JP2008095720A - Thrust washer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the relative rotation between a thrust washer 1 and a mating member 3 at a low cost. <P>SOLUTION: The thrust washer 1 made of synthetic resin is arranged between a rotary member 2 and the non-rotary member 3 opposed to each other in the axial direction. The thrust washer 1 has a sliding surface 11a formed on one end in the axial direction, and also has a cylindrical fitting portion 12 formed on the outer peripheral portion of the other end so as to project in the axial direction. An engaging surface 12a formed on the cylindrical fitting portion 12 so as to undulate in the radial direction is press fitted into the non-rotary member 3 with a friction force larger than the sliding torque to be applied on the sliding surface 11a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a thrust washer made of a synthetic resin that is used as a thrust bearing or a spacer that receives a thrust load between members that rotate relative to each other, and is used, for example, in a transmission of a vehicle.

  A needle bearing that receives a thrust load is used between metal members that rotate relative to each other in a power train portion, a stator portion, and a cover portion of an automatic transmission (AT) of a vehicle. However, this type of needle bearing is excellent as a means for reducing sliding resistance between relatively rotating metal members, but holds a large number of needle rollers arranged in the circumferential direction and both sides from the axial direction. Since it is composed of a pair of bearing races, it is difficult to reduce the space in the axial direction, and the material cost and manufacturing cost are high, so that it is difficult to reduce the cost.

  Therefore, in recent years, in order to realize space saving and cost reduction in the axial direction, synthetic resin thrust washers are being applied instead of needle bearings. On the other hand, as one of the measures for improving the fuel consumption of vehicles, the weight reduction of vehicles has been promoted. In particular, aluminum light metals (hereinafter abbreviated as AL materials) are used in various automatic transmissions. AL materials are also used in cases of automatic transmissions, stators in torque converters, and parts of various shafts. However, when the AL material slides with a component made of a synthetic resin, abnormal wear may be induced. Therefore, when a thrust washer made of a synthetic resin is used, the AL material is not slid with the component made of the AL material. There is a need.

That is, when a thrust washer made of synthetic resin is held on a part made of an AL material, a plurality of protrusions are formed on the thrust washer in order to prevent sliding of both, and this is provided on a part made of an AL material. It is known to prevent rotation by inserting it into a hole (for example, refer to the following patent document).
JP 2002-147442 A Japanese Patent Laid-Open No. 11-170397

  However, in the case of a part made of AL material, in the case of a molded product by aluminum die-casting, the accuracy of the hole for preventing rotation becomes rough, so that play is generated between the protrusion formed on the thrust washer. Since stress due to torque or the like tends to concentrate on the engaging portion formed by the protrusion and the hole, if there is a backlash in the engaging portion, a load is repeatedly applied to the protrusion, and the protrusion is quickly worn and damaged. Therefore, it is necessary to keep the backlash small enough not to interfere with the wearability.

  In order to reduce the backlash between the projection of the thrust washer and the hole of the part made of the AL material as much as possible, the accuracy of the hole is generally increased by additional machining. However, high-precision additional machining of holes at a plurality of locations increases the processing cost, and thus hinders cost reduction due to the use of a thrust washer made of synthetic resin.

  The present invention has been made in view of the above points, and a technical problem thereof is to realize relative rotation prevention between the thrust washer and the counterpart member at a low cost.

  As a means for effectively solving the technical problem described above, the present invention is a thrust washer made of a synthetic resin interposed between a rotating member and a non-rotating member facing each other in the axial direction. A sliding surface is formed at one end, and a fitting cylindrical portion protruding in the axial direction is formed at the outer peripheral portion or the inner peripheral portion at the other end, and the fitting cylindrical portion is formed of the rotating member and the non-rotating member. Either one of them is press-fitted with a frictional force larger than the sliding torque on the sliding surface. That is, the thrust washer according to the present invention has a fitting cylinder portion projecting in the axial direction press-fitted to the outer peripheral surface or the inner peripheral surface of the rotating member or the non-rotating member, so that the friction torque prevents the rotation between the two. Therefore, it is not necessary to process a hole for preventing rotation on the rotating member or the non-rotating member.

  In the above configuration, more preferably, the fitting cylinder part and the fitting surface of the rotating member or the non-rotating member form a radially undulating surface corresponding to each other, thereby fitting cylinder part at the time of mounting. It is possible to prevent axial slippage due to the spring back.

  According to the thrust washer according to the present invention, since the relative rotation between the thrust washer and the mating member is prevented by the frictional force between the fitting cylinder portion formed on the thrust washer and the mating member, There is no need to additionally process a rotation-preventing hole in the rotating member, and the rotation prevention between the thrust washer and the counterpart member can be realized at a low cost.

  Hereinafter, a preferred embodiment of a thrust washer according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a thrust washer according to a first embodiment of the present invention cut along a plane passing through its axis, and FIG. 2 is a perspective view showing a state where the thrust washer according to the first embodiment is mounted. It is sectional drawing cut | disconnected and shown by the plane which passes.

  First, a thrust washer 1 shown as a single unit in FIG. 1 is formed in a ring shape with a nylon-based synthetic resin, such as polyamide 66, which has excellent heat resistance, oil resistance and mechanical strength, and has an elongation. A main body part 11 having one end surface in the direction as a sliding surface 11a and a fitting cylinder part 12 protruding in the axial direction from the outer peripheral part of the other axial end surface (back surface) 11b of the main body part 11 are formed.

  As shown in FIG. 2, the thrust washer 1 is formed between a rotating member 2 and a non-rotating member 3 that are axially opposed to each other in a power train portion, a stator portion, or a cover portion of an automatic transmission device of a vehicle, for example. It is intervened. The non-rotating member 3 is a die-cast molded product made of an aluminum-based light metal, and the thrust washer 1 is held on the non-rotating member 3 side and slides on the sliding surface 11 a of the main body 11 with the rotating member 2. It is movably contacted and used under oil lubrication conditions such as with ATF (automatic transmission oil). The sliding surface 11a is formed with a large number of lubrication grooves (not shown) extending in the radial direction in order to reduce sliding resistance and wear.

  The inner peripheral fitting surface 12a of the fitting cylindrical portion 12 has a substantially S-shaped undulating surface having a relatively small diameter on the tip side and a relatively large diameter on the base side. 12a has a cross-sectional shape corresponding thereto and is formed on the outer peripheral surface of the end portion of the non-rotating member 3, and is closely fitted to a undulating surface 3a having a relatively large tip side in a retaining state, The back surface 11 b of the main body 11 is abutted and supported on the tip surface 3 b of the non-rotating member 3.

  The fitting cylinder portion 12 of the thrust washer 1 has a required tightening margin with respect to the outer peripheral surface of the end portion of the non-rotating member 3. This tightening allowance takes into account the difference in coefficient of linear expansion from the non-rotating member 3, and the outer peripheral surface of the end of the non-rotating member 3 even at the MAX temperature of the usage environment (for example, 120 to 165 ° C. in the case of an automatic transmission of a vehicle). On the other hand, the frictional force is set to be larger than the sliding torque with the rotating member 2 on the sliding surface 11a.

  FIG. 3 is a cross-sectional view showing a state in which the thrust washer according to the second embodiment of the present invention is mounted by cutting along a plane passing through its axis. The thrust washer 1 according to this embodiment is different from the first embodiment described above in that the fitting tube portion 12 is formed to protrude from the inner peripheral portion of the back surface 11b of the main body portion 11 in the axial direction.

  The outer peripheral fitting surface 12b of the fitting cylinder portion 12 forms a substantially S-shaped undulating surface such that the distal end side has a relatively large diameter and the base portion side has a relatively small diameter. The main body portion 11 is closely fitted to a undulating surface 3c formed on the inner peripheral surface of the end portion of the non-rotating member 3 with a corresponding cross-sectional shape and having a relatively small diameter at the distal end side, and in a retaining state. The back surface 11b of the non-rotating member 3 is in contact with and supported by the front end surface 3b. Other configurations are basically the same as those in the first embodiment.

  As shown in FIG. 2 or FIG. 3, the thrust washer 1 according to each of the above embodiments is fixed to the non-rotating member 3 in the fitting cylinder portion 12, and the rotating member 2 on the sliding surface 11 a of the main body portion 11. It is slidably contacted and receives a thrust load. And since the frictional force of the fitting cylinder part 12 with respect to the outer peripheral surface of the end part of the non-rotating member 3 is larger than the sliding torque with the rotating member 2 on the sliding surface 11a, the non-rotating member 3 made of an aluminum-based metal is There is no relative rotation with the thrust washer 1, and this state is maintained even if the use environment temperature rises to the MAX temperature. Therefore, abnormal wear of the non-rotating member 3 due to sliding with the thrust washer 1 made of synthetic resin is effectively prevented.

  The thrust washer 1 is attached to the non-rotating member 3 by press-fitting the fitting cylinder portion 12 into the end of the non-rotating member 3. At this time, the non-rotating member 3 and the thrust washer 1 are Positioning in the circumferential direction is not necessary. And since the fitting surface of the fitting cylinder part 12 and the non-rotating member 3 makes a radial undulation surface corresponding to each other, the axial removal by the spring back or the like of the fitting cylinder part 12 is effective after mounting. The state in which the back surface 11b of the main body 11 is in contact with the front end surface 3b of the non-rotating member 3 is maintained.

  In addition, although the thrust washer 1 according to each of the above-described embodiments is configured such that the fitting cylinder portion 12 is press-fitted and fitted to the non-rotating member 3 and is slid with the rotating member 2, the thrust washer 1 may be attached to the rotating member side. Can be implemented similarly.

  FIG. 4 shows a thrust washer 1 according to the embodiment shown in FIG. 1 (a sample in which the inner diameter of the fitting cylinder 12 is φ54.1, φ54.3, φ54.5, respectively) fitted to a mating member made of aluminum. The test results of measuring the torque due to the frictional force between the mating member and the thrust washer 1 using a torque wrench after being left in a temperature environment of 140 ° C. while being immersed in ATF are shown in relation to the immersion time. Is.

  From this test result, until 30 hours after fitting to the mating member, there is a decrease in torque due to a decrease in tightening allowance that seems to be due to creep of the fitting tube portion 12, but thereafter a stable torque is observed. Thus, it was confirmed that the sliding surface 11a can be maintained at a value sufficiently higher than the sliding torque with the rotating member.

It is sectional drawing which cut | disconnects and shows the thrust washer by the 1st form of this invention by the plane which passes along the axial center. It is sectional drawing which cut | disconnects and shows the mounting state of the thrust washer by the 1st form of this invention by the plane which passes along the axial center. It is sectional drawing which cut | disconnects and shows the mounting state of the thrust washer by the 2nd form of this invention by the plane which passes along the axial center. It is explanatory drawing which shows a test result.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thrust washer 11 Main-body part 11a Sliding surface 11b Back surface 12 Fitting cylinder part 12a Inner peripheral fitting surface 12b Outer peripheral fitting surface 2 Rotating member 3 Non-rotating member 3a, 3c Unraveling surface 3b Tip surface

Claims (2)

  A synthetic resin thrust washer (1) interposed between a rotating member (2) and a non-rotating member (3) facing each other in the axial direction, and a sliding surface (11a) is formed at one axial end. In addition, a fitting tube portion (12) projecting in the axial direction is formed on the outer peripheral portion or the inner peripheral portion at the other end, and the fitting tube portion (12) is formed by the rotating member (2) and the non-rotating member. A thrust washer, wherein the thrust washer is press-fitted into any one of (3) with a frictional force larger than a sliding torque on the sliding surface (11a).   The thrust washer according to claim 1, characterized in that the fitting surface of the fitting tube portion (12) and the rotating member (2) or the non-rotating member (3) forms a corresponding radial undulation surface. .

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