JP5184235B2 - Sliding constant velocity universal joint - Google Patents

Description

  The present invention is incorporated in a power transmission shaft such as a drive shaft used in an automobile such as a 4WD vehicle and an FR vehicle, for example, and enables sliding between the drive shaft and the driven shaft to allow angular displacement and axial displacement. The present invention relates to a dynamic constant velocity universal joint.

  Drive shafts used in automobiles such as 4WD vehicles and FR vehicles are provided with a sliding constant velocity universal joint so as to be able to cope with axial displacement and angular displacement due to a relative position change between the transmission and the differential. As this sliding type constant velocity universal joint, a ball type double offset constant velocity universal joint (DOJ) using a ball as a torque transmission element is well known.

  As shown in FIGS. 7 and 8, the double offset type constant velocity universal joint incorporated in the propeller shaft is incorporated between the outer ring 110 as the outer joint member, the inner ring 120 as the inner joint member, and the outer ring 110 and the inner ring 120. The main components are a plurality of balls 130 and a cage 140 that is interposed between the outer ring 110 and the inner ring 120 and holds the balls 130.

  The outer ring 110 has a cylindrical shape in which a plurality of linear track grooves 112 parallel to the axis thereof are formed on the cylindrical inner peripheral surface 114 at equal intervals in the circumferential direction. The inner ring 120 is formed with a plurality of linear track grooves 122 on the spherical outer peripheral surface 124 in parallel with the axis corresponding to the track grooves 112 of the outer ring 110. A ball 130 for transmitting torque is disposed on a ball track formed by cooperation between the track groove 112 of the outer ring 110 and the track groove 122 of the inner ring 120. Each ball 130 is accommodated in a pocket 146 of a cage 140 interposed between the inner peripheral surface 114 of the outer ring 110 and the outer peripheral surface 124 of the inner ring 120.

  The conventional constant velocity universal joint employs a structure in which an annular groove 118 is provided on the inner peripheral surface of the opening end portion 116 of the outer ring 110 and a circlip 150 is fitted into the annular groove 118. By adopting such a structure, the axial displacement of the ball 130 is regulated by the ball 130 interfering with the circlip 150 when the internal component 160 including the inner ring 120, the ball 130 and the cage 140 is displaced in the axial direction. The internal parts 160 are prevented from coming off.

  On the other hand, each of the constituent members including the outer ring 110, the inner ring 120, the ball 130, and the cage 140 described above includes the track groove 112 of the outer ring 110, the PCD clearance between the track groove 122 of the inner ring 120 and the ball 130, and the cylinder of the outer ring 110. The clearance between the inner peripheral surface 114 and the outer peripheral surface 142 of the cage 140, the clearance between the spherical outer peripheral surface 124 of the inner ring 120 and the inner peripheral surface 144 of the cage 140, and the pocket between the pocket 146 of the cage 140 and the ball 130. A constant velocity universal joint can be assembled by combining the internal clearances to be appropriate values.

Conventionally, in order to reduce the cost of a constant velocity universal joint, an internal clearance such as a PCD clearance is within a specified value range from among a large number of outer rings 110, inner rings 120, balls 130 and cages 140. In addition, there is a configuration in which the constituent members including the outer ring 110, the inner ring 120, the ball 130, and the cage 140 are not selected and combined, and the constituent members are combined by random matching (see, for example, Patent Document 1). ).
JP 2008-2624 A

  By the way, in the constant velocity universal joint disclosed in Patent Document 1, the constituent members are combined by random matching for cost reduction, and the track groove 112 of the outer ring 110 and the track groove 122 of the inner ring 120 cooperating therewith are combined. The PCD clearance of the formed ball track is defined as -0.02 to +0.3 mm. By defining the PCD clearance within this range, it is possible to suppress the backlash between the constituent members to the minimum necessary while ensuring the operability of the constant velocity universal joint. Further, in order to suppress noise due to rattling between the constituent members, a sound absorbing material is provided on the outer ring 110 as noise suppression means.

  However, in the conventional constant velocity universal joint described above, only the PCD clearance is defined in order to suppress the backlash between the constituent members to the necessary minimum while ensuring the operability. Other internal clearances such as the clearance between the cylindrical inner peripheral surface 114 and the outer peripheral surface 142 of the cage 140, the clearance between the spherical outer peripheral surface 124 of the inner ring 120 and the inner peripheral surface 144 of the cage 140, the pocket clearance of the cage 140, etc. It was not stipulated. In addition, it is necessary to provide a sound absorbing material on the outer ring 110 in order to suppress noise caused by rattling between the constituent members.

  Therefore, the present invention has been proposed in view of the above-mentioned problems, and the object of the present invention is to combine the constituent members with the minimum necessary matching to ensure the operability between the constituent members. It is an object of the present invention to provide a sliding type constant velocity universal joint that can suppress rattling at the minimum and can suppress abnormal noise without a sound absorbing material.

As technical means for achieving the above-described object, the present invention provides an outer joint member in which a plurality of linear track grooves extending in the axial direction are formed on a cylindrical inner peripheral surface, and a track groove of the outer joint member, A plurality of linear track grooves extending in the axial direction in pairs are interposed between the inner joint member formed on the spherical outer peripheral surface, and between the track groove of the outer joint member and the track groove of the inner joint member. A plurality of balls for transmission and a cage for holding the balls interposed between the cylindrical inner peripheral surface of the outer joint member and the spherical outer peripheral surface of the inner joint member, and having an internal clearance between the members. In the dynamic constant velocity universal joint, of the internal clearance, the PCD clearance is -0.02 to +0.3 mm, and the clearance between the cylindrical inner peripheral surface of the outer joint member and the outer peripheral surface of the cage is +0.01 to +0.3 mm. , Spherical outer surface of inner joint member The gap between the surface and the spherical inner peripheral surface of the cage + 0.01 to + 0.3 mm, characterized in that the pocket clearance of the cage was -0.050~ -0.005 mm. It should be noted that “−” in the numerical values of the PCD clearance and the pocket clearance described above means that it is an allowance.

  In the sliding type constant velocity universal joint according to the present invention, among the internal clearances between the constituent members, the PCD clearance, the clearance between the cylindrical inner peripheral surface of the outer joint member and the outer peripheral surface of the cage, the spherical shape of the inner joint member By ensuring that the clearance between the outer peripheral surface and the cage inner peripheral surface and the cage pocket clearance are within the specified value range described above, the operability of the constant velocity universal joint is ensured by combining the components with the minimum required matching. However, it is possible to suppress the backlash between the constituent members to the minimum necessary, and to suppress the abnormal noise based on the backlash between the constituent members without the sound absorbing material. Further, it is possible to form the outer joint member without the internal component retaining structure.

  In the present invention, it is preferable that at least one of the track groove of the outer joint member or the track groove of the inner joint member is formed by cold forging. In this way, when the track groove is formed, the grinding finish after turning or heat treatment is not required, so that the cost of the constant velocity universal joint can be reduced.

  In the present invention, the cross-sectional shape of the track groove of the outer joint member and the track groove of the inner joint member is preferably a Gothic arch shape that makes angular contact with the ball. In this way, it is possible to stabilize the contact state of the ball with the track groove.

  In the present invention, a structure in which chamfers are provided on both shoulder portions of the track groove of the outer joint member and the track groove of the inner joint member is desirable. In this way, stress concentration due to ball contact at both shoulder portions of the track groove can be avoided.

  The chamfers on both shoulders of the track groove are preferably formed by simultaneous forging with the track groove. In this way, when the track groove is formed, grinding and finishing after heat treatment are not necessary, and the cost of the constant velocity universal joint can be reduced.

  The present invention is applicable to a constant velocity universal joint of 5 to 8 balls that are interposed between the track grooves of the outer joint member and the track grooves of the inner joint member and transmit torque.

  According to the present invention, among the internal clearances between the constituent members, the PCD clearance, the clearance between the cylindrical inner peripheral surface of the outer joint member and the outer peripheral surface of the cage, the spherical outer peripheral surface of the inner joint member and the inner periphery of the cage By making the clearance with the surface and the pocket clearance of the cage within the specified value range described above, combining the components with the minimum required matching, while ensuring the operability of the constant velocity universal joint, The noise due to the shakiness between the constituent members can be suppressed even without a sound absorbing material. As a result, a high-quality and high-reliability sliding constant velocity universal joint can be provided, and the cost reduction of the constant velocity universal joint can be easily realized.

  1 is a longitudinal sectional view showing a double offset type sliding constant velocity universal joint (DOJ) incorporated in a drive shaft according to an embodiment of the present invention, and FIG. 2 is a double offset type constant velocity universal of FIG. It is a cross-sectional view of a joint.

  The constant velocity universal joint of the embodiment shown in FIGS. 1 and 2 includes an outer ring 10 as an outer joint member, an inner ring 20 as an inner joint member, and a plurality of balls 30 incorporated between the outer ring 10 and the inner ring 20. The main component is a cage 40 that is interposed between the outer ring 10 and the inner ring 20 and holds the ball 30.

  The outer ring 10 has a cylindrical shape in which a plurality of linear track grooves 12 parallel to the axis thereof are formed on the cylindrical inner peripheral surface 14 at equal intervals in the circumferential direction. Further, the inner ring 20 is formed with a plurality of linear track grooves 22 parallel to the axis line on the spherical outer peripheral surface 24 so as to correspond to the track grooves 12 of the outer ring 10. The track groove 12 of the outer ring 10 and the track groove 22 of the inner ring 20 are formed by cold forging. If the track grooves 12 and 22 are formed by cold forging as described above, the cost of the constant velocity universal joint can be reduced because the grinding or finishing after the heat treatment is unnecessary.

  A ball 30 for transmitting torque is disposed on a ball track formed by the track groove 12 of the outer ring 10 and the track groove 22 of the inner ring 20 in cooperation. Each ball 30 is accommodated in a pocket 46 of a cage 40 interposed between the inner peripheral surface 14 of the outer ring 10 and the outer peripheral surface 24 of the inner ring 20. In the illustrated embodiment, the case where six balls are used as the plurality of balls 30 is illustrated, but other five, seven, or eight balls may be used.

  Each of the constituent members including the outer ring 10, the inner ring 20, the ball 30, and the cage 40 described above includes the track groove 12 of the outer ring 10 and the clearance between the track groove 22 of the inner ring 20 and the ball 30, that is, the track groove 12 of the outer ring 10. PCD clearance of the ball track formed by the track groove 22 of the inner ring 20 cooperating with the inner ring 20, the clearance between the cylindrical inner peripheral surface 14 of the outer ring 10 and the outer peripheral surface 42 of the cage 40, and the spherical outer peripheral surface 24 of the inner ring 20 A constant velocity universal joint is assembled by combining the clearance with the inner peripheral surface 44 of the cage 40 and the internal clearance formed by the pocket clearance between the pocket 46 of the cage 40 and the ball 30 to an appropriate value.

  Here, “PCD (pitch circle diameter) clearance” means the PCD (outer ring PCD) of the ball 30 in contact with the track groove 12 of the outer ring 10 and the inner ring 20 as shown in FIGS. It means a difference from the PCD (inner ring PCD) of the ball 30 in a state in contact with the track groove 22. Further, “the clearance between the cylindrical inner peripheral surface 14 of the outer ring 10 and the outer peripheral surface 42 of the cage 40” means the inner diameter (outer ring) of the outer ring 10 on the cylindrical inner peripheral surface 14 as shown in FIGS. 3 and 5. It means the difference between the inner diameter) and the maximum outer diameter (cage outer diameter) on the outer peripheral surface 42 of the cage 40. As shown in FIGS. 4 and 5, “the clearance between the spherical outer peripheral surface 24 of the inner ring 20 and the inner peripheral surface 44 of the cage 40” refers to the outer diameter (outer diameter of the inner ring) at the spherical outer peripheral surface 24 of the inner ring 20. ) And the maximum inner diameter (cage inner diameter) on the inner peripheral surface 44 of the cage 40. Further, the “pocket clearance” means a difference between the axial width (cage pocket width) of the pocket 46 of the cage 40 and the outer diameter (ball diameter) of the ball 30 as shown in FIGS. 3 and 5.

  The internal clearance in the constant velocity universal joint of this embodiment is that the PCD clearance is -0.02 to +0.3 mm, and the clearance between the cylindrical inner peripheral surface 14 of the outer ring 10 and the outer peripheral surface 42 of the cage 40 is +0.01 to +0. 3 mm, the clearance between the spherical outer peripheral surface 24 of the inner ring 20 and the inner peripheral surface 44 of the cage 40 is +0.01 to +0.3 mm, and the pocket clearance of the cage 40 is −0.050 to 0 mm.

  If the aforementioned PCD clearance is smaller than -0.02 mm, it is difficult to ensure the operability of the constant velocity universal joint. If the PCD clearance is larger than +0.3 mm, the backlash between the components becomes too large. The vibration in the vehicle gets worse. Further, if the clearance between the cylindrical inner peripheral surface 14 of the outer ring 10 and the outer peripheral surface 42 of the cage 40 is smaller than +0.01 mm, it becomes difficult to ensure the operability of the constant velocity universal joint, and the clearance is more than +0.3 mm. If it is too large, the backlash between the constituent members becomes too large, and the vibration in the vehicle deteriorates. Further, if the clearance between the spherical outer peripheral surface 24 of the inner ring 20 and the inner peripheral surface 44 of the cage 40 is smaller than +0.01 mm, it becomes difficult to ensure the operability of the constant velocity universal joint, and the clearance is more than +0.3 mm. If it is too large, the backlash between the constituent members becomes too large, and the vibration in the vehicle deteriorates. Furthermore, if the pocket clearance of the cage 40 is smaller than −0.050 mm, the tightening allowance between the pocket 46 and the ball 30 is excessive, and the durability of the constant velocity universal joint is reduced, and the pocket clearance is 0 mm or more. Then, rattling of the ball 30 occurs in the pocket 46 and abnormal noise is generated.

  Regarding the above-described PCD clearance, the clearance between the cylindrical inner peripheral surface 14 of the outer ring 10 and the outer peripheral surface 42 of the cage 40, and the clearance between the spherical outer peripheral surface 24 of the inner ring 20 and the inner peripheral surface 44 of the cage 40, Selection to select and combine the constituent members composed of the outer ring 10, the inner ring 20, the ball 30 and the cage 40 so that the clearances are within the specified value range from the outer ring 10, the inner ring 20, the ball 30 and the cage 40. It is possible to combine the constituent members by random matching without performing the combination.

  The pocket clearance needs to be selected and combined so that the balls 30 and the cage 40 are selected and combined so as to be within the range of the above-mentioned specified value. However, when the pockets 46 of the cage 40 are subjected to grinding after heat treatment or hardened steel cutting, the balls 30 and the cage 40 can be combined by random matching.

Regarding the relationship between this pocket clearance and abnormal noise, the present applicant conducted a tabletop acoustic test under the conditions of a torque of 200 Nm and a rotation speed of 300 rpm. The two specimens to be compared include the PCD clearance, the clearance between the inner peripheral surface 14 of the outer ring 10 and the outer peripheral surface 42 of the cage 40, and the clearance between the outer peripheral surface 24 of the inner ring 20 and the inner peripheral surface 44 of the cage 40. The same values were used within the specified value range, and only the pocket clearance was varied between 0 mm (within the specified value range) and 0 mm or more (outside the specified value range). The comparison results are shown in the table below.

  As is apparent from the results in the above table, when the pocket clearance is less than 0 mm (within the specified value range) and a tightening margin is provided between the pocket 46 and the ball 30, which operating angle is taken. No abnormal noise was generated. On the other hand, if the pocket clearance is 0 mm or more (out of the specified range) and no allowance is provided between the pocket 46 and the ball 30, the generation of abnormal noise is confirmed with a large operating angle. It was done.

  In the above description, the pocket clearance is defined as -0.050 to 0 mm, but is preferably set to -0.050 to -0.005 mm. In this way, by setting the upper limit value of the pocket clearance to -0.005 mm and completely tightening the space between the pocket 46 and the ball 30, even when the internal component 60 is detached from the outer ring 10, the ball 30 is separated from the internal component 60. The internal parts 60 can be reassembled without falling off and falling off. As a result, the conventional constant velocity universal joint (see FIG. 7) eliminates the need for processing the annular groove 118 and the circlip 150 provided in the opening end portion 116 of the outer ring 110 as a structure for preventing the internal component 160 from coming off (FIG. 1). Reference), the number of processing steps and the number of parts can be reduced, and the cost can be further reduced.

  As described above, in this constant velocity universal joint, of the internal clearances between the constituent members, the PCD clearance, the clearance between the inner peripheral surface 14 of the outer ring 10 and the outer peripheral surface 42 of the cage 40, the outer peripheral surface 24 of the inner ring 20, By ensuring that the clearance with the inner peripheral surface 44 of the cage 40 and the pocket clearance of the cage 40 are within the specified value range described above, the operability of the constant velocity universal joint is ensured by combining the components with the minimum required matching. However, it is possible to suppress the backlash between the constituent members to the minimum necessary, and to suppress the abnormal noise based on the backlash between the constituent members without the sound absorbing material.

  Further, the cross-sectional shape of the track groove 12 of the outer ring 10 and the track groove 22 of the inner ring 20 is a Gothic arch shape that makes angular contact with the ball 30 as shown in FIG. The track grooves 12 and 22 having the Gothic arch shape have two ball contact points P and Q (ball contact angle α) that make angular contact with the ball 30. Such angular contact is preferable in that the contact state of the ball 30 with the track grooves 12 and 22 is stabilized.

  Further, chamfers 16 and 26 are provided on both shoulders of the track groove 12 of the outer ring 10 and the track groove 22 of the inner ring 20. By providing such chamfers 16 and 26, stress concentration due to ball contact at both shoulder portions of the track grooves 12 and 22 can be avoided. Although the illustrated chamfers 16 and 26 are illustrated as being tapered, the track groove 12 and the inner peripheral surface 14 of the outer ring 10 and the track groove 22 and the outer peripheral surface 24 of the inner ring 20 are connected smoothly and continuously. It can also be formed in an R shape. The chamfers 16 and 26 may be formed by simultaneous cold forging with the track groove 12 of the outer ring 10 and the track groove 22 of the inner ring 20. This eliminates the need for turning and grinding after heat treatment, thus contributing to the cost reduction of the constant velocity universal joint.

  The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the gist of the present invention. It includes the equivalent meanings recited in the claims and the equivalents recited in the claims, and all modifications within the scope.

FIG. 3 is a longitudinal sectional view taken along the line B-O-B in FIG. 2, showing the overall configuration of the sliding type constant velocity universal joint in the embodiment of the present invention. It is a cross-sectional view which follows the AA line of FIG. It is sectional drawing which shows the outer ring | wheel of FIG. It is sectional drawing which shows the inner ring | wheel of FIG. It is sectional drawing which shows the cage of FIG. It is a principal part expanded sectional view which shows the contact state of a track groove and a ball | bowl. It is a longitudinal cross-sectional view which shows the whole structure of the conventional sliding-type constant velocity universal joint, and follows the DOD line of FIG. It is a cross-sectional view which follows the CC line of FIG.

Explanation of symbols

10 Outer joint member (outer ring)
12 Track groove 14 Cylindrical inner peripheral surface 20 Inner joint member (inner ring)
22 Track groove 24 Spherical outer peripheral surface 30 Ball 40 Cage 42 Outer peripheral surface 44 Inner peripheral surface 46 Pocket 60 Internal parts

Claims (7)

An outer joint member in which a plurality of linear track grooves extending in the axial direction are formed on the cylindrical inner peripheral surface, and a plurality of linear track grooves extending in the axial direction are paired with the track grooves of the outer joint member in a spherical shape An inner joint member formed on the outer peripheral surface; a plurality of balls that are interposed between the track grooves of the outer joint member and the track grooves of the inner joint member; and a cylindrical inner portion of the outer joint member In a slide type constant velocity universal joint having a cage for holding a ball interposed between the peripheral surface and the spherical outer peripheral surface of the inner joint member, and having an internal clearance between the members,
Among the internal clearances, the PCD clearance is -0.02 to +0.3 mm, the clearance between the cylindrical inner peripheral surface of the outer joint member and the outer peripheral surface of the cage is +0.01 to +0.3 mm, and the inner joint member The clearance between the spherical outer peripheral surface of the cage and the spherical inner peripheral surface of the cage is +0.01 to +0.3 mm, and the pocket clearance of the cage is −0.050 to −0.005 mm. Dynamic constant velocity universal joint.   The sliding type constant velocity universal joint according to claim 1, wherein at least one of the track groove of the outer joint member or the track groove of the inner joint member is formed by cold forging.   The sliding type constant velocity universal joint according to claim 1 or 2, wherein the cross-sectional shape of the track groove of the outer joint member and the track groove of the inner joint member is a Gothic arch shape that makes an angular contact with the ball.   The sliding type constant velocity universal joint according to any one of claims 1 to 3, wherein chamfers are provided on both shoulders of the track groove of the outer joint member and the track groove of the inner joint member.   The sliding constant velocity universal joint according to claim 4, wherein the chamfer is formed by simultaneous forging with the track groove.   The sliding type constant velocity universal joint according to any one of claims 1 to 5, wherein the outer joint member does not have an internal component retaining structure.   The said ball | bowl is 5-8 pieces, The sliding type constant velocity universal joint as described in any one of Claims 1-6.

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