Spherical constant velocity universal joint

Abstract

The present invention relates to a spherical type constant velocity universal joint. The constant velocity universal joint includes an outer race having one open side and one closed side, an outer cage provided in the outer race, an inner cage provided in the outer cage, an inner race provided in the inner cage, outer balls respectively accommodated in first windows provided in the outer cage and provided in outer ball tracks formed by a combination of a track formed on an inner peripheral surface of the outer race and a track formed on an outer peripheral surface of the outer cage, and an inner ball accommodated in second windows provided in the inner cage and provided in inner ball tracks formed by a combination of a track formed on an inner peripheral surface of the outer cage and a track formed on an outer peripheral surface of the inner race.

Description

Technical Field

[0001] This invention relates to a spherical constant velocity universal joint. Background Technology

[0002] A constant velocity joint is a device used to transmit rotational driving force, primarily for transmitting rotational power from a vehicle's power source.

[0003] Constant velocity joints (CV joints) need to have articulation capabilities, and increasing the maximum articulation angle is a major challenge. As a way to increase the maximum articulation angle, a CV joint with an increased final articulation angle has been introduced. This CV joint achieves two articulations by arranging two inner rings within the outer ring: the articulation between the outer and outer inner rings, and the articulation between the outer inner ring and the inner inner ring. This type of CV joint is called an integrated CV joint.

[0004] Traditional integrated constant velocity joints have the problem of not being able to control the sequence of movement between the two joints, and structural optimization is still required.

[0005] The information disclosed in this background section is only intended to enhance the understanding of the background of this invention and should not be construed as an admission that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] Technical issues

[0007] The purpose of this invention is to provide an integrated spherical constant velocity universal joint that can achieve ultra-high joint motion angles and has an optimized structure.

[0008] Technical solution

[0009] According to an embodiment of the present invention, a constant velocity universal joint includes: an outer ring having an open side and a closed side; an outer ball cage disposed within the outer ring; an inner ball cage disposed within the outer ball cage; an inner ring disposed within the inner ball cage; an outer ball respectively housed in a first window disposed in the outer ball cage and disposed in an outer ball track formed by a combination of a track formed on the inner circumferential surface of the outer ring and a track formed on the outer circumferential surface of the inner ball cage; and an inner ball housed in a second window disposed in the inner ball cage and disposed in an inner ball track formed by a combination of a track formed on the inner circumferential surface of the outer ball cage and a track formed on the outer circumferential surface of the inner ring.

[0010] When the inner ring moves at a predetermined angle relative to the outer ring joint, the inner ball cage moves at an angle corresponding to two-thirds of the predetermined angle relative to the outer ring joint, and the outer ball cage moves at an angle corresponding to one-third of the predetermined angle relative to the outer ring joint.

[0011] At least a portion of the outer peripheral surface of the outer ball cage surrounding the first window is removed to form a recessed shape, and at least a portion of the outer peripheral surface of the inner ball cage surrounding the second window is removed to form a recessed shape.

[0012] The bottom line of the track formed on the inner circumferential surface of the outer ring includes a first arc and a second arc. The first arc has a radially outward convex curvature, and the second arc connects to the first arc to be positioned closer to the opening side of the outer ring and has a curvature opposite to that of the first arc.

[0013] The inner spherical track and the outer spherical track are formed to expand in opposite directions.

[0014] Beneficial effects

[0015] According to embodiments of the present invention, structural optimization can be achieved while realizing large joint movement angles. Attached Figure Description

[0016] Figure 1 This is a perspective view of a spherical constant velocity universal joint according to an embodiment of the present invention.

[0017] Figure 2 This is an exploded perspective view of a spherical constant velocity universal joint according to an embodiment of the present invention.

[0018] Figure 3 A perspective view illustrating the joint motion state of a spherical constant velocity universal joint according to an embodiment of the present invention.

[0019] Figure 4 This is a view illustrating the joint motion state of a ball-type constant velocity universal joint coupled to the power transmission shaft according to an embodiment of the present invention.

[0020] Figure 5 This is a view showing the outer and inner ball cages in an exploded state according to another embodiment of the present invention.

[0021] Figure 6 This is a cross-sectional view of the outer ring and inner ball cage of a spherical constant velocity universal joint according to another embodiment of the present invention.

[0022] Figure 7 This is a view showing the outer ball cage and inner ring of a spherical constant velocity universal joint in an exploded state according to another embodiment of the present invention.

[0023] Figure 8 To show by Figure 7 A view showing the shape of the inner ball track formed by the outer ball cage and the inner ring.

[0024] Figure 9 This is a view showing the outer ring and inner ball cage of a spherical constant velocity universal joint in an exploded state according to another embodiment of the present invention.

[0025] Figure 10 To show by Figure 9 A view of the shape of the outer sphere track formed by the outer ring and the inner sphere cage.

[0026] Detailed description of the invention

[0027] The embodiments of the present invention are provided to illustrate the invention more fully to those skilled in the art, and the following embodiments can be modified in various ways; the scope of the invention is not limited to the following embodiments. Rather, these embodiments are provided to make this disclosure more thorough and complete, and to fully convey the concept of the invention to those skilled in the art.

[0028] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can readily implement the present invention.

[0029] Figure 1 This is a perspective view of a spherical constant velocity universal joint according to an embodiment of the present invention. Figure 2 This is an exploded perspective view of a spherical constant velocity universal joint according to an embodiment of the present invention. Figure 3 A perspective view illustrating the joint motion state of a spherical constant velocity universal joint according to an embodiment of the present invention. (Refer to...) Figures 1 to 3 According to an embodiment of the present invention, the spherical constant velocity universal joint 10 includes an outer ring 11, an inner ring 12, an outer ball cage 13, an inner ball cage 14, a plurality of outer balls 15, and a plurality of inner balls 16.

[0030] The outer ring 11 may have a shape that is open on one side and closed on the other, and may have a generally cup-shaped shape as shown in the attached figures. The inner ring 12 is disposed within the outer ring 11. As is known, the outer ring 11 and the inner ring 12 are configured such that rotational power is transmitted between them.

[0031] An outer ball cage 13 and an inner ball cage 14 are disposed in the space between an outer ring 11 and an inner ring 12. The outer ball cage 13 is disposed within the outer ring 11, the inner ball cage 14 is disposed within the outer ball cage 13, and the inner ring 12 is disposed within the inner ball cage 14. To achieve joint movement, the outer ball cage 13 is configured to joint movement relative to the outer ring 11, the inner ball cage 14 is configured to joint movement relative to the outer ball cage 13, and the inner ring 12 is configured to joint movement relative to the inner ball cage 14. Consequently, the angle of joint movement of the inner ring 12 relative to the outer ring 11 corresponds to the total joint movement angle. Figure 3 and Figure 4The joint motion state is shown. The power transmission shaft 17 can be coupled to the inner ring 12, and the power transmission shaft 17 rotates together with the inner ring 12 about the longitudinal axis.

[0032] Multiple outer spheres 15 can be arranged at equal intervals in the circumferential direction. Each outer sphere 15 is disposed in a corresponding outer sphere track 33, which is formed by a track 31 formed on the inner circumferential surface of the outer ring 11 and a track 32 formed on the outer circumferential surface of the inner sphere cage 14. The number of outer sphere tracks 33 is the same as the number of outer spheres 15, and each outer sphere 15 is disposed in a corresponding outer sphere track 33. There can be six outer spheres 15 and six outer sphere tracks 33. In this case, the outer sphere cage 13 may include windows 22 for accommodating the outer spheres 15 respectively. With each outer sphere 15 accommodated in a corresponding window 22, the outer portion of the outer sphere 15 is accommodated in the track 31 of the outer ring 11, and the inner portion of the outer sphere 15 is accommodated in the track 32 of the inner sphere cage 14. Thus, the outer ring 11 and the inner sphere cage 14 rotate together at a constant speed via the outer spheres 15, and the outer sphere cage 13 also rotates together via the outer spheres 15.

[0033] Multiple inner spheres 16 can be arranged at equal intervals in the circumferential direction. Each inner sphere 16 is disposed in a corresponding inner sphere track 37, which is formed by a track 35 formed on the inner circumferential surface of the outer sphere cage 13 and a track 36 formed on the outer circumferential surface of the inner ring 12. The number of inner sphere tracks 37 is the same as the number of inner spheres 16, and each inner sphere 16 is disposed in a corresponding inner sphere track 37. There can be six inner spheres 16 and six inner sphere tracks 37. In this case, the inner sphere cage 14 may include windows 24 for accommodating the inner spheres 16 respectively. With each inner sphere 16 accommodated in a corresponding window 24, the outer portion of the inner sphere 16 is accommodated in the track 35 of the outer sphere cage 13, and the inner portion of the inner sphere 16 is accommodated in the track 36 of the inner ring 12. Thus, the outer sphere cage 13 and the inner ring 12 rotate together at the same speed via the inner spheres 16, and the inner sphere cage 14 also rotates together via the inner spheres 16.

[0034] Six outer spheres 15 are arranged at equal angular intervals of 60 degrees in the circumferential direction, and six inner spheres 16 are also arranged at equal angular intervals of 60 degrees in the circumferential direction. In this arrangement, adjacent outer spheres 15 and inner spheres 16 in the circumferential direction can have a 30-degree phase difference. To facilitate universal joint operation and reduce package size, the diameter of the inner spheres 16 can be larger than the diameter of the outer spheres 15.

[0035] Therefore, the outer ring 11, inner ring 12, outer ball cage 13 and inner ball cage 14 can rotate together, and as a result, rotational power can be transmitted from the outer ring 11 to the inner ring 12, or vice versa.

[0036] In one embodiment of the invention, when the constant velocity universal joint 10 moves N degrees, the inner ring 12 and the power transmission shaft 17 move N degrees relative to the longitudinal axis X of the outer ring 11, the inner ball cage 14 moves 2N / 3 degrees, and the outer ball cage 13 moves N / 3 degrees. For example, refer to... Figure 4 When the constant velocity universal joint moves 60 degrees, the inner ring 12 moves 60 degrees relative to the longitudinal axis X of the outer ring 11, the inner ball cage 14 moves 40 degrees relative to the longitudinal axis X of the outer ring 11, and the outer ball cage 14 moves 20 degrees relative to the longitudinal axis X of the outer ring 11. At this time, joint movements exceeding the maximum range of motion can be controlled by interference between the end of the outer ring 11 and the power transmission shaft 17.

[0037] Figure 5 A view showing the outer and inner ball cages in an exploded state according to another embodiment of the present invention. (Refer to...) Figure 5 The inner ball cage 41 includes tracks 42 on its outer circumferential surface and windows 43 in the protrusions between the tracks 42. Here, at least a portion surrounding each window 43 in the protrusions between the tracks 42 is removed to form a recessed shape. This allows the inner ball 16, housed in the window 43, to more fully contact the surface of the tracks 52 formed on the inner circumferential surface of the outer ball cage 51. Furthermore, the outer ball cage 51 includes windows 53 in which an outer ball 15 is housed, and at least a portion surrounding each window 53 is removed to form a recessed shape. This allows the outer ball 15, housed in the window 53, to more fully contact the surface of the tracks 31 formed on the inner circumferential surface of the outer ring 11. With this configuration, while the inner and outer ball cages 41 and 51 are formed to be sufficiently thick to ensure strength, interference between the outer balls 15 and 16 and the outer and inner ball cages 13 and 14 can be minimized.

[0038] Figure 6 This is a cross-sectional view of the outer ring and inner ball cage of a spherical constant velocity universal joint according to another embodiment of the present invention. To ensure a large joint angle, the bottom line of the track 31 of the outer ring 11 is configured to form a reverse arch on the opening side. That is, referring to... Figure 6 The bottom line of the track 31 of the outer ring 11 includes a first portion C1 and a second portion C2. The first portion C1 has a predetermined radially outward convex radius of curvature R1, and the second portion C2 is connected to the first portion C1 and has a radius of curvature R2 in the opposite direction. Correspondingly, the inner ball cage 14 includes a first portion C3 and a second portion C4. The first portion C3 has a predetermined radially outward convex radius of curvature R3, and the second portion C4 is connected to the first portion C3 and has a radius of curvature R4 in the opposite direction. Because the portion of the track 31 of the outer ring 11 located on the opening side is formed as a radially inward convex arc, the range of joint movement of the power transmission shaft 17 during joint movement is increased, thereby enabling a larger maximum joint movement angle.

[0039] Figure 7 To illustrate the exploded view of the outer ball cage and inner ring of a spherical constant velocity universal joint according to another embodiment of the present invention, Figure 8 To show by Figure 7 A view showing the shape of the inner ball track formed by the outer ball cage and the inner ring. Figure 9 To illustrate the exploded view of the outer ring and inner ball cage of a spherical constant velocity universal joint according to another embodiment of the present invention, Figure 10 To show by Figure 9 A view showing the shape of the outer sphere track formed by the outer ring and inner sphere cage. (Refer to...) Figures 7 to 10 The inner ball track 37, formed by the combination of the track 36 formed on the outer circumferential surface of the inner ring 12 and the track 35 formed on the inner circumferential surface of the outer ball cage 13, expands toward the closed side of the outer ring 11 in a non-joint motion state, and the outer ball track 33, formed by the combination of the track 31 formed on the inner circumferential surface of the outer ring 11 and the track 32 formed on the outer circumferential surface of the inner ball cage 14, expands toward the open side of the outer ring 11 in a non-joint motion state. That is, referring to... Figure 8 and Figure 10 The inner spherical orbit 37 and the outer spherical orbit 33 are formed to expand in opposite directions. Thus, the inner sphere 16 is located in... Figure 8 The inner sphere orbits 37, which expand to the right from the center, while the outer sphere 15 is located in... Figure 10 The outer ball track 33 expands to the left. Due to this track shape, the forces of balls 15 and 16 pushing cages 13 and 14 act in opposite directions and cancel each other out. Thus, the outer ball cage 13 and the inner ball cage 14 can be located at the center of the universal joint, thereby improving durability.

[0040] The above description is merely one embodiment for implementing the present invention, and the present invention is not limited to the above embodiment. As described in the appended claims, the technical concept of the present invention extends to the scope of various modifications that can be made by any person skilled in the art without departing from the spirit of the present invention.

Claims

1. A constant velocity universal joint, comprising: The outer ring has an open side and a closed side; The outer ball cage is disposed within the outer ring; The inner ball cage is located inside the outer ball cage; The inner ring is located inside the inner ball cage; The outer spheres are respectively housed in the first windows provided in the outer sphere cage, and are provided in the outer sphere tracks formed by a combination of tracks formed on the inner circumferential surface of the outer ring and tracks formed on the outer circumferential surface of the inner sphere cage; as well as The inner sphere is housed in a second window disposed within the inner sphere cage and is disposed in an inner sphere track formed by a combination of a track formed on the inner circumferential surface of the outer sphere cage and a track formed on the outer circumferential surface of the inner ring.

2. The constant velocity universal joint according to claim 1, wherein, When the inner ring moves at a predetermined angle relative to the outer ring joint, the inner ball cage moves at an angle corresponding to two-thirds of the predetermined angle relative to the outer ring joint, and the outer ball cage moves at an angle corresponding to one-third of the predetermined angle relative to the outer ring joint.

3. The constant velocity universal joint according to claim 1, wherein, At least a portion of the outer periphery of the outer ball cage surrounding the first window is removed to form a recessed shape, and In this configuration, at least a portion of the outer peripheral surface of the inner ball cage surrounding the second window is removed to form a recessed shape.

4. The constant velocity universal joint according to claim 1, wherein, The bottom line of the track formed on the inner circumferential surface of the outer ring includes a first arc and a second arc. The first arc has a radially outward convex curvature, and the second arc connects to the first arc to be positioned closer to the opening side of the outer ring and has a curvature opposite to that of the first arc.

5. The constant velocity universal joint according to claim 1, wherein, The inner spherical track and the outer spherical track are formed to expand in opposite directions.

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