Composite transmission device for high-speed high-torque new energy automobile electric drive assembly

Abstract

The invention provides a composite transmission device for an electric drive assembly of a high-speed high-torque new energy automobile, which comprises a rotor shaft mounted on a motor, a transmission shaft arranged on a speed reducer and a composite sliding sleeve used for connecting the rotor shaft and the transmission shaft, and the transmission shaft is provided with a direct-drive internal spline matched and connected with the direct-drive spline teeth correspondingly. The rotor shaft and the transmission shaft in the device transmit torque in a split mode through the first transmission structure and the second transmission structure, so that under the condition that rated transmission torque is not reduced, the load of the small-diameter transmission shaft is reduced, stress distribution is improved, and the pain points of early failures such as breakage and fretting wear of a new energy electric drive transmission shaft under severe working conditions are solved. The axial positioning rigidity of the transmission structure can be improved, so that shaft deformation and fatigue fracture caused by impact load are reduced; the composite sliding sleeve can slide in the axial direction and can also be used for axial positioning of a bearing and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of the transmission structure of an electric drive assembly, and particularly to a composite transmission device for an electric drive assembly of a high-speed and high-torque new energy vehicle. Background Technique

[0002] Since the vehicle drive motor of new energy vehicles is developing towards higher speed, smaller size, and lighter weight, the diameter of the motor shaft as the drive becomes more compact, the diameter of the spline structure at the connection part is smaller, and the load-bearing capacity is weaker, and fretting wear, torsional deformation, and impact fatigue fracture often occur.

[0003] Most of the existing torque transmission devices connecting the motor and the reducer adopt the form of internal and external involute spline structures. Since the traditional spline structure cannot withstand higher stress and wear after the size is reduced, its disadvantages are as follows:

[0004] 1) Stress concentration, the small shaft diameter causes a significant increase in the tooth root stress. There is still stress concentration at the tooth root (although it is smaller than that of a flat key, there is still stress concentration), and it often breaks due to the overload impact under large torque;

[0005] 2) There is difficult-to-overcome fretting wear in the spline connection under high-speed rotation conditions, and then fatigue damage and failure occur;

[0006] 3) Insufficient impact resistance: The pure circumferential meshing structure has poor torsional deformation resistance.

[0007] In view of the design pain points of the failure of the ordinary spline connection at the high-speed and high-torque motor drive shaft end, therefore, a composite transmission device for an electric drive assembly of a high-speed and high-torque new energy vehicle is needed to solve the above technical problems. Summary of the Invention

[0008] The technical problem solved by the present invention is to provide a composite transmission device for an electric drive assembly of a high-speed and high-torque new energy vehicle to solve the problems raised in the above background technique.

[0009] The technical problem solved by the present invention is achieved by the following technical solutions: A composite transmission device for an electric drive assembly of a high-speed and high-torque new energy vehicle includes a rotor shaft installed on the motor, a transmission shaft provided on the reducer, and a composite sliding sleeve for connecting the rotor shaft and the transmission shaft. A direct drive spline tooth is integrally provided on the outer side of the rotor shaft, and a direct drive internal spline for cooperating with the direct drive spline tooth is provided on the transmission shaft corresponding to the direct drive spline tooth. The rotor shaft is inserted into the corresponding inner hole of the transmission shaft to be in transmission connection through the direct drive spline tooth and the direct drive internal spline, forming a first transmission structure. The composite sliding sleeve is slidably installed on the rotor shaft, and one side of the composite sliding sleeve is in transmission connection with the rotor shaft, and the other side is in rotational connection with the transmission shaft, forming a second transmission structure.

[0010] As a further aspect of the present invention:

[0011] One side of the rotor shaft away from the direct drive spline teeth is integrally provided with a first shaft column and a second shaft column. The first shaft column and the second shaft column are connected in sequence, and the diameter of the second shaft column is greater than that of the first shaft column.

[0012] As a further solution of the present invention:

[0013] The outer end of the first shaft column is provided with split torque rectangular concave teeth. One side of the composite sliding sleeve is correspondingly provided with split torque rectangular convex teeth connected thereto. The split torque rectangular convex teeth are inserted into the tooth grooves of the split torque rectangular concave teeth for clamping connection, so that the composite sliding sleeve is in transmission connection with the rotor shaft.

[0014] As a further solution of the present invention:

[0015] One side of the composite sliding sleeve located at the split torque rectangular convex teeth is integrally provided with a first ring plate. The outer end of the first shaft column is sleeved and installed with a first bearing. One side of the outer ring of the first bearing abuts against the second shaft column, and the other side abuts against the outer end of the first ring plate to clamp and fix the first bearing, improving the installation stability of the first bearing.

[0016] As a further solution of the present invention:

[0017] The side of the composite sliding sleeve facing the transmission shaft is annularly distributed with split torque dog teeth. The transmission shaft is correspondingly provided with a split torque dog ring. The split torque dog ring is inserted into the tooth grooves corresponding to the split torque dog teeth, so that the composite sliding sleeve is in transmission connection with the transmission shaft.

[0018] As a further solution of the present invention:

[0019] The composite sliding sleeve is connected by the clamping of the split torque dog teeth and the split torque dog ring, so that the composite sliding sleeve is clamped between the first shaft column and the transmission shaft, and an axial pre-tightening gap is left between the composite sliding sleeve and the rotor shaft and the transmission shaft, effectively compensating for the thermal deformation under high speed and high temperature of the new energy electric drive, improving the axial positioning stiffness, and thus reducing the shaft deformation and fatigue fracture caused by the impact load.

[0020] As a further solution of the present invention:

[0021] The tooth surface parts of the rotor shaft, the composite sliding sleeve and the transmission shaft are nitrided and coated with wear-resistant coatings to improve the wear resistance of the tooth surface.

[0022] As a further solution of the present invention:

[0023] The power splitting method of the composite transmission device is as follows: the rotor shaft is externally connected to the power input, and the torque is split and transmitted through the first transmission structure and the second transmission structure, wherein the first transmission structure is connected by a direct drive spline tooth and a direct drive internal spline transmission to transmit the torque to the transmission shaft; the second transmission structure is connected by a torque-split concave tooth and a torque-split convex tooth to transmit the torque to the composite sliding sleeve, and the torque-split dog tooth body at the outer end of the composite sliding sleeve is connected to the torque-split dog tooth ring to transmit the torque to the transmission shaft; thereby reducing the load on the small-diameter transmission shaft without reducing the rated transmission torque, and solving the pain points of early failure of the new energy electric drive transmission shaft such as fracture and micro-wear under harsh working conditions.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: the rotor shaft and the transmission shaft in the device transmit the torque through the first transmission structure and the second transmission structure, thereby reducing the load of the small diameter transmission shaft without reducing the rated transmission torque, improving the stress distribution, and solving the pain points of early failure such as fracture and micro-wear of the new energy electric drive transmission shaft under harsh working conditions. And it can improve the axial positioning stiffness of the transmission structure, thereby reducing the shaft deformation and fatigue fracture caused by impact loads; the composite sleeve can slide along the axial direction, and can also be used for axial positioning of bearings. It is easier to assemble, repair and disassemble, suitable for the application of a variety of high-speed and high-torque new energy electric drive structures, meet the lightweight requirements of high-speed electric drive systems, improve reliability, and reduce the frequency of after-sales maintenance; improve dynamic adaptability, and the thermal deformation design has an axial preload clearance compensation amount to ensure stability under high-speed conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The structure of the present invention is schematically shown Figure 1 ;

[0026] Figure 2 The structure of the present invention is schematically shown Figure 2 ;

[0027] Figure 3 It is a schematic diagram of the power splitting circuit structure of the present invention;

[0028] Markings in the figure: 1. rotor shaft; 2. transmission shaft; 3. composite sleeve; 4. first bearing; 11. direct drive spline teeth; 12. first shaft column; 13. second shaft column; 14. torque-shaping concave teeth; 21. direct drive internal spline; 22. torque-shaping dog ring; 31. torque-shaping convex teeth; 32. first ring plate; 33. torque-shaping dog teeth. DETAILED DESCRIPTION

[0029] In order to make the technical means for realizing the present invention, the creative features, the objectives and effects to be achieved easily understood, the present invention is further described below with reference to specific diagrams.

[0030] like Figures 1 - 3 As shown,

[0031] This embodiment provides a composite transmission device for a high-speed and high-torque new energy vehicle electric drive assembly, including a rotor shaft 1 installed on the motor, a drive shaft 2 arranged on the reducer, and a composite sliding sleeve 3 for connecting the rotor shaft 1 and the drive shaft 2. A direct drive spline tooth 11 is integrally provided on the outer side of the rotor shaft 1, and a direct drive internal spline 21 is provided on the drive shaft 2 corresponding to the direct drive spline tooth 11 for mating connection therewith. The rotor shaft 1 is inserted into the corresponding inner hole of the drive shaft 2 to be in transmission connection through the direct drive spline tooth 11 and the direct drive internal spline 21, forming a first transmission structure. The composite sliding sleeve 3 is slidably installed on the rotor shaft 1, and one side of the composite sliding sleeve 3 is in transmission connection with the rotor shaft 1, and the other side is in rotational connection with the drive shaft 2, forming a second transmission structure.

[0032] In this embodiment, a first shaft column 12 and a second shaft column 13 are integrally provided on the side of the rotor shaft 1 away from the direct drive spline tooth 11. The first shaft column 12 and the second shaft column 13 are connected in sequence, and the diameter of the second shaft column 13 is larger than that of the first shaft column 12.

[0033] A split torque rectangular concave tooth 14 is provided at the outer end of the first shaft column 12. A split torque rectangular convex tooth 31 connected thereto is provided on one side of the composite sliding sleeve 3 corresponding to the split torque rectangular concave tooth 14. The split torque rectangular convex tooth 31 is inserted into the tooth groove of the split torque rectangular concave tooth 14 for clamping connection, so that the composite sliding sleeve 3 is in transmission connection with the rotor shaft 1.

[0034] In this embodiment, a first ring plate 32 is integrally provided on one side of the composite sliding sleeve 3 where the split torque rectangular convex tooth 31 is located. A first bearing 4 is sleeved and installed at the outer end of the first shaft column 12. One side of the outer ring of the first bearing 4 abuts against the second shaft column 13, and the other side abuts against the outer end of the first ring plate 32 to clamp and fix the first bearing 4, improving the installation stability of the first bearing 4.

[0035] Split torque dog teeth 33 are annularly distributed on the side of the composite sliding sleeve 3 facing the drive shaft 2. A split torque dog ring 22 is provided on the drive shaft 2 corresponding to the split torque dog teeth 33. The split torque dog ring 22 is inserted into the corresponding tooth groove of the split torque dog teeth 33, so that the composite sliding sleeve 3 is in transmission connection with the drive shaft 2.

[0036] In this embodiment, through the clamping connection of the split torque dog teeth 33 and the split torque dog ring 22, the composite sliding sleeve 3 is clamped between the first shaft column 12 and the drive shaft 2, and an axial pre-tightening gap is left between the composite sliding sleeve 3 and the rotor shaft 1 and the drive shaft 2, effectively compensating for the thermal deformation of the new energy electric drive under high speed and high temperature, improving the axial positioning stiffness, and thus reducing the shaft deformation and fatigue fracture caused by the impact load.

[0037] The tooth surface parts of the rotor shaft 1, the composite sliding sleeve 3 and the drive shaft 2 are nitrided and coated with a wear-resistant coating to improve the tooth surface wear resistance.

[0038] The present embodiment discloses a power splitting method of a composite transmission device for a high-speed and high-torque new energy vehicle electric drive assembly, wherein the rotor shaft 1 is externally connected to a power input, and the torque is split and transmitted through a first transmission structure and a second transmission structure, wherein the first transmission structure is connected by a direct drive spline tooth 11 and a direct drive internal spline 21 to transmit the torque to the transmission shaft 2; the second transmission structure is connected by a torque-split concave tooth 14 and a torque-split convex tooth 31 to transmit the torque to the composite sleeve 3, and the torque-split dog tooth 33 at the outer end of the composite sleeve 3 is connected to the torque-split dog tooth 33 ring to transmit the torque to the transmission shaft 2; thereby, the load of the small-diameter transmission shaft 2 is reduced without reducing the rated transmission torque, and the pain points of early failure of the new energy electric drive transmission shaft 2 such as fracture and micro-wear under harsh working conditions are solved.

[0039] The structure of the present invention adopts a direct drive spline + larger diameter end face composite dog tooth structure, which can divert the torque when transmitting large torque. One way is transmitted by the traditional direct drive internal and external spline structure, and the other way is transmitted by the torsion-dividing dog teeth 33 and the torsion-dividing dog ring 22. Therefore, without reducing the rated transmission torque, the load of the small diameter rotor shaft 1 is reduced, and the pain points of early failure of the new energy electric drive rotor shaft 1 such as fracture and micro-wear under harsh working conditions are solved.

[0040] Composite dog tooth structure design data:

[0041] Structure type Key points of structural parameter design Functional advantages 1 Involute spline Module 0.5 - 1.5, pressure angle 30° Achieve circumferential main drive 2 End face trapezoidal teeth (dog teeth) Tooth height 3 - 9 mm, meshing angle 37.5° - 60° Axial positioning + power splitting 3 Transition zone design ≥5 large - module dog teeth, tooth root R - angle ≥1.5 mm Reduce stress concentration 4 Tooth surface wear - resistant treatment process Tooth surface nitriding treatment, combined with wear - resistant coating Improve wear resistance

[0042] Composite dog tooth test verification data:

[0043]

[0044] The transmission device adopts a two-way transmission structure, using a direct drive spline + end face composite dog tooth structure with the following advantages:

[0045] 1) Improve the connection strength through direct drive spline + end face composite dog tooth structure (convex and concave trapezoidal teeth);

[0046] 2) The end face composite dog tooth structure (convex and concave trapezoidal teeth) can share part of the torque through end face tooth engagement, thereby reducing the load on the spline. This structure can increase the contact area, improve stress distribution, and reduce micro-motion wear;

[0047] 3) The connection structure of the composite sleeve 3 can improve the axial positioning stiffness, thereby reducing the shaft deformation and fatigue fracture caused by the impact load;

[0048] 4) The composite sleeve 3 can slide along the axial direction and can also be used for axial positioning of bearings, etc. It is easier to assemble, repair and disassemble, and is suitable for the application of various high-speed and high-torque new energy electric drive structures.

[0049] Thus, a breakthrough in torque density is achieved. Through the double meshing of end face teeth and splines, the torque bearing capacity is improved, meeting the lightweight requirements of high-speed electric drive systems, enhancing reliability, and reducing the frequency of after-sales maintenance; improving dynamic adaptability, with an axial preload clearance compensation amount in the thermal deformation design to ensure stability under high-speed conditions of 20,000 rpm.

[0050] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents. It should be noted that in this text, if there are relational terms such as first and second, they are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprising", "including", or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements not only includes those elements but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article, or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article, or device comprising the said element.

Claims

1. A composite transmission device for a high-speed and high-torque new energy vehicle electric drive assembly, characterized in that: The invention comprises a rotor shaft (1) mounted on a motor, a transmission shaft (2) arranged on a reducer, and a composite sliding sleeve (3) for connecting the rotor shaft (1) and the transmission shaft (2); the outer side of the rotor shaft (1) is integrally provided with direct drive spline teeth (11); the transmission shaft (2) is provided with direct drive internal splines (21) corresponding to the direct drive spline teeth (11) and matched with the direct drive spline teeth; the rotor shaft (1) is inserted into an inner hole corresponding to the transmission shaft (2) so as to be transmission-connected with the direct drive internal splines (21) through the direct drive spline teeth (11), thereby forming a first transmission structure; the composite sliding sleeve (3) is slidably mounted on the rotor shaft (1); one side of the composite sliding sleeve (3) is transmission-connected with the rotor shaft (1) and the other side is rotationally connected with the transmission shaft (2), thereby forming a second transmission structure.

2. A composite transmission device for a high-speed and high-torque new energy vehicle electric drive assembly according to claim 1, characterized in that: A first shaft column (12) and a second shaft column (13) are integrally provided on a side of the rotor shaft (1) away from the direct drive spline teeth (11); the first shaft column (12) and the second shaft column (13) are connected in sequence, and the diameter of the second shaft column (13) is greater than the diameter of the first shaft column (12).

3. A composite transmission device for a high-speed and high-torque new energy vehicle electric drive assembly according to claim 2, characterized in that: The outer end of the first shaft column (12) is provided with a torque-dividing concave tooth (14), and one side of the composite sleeve (3) is provided with a torque-dividing convex tooth (31) corresponding to the torque-dividing concave tooth (14) and connected thereto, and the torque-dividing convex tooth (31) is inserted into the tooth groove of the torque-dividing concave tooth (14) for clamping, so that the composite sleeve (3) is transmission-connected with the rotor shaft (1).

4. A composite transmission device for a high-speed and high-torque new energy vehicle electric drive assembly according to claim 3, characterized in that: The composite sleeve (3) is integrally provided with a first ring plate (32) on one side of the torque-dividing convex tooth (31); the outer end of the first shaft column (12) is sleeved with a first bearing (4); one side of the outer ring of the first bearing (4) is abutted against the second shaft column (13), and the other side is abutted against the outer end of the first ring plate (32) to clamp and fix the first bearing (4).

5. The composite transmission device for a high-speed and high-torque new energy vehicle electric drive assembly according to claim 3 is characterized in that: The composite sleeve (3) is provided with torsion splitting dog teeth (33) in an annular distribution on one side of the transmission shaft (2); the transmission shaft (2) is provided with a torsion splitting dog ring (22) corresponding to the torsion splitting dog teeth (33); the torsion splitting dog ring (22) is inserted into the tooth groove corresponding to the torsion splitting dog teeth (33), so that the composite sleeve (3) is connected to the transmission shaft (2) in a transmission manner.

6. A composite transmission device for a high-speed and high-torque new energy vehicle electric drive assembly according to claim 5, characterized in that: The composite sleeve (3) is connected to the torsion dog teeth (33) by snapping with the torsion dog ring (22), so that the composite sleeve (3) is clamped between the first shaft column (12) and the transmission shaft (2), and an axial pre-tightening gap is left between the composite sleeve (3) and the rotor shaft (1) and the transmission shaft (2).

7. The composite transmission device for a high-speed and high-torque new energy vehicle electric drive assembly according to claim 1, characterized in that: The tooth surfaces of the rotor shaft (1), the composite sliding sleeve (3) and the transmission shaft (2) are nitrided and coated with a wear-resistant coating.

8. The composite transmission device for a high-speed and high-torque new energy vehicle electric drive assembly according to claim 1, characterized in that: The power splitting method of the composite transmission device is as follows: the rotor shaft (1) is externally connected to power input, and the torque is split and transmitted through a first transmission structure and a second transmission structure, wherein the first transmission structure is connected by a direct drive spline tooth (11) and a direct drive internal spline (21) to transmit the torque to the transmission shaft (2); the second transmission structure is connected by a torque splitting concave tooth (14) and a torque splitting convex tooth (31) to transmit the torque to the composite sliding sleeve (3), and the torque splitting dog tooth (33) body at the outer end of the composite sliding sleeve (3) is connected to the torque splitting dog tooth (33) ring to transmit the torque to the transmission shaft (2).

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