracket 42 are joined by resistance welding.

As shown in FIG. 3, a concave groove 42d extending in the front-rear direction is formed at the lowermost portion of the inner surface 42f of the mounting bracket 42. The concave groove 42d is a groove portion having a rectangular cross section, and is formed from the front edge portion of the mounting bracket 42 to the rear edge portion. The concave groove 42d is formed by projecting the lowermost part of the mounting bracket 42 radially outward.
As shown in FIG. 4, in the state where the outer peripheral surface 41a of the ring bracket 41 is overlapped with the inner surface 42f of the mounting bracket 42, a space penetrating in the front-rear direction is formed in the lowermost portion of the bracket 40 by the concave groove 42d.

  The attachment portion 42b is a portion that horizontally protrudes from both upper end portions of the attachment bracket 42 toward the left and right outer sides (see FIG. 3). A mounting hole 42c passes through the mounting portion 42b in the vertical direction. The bracket 40 can be attached to the vehicle body lower portion V by screwing a bolt (not shown) inserted through the attachment hole 42c from below into a screw hole (not shown) formed in the vehicle body lower portion V. .

  The weight 50 includes an arm 51 sandwiched between the outer peripheral surface 41a of the ring bracket 41 and the inner surface 42f of the mounting bracket 42, and two weight main bodies 52 supported by the arm 51 (FIG. 3). reference).

As shown in FIG. 3, the arm 51 is formed by bending both ends of a metal flat plate. The arm 51 is formed with an intermediate portion 51b extending in the front-rear direction and a bent portion 51a formed by bending the front and rear end portions of the intermediate portion 51b downward at a right angle.
As shown in FIG. 4, the intermediate portion 51b of the arm 51 is a portion that fits into the concave groove 42d of the mounting bracket 42 (see FIG. 5), and the thickness of the intermediate portion 51b is the same as the depth of the concave groove 42d. Or slightly larger.
The intermediate portion 51b of the arm 51 may be joined to the concave groove 42 of the mounting bracket 42 by a joining method such as welding.

  As shown in FIG. 3, the weight main body 52 is a metal rectangular parallelepiped. Two weight main bodies 52 are respectively attached to the inner surfaces of the bent portions 51 a of the arm 51. In the weight main body 52, an intermediate portion of the outer surface 52a in the left-right direction is joined to the bent portion 51a by arc welding.

Next, a method for manufacturing the bearing structure 10 will be described.
First, as shown in FIG. 3, the weight body 52 is joined to the both bent portions 51 a of the arm 51 by arc welding to complete the weight 50.

  After painting the weight 50, as shown in FIG. 5, the intermediate portion 51 b of the arm 51 is fitted into the concave groove 42 d of the mounting bracket 42, and the weight 50 is placed on the inner surface 42 f of the mounting bracket 42.

  Further, as shown in FIG. 4, the lower half of the outer peripheral surface 41a of the ring bracket 41 is overlapped with the inner surface 42f of the mounting bracket 42, the ring bracket 41 and the mounting bracket 42 are sandwiched between two electrodes, and current is passed between both electrodes. By doing so, the ring bracket 41 and the mounting bracket 42 are joined by resistance welding.

As a result, the arm 51 is sandwiched between the ring bracket 41 and the mounting bracket 42, and the weight 50 is held by the bracket 40. Both end portions of the arm 51 protrude from the front and rear sides of the mounting bracket 42, and the two weight bodies 52 are suspended from the lower portion of the bracket 40.
Further, since the arm 51 is sandwiched between the ring bracket 41 and the mounting bracket 42, the weight 50 can be stabilized with respect to the bracket 40.

  Then, after painting the bracket 40, the vibration isolation member 30 is press-fitted into the ring bracket 41 as shown in FIG.

  Further, the bearing 20 fitted on the connecting shaft portion 4a is press-fitted into the vibration isolating member 30, and both attachment portions 42b are attached to the vehicle body lower portion V (see FIG. 4). As a result, the propulsion shaft 1 is rotatably supported by the vehicle body lower portion V by the bearing structure 10.

  In the bearing structure 10 and the manufacturing method of the present embodiment as described above, it is not necessary to weld the weight 50 to the bracket 40 and the bracket 40 can be prevented from being deformed, as shown in FIG. The bracket 41 can be kept in a perfect circle, and the vibration isolation member 30 (see FIG. 2) can be easily press-fitted into the ring bracket 41. Further, the assembly work of the weight 50 is simplified. Therefore, the productivity of the bearing structure 10 can be improved.

  Further, as shown in FIG. 3, the weight main body 52 is supported at both ends of the arm 51 and is away from the bracket 40, so that the degree of freedom of the shape of the weight main body 52 can be increased. Therefore, the weight main body 52 can be formed into a shape that can be easily processed. Further, since the weight of the weight main body 52 can be finely adjusted, the adjustment range of the resonance characteristics of the bracket 40 can be further increased, and the vibration of the bracket 40 can be effectively reduced.

  Further, after the weight 50 is painted, the weight 50 can be attached to the bracket 40, and the gap between the bracket 40 and the weight 50 can be reduced, so that the corrosion resistance of the bearing structure 10 can be improved.

  In addition, weight main bodies 52 are respectively attached to the front and rear end portions of the arm 51 projecting from the front and rear sides of the bracket 40. Furthermore, the weight 50 is positioned with respect to the bracket 40 by fitting the arm 51 into the concave groove 42 d formed on the inner surface 42 f of the mounting bracket 42. In these configurations, the stability of the weight 50 with respect to the bracket 40 can be enhanced.

The embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention.
In this embodiment, as shown in FIG. 3, the arm 51 and the weight main body 52 are joined by arc welding, but the joining method is not limited.
For example, a rubber member is interposed between the arm 51 and the weight main body 52, and the weight main body 52 is joined to the arm 51 by vulcanizing and bonding the arm 51 and the rubber member and the weight main body 52 and the rubber member, respectively. Also good. In this configuration, the arm 51 and the weight main body 52 can be easily joined without welding. Moreover, you may join the arm 51 and the weight main body 52 using fixing members, such as a volt | bolt.

  Further, the shape of the mounting portion 42b of the bracket 40 is not limited, and is formed corresponding to the shape of the lower part of the vehicle body.

  In the present embodiment, as shown in FIG. 1, a bearing structure 10 that supports a propulsion shaft 1 of an automobile is described as an example. However, the bearing structure of the present invention includes various shaft members and external members. It is applicable to.

Reference Signs List 1 propulsion shaft 3 first propulsion shaft 4 second propulsion shaft 4a connecting shaft portion 5 first joint 6 constant velocity joint 7 second joint 10 bearing structure 20 bearing 30 vibration isolating member 40 bracket 41 ring bracket 41a outer peripheral surface 42 mounting bracket 42b Mounting part 42d Dent groove 50 Weight 51 Arm 51a Bending part 51b Intermediate part 52 Weight body V Lower body

Claims (5)

A bearing structure that supports a shaft member rotatably around an axis,
A bearing externally fitted to the shaft member;
An anti-vibration member that is externally fitted to the bearing and has elasticity;
A bracket externally fitted to the vibration isolation member;
A weight attached to the bracket,
The bracket is
A ring bracket externally fitted to the vibration isolating member;
Attached to the outer peripheral surface of the ring bracket, and provided with a mounting bracket attached to an external member,
The weight is
An arm sandwiched between the mounting bracket and the ring bracket;
And a weight body supported by the arm. The arm protrudes on both sides of the bracket in the axial direction of the ring bracket,
The bearing structure according to claim 1, wherein the weight main body is attached to both ends of the arm. A concave groove extending in the axial direction of the ring bracket is formed on the inner surface of the mounting bracket,
The bearing structure according to claim 1, wherein the arm is fitted in the concave groove. A rubber member is interposed between the arm and the weight body,
The bearing structure according to any one of claims 1 to 3, wherein the arm, the weight main body, and the rubber member are bonded by vulcanization. A method for producing a bearing structure according to any one of claims 1 to 4,
Placing the arm on the inner surface of the mounting bracket;
Superposing the outer surface of the ring bracket on the inner surface of the mounting bracket and sandwiching the arm between the ring bracket and the mounting bracket;
Joining the mounting bracket and the ring bracket, and holding the weight on the bracket. A method for manufacturing a bearing structure, comprising:

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