WO2007074691A1

WO2007074691A1 - Tripod-type constant velocity universal joint

Info

Publication number: WO2007074691A1
Application number: PCT/JP2006/325353
Authority: WO
Inventors: Minoru Ishijima; Junichi Izumino
Original assignee: Ntn Corporation
Priority date: 2005-12-28
Filing date: 2006-12-20
Publication date: 2007-07-05

Abstract

A tripod-type constant velocity universal joint in which rollers roll straight in parallel to track grooves of an outer joint member. In the joint, contact surface pressure of rolling bodies placed between the rollers and leg shafts is reduced. The peripheral surface of each leg shaft is formed in a spherical shape with a predetermined curvature radius. A bore surface (15b) of each roller (15) is formed in a projected round surface with the curvature radius same as the predetermined curvature radius. Hourglass-shaped rolling bodies having a concave surface having the same curvature radius as the predetermined curvature radius are arranged in the circumferential direction between the spherical surface of each leg shaft and the bore surface of each roller. The center in the axial direction of each rolling body is displaced in the direction of the axis of the joint from the position of the minimum inner diameter of each roller. By this, when the axis of each rolling body is tilted, one end of the rolling body which one end is on the center side of the joint is separated from one end of an adjacent rolling body, and at the same time, the other end on the opposite side of the joint center is in contact with the other end of the adjacent rolling body. The diameter d of an inscribing circle of the ends of the rolling bodies that are separated from each other is set greater the outer diameter D of the spherical surface of each leg shaft.

Description

Tri-board type constant velocity universal joint

Technical field

The present invention relates to a tri-board type constant velocity universal joint that is incorporated in, for example, a driving system of an automobile and transmits a rotational force at a constant speed between rotating shafts that exist on a non-linear line.

Background art

[0002] A constant velocity universal joint is a type of universal joint capable of transmitting a rotational force at a constant speed even when there is an angle between the two axes by connecting two shafts on the driving side and the driven side. The constant velocity universal joint has a fixed type and a sliding type. The sliding type allows relative axial displacement between the two axes by plunging the joint. A tri-board type is a type of sliding constant velocity universal joint.

[0003] The triboard type constant velocity universal joint includes an outer joint member and a tripod member. One of the two shafts to be coupled is connected to the outer joint member, and the other shaft is connected to the tripod member. The outer joint member has a bottomed cylindrical shape with one end opened, and has three track grooves extending in the axial direction on the inner periphery thereof. The tripod member has three leg shafts projecting radially outward from the cylindrical boss, and these leg shafts engage with the track grooves of the outer joint member to transmit torque. A roller is rotatably fitted on the leg shaft, and the roller rolls along a pair of roller guide surfaces facing each other in the track groove, thereby smoothly smoothing angular displacement and axial displacement between the two connecting shafts. To do.

[0004] By the way, when the connecting two shafts rotate in a state where the triboard type constant velocity universal joint takes an operating angle, each roller performs a complicated motion. That is, each roller moves along the roller guide surface while changing its direction in the axial direction of the outer joint member, and the force is also displaced in the axial direction of the leg shaft. When each roller moves in such a complicated manner, the relative displacement between the outer peripheral surface of the roller and the roller guide surface is not necessarily smoothly performed, and a relatively large friction is generated between these two surfaces. As a result, a tertiary axial force is generated while the two connecting shafts rotate once. When a constant velocity universal joint is incorporated in an automobile and takes a large operating angle while transmitting a large torque, a large vibration called a shudder may be generated by the tertiary axial force. [0005] To prevent such shudder, there is a double roller type in which another roller is inserted inside a roller via a rolling element such as a one-dollar roller (see Patent Documents 1 and 2). In this double roller type, the roller guide surface of the track groove is formed in a Gothic arch shape so that the contact with the outer side roller is an angular contact, while the leg shaft is swingable with respect to the inner roller. Angular contact makes the roller rolling direction parallel to the track groove direction, thereby reducing the rolling resistance of the roller and reducing the third-order induced thrust! / Disclosure of the invention

Problems to be solved by the invention

[0006] However, the double roller type requires an extra inner roller, and also requires a mechanism for holding the inner roller at a fixed position in the axial direction of the leg shaft. For this reason, assembly takes time and costs increase.

[0007] Therefore, a tri-board type constant velocity universal joint devised to roll in a straight line along the track groove without using the inner roller has been proposed (Patent Document 3). . In this single roller type, the circumferential surface of the leg shaft is spherical, and a plurality of one-dollar rollers are arranged in a full roller state between the spherical leg shaft and the roller. In addition, the roller guide surfaces facing each other in the track groove are configured as flat surfaces, and the rollers are linearly brought into linear contact with the roller guide surface by making the outer peripheral surface of the roller cylindrical, thereby preventing induced thrust. ing. In this configuration, only the leg shaft can be tilted without swinging the roller, but the contact surface pressure increases because the spherical outer peripheral surface of the leg shaft makes point contact with the needle roller, which may shorten the service life. There is.

[0008] In order to reduce the contact surface pressure between the spherical outer peripheral surface of the leg shaft and the one-dollar roller, the needle roller is connected to form a linear contact with the spherical outer peripheral surface of the leg shaft. There is a tri-board type constant velocity universal joint (see Patent Document 4). However, this joint is a fixed joint, and the leg shaft and the roller oscillate without changing the relative angle, and thus have nothing to do with prevention of induced thrust.

[0009] An object of the present invention is to provide a simple roller triboard type constant velocity universal joint having a simple structure, in which the roller rolls straight in a direction parallel to the track groove of the outer joint member and The contact surface pressure of the roller placed between the arm and the leg shaft is reduced, resulting in lower cost, lower vibration, and longer length. An object of the present invention is to provide a tri-board type constant velocity universal joint that enables the entire life.

Patent Document 1: Japanese Patent Publication No. 4-503554

Patent Document 2: Japanese Patent Laid-Open No. 5-215141

Patent Document 3: Japanese Patent Laid-Open No. 2000-74086

Patent Document 4: Japanese Patent Laid-Open No. 58-627

Means for solving the problem

[0010] The invention of claim 1 includes an outer joint member provided with three track grooves extending in the axial direction on the inner periphery, and provided with roller guide surfaces facing each other on the inner wall of each track groove, and a distal end thereof. A tripod member having three leg shafts inserted into the track groove, and a mouth ring rotatably supported by the leg shaft and rotatably inserted into the track groove of the outer joint member; In the tri-board type constant velocity universal joint provided with the above-mentioned, the peripheral surface of the leg shaft has a partial spherical shape with a predetermined curvature radius, and the inner diameter surface of the roller has a convex R surface with the same curvature as the predetermined curvature radius. A plurality of zigzag rollers having a concave R surface having the same curvature as the predetermined curvature radius are arranged in a circumferential direction between the shaft circumferential surface and the roller inner surface.

[0011] In the present invention, a plurality of zigzag rollers having a concave R surface having the same curvature as the leg spherical surface and the inner convex R surface are arranged in the circumferential direction between the spherical spherical surface and the inner convex R surface of the roller. Therefore, the leg shaft and the roller can be brought into line contact with the hooked piece, thereby reducing the surface pressure at the contact portion and increasing the joint life.

[0012] Further, by setting the inscribed circle diameter d of the roller ends spaced apart from each other when the roller is displaced to one side to be larger than the spherical outer diameter of the leg shaft, In contrast, the spherical surface of the leg shaft can be easily inserted.

[0013] The invention of claim 2 is the invention of claim 1, wherein the plurality of rollers have their axial axes shifted in the axial direction of the joints relative to the minimum inner diameter position of the rollers. When tilted, one end of the roller on the joint center side is separated from each other and the other end on the opposite side of the roller joint is in contact with each other, and the inscribed circle of the separated roller end at this time The diameter d is set to be larger than the spherical outer diameter of the leg shaft.

[0014] Thereby, the leg axis spherical surface can be easily inserted into the inner side of the roller. [0015] In the invention of claim 3, when the axial center position of the roller is deviated in the joint axial direction from the minimum inner diameter position of the roller and the roller axis is inclined, the one end of the roller on the joint center side is The roller joint center and the other end on the opposite side abut each other, and the inscribed circle diameter d of the roller ends separated at this time is slightly smaller than the spherical outer diameter of the leg shaft. It is set so that

[0016] The concave R surface of the tapered roller makes a line contact with the spherical surface of the leg shaft and the inner surface of the roller, thereby lowering the contact surface and increasing the joint life. In addition, the inscribed circle diameter d at the roller end when the pinch roller is displaced to the maximum extent is slightly smaller than the spherical outer diameter of the leg shaft, so that the leg shaft can be inserted into the roller by press-fitting. Can prevent the roller from falling off.

[0017] In the invention of claim 4, in the invention of claim 3, when the outer diameter in the joint circumferential direction of the leg shaft is D and the outer diameter in the joint axial direction is C, C <D. As described above, the cross-sectional shape of the leg shaft is a non-circular shape, and the inscribed circle diameter d of the roller end is set to a size intermediate between the outer diameters C and D.

[0018] Thereby, while allowing the elastic diameter reduction of the roller in the joint axis direction of the leg shaft, sufficient press-fitting dimensions can be obtained by utilizing the elastic diameter expansion of the roller in the joint circumferential direction of the leg shaft. Is possible.

[0019] Thus, by inserting the leg shaft into the inner side of the toothed roller, the assembly body strength of the tri-board member, the roller and the toothed roller can be prevented from accidentally falling off. In a stable assembled state Can be handled.

[0020] The invention of claim 5 is the invention of claim 4, wherein the outer diameter D of the leg shaft in the circumferential direction of the joint is formed within a predetermined angular range in the circumferential direction of the leg shaft, and exceeds the predetermined angular range. In this region, the outer diameter D is gradually reduced and connected to the outer diameter C of the leg shaft in the joint axis direction.

[0021] The invention of claim 6 is characterized in that, in the invention of claim 5, the predetermined angle range is 90 ° or more and 150 ° or less.

[0022] The invention of claim 7 is the invention of claim 1, wherein a protruding portion protruding from the convex R surface is formed at a joint center side edge of the convex R surface, and the leg shaft peripheral surface and the roller inner surface are formed. In between, a plurality of pinched rollers having concave R surfaces with the same curvature as the predetermined curvature radius are arranged in the circumferential direction. It is characterized by that.

[0023] The invention according to claim 8 is the invention according to claim 7, wherein the indentation of one end portion of the roller when the pinch roller is displaced until the end portion on the joint center side abuts against the protruding portion. The circular diameter d is set to be slightly smaller than the spherical outer diameter of the leg shaft.

[0024] The inscribed circle diameter d of the roller end when the pinch roller is displaced to the maximum extent is slightly smaller than the spherical outer diameter of the leg shaft, so that the leg shaft can be inserted into the inner side of the roller. It can be press-fitted, and the roller can be prevented from falling off and stable assembly can be handled.

[0025] In the invention of claim 9, in the invention of claim 8, when the outer diameter in the joint circumferential direction of the leg shaft is D and the outer diameter in the joint axial direction is C, C <D As described above, the cross-sectional shape of the leg shaft is a non-circular shape, and the inscribed circle diameter d of the roller end is set to a size intermediate between the outer diameters C and D.

[0026] Thereby, while allowing the elastic diameter reduction of the roller in the joint axis direction of the leg shaft, sufficient press-fitting dimensions can be obtained by utilizing the elastic diameter expansion of the roller in the joint circumferential direction of the leg shaft. Is possible.

[0027] The invention of claim 10 is the invention of claim 9, wherein the outer diameter D of the leg shaft in the circumferential direction of the joint is formed within a predetermined angular range in the circumferential direction of the leg shaft, and exceeds the predetermined angular range. In this region, the outer diameter D is gradually reduced to connect to the outer diameter C of the leg shaft in the joint axis direction.

[0028] The invention of claim 11 is characterized in that, in the invention of claim 10, the predetermined angle range is 90 ° or more and 150 ° or less.

In addition, the convex R surface of the leg shaft has an axial longitudinal sectional shape in which the center of curvature is offset from the center of the leg shaft to the side opposite to the outer peripheral surface side, and the curvature radius of the convex R surface of the roller is the curvature radius of the leg shaft. By making the same, the convex R surface of the leg shaft and the roller becomes R larger than the true spherical surface, so that the internal contact of the drum roller when the drum roller displaces along the inner peripheral surface of the mouth roller. The amount of increase in diameter can be reduced, and the play in the rotational direction of the joint at a high operating angle can be reduced. The invention's effect

[0029] According to the present invention, the life of the joint can be extended by reducing the contact surface pressure of the hourglass roller disposed between the roller and the leg shaft. Also, the roller is against the track groove of the outer joint member. Because it rolls in parallel, low-induced thrust performance (suppression of vehicle shudder phenomenon) and low backlash in the rotational direction are both achieved. A universal joint can be provided.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1 (A), the tri-board type constant velocity universal joint 10 of the present invention has an outer joint member 11 and a tripod member 12. The outer joint member 11 has a bottomed cylindrical shape, and one end of the rotating shaft is connected to the center of the bottom wall. Three track grooves 13 are formed on the inner peripheral surface of the outer joint member 11 at equal intervals in the circumferential direction. Each track groove 13 is formed by a pair of roller guide surfaces 13a facing each other and a bottom surface 13b connecting the pair of roller guide surfaces 13a. The roller guide surface 13a has an arc-shaped cross section and extends linearly in the axial direction of the outer joint member 11. The bottom surface 13b of the track groove 13 has a central plane 13bl and both side surfaces 13b2. Both side surfaces 13b2 are provided to ensure that the rollers 15 described later are prevented from tilting. Note that the outer peripheral surface of the outer joint member 11 is reduced in thickness by forming an arc-shaped recess 14 in a portion corresponding to the space between the track grooves 13 because of the light weight.

[0031] The tripod member 12 has three leg shafts 12b integrally formed radially at equal intervals in the circumferential direction (120 ° intervals) on the outer peripheral surface of a cylindrical central boss portion 12a. One end of a rotating shaft different from the rotating shaft of the outer joint member 11 is connected to the shaft hole 12c of the boss portion 12a by a spline or the like. The tips of the three leg shafts 12b extend in the radial direction to the vicinity of the bottom surface 13b of the track groove 13. The peripheral surface of the leg shaft 12b is a spherical surface S having a diameter D as shown in FIGS. 1 and 2, the tip end surface is a loose convex R surface, and faces the bottom surface 13b of the track groove 13 with a predetermined interval. The base portion of the leg shaft 12b is connected to the boss portion 12a via the constricted portion 12d.

A roller 15 is disposed between the roller guide surface 13 a of the track groove 13 of the outer joint member 11 and the leg shaft spherical surface S. The outer peripheral surface 15a of the roller 15 has an arcuate longitudinal section and is configured to be in line contact with the roller guide surface 13a. The roller 15 rolls parallel to the track groove 13 to reduce the induced thrust and prevent the vehicle from shuddering.

[0033] The inner diameter surface 15b of the roller 15 is a convex R surface having the same curvature as the leg axis spherical surface S, and a plurality of intergrated rollers 16 are disposed between the roller inner diameter surface 15b and the leg axis spherical surface S. Arranged in a state. The circumferential surface of the tapered roller 16 has a concave R surface with the same curvature as that of the leg shaft 12b and the roller inner surface 15b. Is done. The concave R surface of the tapered roller 16 is in rolling contact with both the leg shaft spherical surface S and the roller inner surface 15b without any gap on the torque acting side. That is, the toothed rollers 16 are in line contact with the leg axis spherical surface S and the guide roller guide surface 13a, respectively, to ensure a low surface pressure.

[0034] There is a slight gap between the pinched rollers 16. This gap is based on the center line L that bisects the thickness direction of the roller 15 as shown in Fig. 1 (B), Fig. 3 (B), and Fig. 4 during assembly of the joint. This is to allow displacement in the vertical direction in the figure. That is, when the roller 16 is displaced in the joint axial direction from the center line L, which is the minimum inner diameter position of the roller 15, and the roller 16 is inclined, the roller 16 is tilted as shown in Figs. ), The joint center side one end 16a of the roller 16 is separated from each other, and the other end 16b opposite to the joint center of the roller 16 is in contact with each other. When the roller 16 is displaced in such a state, the roller 16 cannot be displaced further in the axial direction of the joint. In other words, the inscribed circle diameter d of the roller 16 ends 16a that are spaced apart from each other does not increase any further. In the present invention, the inscribed circle diameter d is set to be slightly larger than the outer diameter of the spherical surface S of the leg shaft 12b. This facilitates insertion of the leg shaft 12b into the inner side of the tapered roller 16. After the insertion, appropriate gaps are formed between the rollers 16 and between the rollers 16 and the leg shaft 12b, and between the rollers 16 and 15, so that good operability can be secured and the rollers 16 can be prevented from leaking.

The triboard type constant velocity universal joint of the present invention is configured as described above, and when the roller 15 is attached to the leg shaft 12b of the tripod member 12, the tapered roller 16 is made thicker than the roller 15 as shown in FIG. Arranged so that it is displaced to the maximum from the center of the scanning direction. In this state, the leg shaft 12b is pushed also in the direction of the arrow toward the inner diameter d of the outer end portion of the roller 16. At this time, since the inner ends of the rollers 16 are in contact with each other, the inner diameter d does not increase any further. Since the diameter D of the leg shaft 12b is smaller than the inner diameter d of the end portion 16 of the leg 16, the leg shaft 12b can be inserted very smoothly. After the leg shaft 12b is inserted, the roller 16 is in the position shown in FIG. 1 (A), and an appropriate gap is created between the rollers 16. Next, the tri-board type constant velocity universal joint 10 is completed by inserting the roller 15 into the track groove 13 of the outer joint member 11 from the end thereof.

The triboard constant velocity universal joint 10 transmits torque between the track groove 13 of the outer joint member 11 and the leg shaft 12b of the tripod member 12. The roller 15 mounted rotatably on the leg shaft 12b can roll along the track groove 13, so the outer joint member 11 and the tripod member 12 is relatively displaceable in the axial direction. Before and after this axial displacement, torque transmission remains unchanged.

[0037] When an angle difference is generated between the outer joint member 11 and the tripod member 12, the leg shaft 12b is inclined relative to the track groove 13. At the same time, the roller 15 rolls along the track groove 13. At this time, the roller 15 rolls straight in the direction of the track groove 13 without inclining with respect to the track groove 13 to prevent generation of induced thrust. When the leg shaft 12b is inclined, the pinched rollers 16 are slightly displaced toward the joint center as shown in FIG. 1 (b). Even in this state, the peripheral surface of the roller 16 maintains line contact with the leg shaft 12b and the roller 15, and enables torque transmission with low surface pressure.

[0038] Next, a first modification of the present invention will be described with reference to Figs. In this first modification, the inscribed circle diameter d shown in FIG. 6 is set to be slightly smaller than the outer diameter of the spherical surface S of the leg shaft 12b. As a result, the insertion of the leg shaft 12b into the inside of the pinched roller 16 is press-fitted, and after insertion, an appropriate gap is formed between the rollers 16 and between the roller 16 and the leg shaft 12b, and between the roller 16 and the roller 15. , Ensure good operability and prevent roller 16 from leaking. In addition, the tri-board member 12, the roller 15 and the tabular roller 16 can be handled in a stable assembly state.

[0039] The cross-sectional shape of the leg shaft 12b is a perfect circle, and as shown in Fig. 5 (only one leg shaft 12b is shown), the outer diameter C in the joint axial direction and the outer diameter D in the joint circumferential direction It can be a non-circular circle that is different from As described above, it is desirable to press-fit the insertion of the leg shaft 12b into the inner side of the toothed roller 16, but it is the leg shaft configuration of FIG. 5 that makes this press-fitting more effective. That is, the outer diameters C and D of the leg shaft 12b are set so as to satisfy the relational expression C <d <D with respect to the inscribed circle diameter d. With such a dimensional relationship, a clearance is formed between the leg shaft 12b and the roller 16 in the joint axis direction (outer diameter C direction) to allow elastic reduction of the roller 15, while the leg shaft 12b In the joint circumferential direction (outer diameter D direction) of 12b, it is possible to obtain sufficient press-fitting dimensions by utilizing the inertial expansion by the reduced diameter of the roller 15.

[0040] Further, paying attention to the fact that the pressure acting on the spherical surface S of the leg shaft 12b during torque transmission is unevenly distributed in the joint circumferential direction, as shown in FIG. Within the range of Θ, the outer diameter of the leg shaft 12b is the same as the outer diameter D, and when outside the range of angle 2 Θ, the leg shaft 12b The outer diameter may be gradually reduced so that the outer diameter C is smoothly connected. The predetermined angle Θ is, for example, 0 = 45 ° (90 ° for 20) or more and 75 ° (150 ° for 20) or less. Within this angular range, the outer diameter surface of the leg shaft 12b is a perfect circle, so that the contact pressure with the roller 16 can be evenly distributed to reduce the contact pressure and increase the joint life. If the perfect circle of the outer diameter of the leg shaft is expanded to the range exceeding the angle Θ force of 75 °, the gap between the leg shaft 12b and 16 will be narrowed, and the diameter of the roller 15 will be reduced in the joint axis direction. As a result, the diameter of the roller 15 in the circumferential direction of the joint 15 decreases, and it becomes difficult to obtain a sufficient press-fitting dimension of the leg shaft 12b.

[0041] The tri-board type constant velocity universal joint of the first modified example of the present invention is configured as described above. When the roller 15 is mounted on the leg shaft 12b of the tripod member 12, the tapered roller as shown in FIG. 16 is arranged with the maximum deviation from the center in the thickness direction of the roller 15, and the leg shaft 12b is pushed in from the direction of the arrow toward the inner diameter d of the outer end of the roller 16. At this time, since the inner ends of the rollers 16 are in contact with each other, the inner diameter d does not increase any further. Since the diameter D of the leg shaft 12b is larger than the inner diameter d of the end of the roller 16, the leg shaft 12b is pressed in. After press-fitting the leg shaft 12b, the roller 16 is in the position shown in FIG. 1 (A), and an appropriate gap is created between the rollers 16. Next, by inserting the end force of the roller 15 into the track groove 13 of the outer joint member 11, the triboard type constant velocity universal joint 10 is completed.

Next, a second modification of the present invention will be described with reference to FIG. In this second modification, the inner surface 15b of the roller 15 is formed as a convex R surface having the same curvature as that of the leg spherical surface S, and a convex center edge of the convex R surface is projected as shown in FIG. A protruding portion 15c that is raised from the R surface is formed. The protruding portion 15c may be configured by a plane parallel to the axial direction of the roller 15. The protruding portion 15c continues to the end surface of the roller 15 via the R chamfer. Further, the inscribed circle diameter d of the roller 16 end portions 16a that are spaced apart from each other is set to be slightly smaller than the outer diameter of the spherical surface S of the leg shaft 12b. As a result, the insertion of the leg shaft 12b into the inside of the pinched roller 16 is press-fitted, and after insertion, appropriate gaps are formed between the rollers 16 and between the rollers 16 and the leg shaft 12b and between the rollers 16 and 15. Therefore, good operability can be secured, and the roller 16 can be prevented from leaking. In addition, the tripod member 12, the roller 15, and the collapsible roller 16 can be handled in a stable assembled state.

[0043] The cross-sectional shape of the leg shaft 12b is a perfect circle, as shown in Fig. 5 (only one leg shaft 12b is shown). In addition, the outer diameter C in the joint axial direction and the outer diameter D in the circumferential direction of the joint may be different from each other. That is, the outer diameters C and D of the leg shaft 12b can be set so as to satisfy the relational expression C <d <D with respect to the inscribed circle diameter d.

Furthermore, paying attention to the fact that the pressure acting on the spherical surface S of the leg shaft 12b during torque transmission is unevenly distributed in the joint circumferential direction, as shown in FIG. 5, a predetermined angle on both sides from the center line M in the joint circumferential direction, as shown in FIG. The outer diameter of the leg shaft 12b may be the same as the outer diameter D within the range of Θ, and the outer diameter of the leg shaft 12b may be gradually reduced outside the range of angle 2 Θ so that the outer diameter C is smoothly connected. The predetermined angle Θ is, for example, 0 = 45 ° (90 ° for 20) or more and 75 ° (150 ° for 20) or less.

[0045] When the roller 15 is mounted on the leg shaft 12b of the tripod member 12, as in FIG. 7, the pinched rollers 16 are arranged in a state in which the center force in the thickness direction of the roller 15 is displaced as much as possible. Push the leg shaft 12b in the direction of the arrow toward the inner diameter d of the outer edge of the arm. At this time, since one end portion of the roller 16 is in contact with the protruding portion 15c, the inner diameter d does not increase further. Since the diameter D of the leg shaft 12b is larger than the inner diameter d of the end of the roller 16, the leg shaft 12b is pushed in. After press-fitting the leg shaft 12b, the roller 16 is in the position shown in FIG. 1 (A), and an appropriate gap is created between the rollers 16. In this state, since the protruding portion 15c is separated from the roller 16, it does not hinder the roller 16 from rolling. Next, by inserting the end force of the roller 15 into the track groove 13 of the outer joint member 11, the triboard type constant velocity universal joint 10 is completed.

[0046] Next, a second embodiment of the present invention will be described with reference to Figs.

Brief Description of Drawings

FIG. 1A is a cross-sectional view of a triboard constant velocity universal joint according to the present invention, and FIG. 1B is a side view showing a state in which a tripod member is inclined with respect to a roller of the joint.

FIG. 2 is a plan view of the tripod member viewed from the distal end side of the leg shaft.

[Fig. 3] (A) is a plan view of the roller also showing the leg shaft tip side force, and (B) is a bottom view of the roller also showing the joint axis side force.

FIG. 4 is a cross-sectional view showing a state where a leg shaft of a tripod member is press-fitted into a roller.

FIG. 5 is a plan view of a tripod member of a triboard type constant velocity universal joint according to a first modification of the present invention as viewed from the front end side of the leg shaft.

[Fig. 6] Bottom view of the roller shaft side force. 7] A sectional view showing a state in which the leg shaft of the tripod member is press-fitted into the roller.

FIG. 8 shows a roller of a tri-board type constant velocity universal joint according to a first modified example of the present invention. The bottom view seen from the mind side. 9] This is a transverse plane with respect to the axis of the tri-board type constant velocity universal joint according to the second embodiment of the present invention.

[FIG. 10] A longitudinal sectional view with respect to the axis of the triboard type constant velocity universal joint, showing a state in which the tripod member has an operating angle with respect to the outer joint member.

FIG. 11 is a view of the roller and the hourglass roller of FIG.

[Fig. 12] This is for explaining the assembly of rollers and drum rollers and leg shafts. (A) is a top view of the rollers and drum rollers of (b), (b) is the rollers and drum rollers. Sectional view showing tapered rollers

(C) is the figure which looked at the roller and drum-shaped roller of (b) from the bottom.

[13] FIG. 13 is a view of one leg shaft of the tripod member also viewed from the axial end side force.

14] A modification of the present invention, showing a leg shaft, a roller, and a drum roller. 15] Another modification of the present invention is shown, and is a view of one leg shaft of the tripod member as seen from the shaft end side.

Claims

The scope of the claims

[1] An outer joint member provided with three track grooves extending in the axial direction on the inner periphery and provided with roller guide surfaces facing each other on the inner wall of each track groove, and three of which the tip is inserted into the track groove A tripod type constant velocity universal joint comprising a tripod member having a leg shaft and a roller rotatably supported by the leg shaft and inserted into a track groove of the outer joint member. ,

The peripheral surface of the leg shaft is formed into a partial spherical shape with a predetermined radius of curvature, and the inner diameter surface of the roller is a convex R surface having the same curvature as the predetermined radius of curvature, and between the leg shaft peripheral surface and the roller inner diameter surface, A tri-board type constant velocity universal joint characterized in that a plurality of pinched rollers having concave R surfaces having the same curvature as the predetermined radius of curvature are arranged in the circumferential direction.

[2] When the plurality of rollers have their axial center positions displaced in the joint axial direction from the minimum inner diameter position of the rollers and the roller axes are inclined, one end of the rollers on the joint center side Are spaced apart from each other and the other end opposite to the joint center of the roller is in contact with each other. The inscribed circle diameter d of the separated roller ends is determined by the spherical outer diameter of the leg shaft. A tri-board type constant velocity universal joint characterized by being set to be large.

[3] When the plurality of rollers have their axial center positions displaced in the joint axial direction from the minimum inner diameter position of the rollers and the roller axes are inclined, one end of the rollers on the joint center side Are spaced apart from each other and the other end opposite to the joint center of the roller is in contact with each other. The inscribed circle diameter d of the separated roller ends is determined by the spherical outer diameter of the leg shaft. 2. The tri-board type constant velocity universal joint according to claim 1, wherein the tri-board type constant velocity universal joint is set to be slightly smaller.

[4] When the outer diameter in the joint circumferential direction of the leg shaft is D and the outer diameter in the joint axis direction is C, the cross-sectional shape of the leg shaft is a non-circular shape so that C <D. 4. The tri-board type constant velocity universal joint according to claim 3, wherein an inscribed circle diameter d of the roller end portion is set to an intermediate size between the outer diameters C and D.

[5] The outer diameter D in the joint circumferential direction of the leg shaft is formed within a predetermined angular range in the circumferential direction of the leg shaft, and at the same time, the outer diameter D is gradually decreased in a region exceeding the predetermined angular range. The triboard type constant velocity universal joint according to claim 4, wherein the joint is connected to an outer diameter C in the axial direction.

[6] The tripod according to claim 5, wherein the predetermined angle range is not less than 90 ° and not more than 150 °.

Type constant velocity universal joint.

7. The tri-board type constant velocity universal joint according to claim 1, wherein the convex R surface is formed with a protruding portion protruding from the convex R surface at a joint center side edge.

[8] The inscribed circle diameter d of one end of the roller when the pinched roller is displaced until one end on the joint center side comes into contact with the protruding portion is slightly smaller than the spherical outer diameter of the leg shaft. The tri-board type constant velocity universal joint according to claim 7, wherein the tri-board type constant velocity universal joint is set to be smaller.

[9] When the outer diameter in the joint circumferential direction of the leg shaft is D and the outer diameter in the joint axial direction is C, the cross-sectional shape of the leg shaft is a non-circular shape so that C <D. 9. The tri-board type constant velocity universal joint according to claim 8, wherein an inscribed circle diameter d of the roller end portion is set to an intermediate size between the outer diameters C and D.

[10] The outer diameter D of the joint shaft in the circumferential direction of the leg shaft is formed within a predetermined angular range in the circumferential direction of the leg shaft, and the outer diameter D is gradually decreased in a region exceeding the predetermined angular range. The triboard type constant velocity universal joint according to claim 9, wherein the joint is connected to an outer diameter C in the axial direction.

[11] The tri-board type constant velocity universal joint according to claim 10, wherein the predetermined angle range is 90 ° or more and 150 ° or less.

[12] The outer peripheral surface of the leg shaft and the inner peripheral surface of the roller are convex R surfaces having the same radius of curvature, and the convex R surface of the leg shaft is the center of curvature from the center of the leg shaft to the side opposite to the outer peripheral surface side. The tri-board type constant velocity universal joint according to claim 1, wherein the tri-board type constant velocity universal joint has an axial longitudinal cross-sectional shape that is offset.

[13] By displacing all of the hourglass rollers toward the joint center side along the inner peripheral surface of the roller, one end portions on the joint center side of the hourglass rollers are separated from each other and the center of the hourglass roller joint The inscribed diameter formed by the one end portions of the spaced apart hourglass rollers is set to be slightly smaller than the outer diameter of the leg shaft in a state where the other end portions opposite to each other are in contact with each other. The described tri-board type constant velocity universal joint.

14. The tri-board type constant velocity universal joint according to claim 13, wherein a protruding portion that protrudes beyond the convex R surface is provided at least on the joint central side edge portion of the inner peripheral surface of the roller.

[15] When the outer diameter in the joint axis direction of the leg shaft is C and the outer diameter in the joint circumferential direction is D, the cross-sectional shape of the leg shaft is non-circular so that the relationship C <D is satisfied. The inscribed diameter of one end of the hourglass roller is set in a range larger than the outer diameter C of the leg shaft and smaller than the outer diameter D of the leg shaft. The tri-board type constant velocity universal joint according to any one of 12 to 14.

[16] A predetermined angle range in the circumferential direction of the leg shaft at the outer diameter D in the joint circumferential direction of the leg shaft is a perfect circle, and the outer diameter D is gradually decreased in a region exceeding the predetermined angle range to The triboard constant velocity universal joint according to claim 15, wherein the joint is connected to an outer diameter C in the axial direction.

[17] The tri-board type constant velocity universal joint according to claim 16, wherein the predetermined angle range is 90 ° or more.