Ball-type constant velocity joint

Abstract

The present invention relates to a ball-type constant velocity joint. The constant velocity joint comprises: an outer race having one open side and one closed side; an outer ball cage disposed inside the outer race; an inner ball cage disposed inside the outer ball cage; an inner race disposed inside the inner ball cage; outer balls arranged in an outer ball track formed by a combination of a track formed on an inner circumferential surface of the outer race and a track formed on an outer circumferential surface of the inner ball cage, each outer ball being received in a respective first window provided in the outer ball cage; and inner balls arranged in an inner ball track formed by a combination of a track formed on an inner circumferential surface of the outer ball cage and a track formed on an outer circumferential surface of the inner race, the inner balls being accommodated in respective second windows provided in the inner ball cage.

Description

Ball type constant velocity joint

[0001] The present invention relates to a ball type constant velocity joint.

[0002] A constant velocity joint is a device that transmits rotational driving force and is mainly used to transmit the rotational power of an automobile's power source.

[0003] Constant velocity joints require a angular function, and improving the maximum angular angle is a key issue for constant velocity joints. To increase the maximum angular angle, two inner races were placed within an outer race, resulting in two angular angles: one between the outer race and the outer inner race, and one between the outer inner race and the inner inner race. This increased ultimate angular angle resulted in the introduction of a constant velocity joint. This type of constant velocity joint is called an integrated constant velocity joint.

[0004] The existing integrated constant velocity joint has the problem of not being able to control the order between the two angles, and also requires optimization in terms of structure.

[0005] The above-described information disclosed in the background technology of this invention is only intended to improve understanding of the background of the present invention, and therefore may include information that does not constitute prior art.

[0006] The problem to be solved by the present invention is to provide an integrated ball type constant velocity joint that is structurally optimized and capable of implementing ultra-high angles.

[0007] A constant velocity joint according to an embodiment of the present invention includes an outer race having an open side and a closed side, an outer ball cage disposed inside the outer race, an inner ball cage disposed inside the outer ball cage, an inner race disposed inside the inner ball cage, an outer ball disposed in an outer ball track formed by a combination of a track formed on an inner surface of the outer race and a track formed on an outer surface of the inner ball cage while being accommodated in first windows provided in the outer ball cage, and an inner ball disposed in an inner ball track formed by a combination of a track formed on an inner surface of the outer ball cage and a track formed on an outer surface of the inner race while being accommodated in second windows provided in the inner ball cage.

[0008] When the inner race is cut at a predetermined angle with respect to the outer race, the inner ball cage may be cut at a size corresponding to 2 / 3 of the predetermined angle with respect to the outer race, and the outer ball cage may be cut at a size corresponding to 1 / 3 of the predetermined angle with respect to the outer race.

[0009] At least a portion of the outer surface of the outer ball cage surrounding the first window may be removed to form a sunken shape, and at least a portion of the outer surface of the inner ball cage surrounding the second window may be removed to form a sunken shape.

[0010] The bottom line of the track formed on the inner surface of the outer race may include a first arc having a curvature convex in a radially outward direction, and a second arc connected to the first arc and having a curvature in an opposite direction to the first arc, the second arc being positioned close to the open side of the outer race.

[0011] The inner ball track and the outer ball track can be formed to spread out in opposite directions.

[0012] According to an embodiment of the present invention, structural optimization is possible while implementing a large angle of incision.

[0013] FIG. 1 is a perspective view of a ball type constant velocity joint according to an embodiment of the present invention.

[0014] Figure 2 is an exploded perspective view of a ball type constant velocity joint according to an embodiment of the present invention.

[0015] Fig. 3 is a perspective view showing the cutting state of a ball type constant velocity joint according to an embodiment of the present invention.

[0016] FIG. 4 is a drawing showing a state in which a power transmission shaft is connected to a ball type constant velocity joint and cut according to an embodiment of the present invention.

[0017] FIG. 5 is a drawing showing an exploded state of an outer ball cage and an inner ball cage according to another embodiment of the present invention.

[0018] FIG. 6 is a cross-sectional view of an outer race and an inner ball cage of a ball-type constant velocity joint according to another embodiment of the present invention.

[0019] FIG. 7 is a drawing showing an exploded state of an outer ball cage and an inner race of a ball type constant velocity joint according to another embodiment of the present invention.

[0020] Fig. 8 is a drawing showing the shape of the inner ball track formed by the outer ball cage and inner race of Fig. 7.

[0021] FIG. 9 is a drawing showing an exploded state of an outer race and an inner ball cage of a ball type constant velocity joint according to another embodiment of the present invention.

[0022] Fig. 10 is a drawing showing the shape of an outer ball track formed by the outer race and inner ball cage of Fig. 9.

[0023] The embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art. The following embodiments may be modified in various ways, and the scope of the present invention is not limited to the embodiments described below. Rather, these embodiments are provided to more faithfully and completely explain the present disclosure and fully convey the spirit of the present invention to those skilled in the art.

[0024] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings so that a person having ordinary skill in the art to which the present invention pertains can easily carry out the present invention.

[0025] Fig. 1 is a perspective view of a ball type constant velocity joint according to an embodiment of the present invention, and Fig. 2 is an exploded perspective view of a ball type constant velocity joint according to an embodiment of the present invention. Fig. 3 is a perspective view showing a cut state of a ball type constant velocity joint according to an embodiment of the present invention. Referring to Figs. 1 to 3, a ball type constant velocity joint (10) according to an embodiment of the present invention includes an outer race (11), an inner race (12), an outer ball cage (13), an inner ball cage (14), a plurality of outer balls (15), and a plurality of inner balls (16).

[0026] The outer race (11) may have one side open and the other side closed, and may have a roughly cup shape as illustrated in the drawing. The inner race (12) is arranged within the outer race (11). As is known, it is configured to transmit rotational power between the outer race (11) and the inner race (12).

[0027] The outer ball cage (13) and the inner ball cage (14) are arranged in the space between the outer race (11) and the inner race (12). The outer ball cage (13) is arranged in the outer race (11), the inner ball cage (14) is arranged in the outer ball cage (13), and the inner race (12) is arranged in the inner ball cage (14). At this time, for the purpose of the angle, the outer ball cage (13) is configured to be bent with respect to the outer race (11), the inner ball cage (14) is configured to be bent with respect to the outer ball cage (13), and the inner race (12) is configured to be bent with respect to the inner ball cage (14). As a result, the angle at which the inner race (12) is bent with respect to the outer race (11) corresponds to the overall angle. The angle state is illustrated in FIGS. 3 and 4. A power transmission shaft (17) can be coupled to the inner race (12), and the power transmission shaft (17) rotates together with the inner race (12) around the longitudinal axis.

[0028] A plurality of outer balls (15) can be arranged at equal intervals along the circumferential direction. Each outer ball (15) is arranged in an outer ball track (33) formed by a track (31) formed on the inner surface of the outer race (11) and a track (32) formed on the outer surface of the inner ball cage (14). The number of outer ball tracks (33) is equal to the number of outer balls (15), and each outer ball (15) is arranged in an outer ball track (33). The number of outer balls (15) and outer ball tracks (33) can be six each. At this time, the outer ball cage (13) may include a window (22) that accommodates each outer ball (15), and the outer ball (15) is accommodated in the window (22), and the outer portion is accommodated in the track (31) of the outer race (11) and the inner portion is accommodated in the track (32) of the inner ball cage (14). Accordingly, the outer race (11) and the inner ball cage (14) rotate together at a constant speed via the outer ball (15), and the outer ball cage (13) also rotates together with the outer ball (15).

[0029] A plurality of inner balls (16) can be arranged at equal intervals along the circumferential direction. Each inner ball (16) is arranged in an inner ball track (37) formed by a track (35) formed on the inner surface of the outer ball cage (13) and a track (36) formed on the outer surface of the inner race (12). The number of inner ball tracks (37) is the same as the number of inner balls (16), and each inner ball (16) is arranged in each inner ball track (37). There can be six inner balls (16) and six inner ball tracks (37). At this time, the inner ball cage (14) may include a window (24) that accommodates each inner ball (16), and the inner ball (16) is accommodated in the window (24), with the outer portion accommodated in the track (35) of the outer ball cage (13) and the inner portion accommodated in the track (36) of the inner race (12). Accordingly, the outer ball cage (13) and the inner race (12) rotate together at a constant speed via the inner ball (16), and the inner ball cage (14) also rotates together with the inner ball (16).

[0030] Six outer balls (15) are arranged at equal angles along the circumference at 60-degree intervals, and six inner balls (16) are also arranged at equal angles along the circumference at 60-degree intervals. At this time, outer balls (15) and inner balls (16) adjacent to each other in the circumferential direction may be arranged to have a phase difference of 30 degrees. In order to facilitate operation of the joint and reduce the packaging size, the inner ball (16) may have a larger diameter than the outer ball (15).

[0031] Accordingly, the outer race (11), inner race (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 race (11) to the inner race (12) or vice versa.

[0032] In an embodiment of the present invention, when the constant velocity joint (10) is cut by N degrees, the inner race (12) and the power transmission shaft (17) are configured to be cut by N degrees based on the longitudinal axis (X) of the outer race (11), the inner ball cage (14) is cut by 2N / 3 degrees, and the outer ball cage (13) is cut by N / 3 degrees. For example, referring to FIG. 4, when the constant velocity joint is cut by 60 degrees, the inner race (12) is cut by 60 degrees based on the longitudinal axis (X) of the outer race (11), the inner ball cage (14) is cut by 40 degrees based on the longitudinal axis (X) of the outer race (11), and the outer ball cage (14) is cut by 20 degrees based on the longitudinal axis (X) of the outer race (11). At this time, the angle exceeding the maximum angle range can be controlled by interference between the end of the outer race (11) and the power transmission shaft (17).

[0033] FIG. 5 is a drawing showing an exploded state of an outer ball cage and an inner ball cage according to another embodiment of the present invention. Referring to FIG. 5, the inner ball cage (41) has tracks (42) on its outer circumferential surface, and windows (43) on protruding portions between the tracks (42). At this time, among the protruding portions between the tracks (42), at least a portion surrounding the window (43) is removed, i.e., has a sunken shape. Accordingly, the inner ball (16) accommodated in the window (43) can more sufficiently contact the surface of the track (52) formed on the inner circumferential surface of the outer ball cage (51). In addition, the outer ball cage (51) has windows (53) in which outer balls (15) are accommodated, and at least a portion surrounding the window (53) is removed, i.e., has a sunken shape. By this, the outer ball (15) accommodated in the window (53) can more sufficiently contact the surface of the track (31) formed on the inner surface of the outer race (11). Through this structure, the inner ball cage (41) and the outer ball cage (51) can be formed thick enough to secure strength, while minimizing interference between the outer and inner balls (15, 16) and the outer and inner ball cages (13, 14).

[0034] Fig. 6 is a cross-sectional view of an outer race and an inner ball cage of a ball-type constant velocity joint according to another embodiment of the present invention. In order to secure a high cutting angle, the bottom line of the track (31) of the outer race (11) is configured to form a reverse arch on the open side. That is, referring to Fig. 6, the bottom line of the track (31) of the outer race (11) includes a first portion (C1) having a predetermined radius of curvature (R1) that is convex radially outward, and a first portion (C2) that 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) having a predetermined radius of curvature (R3) that is convex radially outward, and a second portion (C4) that is connected to the first portion (C3) and has a radius of curvature (R4) in the opposite direction. Since the part located on the open side of the track (31) of the outer race (11) is formed as a convex arc radially inward, the range in which the power transmission shaft (17) can be bent when cutting increases, so that a larger maximum cutting angle can be formed.

[0035] FIG. 7 is a drawing showing an exploded state of an outer ball cage and an inner race of a ball type constant velocity joint according to another embodiment of the present invention, and FIG. 8 is a drawing showing a shape of an inner ball track formed by the outer ball cage and the inner race of FIG. 7. FIG. 9 is a drawing showing an exploded state of an outer race and an inner ball cage of a ball type constant velocity joint according to another embodiment of the present invention, and FIG. 10 is a drawing showing a shape of an outer ball track formed by the outer race and the inner ball cage of FIG. 9. Referring to FIGS. 7 to 9, the inner ball track (37) formed by the combination of the track (36) formed on the outer surface of the inner race (12) and the track (35) formed on the inner surface of the outer ball cage (13) opens toward the closed side of the outer race (11) in a non-cut state, and the outer ball track (33) formed by the combination of the track (31) formed on the inner surface of the outer race (11) and the track (32) formed on the outer surface of the inner ball cage (14) opens toward the open side of the outer race (11) in a non-cut state. That is, referring to FIGS. 8 and 10, the inner ball track (37) and the outer ball track (33) are formed to open in opposite directions. Accordingly, the inner ball (16) is placed on the inner ball track (37) that is flared to the right in FIG. 8, and the outer ball (15) is placed on the outer ball track (33) that is flared to the left in FIG. 10. Due to this track shape, the forces that the balls (15, 16) exert on the cages (13, 14) act in opposite directions and cancel each other out. As a result, the outer ball cage (13) and the inner ball cage (14) can be placed in a neutral position at the center of the joint, thereby improving durability.

[0036] The above description is only one embodiment for carrying out the present invention, and the present invention is not limited to the above-described embodiment, and as claimed in the following claims, it will be said that the technical spirit of the present invention exists to the extent that anyone with ordinary skill in the art to which the present invention pertains can make various modifications without departing from the gist of the present invention.

Claims

1. Outer race having an open side and a closed side; An outer ball cage arranged on the inner side of the above outer race, An inner ball cage arranged inside the outer ball cage, An inner race arranged on the inside of the inner ball cage; An outer ball arranged in an outer ball track formed by a combination of a track formed on the inner surface of the outer race and a track formed on the outer surface of the inner ball cage, each of which is accommodated in a first window provided in the outer ball cage, and A constant velocity joint including an inner ball arranged in an inner ball track formed by a combination of a track formed on an inner surface of the outer ball cage and a track formed on an outer surface of the inner race, the inner ball being accommodated in a second window provided in the inner ball cage.

2. In paragraph 1, A constant velocity joint in which the inner race is cut at a predetermined angle with respect to the outer race, the inner ball cage is cut at a size corresponding to 2 / 3 of the predetermined angle with respect to the outer race, and the outer ball cage is cut at a size corresponding to 1 / 3 of the predetermined angle with respect to the outer race.

3. In paragraph 1, At least a portion of the outer surface of the outer ball cage surrounding the first window is removed to form a sunken shape, A constant velocity joint configured such that at least a portion of the outer surface of the inner ball cage surrounding the second window is removed to form a sunken shape.

4. In paragraph 1, A constant velocity joint, wherein the bottom line of the track formed on the inner surface of the outer race includes a first arc having a radially outwardly convex curvature, and a second arc connected to the first arc and positioned close to an open side of the outer race and having a curvature in the opposite direction to the first arc.

5. In paragraph 1, A constant velocity joint in which the inner ball track and the outer ball track are formed to spread in opposite directions.

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