Constant velocity joint of dual joint structure

Abstract

This constant velocity joint comprises an outer race; a first inner race combined with the outer race and forming a first joint; a second inner race combined with the outer race and forming a second joint; a first shaft fastened to the first inner race so as to rotate with the first inner race and configured to be angularly displaceable with respect to the outer race; a second shaft fastened to the second inner race so as to rotate with the second inner race and configured to be angularly displaceable with respect to the outer race; and a first angular interlocking member and a second angular interlocking member fastened to the first shaft and the second shaft, respectively, so as to interlock an angular displacement of the first shaft with respect to the outer race and an angular displacement of the second shaft with respect to the outer race.

Description

Constant velocity joint with dual joint structure

[0001] The present disclosure relates to a constant velocity joint used to transmit rotational power of a vehicle.

[0002] The driveshaft, also known as a halfshaft, consists of an inboard joint that receives rotation from the transmission or motor, an outboard joint that transmits rotational force to the wheels, and an interconnecting shaft that links the inboard and outboard joints. Generally, the outboard joint is configured to allow rotational displacement of the wheels, while the inboard joint is configured to allow for both the length and rotational displacement of the suspension and the wheels.

[0003] A constant velocity joint configured to allow rotational displacement without allowing axial longitudinal displacement is commonly referred to as a fixed constant velocity joint. A fixed constant velocity joint comprises an outer race, an inner race, a ball cage, and a plurality of balls. The ball cage is equipped with a plurality of windows arranged along the circumferential direction, and the balls are received in the windows. Additionally, the balls are inserted into ball grooves formed in the outer race and ball grooves formed in the inner race, respectively, and act as a medium for transmitting rotational force between the inner race and the outer race. In a fixed constant velocity joint, the outer surface of the ball cage and the inner surface of the outer race are configured to make spherical contact, and the inner surface of the ball cage and the outer surface of the inner race are also configured to make spherical contact. Accordingly, the outer race, ball cage, and inner race can rotate relative to each other along a spherical surface; due to this structure, relative axial displacement of each part is constrained, allowing only relative rotation, or angular cutting. Considering that axial relative displacement is blocked and angular cutting is possible under these operating conditions, such a constant velocity joint is commonly referred to as a fixed constant velocity joint. Furthermore, such a constant velocity joint can be classified as a so-called Rzeppa joint.

[0004] As mentioned earlier, fixed constant velocity joints are primarily mounted on the wheels of a vehicle, and the fixed constant velocity joints mounted on the wheels serve to transmit torque from the inboard joint through the connecting shaft to the wheels. Outboard fixed constant velocity joints must not only possess the durability to accommodate the torque required to drive the vehicle but also the ability to achieve large angles of inclination caused by these two displacements. Fixed constant velocity joints used as outboard joints must be able to accommodate large angles of inclination caused by steering displacement and suspension displacement while ensuring the durability and rigidity required to accommodate the torque of the engine or motor; however, securing rigidity and improving angles of inclination are conflicting aspects.

[0005] The matters described in the technical background section of this invention are written to enhance understanding of the background of the invention and may include matters that are not prior art already known in the field to which this technology belongs.

[0006] The problem that the present invention aims to solve is to provide a constant velocity joint having significantly increased durability and rigidity, and a greatly reduced outer diameter, while securing a large maximum cutting angle.

[0007] The technical problems that the present invention aims to solve are not limited to those mentioned above, and other technical problems not mentioned will be understood by those skilled in the art from the description below.

[0008] A constant velocity joint according to an embodiment of the present invention comprises: an outer race; a first inner race that is combined with the outer race to form a first joint; a second inner race that is combined with the outer race to form a second joint; a first shaft that is connected to the first inner race to rotate together with the first inner race and is configured to be angle-detachable with respect to the outer race; a second shaft that is connected to the second inner race to rotate together with the second inner race and is configured to be angle-detachable with respect to the outer race; and a first angle-detachable linkage member and a second angle-detachable linkage member that are respectively connected to the first shaft and the second shaft to link the angle-detachable of the first shaft with respect to the outer race and the angle-detachable of the second shaft with respect to the outer race.

[0009] The first and second angle interlocking members may be fixed to each other and configured to move together when an angle is cut in the first and second joints.

[0010] The first and second angle-joining members fixed to each other may be configured to move together on a plane perpendicular to the longitudinal axis of the outer race.

[0011] The outer race may include a guide disc protruding radially inward. Each of the first and second angle interlocking members may include a support plate movably supported on the guide disc; and a ball portion protruding from the support plate.

[0012] The support plates of the first and second angle-interlocking members can be spaced apart from each other by a predetermined distance along the longitudinal axis of the outer race to form a receiving space, and the guide disc can be inserted into the receiving space.

[0013] The support plates of the first and second angle-interlocking members may be configured to be in close contact with each side of the guide disk, thereby blocking relative movement with respect to the outer race along the longitudinal axis of the outer race, while enabling orbital motion on a plane orthogonal to the longitudinal axis of the outer race.

[0014] The first and second shafts may each include a first and second guide hole, and the ball portions of the first and second angle interlocking members may be inserted into the first and second guide holes, respectively.

[0015] A constant velocity joint according to another embodiment of the present invention comprises: an outer race including a plurality of first outer ball grooves and a plurality of second outer ball grooves; a first inner race including a plurality of first inner ball grooves paired with the plurality of first outer ball grooves; a second inner race including a plurality of second inner ball grooves paired with the plurality of second outer ball grooves; a plurality of first torque transmission balls each disposed in a plurality of spaces formed by the plurality of first outer ball grooves and the plurality of first inner ball grooves; a first ball cage interposed between the outer race and the first inner race and accommodating the plurality of first torque transmission balls; a plurality of second torque transmission balls each disposed in a plurality of spaces formed by the plurality of second outer ball grooves and the plurality of second inner ball grooves; and a second ball cage interposed between the outer race and the second inner race and accommodating the plurality of second torque transmission balls. It includes: a first shaft connected to the first inner race to rotate together with the first inner race and configured to be angularly articulated with respect to the outer race; a second shaft connected to the second inner race to rotate together with the second inner race and configured to be angularly articulated with respect to the outer race; a first angularly articulated member connected to the first shaft to transmit a force for angular articulated

[0016] The outer race may include a guide disc protruding radially inward. Each of the first and second angle interlocking members may include a support plate movably supported on the guide disc; and a ball portion protruding from the support plate.

[0017] The support plates of the first and second angle-interlocking members can be spaced apart from each other by a predetermined distance along the longitudinal axis of the outer race to form a receiving space, and the guide disc can be inserted into the receiving space.

[0018] According to the present invention, a dual-structure constant velocity joint can be implemented that forms a high angle of cut and has excellent effects in terms of structural aspects and operational stability.

[0019] In addition to this, various effects that can be obtained or predicted by the embodiments of the present invention are disclosed directly or implicitly in the detailed description of the embodiments of the present invention.

[0020] The drawings attached below are intended to aid in understanding the present invention and provide embodiments of the invention together with the detailed description. However, the technical features of the present invention are not limited to specific drawings, and the features disclosed in each drawing may be combined with one another to form new embodiments. The embodiments of this specification may be better understood by referring to the following description in conjunction with the attached drawings, in which similar reference numerals refer to identical or functionally similar elements.

[0021] FIG. 1 is a cross-sectional view of a constant velocity joint with a dual joint structure according to an embodiment of the present invention.

[0022] FIG. 2 is a cross-sectional view showing the constant velocity joint of a dual joint structure according to an embodiment of the present invention in a cut-angled state.

[0023] FIG. 3 is a cross-sectional view of the outer race of a constant velocity joint with a dual joint structure according to an embodiment of the present invention.

[0024] FIG. 4 is an exploded cross-sectional perspective view of an angle link member of a constant velocity joint of a dual joint structure according to an embodiment of the present invention.

[0025] FIG. 5 is a drawing for explaining the movement of an angle-cut link member when the constant velocity joint of a dual joint structure according to an embodiment of the present invention operates in an angle-cut state.

[0026] Embodiments of the present invention are described below with reference to the attached drawings so that those skilled in the art can easily implement the invention. However, the present invention may be embodied in various different forms and is not limited to the described embodiments.

[0027] The terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the invention. As used herein, the singular form is intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising” and / or “comprising” as used herein indicate the presence of the specified features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, components, and / or groups thereof. As used herein, the term “and / or” includes any one or all combinations of one or more items listed in association. The term “combined” indicates a physical relationship between two components where the components are directly connected to each other or indirectly connected through one or more mediating components.

[0028] In describing the components of the present invention, terms such as first, second, A, B, (a), (b), etc., may be used. These terms are intended only to distinguish the components from other components and do not limit the essence, order, or sequence of the components. Where it is stated that a component is "connected," "combined," or "connected" to another component, it should be understood that the component may be directly connected, combined, or connected to the other component, but that another component may also be "connected," "combined," or "connected" between each component.

[0029] FIG. 1 is a cross-sectional view of a constant velocity joint with a dual joint structure according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing the constant velocity joint with a dual joint structure according to an embodiment of the present invention in a cut state. Referring to FIG. 1 and FIG. 2, the constant velocity joint (10) has a dual joint structure that implements two joints (11, 12). The constant velocity joint (10) includes one outer race (13) and two inner races (15, 16), and the outer race (13) is used in common for the two joints (11, 12). The outer race (13) and the first inner race (15) are combined to form the first joint (11), and the outer race (13) and the second inner race (16) are combined to form the second joint (12). The first and second inner laces (15, 16) are spaced apart along the longitudinal axis (X0) of the outer lace (13).

[0030] The first and second joints (11, 12) are each implemented as fixed constant velocity joints, for example, Rzeppa joints. Since the first and second joints (11, 12) are each configured to allow for angle cutting, the sum of the angle cutting amount of the first joint (11) and the angle cutting amount of the second joint (12) becomes the angle cutting amount of the constant velocity joint (10). Accordingly, the constant velocity joint according to the embodiment of the present invention can achieve a maximum angle cutting (for example, a maximum angle cutting of 60 degrees or more) that is significantly increased compared to conventional fixed constant velocity joints.

[0031] The first and second joints (11, 12) are configured so that the angles are interlocked with each other by means of the angle interlocking members (41, 42). The structure and function of the angle interlocking members (41, 42) will be explained again later.

[0032] The outer race (13) is penetrated along the longitudinal axis (X0), and one side along the longitudinal direction (right side in FIG. 1) is used to form the first joint (11), and the other side along the longitudinal direction (left side in FIG. 1) is used to form the second joint (12). As shown in FIG. 1, the one side and the other side of the outer race (13) are arranged along the longitudinal axis (X0), and an intermediate part is located between the one side and the other side.

[0033] A first inner race (15) is inserted into one side of the outer race (13), and a second inner race (16) is inserted into the other side of the outer race (13). Additionally, a first ball cage (17) is interposed between the outer race (13) and the first inner race (15), and a second ball cage (18) is interposed between the outer race (13) and the second inner race (16). The outer and inner surfaces of the first and second ball cages (17, 18) are spherical, and correspondingly, the inner surfaces of the one side and the other side of the outer race (13), and the outer surfaces of the first and second inner races (15, 16) are also spherical. Due to spherical contact, the axial relative displacement between the outer race (13), the first and second ball cages (17, 18), and the first and second inner races (15, 16) is limited, and the relative angular displacement is possible.

[0034] The outer race (13) includes a plurality of first outer ball grooves (21) formed on the inner surface of one side, and correspondingly, the first inner race (15) includes a plurality of first inner ball grooves (23) formed on the outer surface. Additionally, the outer race (13) includes a plurality of second outer ball grooves (25) formed on the inner surface of the other side, and correspondingly, the second inner race (16) includes a plurality of second inner ball grooves (27) formed on the outer surface.

[0035] A first torque-transmitting ball (31) is placed in a space formed by the combination of a first outer ball groove (21) and a first inner ball groove (23). The first torque-transmitting ball (31) is received in a window provided in the first ball cage (17), and the portions protruding outward and inward from the first ball cage (17) are inserted into the first outer ball groove (21) and the first inner ball groove (23), respectively. At this time, a plurality of torque-transmitting balls (31) are arranged along the circumferential direction and may be provided in, for example, eight. Likewise, a second torque-transmitting ball (32) is placed in a space formed by the combination of a second outer ball groove (25) and a second inner ball groove (27). The second torque transmission ball (32) is received in a window provided in the second ball cage (18), and the portions protruding outward and inward from the second ball cage (18) are inserted into the second outer ball groove (25) and the second inner ball groove (27), respectively. At this time, a plurality of torque transmission balls (32) are arranged along the circumferential direction.

[0036] Referring to FIG. 1, the distance (L1) between the center plane (C1) of the first joint (11) and the center plane (C0) of the outer race (13) is formed to be equal to the distance (L2) between the center plane (C2) of the second joint (12) and the center plane (C0) of the outer race (13). Here, the center planes (C1, C2) of the first and second joints (11, 12) are defined as planes passing through the centers of a plurality of torque transmission balls (31, 32) in a non-angled state, and the center plane (C0) of the outer race (13) is defined as a plane passing through the center of the outer race (13) along the longitudinal axis (X0) and perpendicular to the longitudinal axis (X0).

[0037] A first shaft (51) is connected to a first inner race (15) constituting a first joint (11), and a second shaft (52) is connected to a second inner race (16) constituting a second joint (12). As shown in FIG. 1, when the first and second joints (11, 12) are in a non-angled state, the longitudinal axes (X1, X2) of the first and second shafts (51, 52) are coaxial with the longitudinal axis (X0) of the outer race (13). The first shaft (51) is connected to the first inner race (15) to rotate together with the first inner race (15), and can be connected to the first inner race (15), for example, by a spline connection. The second shaft (52) is connected to the second inner race (16) to rotate together with the second inner race (16), and may be connected to the second inner race (16), for example, by a spline connection. For example, the first shaft (51) may be a connecting shaft of a drive shaft, and the second shaft (52) may be a stem shaft for transmitting rotational driving force to the wheel. The stem shaft may be connected to the wheel hub to rotate together with the wheel hub.

[0038] A first retaining ring (61) for fixing the first shaft (51) to the first inner race (15) and a second retaining ring (62) for fixing the second shaft (52) to the second inner race (16) are provided. The first and second retaining rings (61, 62) may have a ring shape with a portion removed and block the first and second shafts (51, 52) from moving relative to the first and second inner races (15, 16) along the longitudinal axis (X1, X2), thereby maintaining the combined state of the first and second shafts (51, 52) and the first and second inner races (15, 16).

[0039] As illustrated in FIG. 1, the inner race (15), ball cage (17), and torque-transmitting ball (31) constituting the first joint (11) and the inner race (16), ball cage (18), and torque-transmitting ball (32) constituting the second joint (12) can be configured to be symmetric with respect to the center plane (C0) of the outer race (13).

[0040] As illustrated in FIG. 1, when the first and second joints (11, 12) are in a non-angled state, the longitudinal axis (X1) of the first shaft (51) and the longitudinal axis (X2) of the second shaft (52) are arranged to be coaxial with the longitudinal axis (X0) of the outer race (13). When the second shaft (52) is angled with respect to the outer race (13), the first shaft (51) is also angled with respect to the outer race (13) in conjunction with the angle of the second shaft (52) by the action of the angle linkage unit (40). For example, as illustrated in FIG. 2, when the second shaft (52) is angled with respect to the outer race (13) at any angle (θ1), the first shaft (51) is angled with respect to the outer race (13) at an angle (θ2) by the action of the angle linkage unit (40). In this case, the angle of cut (θ) by the constant velocity joint (10) corresponds to the sum of the angle of cut (θ2) of the first joint (11) and the angle of cut (θ1) of the second joint (12) (θ=θ1+θ2). In an embodiment of the present invention, the angle of cut (θ1) of the second joint (12) and the angle of cut (θ2) of the first joint (11) can be configured to be the same. Thus, according to an embodiment of the present invention, since the resulting angle of cut of the constant velocity joint is equal to the sum of the angles of cut of the two joints, an increase in the maximum angle of cut can be achieved.

[0041] The first angle-joining member (41) includes a ball part (43) and a support plate (44). Likewise, the second angle-joining member (42) includes a ball part (45) and a support plate (46). The first and second angle-joining members (41, 42) are arranged so that the support plates (44, 46) face each other in close proximity and the ball parts (43, 45) protrude in opposite directions. The ball parts (43, 45) may have a spherical outer surface, and the support plates (44, 46) may have a disc shape. Accordingly, as shown in FIG. 1, the first and second angle-joining members (41, 42) are configured to be approximately symmetric with respect to the center plane (C0) of the outer race (13). The first and second angle-joining members (41, 42) are fixed to each other by a fastening member, for example, a fastening bolt (47), so as to move together. For example, as shown in the drawing, the fastening bolt (47) can be connected to the first angle interlocking member (41) by passing through the second angle interlocking member (42) and connecting to the first angle interlocking member (41), thereby fixing the first and second angle interlocking members (41, 42) to each other.

[0042] Referring to FIGS. 1 and 4, with the first and second angle-joining members (41, 42) joined together by fastening bolts (47), the support plate (44) of the first angle-joining member (41) and the support plate (46) of the first angle-joining member (42) are spaced apart by a distance set along the longitudinal axis (X0) of the outer race (13). Accordingly, a receiving space (48) is formed between the support plate (44) of the first angle-joining member (41) and the support plate (46) of the first angle-joining member (42), having a length set along the longitudinal axis (X0) of the outer race (13) and opening radially outward. A protruding portion is provided on each of the mutually facing surfaces of the support plates (44, 46), and the receiving space (48) can be formed by joining the support plates (44, 46) in a state where these protruding portions are in contact.

[0043] Meanwhile, referring to FIGS. 1 and 3, the outer race (13) is provided with a guide disk (49) that protrudes radially inward from the center portion along the center plane (C0). The guide disk (49) may be formed in the shape of a flange that protrudes radially inward from the inner circumference of the outer race (13). Support plates (44, 46) are supported on both sides of the guide disk (49) with the radially inward portion of the guide disk (49) inserted into the receiving space (48). In the assembly process, this structure can be realized by fixing the first and second angle interlocking members (41, 42) to each other using a fastening bolt (47) while the first and second angle interlocking members (41, 42) are positioned on both sides of the guide disk (49).

[0044] By having the support plates (44, 46) supported on each side of the guide disk (49), the first and second angle-interlocking members (41, 42), which are joined together, are blocked from moving along the longitudinal axis (X0) of the outer race (13). On the other hand, the support plates (44, 46) are configured to be in contact with both sides of the guide disk (49) so that relative movement is possible in a direction perpendicular to the longitudinal axis (X0) of the outer race (13), that is, in a direction parallel to the center plane (C0) of the outer race (13). Accordingly, as shown in FIGS. 1 and 2, the first and second angle-interlocking members (41, 42), which are joined together so that the first and second joints (11, 12) can be angle-interlocked, are guided by the guide disk (49) and can move relative to the outer race (13) in a direction parallel to the center plane (C0).

[0045] The ball portion (43) of the first angle-joining member (41) protrudes toward the first shaft (51) in a direction parallel to the longitudinal axis (X0) of the outer race (13) and is received in the first guide hole (53) formed in the first shaft (51), and the ball portion (45) of the second angle-joining member (42) protrudes toward the second shaft (52) in a direction parallel to the longitudinal axis (X0) of the outer race (13) and is received in the second guide hole (54) formed in the second shaft (52). The first and second guide holes (53, 54) may have a cylindrical shape, and accordingly, the ball portion (43, 45) having a spherical shape may perform relative movements such as sliding within the first and second guide holes (53, 54). Due to this structure, as shown in FIGS. 1 and 2, the alignment of the first and second shafts (51, 52) and the ball portion (43, 45) can be changed when a cutting angle occurs.

[0046] When the second shaft (52) is cut off relative to the outer race (13) by steering displacement or suspension displacement as shown in FIG. 2, the first and second angle-interlocking members (41, 42), which are coupled to each other by the movement of the second shaft (52), are guided by the guide disk (49) and move in a direction parallel to the center plane (C0) of the outer race (13), thereby causing the ball portion (45) of the first angle-interlocking member (42) to cut off the first shaft (51) relative to the outer race (13). When rotational power is transmitted while the first and second angle-interlocking members (41, 42), which are coupled to each other by the cutting, are positioned as shown in FIG. 2, the first and second angle-interlocking members (41, 42), which are coupled to each other, revolve on the guide disk (49) in the direction indicated by the arrow in FIG. 5. In this way, the angles of the first joint (11) and the second joint (12) are interconnected through the angle linkage members (41, 42), and the transmission of rotational power can be achieved.

[0047] Although embodiments of the present invention have been described above, the scope of the present invention is not limited thereto and includes all changes and modifications within the scope recognized as equivalents that can be easily changed by a person skilled in the art from the embodiments of the present invention.

Claims

1. Outer lace; A first inner lace that is combined with the outer lace above to form a first joint; A second inner lace that is combined with the outer lace above to form a second joint; A first shaft connected to the first inner race to rotate together with the first inner race and configured to be angle-removable with respect to the outer race; A second shaft connected to the second inner race to rotate together with the second inner race and configured to be angle-removable with respect to the outer race; and A constant velocity joint comprising a first angle linkage member and a second angle linkage member, respectively connected to the first shaft and the second shaft, to link the angle of cut of the first shaft with respect to the outer race and the angle of cut of the second shaft with respect to the outer race.

2. In Paragraph 1, The first and second angle-interlocking members are fixed to each other and configured to move together when an angle occurs in the first and second joints, forming a constant velocity joint.

3. In Paragraph 2, The first and second angle-interlocking members fixed to each other are configured to move together on a plane perpendicular to the longitudinal axis of the outer race, forming a constant velocity joint.

4. In Paragraph 2, The above outer race includes a guide disc protruding radially inward, and Each of the above first and second angle interlocking members A support plate movably supported on the above guide disc; and A constant velocity joint including a ball portion protruding from the above support plate.

5. In Paragraph 4, The support plates of the first and second angle-interlocking members are spaced apart from each other by a preset distance along the longitudinal axis of the outer race to form a receiving space, and The above guide disc is a constant velocity joint inserted into the above receiving space.

6. In Paragraph 5, A constant velocity joint configured such that the support plates of the first and second angle-joining members are each in close contact with both sides of the guide disk, thereby blocking relative movement with respect to the outer race along the longitudinal axis of the outer race, while enabling orbital motion on a plane perpendicular to the longitudinal axis of the outer race.

7. In Paragraph 4, The first and second shafts each include a first and second guide hole, respectively, and The ball portions of the first and second angle-interlocking members are constant velocity joints that are respectively inserted into the first and second guide holes.

8. An outer lace comprising a plurality of first outer ball grooves and a plurality of second outer ball grooves; A first inner race comprising a plurality of first inner ball grooves paired with the plurality of first outer ball grooves; A second inner race comprising a plurality of second inner ball grooves paired with the plurality of second outer ball grooves; A plurality of first torque transmission balls each disposed in a plurality of spaces formed by the plurality of first outer ball grooves and the plurality of first inner ball grooves; A first ball cage that accommodates the plurality of first torque transmission balls and is interposed between the outer race and the first inner race; A plurality of second torque transmission balls each disposed in a plurality of spaces formed by the plurality of second outer ball grooves and the plurality of second inner ball grooves; A second ball cage that accommodates the plurality of second torque transmission balls and is interposed between the outer race and the second inner race; A first shaft connected to the first inner race to rotate together with the first inner race and configured to be angle-removable with respect to the outer race; A second shaft connected to the second inner race to rotate together with the second inner race and configured to be angle-removable with respect to the outer race; A first angle interlocking member connected to the first shaft to transmit a force for angle cutting to the first shaft; and It includes a second angle interlocking member connected to the second shaft to transmit force by angle from the second shaft, and The first and second angle interlocking members are connected to each other so as to move together, and The first and second angle interlocking members connected to each other are configured to block movement along the longitudinal axis of the outer race and to allow relative movement with respect to the outer race along a direction parallel to the center plane of the outer race.

9. In Paragraph 8, The above outer race includes a guide disc protruding radially inward, and Each of the above first and second angle interlocking members A support plate movably supported on the above guide disc; and A constant velocity joint including a ball portion protruding from the above support plate.

10. In Paragraph 9, The support plates of the first and second angle-interlocking members are spaced apart from each other by a preset distance along the longitudinal axis of the outer race to form a receiving space, and The above guide disc is a constant velocity joint inserted into the above receiving space.

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