JP2006083966A - Tripod constant velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a mounting structure of a seal member so as not to reduce crushing strength of a ball bearing. <P>SOLUTION: In a tripod constant velocity universal joint in which a plurality of balls 36 are arranged between an outer ring 32 turnably inserted into each track groove of an outer joint member and an inner ring 34 externally fitted on each leg shaft of a tripod member and the ball bearing 30 sealing up a space therein arranging the balls 36 by the seal member 38 is provided, the seal member 38 provides a ring-shaped section 38a covering an opening 31 of a bearing, and a circular flange 38b formed on an inner periphery of the ring-shaped section 38a is mounted on a mounting groove 34d formed on an end face 34c of the inner ring 34. Crushing strength of the ball bearing 30 against radial load is improved so that radial load applied on the inner ring 34 can be easily distributed by widening an outer peripheral surface 34a of the inner ring 34. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a tripod type constant velocity universal joint configured to allow torque to be transmitted while allowing angular displacement between two axes and relative movement in the axial direction, and in particular, a ball bearing is interposed between an outer joint member and a tripod member. It is about things.

  As a conventional tripod type constant velocity universal joint, an outer joint member having three track grooves extending in the axial direction on the inner peripheral surface and three leg shafts projecting in the radial direction are provided. There is one provided with a tripod member inserted inside and a roller externally fitted to each leg shaft of the tripod member via a plurality of balls so as to be rotatable and swingable (see, for example, Patent Document 1). As this roller, it has been proposed to use a ball bearing in which a plurality of balls are disposed between the outer ring and the inner ring.

  Generally, a tripod type constant velocity universal joint is filled with a lubricant in the joint or the bearing in order to improve lubricity. When torque is applied to the tripod type constant velocity universal joint, the lubricant flows inside the joint or the bearing as the ball bearing rolls or the tripod member rotates. When an open type bearing with an open end on the bearing end face is used as a ball bearing, if the amount of lubricant flowing out of the bearing exceeds the amount of lubricant flowing into the bearing, Insufficient lubrication occurs. Further, as the lubricant, it is desirable to use a lubricant suitable for the application, and it is assumed that the ball bearing is filled with a different type of lubricant from that filled into the joint.

  Patent Document 1 proposes to seal the bearing interior with a seal member in order to make the joint interior and the bearing interior independent from each other. When the same type of lubricant is sealed in the joint and the bearing, insufficient lubrication in the joint and the bearing can be suppressed. On the other hand, when different types of lubricants are sealed inside the joint and the bearing, for example, a lubricant having a smaller friction coefficient than the lubricant sealed inside the joint is sealed inside the bearing, so that sliding resistance and induced thrust are reduced. Can be reduced.

  By the way, in the conventional tripod type constant velocity universal joint, a step portion is formed on the inner peripheral portion of the end surface of the outer ring and the outer peripheral portion of the end surface of the inner ring so as to face each other, and the annularly formed sealing member is used as the step portion of the inner ring. The outer peripheral portion of the seal member and the step portion of the outer ring constitute a contact or non-contact seal (see FIGS. 3A and 3B of cited document 1). The seal member can be fitted and fixed to the step portion of the outer ring, and a contact or non-contact seal can be constituted by the inner peripheral portion of the seal member and the step portion of the inner ring.

JP 2000-227124 A

  Tripod type constant velocity universal joints are used for applications that transmit high torque, such as propeller shafts and drive shafts of automobiles. When torque is applied to the tripod type constant velocity universal joint, a radial load is applied to the ball bearing. At this time, in the ball bearing, a maximum principal stress is generated at a contact portion between the outer ring and the ball, a contact portion between the inner ring and the ball, or a peripheral portion thereof. For example, in the case of a deep groove ball bearing in which a ball groove is formed on the inner peripheral surface of the outer ring or the outer peripheral surface of the inner ring, the maximum principal stress is generated at the edge of the ball groove.

  When a step portion for attaching a seal member is formed on such a ball bearing as described above, a step portion is also formed on the inner peripheral surface that is the raceway surface of the outer ring and the outer peripheral surface that is the raceway surface of the inner ring. As a result, the area of each track surface is reduced by the stepped portion. If it does so, it will become difficult to disperse | distribute the radial load loaded on the ball bearing, and when an excessive radial load is loaded on the ball bearing, there exists a possibility that an outer ring and / or an inner ring may be crushed.

  The present invention has been made in view of such circumstances, and an object of the present invention is to improve the mounting structure of the seal member with respect to the ball bearing so that the strength of the ball bearing against the radial load does not decrease.

  In order to solve the above problems, the tripod constant velocity universal joint according to the present invention has three track grooves extending in the axial direction on the inner diameter surface, and a pair of guide surfaces facing each side of each track groove is formed. An outer joint member, a tripod member projecting three leg shafts in the radial direction, an outer ring rotatably inserted in each track groove of the outer joint member, and an outer ring on each leg shaft of the tripod member In a tripod type constant velocity universal joint having a ball bearing in which a plurality of balls are arranged between inner rings to be fitted and a space in which the balls are arranged is sealed by a seal member, the seal member is between the outer ring and the inner ring. An annular flange that covers the bearing opening is formed, and an annular flange that protrudes toward the bearing end surface is formed on the outer peripheral portion and / or inner peripheral portion of the annular portion, and is formed on the end surface of either the outer ring or the inner ring. Seal part in the mounting groove It is characterized by attaching the outer peripheral side or the inner circumferential side of the annular flange.

  Since the above-mentioned tripod type constant velocity universal joint has a mounting groove for fixing the seal member on one end face of the outer ring or the inner ring, it is loaded on the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring. It is easy to disperse the radial load, and the strength of the ball bearing against the radial load is increased.

  As described above, since the seal member is attached to the ball bearing in the present invention, it is easy to disperse the radial load applied to the inner peripheral surface of the outer ring and the inner peripheral surface of the inner ring, and the strength of the ball bearing against the radial load is increased. Can be increased. Thereby, even if a high torque is applied to the tripod type constant velocity universal joint and an excessive radial load is applied to the ball bearing, the ball bearing can be prevented from being crushed.

  Hereinafter, an embodiment of a tripod type constant velocity universal joint according to the present invention will be described with reference to the drawings.

  FIG. 1 is an axial cross-sectional view showing an embodiment of a tripod constant velocity universal joint according to the present invention. As shown in FIG. 1, the tripod type constant velocity universal joint includes an outer joint member 10, a tripod member 20, and a ball bearing 30 as main components.

  The outer joint member 10 has three track grooves 12 extending in the axial direction at circumferentially equally divided positions on the inner diameter surface, and a pair of guide surfaces 14 facing both sides of each track groove 12 is formed. . The tripod member 20 has three leg shafts 22 protruding in the radial direction. The leg shaft 22 is inserted into the track groove 12 of the outer joint member 10 with the ball bearing 30 fitted. The ball bearing 30 is arranged between an outer ring 32 that is rotatably inserted into the track groove 12 of the outer joint member 10, an inner ring 34 that is fitted onto the leg shaft 22 of the tripod member 20, and the outer ring 32 and the inner ring 34. A plurality of balls 36 provided, and seal members 38 and 39 for sealing the space in which the balls 36 are disposed are provided.

  The outer peripheral surface of the outer ring 32 is spherical, and the guide surface 14 of the outer joint member 10 is a partial cylindrical surface having a radius of curvature substantially equal to the outer peripheral surface of the outer ring 32. The inner ring 34 can move in the axial direction and swing with respect to the leg shaft 22. For example, by making the cross section of the leg shaft 22 into an elliptical shape and forming the inner peripheral surface of the inner ring 34 in a cylindrical shape, the inner ring 34 can move in the axial direction and swing with respect to the leg shaft 22.

  FIG. 2 is an enlarged view of a main part of FIG. 1 showing a mounting structure of the seal member 38. Hereinafter, the ball bearing 30 will be described in detail with reference to FIG. In addition, about the seal member 39 attached inside the ball bearing 30, since it is the same structure as the seal member 38 attached outside the ball bearing 30, description is abbreviate | omitted.

  The ball bearing 30 in this embodiment is a deep groove ball bearing in which ball grooves 32b and 34b are formed on the inner peripheral surface 32a of the outer ring 32 and the outer peripheral surface 34a of the inner ring 34, respectively. The balls 36 are arranged in a single row and in contact with each other (total ball state).

  A seal groove 32 d that forms a non-contact seal with the seal member 38 is formed on the end surface 32 c of the outer ring 32. A mounting groove 34d for fixing the seal member 38 is formed on the end surface 34c of the inner ring 34. Both the seal groove 32d and the attachment groove 34d are formed in an annular shape. In this embodiment, the seal groove 34d has a concave cross section. On the other hand, the mounting groove 34d has a lateral groove portion 34e inside, and has a substantially L-shaped cross section.

  The seal member 38 is made of a plastic material such as an iron plate or a steel plate, has a ring portion 38a that covers the bearing opening 31 between the outer ring 32 and the inner ring 34, and faces the inner ring end surface 34c on the inner peripheral portion of the ring portion 38a. An annular flange 38b projecting toward the outer ring end face 32c is formed on the outer peripheral portion of the annular portion 38a. The annular flange 38b on the inner peripheral side is formed in a concave shape in cross section, and after being fitted into the mounting groove 34d of the inner ring 34, it is plastically deformed so as to be in close contact with the mounting groove 34d and its peripheral portion, thereby engaging with the lateral groove 34e. An engagement portion 38d1 and a caulking portion 38d2 that engages with the opening edge of the attachment groove 34d are formed. The outer peripheral annular flange 38c is inserted into the seal groove 32d of the outer ring 32 and constitutes a non-contact seal with the seal groove 32d.

  As shown in FIG. 1, the tripod type constant velocity universal joint has a ball bearing 30 interposed between the outer joint member 10 and the tripod member 20, so that either the outer joint member 10 or the tripod member 20 is used. When torque is applied to one of them, a radial load is applied to the ball bearing 30. Due to this radial load, main stresses are generated on the inner peripheral surface 32a of the outer ring 32 and the outer peripheral surface 34a of the inner ring 34 with the ball grooves 32b and 34b as the center. The maximum principal stress is generated near the edges of the ball grooves 32b and 34b. Since the ball bearing 30 has the seal groove 32d and the mounting groove 34d formed on the bearing end surface, the inner peripheral surface 32a of the outer ring 32 and the outer peripheral surface 34a of the inner ring 34 are not narrowed. Specifically, the upper limits of the widths of the inner peripheral surface 32 a of the outer ring 32 and the outer peripheral surface 34 a of the inner ring 34 are determined by the depth of the track groove 12 of the outer joint member 10. By attaching the seal member 38 as described above, the widths of the inner peripheral surface 32a of the outer ring 32 and the outer peripheral surface 34a of the inner ring 34 can be maintained at the upper limit value. Thereby, it is easy to disperse the radial load applied to the ball bearing 30 when torque is applied to the tripod type constant velocity universal joint. If it does so, the generation | occurrence | production area | region of a main stress will spread, a maximum main stress can be reduced, and the crushing strength of the ball bearing 30 with respect to a radial load can be raised.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible. For example, as shown in FIG. A multilayer structure of the covering material 38f may be used. The core material 38e is a rigid material such as metal or resin. The covering material 38f is an elastic material such as rubber or elastomer. Further, an engaging portion 38d1 formed on the annular flange 38b on the inner peripheral side of the seal member 38 and engaged with the lateral groove portion 34e of the inner ring 34 is formed of a covering material 38f and is formed so as to be in close contact with the lateral groove portion 34e in advance. Has been. In this case, since it is not necessary to plastically deform the annular flange 38b on the inner peripheral side in order to attach the seal member 38, the number of mounting steps can be reduced and the manufacturing cost can be suppressed.

  In the above embodiment, the non-contact seal is configured by the seal member 38 and the seal groove 32d. However, as shown in FIG. 4, for example, the annular seal 38c on the outer peripheral side is slidably contacted with the seal groove 32d. It is also possible to configure. In the modification shown in FIG. 4, the annular flange 38c on the outer peripheral side is provided with a protrusion 38g that makes sliding contact with the seal groove 32d.

  In the above embodiment, the seal member 38 is fixed to the inner ring 34 and a seal is formed between the outer ring 32 and the seal member 38. For example, as shown in FIG. 5, the seal member 38 is fixed to the outer ring 32. It is also possible to form a seal between the inner ring 34 and the seal member 38. In the modification of FIG. 5, reference numeral 32d is a mounting groove, reference numeral 32e is a lateral groove portion, and reference numeral 34d is a seal groove 34d.

  Moreover, in the said embodiment, although the ball bearing 30 is comprised with respect to the leg shaft 22 of the tripod member 20 so that an axial movement and a swing are possible, this invention is comprised so that the ball bearing 30 can be swung. It is also applicable to tripod type constant velocity universal joints. For example, the swinging motion of the ball bearing 30 is regulated by forming the cross-sectional shape of the leg shaft 22 into a shape (for example, a circular shape) that matches the inner peripheral surface of the inner ring 34.

  Further, the outer peripheral surface of the outer ring 32 is not limited to the partial spherical shape shown in FIG. 1, but may be a cylindrical surface shape shown in the schematic diagrams of FIGS. Further, in FIG. 1, the present invention is applied to a tripod type constant velocity universal joint in which the guide surface 14 of the outer joint member 10 is formed in a substantially spherical shape that is substantially the same as the outer peripheral surface of the outer ring 32, and the two are in surface contact. However, the present invention can also be applied to a tripod type constant velocity universal joint in which the guide surface 14 is formed in a Gothic arch shape or a V-shape, and the guide surface 14 and the outer ring 32 are in contact at two points.

  Further, in the above-described embodiment, the deep groove ball bearing in which the single row balls 36 are arranged in a total ball state is described as the ball bearing 30. However, other ball bearings may be used. For example, an angular contact ball bearing in which the contact direction of the ball grooves 32b, 34b and the ball 36 is deviated from the bearing radial direction, a double row ball bearing in which the balls 36 are arranged in a double row, or the ball 36 at a predetermined interval in the bearing circumferential direction. A ball bearing or the like provided with a cage for holding it apart may be used.

1 is an axial cross-sectional view showing an embodiment of a tripod type constant velocity universal joint according to the present invention. It is a principal part expanded sectional view of FIG. 1 which shows the attachment structure of the sealing member with respect to a ball bearing. It is a principal part expanded sectional view which shows the modification of the tripod type constant velocity universal joint which concerns on this invention. It is a principal part expanded sectional view which shows the modification of the tripod type constant velocity universal joint which concerns on this invention. It is a principal part expanded sectional view which shows the modification of the tripod type constant velocity universal joint which concerns on this invention.

Explanation of symbols

10 outer joint member 12 track groove 14 guide surface 20 tripod member 22 leg shaft 30 ball bearing 31 bearing opening 32 outer ring 32a outer ring inner peripheral surface 32b ball groove 32c outer ring end surface 32d seal groove 34 inner ring 34a inner ring outer peripheral surface 34b ball groove 34c Inner ring end face 34d Mounting groove 34e Lateral groove portion 36 Ball 38 Seal member 38a Annular portion 38b Inner circumferential side annular flange 38c Outer circumferential side annular flange 38d1 Engaging portion 38d2 Caulking portion 38e Core material 38f Covering material 38g Projection 39 Sealing member

Claims (2)

An outer joint member having three track grooves extending in the axial direction on the inner diameter surface and forming a pair of guide surfaces facing both sides of each track groove, and a tripod having three leg shafts projecting in the radial direction A plurality of balls are disposed between the member, an outer ring that is rotatably inserted into each track groove of the outer joint member, and an inner ring that is fitted onto each leg shaft of the tripod member, and the balls are arranged. In a tripod type constant velocity universal joint provided with a ball bearing in which the established space is sealed by a sealing member,
The seal member has an annular portion that covers the bearing opening between the outer ring and the inner ring, and an annular flange that protrudes toward the bearing end surface is formed on the outer peripheral portion and / or inner peripheral portion of the annular portion, and the outer ring or inner ring A tripod type constant velocity universal joint, wherein an annular flange on an outer peripheral side or an inner peripheral side of a seal member is attached to an attachment groove formed on one of the end faces.   In the case where annular flanges are formed on the outer peripheral portion and inner peripheral portion of the annular portion, a seal groove is formed on the other end surface of the outer ring or inner ring where no mounting groove is formed, and the inner peripheral side or outer peripheral side of the seal member is formed. The tripod type constant velocity universal joint according to claim 1, wherein a seal is configured by inserting an annular flange into the seal groove.