Duplex transmission shaft

Abstract

The invention relates to the technical field of transmission, in particular to a duplex transmission shaft. Comprising a middle fork assembly, a first fork assembly, a second fork assembly and two transmission assemblies. The first fork assembly and the second fork assembly are located on the two opposite sides of the middle fork assembly. Each transmission assembly comprises a four-shaft unit and four rolling units. The four-axis unit comprises a first axis module, a second axis module and a connecting module; the minimum included angle between the projection of the axis of the first axis module on a set plane and the projection of the axis of the second axis module on the set plane is larger than 0 degree and smaller than 90 degrees. The two ends of one first shaft module are rotationally connected with one side of the middle fork assembly. The two ends of the other first shaft module are rotationally connected with the other side of the middle fork assembly. Two ends of a second shaft module are connected with the first fork assembly; the two ends of the other second shaft module are connected with the second fork assembly. The inclination directions of the axes of the two second shaft modules are opposite. Therefore, the problem that the fork arms at the two ends of the duplex transmission shaft interfere with each other when the included angle between the shafts is too large is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of transmission, in particular to a duplex transmission shaft. BACKGROUND

[0002] The duplex transmission shaft is a power transmission assembly composed of two transmission shafts through two universal joints and connecting pieces, mainly used in mechanical systems requiring long-distance or variable-angle power transmission, mainly used in automobile transmission systems, especially when the transmission shaft needs to span a long distance or the included angle between the two shafts is large, the duplex universal joint can ensure the constant-speed transmission of power; it can also be used in other mechanical fields where variable-angle constant-speed transmission is required.

[0003] Although the duplex transmission shafts on the market can adapt to a certain included angle between the shafts, the maximum allowed included angle is usually small. When the included angle between the shafts exceeds the design range, the swing trajectories of the two universal joint yokes may interfere. When the angle is too large, the rotation plane of the universal joint yoke intersects with the movement space of the adjacent yoke, and the yokes at both ends may physically contact when swinging to the limit position, causing jamming or breakage. This physical contact caused by excessive shaft included angle not only causes the jamming of the transmission system, affecting the normal operation of the machinery, but also causes the failure of components such as universal joint yoke breakage and cross shaft damage, increasing the maintenance cost and downtime of the equipment, and more likely to cause safety accidents, posing a threat to the personal safety of operators. SUMMARY

[0004] To solve the problem of mutual interference of the yokes at both ends of the duplex transmission shaft when the included angle between the shafts is too large, the present application provides a duplex transmission shaft, comprising:

[0005] a middle yoke assembly;

[0006] a first yoke assembly located on one side of the middle yoke assembly;

[0007] a second yoke assembly located on the other side of the middle yoke assembly;

[0008] two transmission assemblies, each of which comprises a four-axis unit and four rolling units; the four-axis unit comprises a first shaft module, a second shaft module and a connecting module; the side wall of the first shaft module is connected to the side wall of the second shaft module through the connecting module; the two ends of the first shaft module are respectively rotatably connected to one of the rolling units; the two ends of the second shaft module are respectively rotatably connected to one of the rolling units; wherein the minimum included angle between the axis of the first shaft module in the set plane projection and the axis of the second shaft module in the set plane projection is greater than 0° and less than 90°; the set plane is parallel to the axis of the first shaft module and the axis of the second shaft module;

[0009] Two ends of one of the first shaft modules are respectively connected to one side of the middle fork assembly through two rolling units; two ends of another of the first shaft modules are respectively connected to the other side of the middle fork assembly through two rolling units;

[0010] Two ends of one of the second shaft modules are respectively connected to the first fork assembly through two rolling units; two ends of another of the second shaft modules are respectively connected to the second fork assembly through two rolling units;

[0011] The axes of the two second shaft modules are opposite in the direction of inclination.

[0012] In some embodiments, the minimum angle α between the axis of the first shaft module and the axis of the second shaft module in the projection of the set plane is greater than 75° and less than 90°.

[0013] In some embodiments, the axis of the first shaft module and the axis of the second shaft module are spaced in the radial direction of the first shaft module.

[0014] In some embodiments, D=k×d1; 1≤k≤2; the outer diameter d1 of the first shaft module is the same as the outer diameter d2 of the second shaft module; and D is the spacing between the axis of the first shaft module and the axis of the second shaft module.

[0015] In some embodiments, the connecting module comprises a middle connecting part, a first side connecting part, and a second side connecting part.

[0016] The middle connecting part is connected to the outer peripheral wall of the first shaft module and the outer peripheral wall of the second shaft module respectively; the first side connecting part and the second side connecting part are connected to the middle connecting part respectively.

[0017] The first side connecting part is located between the maximum included angle of the first shaft module and the second shaft module, and is connected to the first shaft module and the second shaft module respectively.

[0018] The second side connecting part is located between the minimum included angle of the first shaft module and the second shaft module, and is connected to the first shaft module and the second shaft module respectively.

[0019] In some embodiments, the maximum dimension of the first side connecting part in the radial direction of the middle connecting part is greater than the maximum dimension of the second side connecting part in the radial direction of the middle connecting part.

[0020] In some embodiments, the connecting module comprises a via; the via penetrates the first side connecting part in the spacing direction of the first shaft module and the second shaft module.

[0021] In some embodiments, the first shaft module includes a first shaft seat, a first left shaft, and a first right shaft; the second shaft module includes a second shaft seat, a second left shaft, and a second right shaft;

[0022] The first axle seat and the second axle seat are connected through the connecting module; the first left shaft and the first right shaft are respectively connected to the two ends of the first axle seat; the second left shaft and the second right shaft are respectively connected to the two ends of the second axle seat.

[0023] In some embodiments, the rolling unit includes a rolling sleeve, a rolling body, and a sealing ring; both ends of the first shaft module and both ends of the second shaft module are sleeved with the rolling sleeve; the sealing ring and the rolling body are arranged in the rolling sleeve, and the rolling body is located between the bottom wall of the rolling sleeve and the sealing ring;

[0024] At both ends of the first shaft module and the second shaft module, the rolling bodies respectively abut against the outer circumferential wall of the corresponding shaft module and the inner circumferential wall of the rolling sleeve, and the sealing ring is sealed between the outer circumferential wall of the corresponding shaft module and the inner circumferential wall of the rolling sleeve.

[0025] In some embodiments, the middle fork assembly includes a middle fork seat, a middle left fork hole, a middle right fork hole, a middle left fork hole, and a middle right fork hole;

[0026] The middle left fork hole and the middle right fork hole are arranged on one side of the middle fork seat; the middle left fork hole and the middle right fork hole are arranged opposite to each other; the two ends of one of the first shaft modules are respectively installed in the middle left fork hole and the middle right fork hole through the rolling unit;

[0027] The second middle left fork hole and the second middle right fork hole are respectively arranged on the other side of the middle fork seat; the second middle left fork hole and the second middle right fork hole are arranged opposite to each other; the two ends of another first shaft module are respectively installed in the second middle left fork hole and the second middle right fork hole through the rolling unit;

[0028] The first fork assembly includes a first fork seat, a first left fork hole, and a first right fork hole; the first left fork hole and the first right fork hole are respectively arranged on the first fork seat; the first left fork hole and the first right fork hole are arranged opposite to each other; two ends of a second shaft module are respectively installed in the first left fork hole and the first right fork hole through the rolling unit;

[0029] The second fork assembly includes a second fork seat, a second left fork hole, and a second right fork hole; the second left fork hole and the second right fork hole are respectively arranged on the second fork seat; the second left fork hole and the second right fork hole are arranged opposite to each other; the two ends of another second axis module are respectively installed in the second left fork hole and the second right fork hole through the rolling unit.

[0030] To solve the problem of interference between the forks at both ends of the double transmission shaft when the angle between the shafts is too large, the present invention has the following advantages:

[0031] The projection of the axes of the first axis module and the second axis module on the set plane forms an angle between 0° and 90°, and the inclination directions of the axes of the two second axis modules are opposite. When the swing angle is large, the movement planes of the first fork assembly, the second fork assembly and the middle fork assembly are dislocated, so that the movement planes of the two are dislocated, and the movement trajectories of the fork arms will not overlap, forming a symmetrical dislocation, and the movement trajectories of the fork arms will not overlap, which can completely eliminate the risk of collision at extreme angles.

[0032] Moreover, as a connecting carrier, the middle fork assembly is more rigid than the traditional slender intermediate shaft connection structure, and can effectively resist lateral thrust, so that the first fork assembly and the second fork assembly can remain stable during operation and avoid interference with other surrounding structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram of a double transmission shaft according to an embodiment;

[0034] Figure 2 for Figure 1 A schematic structural diagram of the first fork assembly and the second fork assembly;

[0035] Figure 3 for Figure 2 A schematic structural diagram of the first fork assembly and the second fork assembly from another perspective;

[0036] Figure 4 for Figure 1 Schematic diagram of the structure of the middle connection module and the middle fork assembly;

[0037] Figure 5 for Figure 4 Schematic diagram of the structure of the middle connection module and the middle fork assembly from another perspective;

[0038] Figure 6 for Figure 4 Schematic diagram of the structure of the middle fork assembly;

[0039] Figure 7 for Figure 6 a cross-sectional view of the middle fork assembly;

[0040] Figure 8 for Figure 4 Schematic diagram of the structure of the connection module;

[0041] Figure 9 for Figure 8 A structural diagram of the connection module from another perspective;

[0042] Figure 10 for Figure 8 A structural diagram of the connection module from another perspective;

[0043] Figure 11 Schematic diagram of the structure of the rolling unit.

[0044] Reference numerals:

[0045] 10. First fork assembly; 11. First fork seat; 12. First left fork hole; 13. First right fork hole; 20. Middle fork assembly; 21. Middle fork seat; 22. Middle left fork hole; 23. Middle right fork hole; 24. Middle left fork hole; 25. Middle right fork hole; 30. Second fork assembly; 31. Second fork seat; 32. Second left fork hole; 33. Second right fork hole; 40. Transmission assembly; 41. Four-axis unit; 411. First axis module; 411 1. First shaft seat; 4112. First left shaft; 4113. First right shaft; 412. Second shaft module; 4121. Second shaft seat; 4122. Second left shaft; 4123. Second right shaft; 413. Connection module; 4131. Middle connection part; 4132. First side connection part; 4133. Second side connection part; 4134. Through hole; 42. Rolling unit; 421. Rolling sleeve; 422. Rolling body; 423. Sealing ring. DETAILED DESCRIPTION

[0046] The present disclosure will now be discussed with reference to several exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the present disclosure, rather than to imply any limitation on the scope of the present disclosure.

[0047] As used herein, the term "including" and its variations are to be interpreted as open-ended terms meaning "including, but not limited to." The term "based on" is to be interpreted as "based, at least in part, on." The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment." The term "another embodiment" is to be interpreted as "at least one other embodiment." Terms such as "upper," "lower," "left," "right," "front," "back," "top," "bottom," "inner," "outer," "vertical," "horizontal," "transverse," and "longitudinal" indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are primarily intended to better describe the present application and its embodiments and are not intended to limit the devices, elements, or components indicated to having a specific orientation, or to being constructed and operated in a specific orientation. Furthermore, some of the above terms may be used to indicate other meanings besides orientation or positional relationships. For example, the term "on" may, in certain circumstances, be used to indicate a dependency or connection relationship. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances. Furthermore, the terms "installed," "disposed," "provided with," "connected," and "connected" are to be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediate medium, or an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances. In addition, the terms "first", "second", etc. are mainly used to distinguish different devices, elements, or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise specified, "plurality" means two or more.

[0048] A tandem driveshaft is a structure used to transmit power in automotive transmission systems, primarily used in vehicles with longer wheelbases. It consists of two driveshaft sections, connected by two central universal joints and fixed to the vehicle frame, forming a front drive, center support, and rear drive assembly.

[0049] When the working angle of the double drive shaft exceeds the design limit, the angle of the universal joint fork arm will be too large, and the rotation plane will intersect with the motion space of the adjacent fork arm. The fork arms at both ends may come into physical contact when swinging to the extreme position, causing jamming or breakage.

[0050] Example 1:

[0051] This embodiment proposes a double transmission shaft, such as Figure 1As shown, it includes a middle fork assembly 20 , a first fork assembly 10 , a second fork assembly 30 , and two transmission assemblies 40 .

[0052] The middle fork assembly 20 serves as a connecting carrier. Compared with the traditional slender intermediate shaft connection structure, the middle fork assembly 20 is more rigid and can effectively resist lateral thrust, so that the first fork assembly 10 and the second fork assembly 30 can remain stable during operation and avoid interference with other surrounding structures.

[0053] The first fork assembly 10 is located on one side of the middle fork assembly 20 and is used to connect to the driving shaft. The second fork assembly 30 is located on the other side of the middle fork assembly 20 and is used to connect to the driven shaft.

[0054] like Figure 4 and Figure 8 As shown, each transmission assembly 40 includes four axis units 41 and four rolling units 42. The four axis units 41 include a first axis module 411, a second axis module 412, and a connecting module 413. The sidewalls of the first axis module 411 are connected to the sidewalls of the second axis module 412 via the connecting module 413. The two ends of the first axis module 411 are each rotatably connected to a rolling unit 42. The two ends of the second axis module 412 are each rotatably connected to a rolling unit 42.

[0055] like Figure 5 As shown, the minimum angle α between the projection of the axis of the first shaft module 411 and the projection of the axis of the second shaft module 412 on the set plane is greater than 0° and less than 90°. The set plane is parallel to the axis of the first shaft module 411 and the axis of the second shaft module 412, respectively. This creates an angle between the axis of the first shaft module 411 and the axis of the second shaft module 412, enabling the dual drive shaft to adapt to transmission with a larger angle between the driving shaft and the transmission shaft.

[0056] like Figure 4 As shown, the two ends of one first shaft module 411 are rotationally connected to one side of the middle fork assembly 20 via two rolling units 42; the two ends of the other first shaft module 411 are rotationally connected to the other side of the middle fork assembly 20 via two rolling units 42. The two first shaft modules 411 are connected to the middle fork assembly 20 via rolling units 42, which significantly reduces frictional heat and wear during large-angle transmission compared to traditional sliding friction, reducing the possibility of jamming.

[0057] The two ends of one second shaft module 412 are connected to the first fork assembly 10 via two rolling units 42, while the two ends of the other second shaft module 412 are connected to the second fork assembly 30 via two rolling units 42. The two second shaft modules 412 are connected to the first fork assembly 10 and the second fork assembly 30 via rolling units 42, respectively. Compared with traditional sliding friction, this can significantly reduce frictional heat and wear during large-angle transmission, reducing the possibility of jamming.

[0058] The axes of the two second shaft modules 412 are tilted in opposite directions. This allows for a symmetrical misalignment of the fork arms, preventing them from overlapping, even when the angle between the driving shaft and the transmission shaft in a dual-drive shaft application is too large. This eliminates the risk of collision at extreme angles by dislocating the motion planes of the first and second fork assemblies 10, 30, and the middle fork assembly 20.

[0059] Further, such as Figure 5 As shown, the minimum angle α between the projection of the axis of the first axis module 411 on the set plane and the projection of the axis of the second axis module 412 on the set plane is greater than 75° and less than 90°. In this way, the movement planes of the first fork assembly 10, the second fork assembly 30 and the middle fork assembly 20 form a nearly vertical spatial dislocation, which can further reduce the overlapping area of ​​the fork arm movement trajectory compared to the angle of 0° to 75°. Combined with the high rigidity structure of the middle fork assembly 20, it can effectively disperse the lateral thrust at large angles, reduce the swing amplitude of the first fork assembly 10 and the second fork assembly 30, and avoid interference with surrounding structures due to component vibration. Specifically, the minimum angle α between the projection of the axis of the first axis module 411 on the set plane and the projection of the axis of the second axis module 412 on the set plane can be between 75° and 80°, or between 85° and 90°. The specific minimum angle α can be set according to the angle and spacing between the driving shaft and the driven shaft.

[0060] Further, such as Figure 8 As shown, the axis of the first shaft module 411 and the axis of the second shaft module 412 are spaced apart in the radial direction of the first shaft module 411. The spacing of the axes of the first shaft module 411 and the second shaft module 412 in the radial direction of the first shaft module 411 further increases the physical separation between the movement spaces of the two, enabling the dual-drive shaft to adapt to the driving shaft and driven shaft with a larger inter-axis angle to operate. At the same time, it prevents rigid contact between the shaft modules when they swing at large angles. The radial load during the transmission process can be dispersed through radial misalignment, reducing local stress concentration in the rolling unit 42.

[0061] Further, such as Figure 9As shown, D=k×d1; 1≤k≤2. The outer diameter d1 of the first shaft module 411 is the same as the outer diameter d2 of the second shaft module 412. D is the distance between the axis of the first shaft module 411 and the axis of the second shaft module 412. In this way, the distance D between the first shaft module 411 and the second shaft module 412 is set to 1-2 times its outer diameter d1, which can ensure that the two shaft modules have sufficient spacing in the radial direction to avoid motion interference, and will not cause the overall volume of the transmission assembly 40 to be bloated due to excessive spacing. At the same time, the unified outer diameter specification reduces the processing complexity, and with a reasonable spacing ratio, it can evenly distribute the radial load, ensure that the rolling unit 42 is more evenly stressed, and further improve the structural compactness and transmission reliability.

[0062] Further, such as Figure 10 As shown, the connection module 413 includes a middle connection portion 4131 , a first side connection portion 4132 , and a second side connection portion 4133 .

[0063] The middle connecting portion 4131 is respectively connected to the outer peripheral wall of the first shaft module 411 and the outer peripheral wall of the second shaft module 412. The middle connecting portion 4131 directly connects the outer peripheral walls of the two shaft modules to form a basic bearing structure.

[0064] The first side connection portion 4132 and the second side connection portion 4133 are respectively connected to the middle connection portion 4131. The first side connection portion 4132 is located between the maximum angle between the first axis module 411 and the second axis module 412. The first side connection portion 4132 is respectively connected to the first axis module 411 and the second axis module 412. The first side connection portion 4132 is located between the maximum angle between the two axes, which can prevent the tendency of separation during large-angle swing.

[0065] The second side connection portion 4133 is located between the minimum angle between the first axis module 411 and the second axis module 412, and is respectively connected to the first axis module 411 and the second axis module 412. The second side connection portion 4133 enhances the restraining force in the fitting direction between the minimum angles.

[0066] The middle connection portion 4131 , the first side connection portion 4132 , and the second side connection portion 4133 cooperate to form a triangular stable support, which can enhance the torsion and bending resistance of the connection module 413 .

[0067] Further, such as Figure 10 As shown, the maximum dimension of the first side connection portion 4132 along the radial direction of the middle connection portion 4131 is greater than the maximum dimension of the second side connection portion 4133 along the radial direction of the middle connection portion 4131 .

[0068] The maximum angle is the area where the two-axis modules have the largest relative swing amplitude and the strongest separation tendency. The first side connection portion 4132 is located in the area with the maximum angle between the two axes. Its larger size can optimize mass distribution, making the overall mass of the connection module 413 more evenly distributed circumferentially, reducing the vibration caused by the center of gravity offset of the connection module 413 during swinging, and improving the stability of the connection module 413 during operation. In addition, the larger size of the first side connection portion 4132 can enhance the structural strength and deformation resistance of this area, effectively resisting tensile and bending stresses at large angles. The force at the minimum angle is relatively mild, and the smaller size of the second side connection portion 4133 can reduce material redundancy, reduce overall weight, and avoid motion interference caused by excessive thickness of the structure in the compact minimum angle area.

[0069] Further, such as Figure 10 As shown, the connection module 413 includes a through hole 4134. The through hole 4134 penetrates the first edge connection portion 4132 along the spacing direction between the first axis module 411 and the second axis module 412.

[0070] First side connection 4132 is located between the maximum angle between the two axis modules and is larger than second side connection 4133. Its mass is relatively concentrated. Uneven mass distribution can easily lead to unbalanced centrifugal force during rotation. Via holes 4134 reduce the mass of first side connection 4132, lowering the overall weight of connection module 413. The specific position and diameter of via holes 4134 can be flexibly adjusted to compensate for mass distribution deviations caused by the angle between the two axis modules with minimal weight loss, further reducing vibration during swinging of connection module 413. Via holes 4134 also reduce redundant materials, reducing the overall weight of connection module 413.

[0071] Furthermore, the first shaft module 411 includes a first shaft seat 4111 , a first left shaft 4112 , and a first right shaft 4113 . The second shaft module 412 includes a second shaft seat 4121 , a second left shaft 4122 , and a second right shaft 4123 .

[0072] The first shaft seat 4111 and the second shaft seat 4121 are connected through the connecting module 413. The first left shaft 4112 and the first right shaft 4113 are respectively connected to the two ends of the first shaft seat 4111. The second left shaft 4122 and the second right shaft 4123 are respectively connected to the two ends of the second shaft seat 4121. The first shaft seat 4111 and the second shaft seat 4121 serve as the core bearing components of the two-shaft modules. Through the connecting module 413, they form a stable basic connection structure, which concentrates the force between the two-shaft modules and enhances the overall rigidity. The first left shaft 4112, the first right shaft 4113 and the second left shaft 4122, the second right shaft 4123 extend from the two ends of the shaft seat respectively, which can disperse the transmitted torque or load, avoid the concentration of force on a single shaft body, and optimize the force transmission path.

[0073] Further, such as Figure 11 As shown, the rolling unit 42 includes a rolling sleeve 421, a rolling body 422, and a sealing ring 423. The rolling sleeves 421 are provided at both ends of the first shaft module 411 and the second shaft module 412. The sealing ring 423 and the rolling body 422 are arranged in the rolling sleeve 421, and the rolling body 422 is located between the bottom wall of the rolling sleeve 421 and the sealing ring 423. The rolling body 422 is located between the outer wall of the shaft module and the inner wall of the rolling sleeve 421. The rolling friction replaces the sliding friction, which greatly reduces the friction resistance during the rotation of the shaft module and reduces energy loss. It is particularly suitable for high-speed transmission scenarios and improves the overall operating efficiency. It is worth noting that the rolling body 422 can be a ball or a roller.

[0074] At both ends of the first and second shaft modules 411, 412, rolling elements 422 abut against the outer circumferential walls of the corresponding shaft modules and the inner circumferential walls of the rolling sleeves 421, respectively. Sealing rings 423 seal between the outer circumferential walls of the corresponding shaft modules and the inner circumferential walls of the rolling sleeves 421. Sealing rings 423 closely adhere to the outer circumferential walls of the shaft modules and the inner circumferential walls of the rolling sleeves 421, forming a reliable seal that effectively blocks external dust, moisture, and impurities from intruding into the rolling elements 42. This prevents leakage of internal grease, ensuring that rolling elements 422 always operate in a clean, lubricated environment, reducing wear and corrosion and significantly extending the service life of the rolling elements 42 and the shaft modules.

[0075] Further, such as Figure 6 and Figure 7 As shown, the middle fork assembly 20 includes a middle fork seat 21, a middle left fork hole 22, a middle right fork hole 23, a middle left fork hole 24, and a middle right fork hole 25.

[0076] The middle left fork hole 22 and the middle right fork hole 23 are provided on one side of the middle fork seat 21. The middle left fork hole 22 and the middle right fork hole 23 are arranged opposite each other. The two ends of a first shaft module 411 are respectively mounted in the middle left fork hole 22 and the middle right fork hole 23 via rolling units 42.

[0077] The second middle left fork hole 24 and the second middle right fork hole 25 are respectively provided on the other side of the middle fork seat 21. The second middle left fork hole 24 and the second middle right fork hole 25 are arranged opposite each other. The other first shaft module 411 is mounted on both ends of the second middle left fork hole 24 and the second middle right fork hole 25 via rolling units 42.

[0078] The two ends of the first shaft module 411 are precisely embedded in the relative fork holes through the rolling unit 42, which can strictly ensure that the axis of the shaft module coincides with the axis of the fork hole, avoiding rotation shaking or jamming caused by eccentric installation, and significantly improving the coaxiality and stability of the shaft module during rotation. It is especially suitable for scenarios requiring high-precision transmission.

[0079] like Figure 2 and Figure 3As shown, the first fork assembly 10 includes a first fork seat 11, a first left fork hole 12, and a first right fork hole 13. The first left fork hole 12 and the first right fork hole 13 are respectively disposed on the first fork seat 11. The first left fork hole 12 and the first right fork hole 13 are disposed opposite each other. A second shaft module 412 has its ends mounted on the first left fork hole 12 and the first right fork hole 13, respectively, via rolling units 42.

[0080] The second fork assembly 30 includes a second fork base 31, a second left fork hole 32, and a second right fork hole 33. The second left fork hole 32 and the second right fork hole 33 are respectively disposed on the second fork base 31. The second left fork hole 32 and the second right fork hole 33 are disposed opposite each other. Another second shaft module 412 has its ends mounted on the second left fork hole 32 and the second right fork hole 33, respectively, via rolling elements 42.

[0081] The first fork assembly 10 serves as a direct carrier for connecting the driving shaft. The rotational torque of the driving shaft directly drives the first fork seat 11 to rotate. The rotation of the first fork seat 11 drives the second shaft module 412 to rotate synchronously through the rolling sleeve 421 and the rolling element 422. The power is transmitted to the first shaft module 411 through the second shaft module 412 and the connecting module 413. Then, it is transmitted to the first shaft module 411, the connecting module 413, and the second shaft module 412 on the other side through the middle fork assembly 20, and finally reaches the second fork assembly 30. The second fork seat 31 is used to connect with the driven shaft, ultimately transmitting the power to the driven shaft.

[0082] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present disclosure, and that in actual applications, various changes may be made thereto in form and detail without departing from the scope of the present disclosure.

Claims

1. A double transmission shaft, characterized in that: The double transmission shaft comprises: Middle fork assembly; a first fork assembly, located on one side of the middle fork assembly; a second fork assembly, located on the other side of the middle fork assembly; Two transmission assemblies, each comprising a four-axis unit and four rolling units; the four-axis unit comprising a first axis module, a second axis module, and a connecting module; the side wall of the first axis module is connected to the side wall of the second axis module via the connecting module; the two ends of the first axis module are respectively rotatably connected to one of the rolling units; the two ends of the second axis module are respectively rotatably connected to one of the rolling units; wherein the minimum angle between the projection of the axis of the first axis module on a set plane and the projection of the axis of the second axis module on the set plane is greater than 0° and less than 90°; the set plane is parallel to the axis of the first axis module and the axis of the second axis module respectively; Two ends of one first shaft module are rotatably connected to one side of the middle fork assembly via two rolling units; two ends of another first shaft module are rotatably connected to the other side of the middle fork assembly via two rolling units; Two ends of one second shaft module are connected to the first fork assembly via two rolling units respectively; two ends of another second shaft module are connected to the second fork assembly via two rolling units respectively; The axes of the two second axis modules are tilted in opposite directions.

2. A double transmission shaft according to claim 1, characterized in that: A minimum angle α between the projection of the axis of the first shaft module on a set plane and the projection of the axis of the second shaft module on the set plane is greater than 75° and less than 90°.

3. The double transmission shaft according to claim 1, characterized in that: An axis of the first shaft module and an axis of the second shaft module are spaced apart in a radial direction of the first shaft module.

4. A double transmission shaft according to claim 3, characterized in that: D=k×d1; 1≤k≤2; the outer diameter d1 of the first shaft module is the same as the outer diameter d2 of the second shaft module; D is the distance between the axis of the first shaft module and the axis of the second shaft module.

5. The double transmission shaft according to claim 1, characterized in that: The connection module includes a middle connection portion, a first side connection portion, and a second side connection portion; The middle connecting portion is connected to the outer peripheral wall of the first shaft module and the outer peripheral wall of the second shaft module respectively; the first side connecting portion and the second side connecting portion are connected to the middle connecting portion respectively; The first side connection portion is located between the maximum included angle of the first shaft module and the second shaft module, and the first side connection portion is connected to the first shaft module and the second shaft module respectively; The second side connection portion is located between the minimum included angle of the first shaft module and the second shaft module, and the second side connection portion is connected to the first shaft module and the second shaft module respectively.

6. The double transmission shaft according to claim 5, characterized in that: A maximum dimension of the first side connection portion along a radial direction of the middle connection portion is greater than a maximum dimension of the second side connection portion along a radial direction of the middle connection portion.

7. The double transmission shaft according to claim 6, characterized in that: The connection module includes a through hole; the through hole passes through the first edge connection portion along a spacing direction between the first axis module and the second axis module.

8. The double transmission shaft according to claim 1, characterized in that: The first shaft module includes a first shaft seat, a first left shaft, and a first right shaft; the second shaft module includes a second shaft seat, a second left shaft, and a second right shaft; The first axle seat and the second axle seat are connected through the connecting module; the first left shaft and the first right shaft are respectively connected to the two ends of the first axle seat; the second left shaft and the second right shaft are respectively connected to the two ends of the second axle seat.

9. The double transmission shaft according to claim 8, characterized in that: The rolling unit includes a rolling sleeve, a rolling body, and a sealing ring; both ends of the first shaft module and the second shaft module are sleeved with the rolling sleeve; the sealing ring and the rolling body are arranged in the rolling sleeve, and the rolling body is located between the bottom wall of the rolling sleeve and the sealing ring; At both ends of the first shaft module and the second shaft module, the rolling bodies respectively abut against the outer circumferential wall of the corresponding shaft module and the inner circumferential wall of the rolling sleeve, and the sealing ring is sealed between the outer circumferential wall of the corresponding shaft module and the inner circumferential wall of the rolling sleeve.

10. The double transmission shaft according to claim 1, characterized in that: The middle fork assembly includes a middle fork seat, a middle left fork hole, a middle right fork hole, a middle left fork hole, and a middle right fork hole; The middle left fork hole and the middle right fork hole are arranged on one side of the middle fork seat; the middle left fork hole and the middle right fork hole are arranged opposite to each other; the two ends of one of the first shaft modules are respectively installed in the middle left fork hole and the middle right fork hole through the rolling unit; The second middle left fork hole and the second middle right fork hole are respectively arranged on the other side of the middle fork seat; the second middle left fork hole and the second middle right fork hole are arranged opposite to each other; the two ends of another first shaft module are respectively installed in the second middle left fork hole and the second middle right fork hole through the rolling unit; The first fork assembly includes a first fork seat, a first left fork hole, and a first right fork hole; the first left fork hole and the first right fork hole are respectively arranged on the first fork seat; the first left fork hole and the first right fork hole are arranged opposite to each other; two ends of a second shaft module are respectively installed in the first left fork hole and the first right fork hole through the rolling unit; The second fork assembly includes a second fork seat, a second left fork hole, and a second right fork hole; the second left fork hole and the second right fork hole are respectively arranged on the second fork seat; the second left fork hole and the second right fork hole are arranged opposite to each other; the two ends of another second axis module are respectively installed in the second left fork hole and the second right fork hole through the rolling unit.

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