JP6039439B2 - Bearing structure - Google Patents

Description

  The present invention relates to a bearing structure that rotatably supports a shaft member.

  2. Description of the Related Art Generally, a shaft member such as a propeller shaft that is disposed at a lower portion of a vehicle body and extends in the vehicle front-rear direction includes a bearing that is externally fitted to the shaft member, and a vibration isolation member that has an inner ring and is externally fitted to the bearing The structure is rotatably supported.

  Further, in Patent Document 1 below, in order to prevent muddy water and dust from entering the bearing, an inner ring that protrudes in the front-rear direction from the front and rear end faces of the bearing and surrounds the outer periphery of the shaft member, and the inner ring A bearing structure including a dust cover surrounding an outer periphery is disclosed.

JP 2010-269716 A

However, in the bearing structure disclosed in Patent Document 1, since the region surrounded by the inner ring is not covered on the outer peripheral surface of the shaft member, there is a risk of rusting due to moisture entering the space surrounded by the inner ring. there were. Especially in areas where salt damage is strong, there is a high possibility that the water will contain salt and the shaft member will rust.
As described above, in the bearing structure disclosed in Patent Document 1, rust generated in the region surrounded by the inner ring may enter the bearing and reduce the sealing performance.

  The present invention is an invention created in view of the above-described problems, and provides a bearing structure capable of improving the corrosion resistance of a region surrounded by a vibration isolating member having an inner ring on the outer peripheral surface of a shaft member. The task is to do.

In order to solve the above-described problems, a bearing structure according to the present invention includes a bearing that is externally fitted to a shaft member, and a vibration-proof member that is externally fitted to the bearing, and supports the shaft member so as to be rotatable about an axis. The vibration isolating member protrudes in an axial direction from the end surface of the bearing so as to surround the outer periphery of the shaft member, and is fitted in a region surrounded by the anti-vibration member on the outer peripheral surface of the shaft member. A tubular body, and the tubular body includes at least one annular projecting portion projecting radially outward of the shaft member, and the at least one projecting portion includes the bearing of the tubular body. One end projecting portion projecting radially outward from one end near the end is included, the one end projecting portion projects at least radially outside the inner diameter of the outer ring of the bearing, and is surrounded by the vibration isolating member in the shaft member The area contacts the end face of the inner ring of the bearing A first enlarged diameter portion for positioning the bearing is provided, and the shaft member is provided with a base portion protruding radially outward from the vibration isolation member, and the axial direction between the base portion and the vibration isolation member is provided. The gap is narrower than the radial gap between the vibration isolator member and the tubular body, and the other end of the tubular body is a ring-like shape extending radially outward along the end surface of the base portion. A ring portion is provided .

According to the above-described invention, the region surrounded by the vibration isolating member on the outer peripheral surface of the shaft member is covered with the fitted tube body, and the corrosion resistance is improved. Therefore, rust hardly occurs in the region surrounded by the vibration isolating member, and the possibility that the rust enters the bearing and the sealing performance is lowered is reduced.
In addition, according to the configuration described above, the annular protrusion prevents the moisture from moving in the axial direction along the outer surface of the tubular body, that is, the intrusion into the bearing. The risk of lowering is reduced.

  Moreover, it is preferable that the said tubular body is manufactured from one selected from the group which consists of a surface-treated steel plate, an aluminum plate, a stainless steel plate, and resin.

  According to the configuration described above, there is no possibility that rust will occur in the pipe body. Therefore, the possibility that the rust generated from the tube enters the bearing and the sealing performance is reduced is reduced.

Also, in the invention, the radially outer end of the ring portion, it is preferable that the coating portion of the annular press-fitted to the base is provided.
In the invention, a concave portion that is recessed in a radial direction is formed in one of the tube body and the shaft member, and a convex portion that engages with the concave portion is formed in either one of the tube body and the shaft member. It is preferable that the part is formed.

  ADVANTAGE OF THE INVENTION According to this invention, the bearing structure body which the corrosion resistance of the area | region enclosed by the vibration isolating member in the outer peripheral surface of the shaft member improved can be provided.

It is a whole lineblock diagram showing the propulsion shaft and bearing structure concerning a 1st embodiment. It is the enlarged view to which the bearing structure of 1st Embodiment was expanded. It is the enlarged view to which the range enclosed with the broken line A in FIG. 2 was expanded. It is the enlarged view which expanded a part of propulsion shaft and bearing structure which concern on 2nd Embodiment. It is the figure shown about the modification of the corrosion-resistant cover of 2nd Embodiment. It is the enlarged view to which a part of propulsion shaft and bearing structure concerning a 3rd embodiment was expanded.

  Embodiments of the present invention will be described with reference to the drawings as appropriate. In the present embodiment, the case where the bearing structure of the present invention is used as a propulsion shaft of an automobile is taken as an example, and after the configuration of the propulsion shaft is first described, the configuration of the bearing structure is described.

As shown in FIG. 1, the propulsion shaft 1 according to the first embodiment is disposed so as to extend in the vehicle front-rear direction by being supported by a bearing structure 10 so as to be rotatable around the shaft, and is mounted on the front portion of the vehicle body. The power from the transmission (not shown) is transmitted to a final reduction gear (not shown) at the rear of the vehicle.
The propulsion shaft 1 includes a first propulsion shaft 3 closer to the front of the vehicle, a second propulsion shaft 4 closer to the rear of the vehicle, and a constant velocity joint 6 that connects the first propulsion shaft 3 and the second propulsion shaft 4. I have.

  The first propulsion shaft 3 is a metal hollow tube, and the front portion of the first propulsion shaft 3 is connected to the output shaft on the transmission side via the first joint 5. The first joint 5 includes a U-shaped yoke 5a joined to the transmission-side output shaft, a U-shaped yoke 5b welded to the front portion of the first propulsion shaft 3, and the yokes 5a, 5b. And a cross-shaped universal shaft joint provided with a cross shaft 5c. The connection angle between the first propulsion shaft 3 and the output shaft on the transmission side can be changed.

The second propulsion shaft 4 is a metal hollow tube, and the base portion 8 a of the stub shaft 8 is welded to the front portion of the second propulsion shaft 4. The configuration of the stub shaft 8 will be described together with the description of the configuration of the bearing structure 10 described later.
The rear portion of the second propulsion shaft 4 is connected to the input shaft of the final reduction gear via the second joint 7. The second joint 7 includes a U-shaped yoke 7a welded to the input shaft of the final reduction gear, a U-shaped yoke 7b welded to the rear end of the second propulsion shaft, and yokes 7a and 7b. This is a cross-shaped universal shaft joint provided with a cross shaft 7c to be connected, and the connection angle between the second propulsion shaft 4 and the input shaft of the final reduction gear can be changed.

  The constant velocity joint 6 is a sliding joint that connects the first propulsion shaft 3 and the second propulsion shaft 4, and includes a cylindrical outer ring member 6 a welded to the rear portion of the first propulsion shaft 3, and a stub. This is a tripart type joint comprising a power transmission member 6b provided at the tip (front part) of the shaft 8.

  As shown in FIGS. 1 and 2, the outer ring member 6 a is a bottomed cylindrical metal part whose bottom is joined to the rear end of the first propulsion shaft 3 and opens rearward. The outer ring member 6a accommodates the tip of the stub shaft 8 inserted from the rear end opening 6f. Further, the gap between the rear end opening 6f and the stub shaft 8 is sealed with a rubber boot 6g.

As shown in FIG. 1, 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. On the other hand, the power transmission member 6b has three rollers 6e arranged at equal intervals in the circumferential direction, and each of the three rollers 6e is slidably assembled in the sliding groove 6d of the outer ring member 6a. For this reason, the outer ring member 6a and the power transmission member 6b are configured to move relative to each other when the roller 6e slides or rolls in the sliding groove 6d in the axial direction.
Further, the outer peripheral surface of the roller 6e is curved, and the roller 6e can smoothly slide in the sliding groove 6d even when the stub shaft 8 is inclined with respect to the outer ring member 6a. .
In the present embodiment, the triport type is described as the constant velocity joint 6, but the present invention is not limited to this and may be a double offset type or a cross groove type. Moreover, it is good also as a cardan joint similar to a 1st joint or a 2nd joint, without setting it as a constant velocity joint.

  As shown in FIG. 2, the bearing structure 10 includes a bearing 20 that is press-fitted and fixed to the stub shaft 8, a vibration isolation member 30 that is externally fitted to the bearing 20, and a ring bracket 41 that is externally fitted to the vibration isolation member 30. A bracket 40 provided, and a dust cover 50 and a corrosion-resistant cover 60 that are externally fitted to the stub shaft 8 so as to be adjacent to the bearing 20 are provided.

As shown in FIG. 3, 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 propulsion shaft 1 is supported so as to be rotatable about the shaft with respect to the bearing 20 by fitting the inner ring 21 to the stub shaft 8.
In the bearing 20, double seals 24 are provided between the inner ring 21 and the outer ring 22 in the front-rear direction of the ball 23 to prevent intrusion of muddy water and dust. Further, the space surrounded by the inner ring 21, the outer ring 22 and the seal 24 is filled with grease for facilitating the rotation of the ball 23.

  As shown in FIG. 2, 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 on the radially outer side of the inner ring 31, and an inner ring 31. And a mount 33 interposed between the ring 31 and the outer ring 32.

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.
As shown in FIG. 3, the inner ring 31 is formed with an annular extending portion 31 a that extends rearward from the rear end of the inner ring 31. Therefore, a region Q (region covered with a dotted line in FIG. 3) on the rear side of the portion where the bearing 20 is fitted in the stub shaft 8 is painted with the outer periphery surrounded by the extending portion 31 a of the inner ring 31. It has become difficult.
Further, as shown in FIG. 2, the mount 33 is a cylindrical rubber part having elasticity, and is integrally formed with the inner ring 31 and the outer ring 32 by insert molding. In the present embodiment, the mount 33 also covers the inner peripheral surface of the inner ring 31 by insert molding.

  The ring bracket 41 is a metal cylindrical part formed by pressing, and the outer ring 32 of the vibration isolation member 30 is press-fitted into the inner peripheral surface of the ring bracket 41. In addition, as the ring bracket 41, for example, it is preferable to use a JIS G 3113 hot rolled steel sheet for automobile structure.

  The bracket 40 is formed by bending a thin metal plate, the ring bracket 41 is welded to support the ring bracket 41, and a pair of seating surfaces 42 provided at both ends thereof. , 42 are provided. A hole 42a penetrating in the vertical direction is formed in the central portion of the seat surface 42, and is fastened by a bolt (not shown) that is screwed into a screw hole in the lower part of the vehicle body. ing.

  As shown in FIG. 3, the dust cover 50 is a part formed by bending a thin metal plate, and includes a substantially cylindrical fitting portion 51 that fits the stub shaft 8 in front of the bearing 20, and a fitting. A cover portion 52 that extends radially outward from the front end portion of the joint portion 51 and covers the front of the bearing 20 is provided to prevent muddy water and dust flying from the front from reaching the bearing 20.

Next, the stub shaft 8 will be described.
As shown in FIG. 2, the stub shaft 8 includes a substantially disc-shaped base portion 8a formed to have the same diameter as the second propulsion shaft 4, and a substantially cylindrical shaft portion 8b protruding forward from the base portion 8a. Yes.
On the rear side of the shaft portion 8b, a bearing fitted portion 8c having a diameter slightly larger than the inner diameter of the inner ring 21 of the bearing 20 is formed, and the bearing 20 is fitted.
Further, as shown in FIG. 3, the shaft portion 8b of the stub shaft 8 is located on the rear side of the bearing fitted portion 8c and surrounded by the inner ring 31 in the region Q that is difficult to be painted. A portion 8d and a second enlarged diameter portion 8e are formed.

  The first enlarged diameter portion 8 d is a portion that is formed behind the bearing fitted portion 8 c and has a larger diameter than the inner ring 21 of the bearing 20. The rear end surface of the inner ring 21 of the bearing 20 is in contact with the front end surface of the first enlarged diameter portion 8d, and the bearing 20 fitted to the bearing fitted portion 8c is positioned.

  The second enlarged diameter portion 8e is a portion that is formed behind the first enlarged diameter portion 8d and has a larger diameter than the first enlarged diameter portion 8d. Therefore, the gap between the second enlarged diameter portion 8e and the extension portion 31a is narrower than the gap between the first enlarged diameter portion 8d and the extension portion 31a of the inner ring 31 that are opposed in the radial direction. Yes. Therefore, it is difficult for muddy water and dust to enter the space surrounded by the extending portion 31a of the inner ring 31, and a dust cover surrounding the outer periphery of the extending portion 31a is not necessary.

Further, a dust cover fitted portion 8f and a groove portion 8g are formed on the shaft portion 8b of the stub shaft 8.
The dust cover fitted portion 8f is provided in front of the bearing fitted portion 8c. The dust cover fitted portion 8f is formed to be slightly larger than the inner diameter of the fitting portion 51 of the dust cover 50, and the press-fit dust cover 50 is fitted therein.
The groove 8g is provided behind the second enlarged diameter portion 8e and is formed to have a smaller diameter than the second enlarged diameter portion 8e. Therefore, the groove 8g is recessed inward in the radial direction as compared with the second enlarged diameter portion 8e, and a water droplet that moves forward of the shaft along the outer surface of the stub shaft 8 moves to the second enlarged diameter portion 8e. Without being stuck in the groove 8g. In addition, since the groove part 8g is not surrounded by the extension part 31a of the inner ring 31, the outer peripheral surface is painted by ASSY coating, and the corrosion resistance is improved.

Next, the corrosion resistant cover 60 will be described.
The corrosion-resistant cover 60 is a tubular body in which each part is formed by processing a steel plate, and extends radially outward from the cylindrical first cylindrical portion 61 and the rear end portion of the first cylindrical portion 61. A disk-shaped disk part 62, a cylindrical second cylindrical part 63 extending rearward from the outer peripheral end of the disk part 62, and a ring-shaped protruding part protruding radially outward from the front end part of the first cylindrical part 61 64. Further, the corrosion resistant cover 60 is surface-treated to enhance the corrosion resistance.
In addition, in this embodiment, although the steel plate is used as a material of the corrosion-resistant cover 60, this invention is not limited to this. The material of the corrosion-resistant cover 60 may be replaced with a steel plate, and a material having high corrosion resistance, for example, aluminum, stainless steel, and resin may be used. When a material having high corrosion resistance is used, surface treatment can be omitted. .

  The inner diameter of the first cylindrical portion 61 is formed slightly smaller than the outer diameter of the first enlarged diameter portion 8d. Moreover, the internal diameter of the 2nd cylindrical part 63 is formed slightly smaller than the outer diameter of the 2nd enlarged diameter part 8e. The first cylindrical portion 61 and the second cylindrical portion 63 are press-fitted into the first enlarged diameter portion 8d and the second enlarged diameter portion 8e, respectively, and the corrosion resistant cover 60 is fitted to the stub shaft 8. For this reason, the first enlarged diameter portion 8 d and the second enlarged diameter portion 8 e of the stub shaft 8 are covered with the corrosion resistant cover 60.

  The protruding portion 64 protrudes radially outward to such an extent that it has substantially the same diameter as the inner diameter of the outer ring 22 of the bearing 20. Therefore, the muddy water that moves along the surface of the anticorrosion cover 60 and the dust flying toward the seal 24 can be prevented from entering the seal 24.

  According to the bearing structure 10 according to the above embodiment, the outer periphery is surrounded and coated by the first enlarged diameter portion 8d and the second enlarged diameter portion 8e of the propulsion shaft 1, that is, the extended portion 31a of the inner ring 31. Since the corrosion resistant cover 60 covers the difficult region Q, the corrosion resistance is improved. Therefore, it is possible to reduce the risk that the rust generated in the region Q surrounded by the inner ring 31 enters the bearing 20 and the sealing performance is lowered.

  The bearing structure 10 according to the first embodiment has been described above, but the present invention is not limited to the example described in the first embodiment. For example, the corrosion-resistant cover 60 corresponding to the shape of the stub shaft 8 is used. You may change the configuration. Therefore, in the second embodiment, a case will be described in which a stub shaft 8A having a shape different from that of the stub shaft 8 used in the first embodiment is used.

  As shown in FIG. 4, the shaft portion 8 b of the stub shaft 8 </ b> A according to the second embodiment is provided with an enlarged diameter portion 8 h in a region Q that is surrounded by the extending portion 31 a of the inner ring 31 and is difficult to be painted. ing. The enlarged diameter portion 8h is formed to have a larger diameter than the inner ring 21 of the bearing 20, and the rear end surface of the inner ring 21 of the bearing 20 is in contact with the front end surface of the enlarged diameter portion 8h.

Further, the axial length of the enlarged diameter portion 8h is slightly longer than the extended portion 31a of the inner ring 31, and the front end face 8i of the base portion 8a provided behind the enlarged diameter portion 8h and the inner ring 31 are formed. The gap with the extending portion 31a is narrow.
Therefore, it is difficult for muddy water and dust to enter the space surrounded by the extending portion 31a of the inner ring 31, and the possibility that the sealing performance of the bearing 20 is lowered is reduced. On the other hand, the front end surface 8i of the base portion 8a is surrounded by the extending portion 31a and is a region Q that is difficult to be painted.

  Further, the corrosion-resistant cover 60A according to the second embodiment includes a cylindrical cylindrical portion 65 that is press-fitted into the enlarged diameter portion 8h, a protruding portion 64 that protrudes radially outward from the front end of the cylindrical portion 65, and the cylindrical portion 65. And a ring-shaped ring portion 66 projecting radially outward from the rear end along the front end surface 8i of the base portion 8a. The ring portion 66 is formed so as to cover the front end surface 8i of the base portion 8a in a state where the cylindrical portion 65 is fitted to the enlarged diameter portion 8h.

  According to the corrosion resistant cover 60A according to the second embodiment described above, the diameter-enlarged portion 8h and the front end surface 8i of the stub shaft 8, which are regions Q that are surrounded by the inner ring 31 and are difficult to be painted, are connected to the corrosion resistant cover 60A. Since it coat | covers, corrosion resistance can be improved.

  As a more desirable example than the corrosion resistant cover 60A according to the second embodiment, a modified corrosion resistant cover 60B is shown in FIG. The corrosion-resistant cover 60B according to the modified example includes an annular covering portion extending rearward from the outer peripheral end of the ring portion 66 in addition to the cylindrical portion 65, the projecting portion 64, and the ring portion 66 that are provided in the corrosion-resistant cover 60A. 67. The covering portion 67 is formed to have an inner diameter slightly smaller than the outer diameter of the base portion 8a and is press-fitted into the base portion 8a.

According to the corrosion-resistant cover 60B according to this modification, since the cylindrical portion 65 and the covering portion 67 are fitted to the stub shaft 8, the corrosion-resistant cover 60A of the second embodiment in which only the cylindrical portion 65 is fitted. It is strongly fitted compared to.
Therefore, the possibility that the corrosion-resistant cover 60B is displaced and a gap is formed between the ring portion 66 and the front end face 8i is reduced, and the possibility of rusting on the front end face 8i is reduced.
Further, even if the corrosion-resistant cover 60B is displaced and a gap is generated between the ring portion 66 and the front end surface 8i, the outer periphery of the gap is surrounded by the covering portion 67. There is a very low risk that rust will occur due to the adhesion of the materials.

Next, a third embodiment will be described.
As shown in FIG. 6, the shaft portion 8b of the stub shaft 8B according to the third embodiment is a stub shaft described in the second embodiment in that a recess 8j is formed in the middle in the axial direction of the diameter-expanded portion 8h. It is different from 8A. The recess 8j is a recess formed in the circumferential direction along the outer peripheral surface of the enlarged diameter portion 8h.

On the other hand, the corrosion-resistant cover 60 </ b> C includes a convex portion 68 that protrudes radially inward on the inner peripheral surface side of the cylindrical portion 65, and a second protruding portion 69 that protrudes from the outer peripheral surface side of the cylindrical portion 65. In the point, it differs from the corrosion-resistant cover 60B which concerns on the modification of 2nd Embodiment.
The convex portion 68 is formed corresponding to the concave portion 8j formed in the enlarged diameter portion 8h, and the cylindrical portion 65 is engaged with the concave portion 8j by fitting into the enlarged diameter portion 8h. The second projecting portion 69 is formed to extend in the circumferential direction along the outer peripheral surface of the cylindrical portion 65.
Note that the corrosion-resistant cover 60c is formed by injection molding rather than being manufactured by bending an aluminum plate or a stainless steel plate because the convex portion 68 and the second projecting portion 69 are formed in the intermediate portion in the axial direction of the cylindrical portion 65. Is preferable because it is easier to manufacture.

According to the corrosion-resistant cover 60C according to the third embodiment described above, since the convex portion 68 is engaged with the concave portion 8j, it is less likely to be displaced than the corrosion-resistant cover 60B according to the modified example of the second embodiment. The risk of rusting on the front end face 8i is reduced.
Further, in addition to the projecting portion 64 projecting radially outward in the extending portion 31a of the inner ring 31, the second projecting portion 69 is further provided, and therefore moves along the surface of the corrosion-resistant cover 60C. The risk of muddy water entering the bearing 20 can be further reduced.

  In the embodiment and the modification, the case where the inner ring 31 of the vibration isolation member 30 surrounds the outer periphery of the propulsion shaft 1 is described as an example. However, the present invention is not limited to this, and the vibration isolation member 30 The present invention can also be applied when the outer periphery of the propulsion shaft 1 is surrounded by the outer ring 32 or the mount 33.

DESCRIPTION OF SYMBOLS 1 Propulsion shaft 6 Constant velocity joint 8 Stub shaft 10 Bearing structure 20 Bearing 30 Vibration isolation member 31 Inner ring 31a Extension part 50 Dust cover 60, 60A, 60B, 60C Corrosion-resistant cover (tube)
64 Projection

Claims (4)

A bearing structure that includes a bearing that is externally fitted to the shaft member, and a vibration isolating member that is externally fitted to the bearing, and supports the shaft member rotatably about the axis,
The vibration isolating member protrudes in the axial direction from the end face of the bearing and surrounds the outer periphery of the shaft member;
A tubular body fitted in a region surrounded by the vibration isolating member on the outer peripheral surface of the shaft member;
The tubular body includes at least one annular projecting portion projecting radially outward of the shaft member,
The at least one or more protrusions include one end protrusions that protrude radially outward from one end of the tubular body near the bearing,
The one end protruding portion protrudes radially outward from at least the inner diameter of the outer ring of the bearing ,
In the region surrounded by the vibration isolating member in the shaft member, a first diameter-expanded portion is provided that contacts the end face of the inner ring of the bearing and positions the bearing,
The shaft member is provided with a base that protrudes radially outward from the vibration-proof member,
The axial gap between the base and the vibration isolation member is narrower than the radial gap between the vibration isolation member and the tubular body,
A bearing structure having a ring-shaped ring portion extending radially outward along the end surface of the base portion at the other end of the tubular body.   The bearing structure according to claim 1, wherein the tubular body is manufactured from one selected from the group consisting of a surface-treated steel plate, an aluminum plate, a stainless steel plate, and a resin. 3. The bearing structure according to claim 1, wherein an annular covering portion that is press-fitted into the base portion is provided at a radially outer end portion of the ring portion. A concave portion that is recessed in the radial direction is formed in either one of the tube body and the shaft member,
The bearing structure according to any one of claims 1 to 3 , wherein a convex portion that engages with the concave portion is formed on the other of the tubular body and the shaft member.

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