JP5398968B2 - Fixed constant velocity universal joint - Google Patents

Description

  The present invention relates to a fixed type constant velocity universal joint that is used in a power transmission system of automobiles and various industrial machines and transmits rotational torque while allowing operating angular displacement between two axes of a driving side and a driven side.

  In automobiles and similar vehicles, rotational power can be transmitted at a constant speed even when there is angular displacement or axial displacement between the two axes in the power transmission path that transmits the driving force from the engine to the wheels. Possible constant velocity universal joints are arranged. The constant velocity universal joint includes a fixed constant velocity universal joint that does not perform plunging motion (axial displacement) and a sliding constant velocity universal joint that performs plunging motion.

  Generally, as shown in FIG. 15, the fixed type constant velocity universal joint includes an outer joint member 110 in which a plurality of track grooves 112 extending in the axial direction are formed on the inner spherical surface 111 at equal circumferential pitches, and an outer spherical surface. The inner joint member 120 in which a plurality of track grooves 122 extending in the axial direction in 121 are formed at equal circumferential pitches, and the torque is interposed between the track grooves 112 and 122 forming a pair of both the joint members 110 and 120. A plurality of torque transmission balls 130 for transmission and a cage 140 interposed between the joint members 110 and 120 and holding the torque transmission balls 130 are provided.

The fixed constant velocity universal joint shown in FIG. 15 is an undercut-free type in which the track grooves 112 and 122 of both joint members 110 and 120 are formed by straight portions 113 and 123 and arc portions 114 and 124, respectively. Hereinafter, it is a joint of UJ type). The center of curvature O ₁ of the arc portion 114 of the track groove 112 of the outer joint member 110 and the center of curvature O ₂ of the arc portion 124 of the track groove 122 of the inner joint member 120 are equidistant from each other in the axial direction across the joint center O. Is just offset.

For example, a conventional UJ type constant velocity universal joint shown in Patent Document 1 below is provided with a center of curvature O ₁ and O ₂ of each track groove of the inner and outer joint members 110 and 120 and a torque transmission ball 130 for reducing the size and weight. The track groove offset angle θ _TRACK formed by the straight line connecting the center Q and the straight line connecting the center Q of the torque transmission ball 130 and the joint center O is set in a range of 4 ° ≦ θ _TRACK ≦ 6 °.

Further, the center of curvature O ₁₀ of the inner spherical surface 111 of the outer joint member 110 and the center of curvature O ₂₀ of the outer spherical surface 121 of the inner joint member 120, in other words, the curvature center O ₁₀ of the outer spherical surface 141 of the cage 140 and the curvature of the inner spherical surface 142. The center O _{20 is} also offset by an equal distance in the axial direction across the joint center O. In the joint shown in Patent Document 1, a straight line connecting the centers of curvature O ₁₀ and O ₂₀ of the inner and outer spherical surfaces 141 and 142 of the cage 140 and the center Q of the torque transmission ball 130, the center Q of the torque transmission ball 130, and the joint center. The offset angle θ _{CAGE of the} cage formed by the straight line connecting O is set in a range of 0 ° <θ _CAGE <1 °. Thus, the cage 140 is formed to have a substantially uniform thickness because the offset angle θ _CAGE is set to be very small.
JP 2005-337304 A

  In recent years, attempts have been made to further reduce the thickness of the cage in order to further reduce the size and weight of the fixed type constant velocity universal joint. On the other hand, when the joint rotates at a high operating angle, a large load is applied to the end of the cage on the joint opening side, so the strength of that portion must be ensured.

  However, in the joint configuration shown in Patent Document 1, when the cage thickness is set to be thin, the cage is uniformly thinned, so that it is difficult to sufficiently secure the strength of the end portion of the cage on the joint opening side. Met. In addition, a decrease in strength at the end of the joint opening due to the reduction in the size and weight of the cage is particularly noticeable in small-sized fixed type constant velocity universal joints applied to small cars and light vehicles.

  Therefore, in view of such circumstances, the present invention is intended to provide a fixed type constant velocity universal joint capable of reducing the size and weight while securing the strength of the cage.

The invention of claim 1 includes an outer joint member having form form a six track grooves that extend in an inner spherical surface in the axial direction, an inner joint member having form form a six track grooves that extend in the outer spherical surface in the axial direction , Six torque transmitting balls arranged one by one in a ball track formed by a pair of a track groove of the outer joint member and a track groove of the inner joint member, an inner spherical surface of the outer joint member, and the inner joint In a fixed type constant velocity universal joint that is interposed between the outer spherical surface of the member and includes a cage that holds the torque transmission ball, a pair of balls adjacent to each other in the circumferential direction, and the pair of balls Each ball circumferential interval pitch between the other pair of balls disposed at the symmetrical position is set smaller than the other ball circumferential interval pitch, and each of the pair of ball circumferential interval pitches is the same. And the other circumferentially set pitches of the balls are set to be the same, and the track grooves of the inner and outer joint members are unequal pitches in the circumferential direction corresponding to the positions of the balls. Of the plurality of inner spherical surfaces disposed between the track grooves of the member, the circumferential length of the opening side end portion of the inner spherical surface disposed within the minimum pitch is smaller than the width of the pocket of the cage. set, the center of curvature of the outer spherical surface on the joint opening side with respect to the joint center of the cage, opposite the center of curvature of the inner spherical surface of the cage on the joint inner side with respect to the joint center, respectively, in the axial direction to each other And a straight line connecting the center of curvature of the outer spherical surface of the cage and the center of the torque transmission ball and the center of the torque transmission ball and the center of the joint when the joint operating angle is 0 °. Straight line And the offset angle θ _CAGE of the cage, the straight line connecting the center of curvature of the inner spherical surface of the cage and the center of the torque transmitting ball, and the center of the torque transmitting ball and the center of the joint when the joint operating angle is 0 ° _Are respectively set in a range of 2.7 ° ≦ θ _CAGE ≦ 5.7 °.

Thus, by setting the cage offset angle θ _CAGE to be larger than the conventional cage offset angle (0 ° <θ _CAGE <1 °), the thickness of the end of the cage on the joint opening side can be reduced. It is molded thicker than this part. By the way, when the cage is assembled into the outer joint member, the pocket of the cage is incorporated so as to face the inner spherical surface disposed within the minimum pitch of the outer joint member. Since the circumferential length of the opening side end of the inner spherical surface disposed within the minimum pitch is set to be smaller than the width of the opposing cage pocket, the inner spherical surface interferes with the outer circumferential surface of the cage. And the cage can be easily incorporated into the outer joint member.

According to a second aspect of the present invention, in the fixed type constant velocity universal joint according to the first aspect, the center of curvature of the track groove of the outer joint member is on the joint opening side with respect to the joint center, and the track groove of the inner joint member is on the joint innermost side center of curvature with respect to the joint center, respectively, with offset equal distances on opposite sides in the axial direction from each other, in the state of the joint operating angle 0 °, the curvature of the track grooves of the inner and outer joint members The track groove offset angle θ _TRACK formed by the straight line connecting the center and the center of the torque transmission ball and the straight line connecting the center of the torque transmission ball and the joint center is substantially the same as the offset angle θ _{CAGE of the} cage. It is set as follows.

  Thereby, it is possible to secure a sufficient depth of the track groove, and it is possible to maintain the joint strength when the joint takes a high operating angle.

A third aspect of the present invention is the fixed constant velocity universal joint according to the first or second aspect, wherein a ratio r1 between a pitch circle diameter (PCD _BALL ) of the torque transmission ball and a diameter (D _BALL ) of the torque transmission ball. (= PCD _BALL / D _BALL ) is set in the range of 3.0 ≦ r1 ≦ 3.3.

  By setting r1 in this way, the joint can be further reduced in size and weight.

According to a fourth aspect of the present invention, in the fixed type constant velocity universal joint according to any one of the first to third aspects, the outer diameter of the outer joint member (D _OUTER ) and the diameter of the torque transmission ball (D _BALL ) Ratio r2 (= D _OUTER / D _BALL ) is set in a range of 4.6 ≦ r2 ≦ 4.8.

  By setting r2 in this way, the joint can be further reduced in size and weight.

According to a fifth aspect of the present invention, in the fixed type constant velocity universal joint according to any one of the first to fourth aspects, the pitch between the track grooves of the inner and outer joint members is symmetrical with respect to the joint center. The phase of the two pitches positioned is set to be smaller than 60 °, and the phase of the remaining four pitches is set to be larger than 60 °, and the inside of the outer joint member disposed within the pitch of the phase smaller than 60 ° The circumferential length of the opening side end of the spherical surface is set smaller than the width of the cage pocket.

  When assembling the cage into the outer joint member, the cage pockets are opposed to the inner spherical surface of the outer joint member disposed within a phase pitch of less than 60 °. Since the circumferential length of the opening side end portion of the inner spherical surface disposed within the pitch smaller than 60 ° is set to be smaller than the width of the opposing cage pocket, the inner spherical surface is formed on the outer circumferential surface of the cage. The cage can be easily incorporated into the outer joint member without interference. Further, since the inner spherical surface (opening side end portion) having a circumferential length smaller than the pocket width is arranged symmetrically with respect to the joint center, it becomes easier to incorporate.

According to a sixth aspect of the present invention, in the fixed type constant velocity universal joint according to the fifth aspect of the present invention , two pillars of the cage disposed within the pitch of the phase smaller than 60 ° are removed, A long pocket capable of holding the torque transmission ball is formed, and the circumferential length of the long pocket is set larger than the width of the inner joint member.

  When the inner joint member is assembled in the cage, one of the outer spherical surfaces disposed between the track grooves of the inner joint member is inserted into the long pocket of the cage, and the inner joint member is accommodated in the cage. Since the circumferential length of the long pocket is set larger than the width of the inner joint member, the outer spherical surface of the inner joint member can be easily inserted without interfering with the long pocket.

A seventh aspect of the present invention is the fixed type constant velocity universal joint according to the fifth aspect , wherein a part of the pillar portion of the cage disposed within the pitch of the phase smaller than 60 degrees is removed to form a cage. A long pocket capable of holding the two torque transmission balls is formed, and the circumferential length of the long pocket is set larger than the width of the inner joint member.

  Similarly to the above, when the inner joint member is assembled into the cage, one of the outer spherical surfaces disposed between the track grooves of the inner joint member is inserted into the long pocket of the cage, and the inner joint member is inserted into the cage. Store in. Since the circumferential length of the long pocket is set larger than the width of the inner joint member, the outer spherical surface of the inner joint member can be easily inserted without interfering with the long pocket.

The invention according to claim 8 is the fixed type constant velocity universal joint according to claim 6 or 7 , wherein the 60 °
The cage pillars disposed within the smaller phase pitch are removed by pressing.

  As a method for removing the column part, press working can be adopted.

The invention of claim 9 is the fixed type constant velocity universal joint according to claim 6 or 7 , wherein the 60
The cage pillars arranged in a pitch with a phase smaller than 0 ° are removed by milling.

  Milling can be employed as a method for removing the column portion.

A tenth aspect of the present invention is the fixed type constant velocity universal joint according to any one of the first to ninth aspects, wherein an inclined portion is provided at a distal end edge portion of the joint inner side of at least one track groove of the inner joint member. Alternatively, a step portion is provided.

  When incorporating the inner joint member into the cage, the track groove of the inner joint member provided with the inclined portion or the stepped portion is straddled over the inlet portion of the cage. At this time, the inner joint member is arranged such that the track groove provided with the inclined portion or the step portion is generally closer to the entrance portion of the cage than the track groove of the conventional inner joint member (without the inclined portion or the like). be able to. Thereby, a large gap can be secured between the outer spherical surface of the inner joint member on the opposite side of the guide groove provided with the inclined portion or the stepped portion and the inlet portion of the cage, and can be easily incorporated.

An eleventh aspect of the present invention is the fixed type constant velocity universal joint according to the tenth aspect , wherein the inclined portion or the stepped portion is formed by plastic working.

  As a processing method of the inclined part or the step part, plastic working can be adopted.

A twelfth aspect of the present invention is the fixed type constant velocity universal joint according to any one of the first to eleventh aspects, wherein the straight cut portion is provided in each track groove of the inner and outer joint members.

  The configuration of the present invention can be applied to an undercut free type fixed constant velocity universal joint.

A thirteenth aspect of the present invention is the fixed type constant velocity universal joint according to any one of the first to eleventh aspects, wherein a taper portion is provided in each track groove of the inner and outer joint members.

  The configuration of the present invention can be applied to a fixed type constant velocity universal joint in which a taper portion is provided in each track groove of the inner and outer joint members.

The invention of claim 14 is the fixed type constant velocity universal joint according to any one of claims 1 to 13 , wherein at least one of the track groove of the outer joint member or the track groove of the inner joint member is plastically processed. It was molded with

  Plastic working can be adopted as a processing method of both or one of the track grooves of the outer joint member and the track groove of the inner joint member.

The invention of claim 15 is the fixed type constant velocity universal joint according to any one of claims 1 to 13 , wherein at least one of the track groove of the outer joint member or the track groove of the inner joint member is ground. Alternatively, it is formed by quenching steel cutting.

  Grinding or hardened steel cutting can be employed as the processing method for both or one of the track grooves of the outer joint member and the track groove of the inner joint member.

  According to the fixed type constant velocity universal joint of the present invention, the thickness of the end portion on the joint opening side of the cage can be formed thicker than other portions. As a result, even if the cage is thinly formed in order to reduce the size and weight of the joint, the end of the cage on the joint opening side can ensure the strength to withstand the load applied when the joint is rotated at a high operating angle. it can.

Hereinafter, embodiments of the fixed type constant velocity universal joint according to the present invention will be described.
1A and 1B show an embodiment of a fixed type constant velocity universal joint according to the present invention, in which FIG. 1A is a longitudinal sectional view of the joint cut in parallel with its axis, and FIG. It is the cross-sectional view which cut | disconnected in the direction orthogonal to the axis. As shown in FIGS. 1A and 1B, the fixed type constant velocity universal joint of the present invention includes an outer joint member 1, an inner joint member 2, a torque transmission ball 3, and a cage 4 as main components. And 1A and 1B show a state where the operating angle formed by the rotation axis of the outer joint member 1 and the rotation axis of the inner joint member 2 is 0 °. The intersection of the rotation axis of the outer joint member 1 and the rotation axis of the inner joint member 2 is the joint center O. In the fixed type constant velocity universal joint, the joint center O is fixed regardless of the operating angle.

  The outer joint member 1 is formed to open on the right side in FIG. 1A, and has a connecting portion (not shown) connected to one of the two shafts of the drive shaft and the driven shaft on the left side of the drawing. An inner peripheral surface 1a of the outer joint member 1 is formed in a spherical shape, and six track grooves 1b extending in the axial direction are formed on the spherical inner peripheral surface 1a (hereinafter referred to as an inner spherical surface) at an equal pitch in the circumferential direction. Yes.

  The inner joint member 2 is a cylindrical member incorporated in the outer joint member 1. The outer peripheral surface 2a of the inner joint member 2 is formed in a spherical shape, and six track grooves 2b extending in the axial direction are formed on the spherical outer peripheral surface 2a (hereinafter referred to as an outer spherical surface) at a constant pitch in the circumferential direction. A spline or serration is formed on the inner peripheral surface 2c of the inner joint member 2 for inserting and fitting the shaft, which is the other of the two shafts. Moreover, as a processing method of both or one of the track groove of the outer joint member and the track groove of the inner joint member, plastic working, grinding, hardened steel cutting, or the like can be employed.

  The joint of this embodiment is a UJ type constant velocity universal joint in which a part of each track groove 1b, 2b of both joint members 1, 2 is formed in a straight shape. Specifically, as shown in FIG. 1 (A), the track groove 1b of the outer joint member 1 includes a straight portion 5 extending in the axial direction on the joint opening side (right side in the figure) and the joint back side (left side in the figure). Arc portion 6. In FIG. 1A, the track groove 2b of the inner joint member 2 is composed of a straight part 7 on the joint back side (left side in the figure) and an arc part 8 on the joint opening side (right side in the figure). .

  The track groove 1b of the outer joint member 1 and the track groove 2b of the inner joint member 2 are paired to constitute a ball track. A total of six torque transmission balls 3 are incorporated in each ball track.

  The cage 4 is provided with six pockets 4a at equal circumferential pitches. One torque transmission ball 3 is housed in each pocket 4a and is held so as to roll freely. Moreover, the outer peripheral surface 4b and the inner peripheral surface 4c of the cage 4 are each formed in a spherical shape. A spherical outer peripheral surface 4b (hereinafter referred to as an outer spherical surface) of the cage 4 is in spherical contact with an inner spherical surface 1a of the outer joint member 1, while a spherical inner peripheral surface 4c (hereinafter referred to as an inner spherical surface) of the cage 4 is an inner joint. The member 2 is in spherical contact with the outer spherical surface 2a.

The center of curvature O ₁₀ of the outer spherical surface 4 b of the cage 4 is arranged on the joint opening side (the right side in FIG. 1A) with respect to the joint center O. On the other hand, the center of curvature O ₂₀ of the inner spherical surface 4 c of the cage 4 is disposed on the joint back side (left side in FIG. 1A) with respect to the joint center O. The respective centers of curvature O ₁₀ and O ₂₀ of the inner and outer spherical surfaces 4b and 4c of the cage 4 are offset from the joint center O by an equal distance on the opposite sides in the axial direction.

FIG. 2 is an enlarged view of the upper half of the axis in FIG. Here, when the joint operating angle shown in FIG. 2 is 0 °, a straight line connecting the center of curvature O ₁₀ of the outer spherical surface 4 b of the cage 4 (or the center of curvature O ₂₀ of the inner spherical surface 4 c) and the center Q of the torque transmitting ball 3. The angle ∠O ₁₀ QO (or the angle ∠O ₂₀ QO) formed by the straight line connecting the center Q of the torque transmission ball 3 and the joint center O is referred to as a cage offset angle θ _CAGE . The offset angle θ _CAGE of the cage 4 is set in a range of 2.7 ° ≦ θ _CAGE ≦ 5.7 °.

Thus, by setting the offset angle θ _CAGE of the cage to be larger than the offset angle of the conventional cage shown in FIG. 15 (0 ° <θ _CAGE <1 °), the joint opening side of the cage 4 (see FIG. 2). The wall thickness at the end of the right side is formed thicker than the other parts. As a result, even if the cage 4 is formed thin in order to reduce the size and weight of the joint, the joint opening side end of the cage 4 has sufficient strength to withstand the load applied when the joint is rotated at a high operating angle. be able to.

When the offset angle θ _{CAGE of the} cage is θ _CAGE <2.7 °, the end portion on the joint opening side of the cage 4 becomes thin, and sufficient strength cannot be secured. When 5.7 ° <θ _CAGE , the thickness of the end portion of the cage 4 on the joint back side (left side in FIG. 2) becomes extremely thin. In the cage manufacturing process, heat treatment is generally performed. However, when the cage 4 is extremely thin, the uncured layer is reduced by heat treatment in the thin portion, and the toughness is reduced and sufficient strength can be secured. Disappear. Moreover, when the thickness difference between the end portion on the joint opening side of the cage 4 and the end portion on the back side of the joint is large, there is a concern about deterioration of workability.

Further, as shown in FIG. 1A, the radius of curvature O ₁ of the track groove 1b (arc portion 6) of the outer joint member ₁ and the radius of curvature of the track groove 2b (arc portion 8) of the inner joint member 2 are set. O ₂ is offset from the joint center O in the axial direction by an equal distance on the opposite sides. In FIG. 1A, the radius of curvature O ₁ of the track groove 1b of the outer joint member 1 is arranged on the joint opening side (right side in the drawing) with respect to the joint center O, and the curvature of the track groove 2b of the inner joint member 2 is. The radius O ₂ is disposed on the joint back side (left side in the figure) with respect to the joint center O.

2, the center of curvature O ₁ of the track groove 1b of the outer joint member ₁ (or the center of curvature O 2 of the track groove 2b of the inner joint member ₂ ) and the torque transmission ball 3 are The angle ∠O ₁ QO (or angle ∠O ₂ QO) formed by the straight line connecting the center Q and the straight line connecting the center Q of the torque transmission ball 3 and the joint center O is called the track groove offset angle θ _TRACK . The track groove offset angle θ _TRACK is set to be substantially the same as the cage offset angle θ _CAGE . By setting the track groove offset angle θ _TRACK in this manner, the depth of the track groove can be sufficiently secured, and the joint strength when the joint takes a high operating angle can be maintained.

In this embodiment, in addition to the above configuration, in order to further reduce the size and weight of the joint, the main dimensions of the joint are set to the following values. The ratio r1 (= PCD _BALL / D _BALL ) between the pitch circular PCD _BALL of the torque transmission ball 3 and the diameter D _BALL of the torque transmission ball 3 shown in FIGS. 1A and 1B is 3.0 ≦ r1 ≦ 3. A range of 3 is set. Here, the pitch circular PCD _BALL of the torque transmission ball 3 refers to the center of curvature O ₁ of the track groove 1 b of the outer joint member 1 or the center of curvature O 2 of the track groove 2 b of the inner joint member ₂ and the torque transmission ball 3. The length of the line segment connecting the center Q of the two is defined as twice the length of PCR (PCD _BALL = PCR × 2).

The reason why 3.0 ≦ r1 ≦ 3.3 is to ensure the strength of the outer joint member, the load capacity and durability of the joint while reducing the size and weight of the joint. That is, in the constant velocity universal joint, it is difficult to significantly change the pitch circular PCD _BALL of the ball in a limited space range. For this reason, the value of r1 depends mainly on the diameter D _BALL of the ball. If r1 <3.0 (mainly when the diameter D _BALL is large), the thickness of other parts (outer joint member, inner joint member, etc.) may become too thin to ensure sufficient strength. Further, if 3.3 <r1 (mainly when the diameter D _BALL is small), the load capacity may be small and durability may not be ensured.

Further, the ratio r2 (= D _OUTER / D _BALL ) between the outer diameter D _OUTER of the outer joint member 1 and the diameter D _BALL of the torque transmission ball 3 is set in the range of 4.6 ≦ r 2 ≦ 4.8. Yes.

The reason why 4.6 ≦ r2 ≦ 4.8 is set is to ensure the strength of the outer joint member, the load capacity and durability of the joint while reducing the size and weight of the joint as described above. That is, if r2 <4.6 (mainly when the diameter D _BALL is large), the thickness of other parts (outer joint member, inner joint member, etc.) may become too thin to ensure sufficient strength. is there. Further, when 4.8 <r2 (mainly when the diameter D _BALL is small), there is a possibility that the load capacity becomes small and the durability cannot be secured.

FIG. 3 shows a cross-sectional view of another embodiment of the present invention. Hereinafter, based on FIG. 3, the structure different from the said embodiment of this embodiment is demonstrated.
In FIG. 3, the track grooves 1b and 2b of the outer joint member 1 and the inner joint member 2 and the torque transmitting balls 3 interposed between the track grooves 1b and 2b are arranged at unequal pitches in the circumferential direction. ing. Specifically, two pitches (P ₂ and P ₅ in FIG. 3) arranged symmetrically with respect to the joint center O among the pitches (P _{1 to} P ₆ ) between the six torque transmission balls 3. ) Is set smaller than other pitches. The phases of the two small pitches (P ₂ and P ₅ ) are set smaller than 60 ° and at the same angle, and the other large pitches (P ₁ , P ₃ , P ₄ , P ₆ ) are set to 60 °. It is larger and set at the same angle as each other.

Further, the cage 4 for holding the torque transmission ball 3 includes a pair of annular portions 9 and 9 and a plurality of column portions disposed between the annular portions 9 and 9, as shown in FIGS. 10. In this embodiment, the column portions 10 are arranged at unequal pitches in the circumferential direction of the annular portion 9. Two types of pockets, that is, a pocket 4a ₁ that is long in the circumferential direction (hereinafter, referred to as a long pocket) and a pocket 4a ₂ that is short in the circumferential direction are formed between the pillar portions 10. Two torque transmission balls 3 and 3 set to a small pitch are accommodated in the long pocket 4a ₁ , and other torque transmission balls 3 are accommodated one by one in the short pocket 4a ₂ . In other words, the column portion 10 of the cage 4 is removed between the torque transmission balls 3 and 3 having a small pitch. Specifically, as a processing method for removing the column portion 10, for example, press processing, milling processing, or the like can be employed. In the embodiment shown in FIGS. 3 and 4, the configuration other than the above-described configuration is the same as that of the embodiment shown in FIGS.

5A to 5F are modifications of the cage 4 shown in FIG. Modification of these cages 4, respectively, in the circumferential center of the long pockets 4a _1, projection 11 is formed. In other words, it is shaped so that the column part is partially removed and a part is left. In the long pocket 4a ₁ shown in FIG. 5 (A), _one protrusion 11 is provided on each of the side surfaces of both annular portions 9 and 9. Further, as shown in FIGS. 5B and 5C, a protrusion 11 may be provided on the side surface of one annular portion 9.

  5A to 5C are formed by a straight surface 11a parallel to the circumferential direction and arcuate surfaces 11b and 11b connected to both ends of the straight surface 11a. The shape is not limited to this. For example, as shown in FIG. 5D, the connecting portion between the straight surface 11a and each of the circular arc surfaces 11b and 11b may be formed in an R shape. Further, as in the modification shown in FIG. 5 (E), the protrusion 11 is composed of a rectangular surface composed of a straight surface 11a parallel to the circumferential direction and orthogonal surfaces 11c and 11c connected orthogonally to both ends of the straight surface 11a. You may form in. Alternatively, as shown in FIG. 5 (F), the protrusion 11 may be formed in a trapezoid shape including a straight surface 11a parallel to the circumferential direction and tapered surfaces 11d and 11d connected to both ends of the straight surface 11a. .

Hereinafter, a method for assembling the cage and the inner joint member and the cage and the outer joint member described in FIGS. 3 to 5 will be described.
First, in order to assemble the inner joint member to the cage, the inner joint member and the cage are arranged so that the axis of each other forms approximately 90 °. 6A, the convex portion 12 having the outer spherical surface 2a of the inner joint member 2 is inserted into the long pocket 4a ₁ of the cage 4, and the inner joint member 2 is accommodated in the cage 4. . At this time, in order to make it difficult for the convex portion 12 to interfere with the edge of the long pocket 4a ₁ , the convex portion 12 having the outer spherical surface 2a disposed in a small pitch (small in the circumferential direction) is formed into the long pocket 4a. It is desirable to insert in ₁ . Further, as shown in FIG. 6B when FIG. 6A is viewed from the arrow X direction, the circumferential length L ₄ of the long pocket 4a ₁ is the width W ₂ of the convex portion 12 of the inner joint member _2. Therefore, the convex portion 12 can be easily inserted without interfering with the long pocket 4a ₁ .

As described above, by removing the column portion (or part thereof) of the cage 4 to form the long pocket 4a ₁ , the assembling property of the inner joint member 2 and the cage 4 is improved. Thereafter, the inner joint member 2 is rotated 90 ° in the cage 4 and assembled so that the axes of both members coincide (not shown). In FIG. 6, the assembling method has been described using an example of the cage 4 having the long pocket 4 a ₁ , but the assembling method in the case of using another modified example is the same, and thus the description thereof is omitted.

In FIG. 3, the long pocket 4a ₁ can be formed in the same manner even if the pillars arranged in the large pitch are removed. It is desirable to remove the arranged pillars and leave the thick pillars arranged in the large pitch.

Next, a method for assembling the cage and the outer joint member will be described with reference to FIG.
The cage and the outer joint member are arranged such that the axis of each other forms approximately 90 °. Then, as shown in FIG. 7, the short pockets 4a ₂ (or long pockets 4a ₁ ) of the cage 4 are arranged between the track grooves 1b disposed at the small pitches (P ₂ and P ₅ ) of the outer joint member 1. The cage 4 is accommodated in the outer joint member 1 so as to correspond to the inner spherical surface 1a. Cage 4 short pockets 4a ₂ (or, long pockets 4a ₁₎ the width W ₄ of, rather than the circumferential length L ₁ of the opening-side end portion of the spherical surface 1a among which is disposed within the corresponding small pitch, Since it is formed large, the cage 4 can be accommodated in the outer joint member 1 without the inner spherical surface 1 a (the opening side end thereof) interfering with the outer circumferential surface of the cage 4.

Thus, the assembling property between the outer joint member 1 and the cage 4 is improved by setting a portion between the track grooves 1b of the outer joint member 1 to a small pitch. Thereafter, the cage 4 is rotated 90 ° within the outer joint member 1 and assembled so that the axes of both members coincide (not shown). In FIG. 7, the assembling method has been described using an example of the cage 4 having the long pocket 4 a _1. However, the assembling method in the case of using another modified example is the same, and thus the description thereof is omitted.

Moreover, in order to improve the assembly | attachment property of an inner joint member and a cage, you may employ | adopt the structure of the inner joint member shown in FIGS.
8 is a perspective view of the inner joint member, FIG. 9 is a view taken in the direction of the arrow Y in FIG. 8, FIG. 10A is a sectional view taken along the line ZZ in FIG. 9, and FIGS. It is drawing which shows the modification of the principal part.

  As shown in FIGS. 8, 9, and 10 (A), the inclined portion 13 is provided in one track groove 2 b of the inner joint member 2. The inclined portion 13 may be provided in at least one of the plural (in this case, six) track grooves 2b. The inclined portion 13 can be formed by, for example, plastic working.

  Specifically, as shown in FIG. 10 (A), the track groove 2b of the inner joint member 2 is formed by cutting in the axial direction of the inner joint member 2, and thus has end edges 14a and 14b at both ends. The inclined portion 13 is provided on the end edge portion 14a on the straight portion 7 side of the track groove 2b among the both end edge portions 14a and 14b. In other words, the inclined portion 13 is provided at the end edge portion 14a on the joint back side (left side in the figure) of the track groove 2b.

  The inclined portion 13 is provided over the entire region of the end edge portion 14a, and is formed with a reduced diameter in a tapered shape facing the outer side in the axial direction. The cross-sectional shape of the inclined portion 13 may be a concave curved surface shape as shown in FIG. 10 (B) or a convex curved surface shape as shown in FIG. 10 (C). Moreover, it is good also as a level | step-difference part instead of an inclination part (illustration omitted). Moreover, as shown in FIG. 11, you may form the inclination part 13 small gradually from the circumferential direction intermediate part of the terminal edge part of the track groove 2b to both sides.

Hereinafter, a method for assembling the inner joint member and the cage shown in FIGS. 8 to 10 will be described.
First, the inner joint member 2 and the cage 4 are arranged so that the axis of each other forms approximately 90 °. In this state, as shown in FIG. 12, the track groove 2 b provided with the inclined portion 13 is straddled over the inlet portion 4 d on the rear side of the joint of the cage 4 (that is, the inner diameter on the left side in the drawing is large). The inner joint member 2 is rotated in the direction of arrow T around the straddled track groove 2b, and the convex portion 12 between the track grooves 2b of the inner joint member 2 is inserted into the pocket 4a of the cage 4, and the inner side The joint member 2 is put into the cage 4. Then, the inner joint member 2 is rotated 90 ° in the cage 4 to be spherically engaged and assembled.

  In the state where the track groove 2b of the inner joint member 2 in which the inclined portion 13 is formed straddles the inlet portion 4d of the cage 4, as shown in FIG. 13 of the VV arrow sectional view of FIG. 13 approaches or contacts the inlet 4d. That is, as compared with the conventional inner joint member having a right angle corner instead of the inclined portion 13, the inner joint member having the inclined portion 13 can be dropped and inserted (in FIG. 13). Thereby, since the clearance gap S between the upper end surface (outer spherical surface 2a) of the inner joint member 2 and the inlet part 4d can be ensured large, assembly becomes easy.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the above-mentioned embodiment, Of course, a various change can be added in the range which does not deviate from the summary of this invention. The structure of the present invention can be applied to a fixed type constant velocity universal joint other than the UJ type fixed type constant velocity universal joint shown in FIG. For example, as shown in FIG. 14, a taper portion 15 that linearly expands toward the joint opening side (right side in the figure) is formed in a part of the track groove 2 b of the outer joint member 1, and the inner joint member The structure of the present invention may be applied to a joint in which a tapered portion 16 linearly expanded toward the joint back side (left side in the figure) is formed in a part of the two track grooves 2b.

It is a figure which shows one Embodiment of the fixed type constant velocity universal joint of this invention, Comprising: (A) is the longitudinal cross-sectional view which cut | disconnected the said fixed type constant velocity universal joint in parallel with the axis line, (B) is the said fixed type etc. It is the cross-sectional view which cut | disconnected the speed universal joint in the orthogonal direction with the axis line. It is a longitudinal cross-sectional view of the said fixed type constant velocity universal joint. It is a cross-sectional view which shows other embodiment of this invention. It is a figure which shows the cage of the said other embodiment, Comprising: (A) is a side view of the said cage, (B) is a perspective view of the said cage. (A)-(F) are side views which show the modification of the said cage. (A) is a figure which shows a mode that a cage and an inner joint member are assembled | attached, (B) is a X arrow directional view of (A). It is a figure which shows a mode that a cage and an outer joint member are assembled | attached. It is a perspective view which shows other embodiment of an inner side coupling member. It is a Y arrow line view of FIG. (A) is ZZ sectional drawing of FIG. 9, Comprising: (B) (C) is principal part sectional drawing which shows the modification of the principal part of (A). It is principal part sectional drawing which shows another modification of the principal part of an inner side coupling member. It is a figure which shows a mode that a cage and an inner joint member are assembled | attached. It is VV arrow sectional drawing of FIG. It is a longitudinal cross-sectional view which shows the example which applied this invention to another fixed type constant velocity universal joint. It is a longitudinal cross-sectional view which shows the conventional fixed type constant velocity universal joint.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer joint member 1a Inner spherical surface 1b Track groove 2 Inner joint member 2a Outer spherical surface 2b Track groove 3 Torque transmission ball 4 Cage 4a Pocket 4b Outer spherical surface 4c Inner spherical surface 10 Column portion 13 Inclined portion 14a End edge 15 Tapered portion 16 Tapered portion O Center of joint O ₁ Center of curvature of track groove of outer joint member O ₂ Center of curvature of track groove of inner joint member O ₁₀ Center of curvature of outer spherical surface of cage O ₂₀ Center of curvature of inner spherical surface of cage ₂₀ Q Center of torque transmission ball

Claims (15)

An outer joint member on the inner spherical surface with forms form a six track grooves that extend in the axial direction, an inner joint member having form form a six track grooves that extend in the outer spherical surface in the axial direction, the tracks of the outer joint member Between six torque transmission balls arranged one by one in a ball track formed by a pair of a groove and a track groove of the inner joint member, and an inner spherical surface of the outer joint member and an outer spherical surface of the inner joint member In a fixed type constant velocity universal joint provided with a cage that is interposed in and holds the torque transmission ball,
Respective ball circumferential interval pitches between a pair of balls adjacent in the circumferential direction and another pair of balls disposed at symmetrical positions of the pair of balls with respect to the joint center are defined as other ball circumferential interval pitches. Smaller than each other, and the pair of balls in the circumferential direction interval pitch is made the same, and the other set in the other circumferential direction pitches of the balls are made the same,
The track grooves of the inner and outer joint members have circumferentially unequal pitches corresponding to the positions of the balls, and the smallest of the plurality of inner spherical surfaces arranged between the track grooves of the outer joint member The circumferential length of the opening side end portion of the inner spherical surface disposed in the pitch is set smaller than the width of the pocket of the cage,
The joint opening side with respect to the joint center to the center of curvature of the outer spherical surface of the cage, equidistant to the opposite side of the center of curvature of the inner spherical surface of the cage on the joint inner side with respect to the joint center, respectively, in the axial direction to each other Only offset,
Cage offset angle formed by a straight line connecting the center of curvature of the outer spherical surface of the cage and the center of the torque transmission ball and a straight line connecting the center of the torque transmission ball and the center of the joint when the joint operating angle is 0 ° θ _CAGE ,
Cage offset angle formed by a straight line connecting the center of curvature of the inner spherical surface of the cage and the center of the torque transmission ball and a straight line connecting the center of the torque transmission ball and the center of the joint when the joint operating angle is 0 °. θ _CAGE
Each of the fixed type constant velocity universal joints is set in a range of 2.7 ° ≦ θ _CAGE ≦ 5.7 °. The joint opening side with respect to the joint center to the center of curvature of the track grooves of the outer joint member, the center of curvature of the track grooves of the inner joint member to the joint innermost side of the joint center, respectively, opposite to each other in the axial direction Offset by an equal distance to the side,
A track formed by a straight line connecting the center of curvature of each track groove of the inner and outer joint member and the center of the torque transmitting ball and a straight line connecting the center of the torque transmitting ball and the center of the joint when the joint operating angle is 0 °. 2. The fixed constant velocity universal joint according to claim 1, wherein an offset angle θ _{TRACK of the} groove is set to be substantially the same as an offset angle θ _{CAGE of the} cage. A ratio r1 (= PCD _BALL / D _BALL ) between the pitch circle diameter (PCD _BALL ) of the torque transmission ball and the diameter (D _BALL ) of the torque transmission ball is set in a range of 3.0 ≦ r1 ≦ 3.3. The fixed type constant velocity universal joint according to claim 1, wherein the fixed type constant velocity universal joint is provided. The ratio r2 (= D _OUTER / D _BALL ) between the outer diameter (D _OUTER ) of the outer joint member and the diameter (D _BALL ) of the torque transmitting ball was set in the range of 4.6 ≦ r 2 ≦ 4.8. The fixed type constant velocity universal joint according to any one of claims 1 to 3, wherein the fixed type constant velocity universal joint is provided. Of the pitches between the track grooves of the inner and outer joint members, the phases of two pitches positioned symmetrically with respect to the joint center are set smaller than 60 °, and the phases of the remaining four pitches are larger than 60 °. The circumferential length of the opening side end portion of the inner spherical surface of the outer joint member disposed within the phase pitch smaller than 60 ° is set smaller than the width of the pocket of the cage. The fixed type constant velocity universal joint according to any one of claims 1 to 4 . The cage pillars disposed within the phase pitch smaller than 60 ° are removed to form a long pocket capable of holding the two torque transmitting balls in the cage, and the circumferential direction of the long pocket The fixed constant velocity universal joint according to claim 5 , wherein a length is set to be larger than a width of the inner joint member . A part of the cage column disposed within the phase pitch smaller than 60 ° is removed to form a long pocket capable of holding the two torque transmitting balls in the cage, and the long pocket 6. The fixed type constant velocity universal joint according to claim 5 , wherein the circumferential length is set to be larger than the width of the inner joint member. The fixed type constant velocity universal joint according to claim 6 or 7 , wherein a column portion of the cage disposed in a pitch having a phase smaller than 60 ° is removed by press working . The fixed type constant velocity universal joint according to claim 6 or 7, wherein a column portion of the cage disposed in a pitch having a phase smaller than 60 ° is removed by milling . The fixed constant velocity according to any one of claims 1 to 9 , wherein an inclined portion or a stepped portion is provided at a distal end edge portion on the joint back side of at least one track groove of the inner joint member. Universal joint. The fixed constant velocity universal joint according to claim 10 , wherein the inclined portion or the stepped portion is formed by plastic working . The fixed type constant velocity universal joint according to any one of claims 1 to 11 , which is an undercut free type in which a straight portion is provided in each track groove of the inner and outer joint members . The fixed type constant velocity universal joint according to any one of claims 1 to 11, wherein each track groove of the inner and outer joint member is provided with a taper portion . The fixed type constant velocity universal joint according to any one of claims 1 to 13 , 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 plastic working. . The fixing according to any one of claims 1 to 13 , 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 grinding or hardened steel cutting. Type constant velocity universal joint.

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