Variable-power electric driving system

Abstract

The invention provides a variable-power electric driving system which comprises a stator assembly, a rotor assembly, a rear end cover, a speed reducer input shaft and a pushing mechanism, the rotor assembly comprises a rotor iron core, a rotating shaft and a sliding sleeve, one end of the rotating shaft is rotationally arranged in the rear end cover, and the other end of the rotating shaft is coaxially connected with the speed reducer input shaft; the sliding sleeve is sleeved outside the rotating shaft, the rotor core is sleeved outside the sliding sleeve, the sliding sleeve is in clearance fit with the rotating shaft, and the rotor core is in interference fit with the sliding sleeve; and the pushing mechanism is arranged on the rotating shaft, the pushing mechanism is connected with the sliding sleeve, and the pushing mechanism is used for pushing the sliding sleeve to slide on the rotating shaft. According to the invention, the motor can be provided with a plurality of high-efficiency areas, so that the motor can work in different high-efficiency areas according to different vehicle conditions, the efficiency of the electric driving system can be improved, and the energy consumption of the whole vehicle can be reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy vehicles, and in particular relates to a variable power electric drive system. Background Art

[0002] The electric drive system is the core component of electric vehicles, which mainly includes a motor, a reducer and a motor controller. The motor mainly includes a motor housing, a stator assembly and a rotor assembly. The stator assembly is interference-fitted with the motor housing. The rotor assembly includes a rotor core and a rotating shaft. One end of the rotating shaft is set on the rear end cover, and the other end of the rotating shaft is matched with the input shaft of the reducer. When in use, the stator winding in the stator assembly will generate a rotating magnetic field after the three-phase alternating current is passed through. The rotor assembly will generate an induced electromotive force and current under the action of the rotating magnetic field, forming an electromagnetic torque, causing the rotor assembly to rotate.

[0003] However, the matching length between the stator and the rotor in the existing electric drive system, that is, the length of the rotor core in the stator assembly is fixed, resulting in a relatively single high-efficiency zone of the electric drive system of the electric vehicle, resulting in a large energy consumption of the entire vehicle.

[0004] Therefore, how to design a variable power electric drive system to improve the energy consumption of the entire vehicle has become a technical problem that technicians in this field urgently need to solve. Summary of the invention

[0005] The purpose of the present invention is to provide a variable power electric drive system to solve the above technical problems in the prior art.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A variable power electric drive system comprises a stator assembly, a rotor assembly, a rear end cover, a reducer input shaft, and a pushing mechanism, wherein the rotor assembly comprises a rotor core, a rotating shaft, and a sliding sleeve, wherein one end of the rotating shaft is rotatably arranged in the rear end cover, and the other end of the rotating shaft is coaxially connected to the reducer input shaft; the sliding sleeve is sleeved outside the rotating shaft, the rotor core is sleeved outside the sliding sleeve, the sliding sleeve is clearance-fitted with the rotating shaft, and the rotor core is interference-fitted with the sliding sleeve; the pushing mechanism is arranged on the rotating shaft, the pushing mechanism is connected to the sliding sleeve, and the pushing mechanism is used to push the sliding sleeve to slide on the rotating shaft.

[0008] Preferably, the pushing mechanism includes a main body, an electromagnetic coil, a push ring and a push plate, the main body is fixedly sleeved on the rotating shaft, the electromagnetic coil is arranged in the first annular cavity of the main body, the push ring is arranged in the second annular cavity of the main body, and the electromagnetic coil is located on the outside of the push ring; the push plate is located on the side of the main body close to the rotor core, and one end of the push ring close to the rotor core passes through the main body and is connected to the push plate, and a through hole is provided on the push plate for the rotating shaft to pass through, and the through hole is matched with the rotating shaft gap; the sliding sleeve is connected to the side of the push plate close to the rotor core.

[0009] Preferably, a fixing ring for connecting with the rotor core is provided on one side of the push plate close to the rotor core.

[0010] Preferably, an annular protrusion is provided on a side of the push ring away from the rotor core, and the annular protrusion is used to block and engage with a side of the second annular cavity away from the rotor core.

[0011] Preferably, a limiting portion is provided on the outer circumferential surface of the push ring, and an end surface of the limiting portion close to the push plate is used to block with the limiting surface of the second annular cavity, and there is a gap between the limiting surface and the end surface of the limiting portion close to the push plate.

[0012] Preferably, the limiting portion is an annular structure.

[0013] Preferably, there are two pushing mechanisms, one of which is disposed on the rotating shaft between the rear end cover and the sliding sleeve, and the other of which is disposed on the rotating shaft between the reducer input shaft and the sliding sleeve.

[0014] Preferably, the rotating shaft is spline-connected to the reducer input shaft.

[0015] The beneficial effects of the present invention are:

[0016] The variable power electric drive system of the present invention, when in use, can push the sliding sleeve to slide on the rotating shaft through the pushing mechanism, so that the rotor core moves with the sliding sleeve, so that the matching length between the rotor core and the stator assembly can be conveniently adjusted, thereby changing the power range of the motor when it is working, so that the motor can have multiple high-efficiency zones, so that the motor can work in different high-efficiency zones according to different vehicle conditions, thereby reducing the energy consumption of the entire vehicle and improving the efficiency of the electric drive system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the embodiments, and further describe the specific embodiments of the present invention in detail in conjunction with the drawings, wherein

[0018] Figure 1 A schematic diagram of a variable power electric drive system provided by an embodiment of the present invention;

[0019] Figure 2 A cross-sectional view of a variable power electric drive system provided by an embodiment of the present invention;

[0020] Figure 3 A schematic diagram of a driving mechanism provided by an embodiment of the present invention;

[0021] Figure 4 A partial enlarged view of the pushing mechanism provided in an embodiment of the present invention.

[0022] Markings in the accompanying drawings:

[0023] 11. stator assembly; 21. rotating shaft; 22. sliding sleeve; 23. rotor core;

[0024] 31. Pushing mechanism, 32. Main body, 33. Electromagnetic coil, 34. Pushing ring,

[0025] 341, annular protrusion, 342, limiting portion,

[0026] 343, an end surface of the limiting portion close to the push plate, 344, a limiting surface,

[0027] 35. Push plate; 36. Fixed ring; 41. Rear end cover; 51. Reducer input shaft. DETAILED DESCRIPTION

[0028] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0029] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0030] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0031] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0032] like Figures 1 to 4 As shown, an embodiment of the present invention provides a variable power electric drive system, which includes a stator assembly 11, a rotor assembly, a rear end cover 41, a reducer input shaft 51, and a pushing mechanism. The rotor assembly includes a rotor core 23, a rotating shaft 21 and a sliding sleeve 22. One end of the rotating shaft 21 is rotatably arranged in the rear end cover 41, and the other end of the rotating shaft 21 is coaxially connected to the reducer input shaft 51; the sliding sleeve 22 is sleeved outside the rotating shaft 21, and the rotor core 23 is sleeved outside the sliding sleeve 22. The sliding sleeve 22 and the rotating shaft 21 are clearance-fitted, and the rotor core 23 and the sliding sleeve 22 are interference-fitted; the pushing mechanism is arranged on the rotating shaft 21, the pushing mechanism is connected to the sliding sleeve, and the pushing mechanism is used to push the sliding sleeve 22 to slide on the rotating shaft 21.

[0033] The variable power electric drive system provided in an embodiment of the present invention, when in use, can push the sliding sleeve 22 to slide on the rotating shaft 21 through a pushing mechanism, so that the rotor core 23 moves with the sliding sleeve, so that the matching length between the rotor core and the stator assembly can be conveniently adjusted, thereby changing the power range of the motor when it is working, so that the motor can have multiple high-efficiency zones, so that the motor can work in different high-efficiency zones according to different vehicle conditions, thereby reducing the energy consumption of the entire vehicle and improving the efficiency of the electric drive system.

[0034] Further, the pushing mechanism 31 includes a body 32, an electromagnetic coil 33, a push ring 34 and a push plate 35, wherein the body 32 is fixedly sleeved on the rotating shaft 21, the electromagnetic coil 33 is arranged in the first annular cavity of the body, the push ring 34 is arranged in the second annular cavity of the body, and the electromagnetic coil is located outside the push ring; the push plate 35 is located on the side of the body close to the rotor core, and one end of the push ring close to the rotor core passes through the body and is connected to the push plate 35, and a through hole for the rotating shaft to pass through is arranged on the push plate, and the through hole is in clearance with the rotating shaft; the sliding sleeve is connected to the side of the push plate close to the rotor core. With this scheme, when the electromagnetic coil is energized, the push ring can be pushed to move left and right in the second annular cavity, and then the push ring drives the push plate, the sliding sleeve and the rotor core to move left and right on the rotating shaft, so that the matching length between the rotor core and the stator assembly, that is, the axial length of the rotor core in the stator assembly can be conveniently adjusted.

[0035] Specifically, a fixing ring 36 for connecting with the rotor core is provided on one side of the push plate 35 close to the rotor core, so that the connection between the push plate and the rotor core can be conveniently achieved through the fixing ring, thereby making it easier to drive the rotor core and the sliding sleeve to move left and right on the rotating shaft.

[0036] Preferably, an annular protrusion 341 is provided on the side of the push ring 34 away from the rotor core, and the annular protrusion is used to block and engage with the side of the second annular cavity away from the rotor core, so that when the annular protrusion blocks and engages with the side of the second annular cavity away from the rotor core, the push ring stops moving, thereby better achieving the limitation of the push ring.

[0037] Furthermore, a limiting portion 342 is provided on the outer circumferential surface of the push ring 34, and an end surface 343 of the limiting portion close to the push plate is used to block with a limiting surface 344 of the second annular cavity, and there is a gap between the limiting surface 344 and an end surface of the limiting portion close to the push plate. With this solution, when the end surface of the limiting portion close to the push plate blocks with the limiting surface, the push plate is limited; at the same time, the length of the gap between the limiting surface 344 and the end surface 343 of the limiting portion close to the push plate in the axial direction of the rotating shaft 21, that is, the horizontal distance between the two, is the stroke of the push ring, the sliding sleeve and the rotor core when they move left and right.

[0038] Preferably, the limiting portion 342 is an annular structure, so as to play a better limiting role.

[0039] In one embodiment, there are two pushing mechanisms 31, one of which is arranged on the rotating shaft 21 between the rear end cover and the sliding sleeve, and the other is arranged on the rotating shaft 21 between the input shaft of the reducer and the sliding sleeve, that is, the two pushing mechanisms are symmetrically arranged on the left and right sides of the sliding sleeve, and the push plates of the two pushing mechanisms are respectively connected to the left and right ends of the sliding sleeve. With this solution, when in use, the push plates of the two pushing mechanisms act synchronously to always keep the sliding sleeve 22 and the rotor core 23 clamped, so that after the sliding sleeve and the rotor core are pushed to the specified position, when the rotor core rotates, the rotating shaft will be driven to rotate with it through the pushing mechanism.

[0040] Preferably, the annular protrusion, the limiting portion and the push ring are an integrated structure.

[0041] Specifically, the rotating shaft 21 is spline-connected to the reducer input shaft 51, thereby conveniently realizing the connection between the rotating shaft and the reducer input shaft. At this time, an external spline may be provided on the right end of the rotating shaft, and an internal spline for matching with the external spline is provided in the left end of the reducer input shaft.

[0042] The specific principle of changing the power of the motor when it is working by adjusting the matching length between the rotor core and the stator assembly is:

[0043] According to the induced electromotive force formula: E=4.44*f*N*Ф, where E is the electromotive force of the coil, f is the frequency, S is the cross-sectional area of ​​the conductor (such as the rotor core) wound around, N is the number of turns, and Ф is the magnetic flux; wherein the magnetic flux calculation formula Ф=B*S*cosθ, when the plane with an area of ​​S is perpendicular to the magnetic field direction, the angle θ is 0, and cosθ is equal to 1, and the formula for the magnetic flux in the embodiment of the present invention becomes Ф=B*S;

[0044] Combining the above two formulas, we can get the formula for calculating the motor magnetic flux intensity: B=E / (4.44*f*N*S);

[0045] According to the Ampere force formula: F=I*L*B*sinα, where I is the current intensity, L is the conductor length (i.e. the matching length of the stator assembly and the rotor core), B is the motor magnetic flux intensity, and α is the angle between the current direction and the magnetic field direction. When the conductor is perpendicular to the magnetic field, the formula becomes F=I*L*B;

[0046] When the force is known, the power calculation formula is P=F*V, and V=2πR 2 , where P is power, V is speed, and R is the radius of the rotor core, we can deduce P=I*L*B*sinα*2πR 2 It can be seen that the power P is proportional to L. When the rotor core moves axially in the stator assembly, the matching length of the rotor core and the stator assembly, i.e., L, can be changed, which also changes the working length of the rotor core and changes the power of the motor accordingly.

[0047] The present invention drives the sliding sleeve to move left and right on the rotating shaft through the pushing mechanism within its stroke to adjust the matching length of the rotor core and the stator assembly, that is, the length of the rotor core extending from the stator assembly, that is, the horizontal distance between the left end face of the rotor core and the left end face of the positioning assembly, and then calibrates the high-efficiency zones at different stator-rotor matching lengths. Then, during driving, according to the requirements of vehicle speed, torque, etc., the pushing mechanism is made to work to different strokes, so that the motor can have multiple high-efficiency zones. Under different vehicle conditions, the motor can work in the high-efficiency zone corresponding to the vehicle condition, thereby improving the efficiency of the electric drive system and reducing energy consumption.

[0048] The present invention improves the traditional single high-efficiency zone electric drive system into a multi-high-efficiency zone electric drive system, which can improve the efficiency of the entire vehicle and reduce the energy consumption of the vehicle.

[0049] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A variable power electric drive system, characterized in that: It includes a stator assembly, a rotor assembly, a rear end cover, a reducer input shaft, and a pushing mechanism. The rotor assembly includes a rotor core, a rotating shaft and a sliding sleeve. One end of the rotating shaft is rotatably arranged in the rear end cover, and the other end of the rotating shaft is coaxially connected to the reducer input shaft; the sliding sleeve is sleeved outside the rotating shaft, the rotor core is sleeved outside the sliding sleeve, the sliding sleeve is clearance-fitted with the rotating shaft, and the rotor core is interference-fitted with the sliding sleeve; the pushing mechanism is arranged on the rotating shaft, the pushing mechanism is connected to the sliding sleeve, and the pushing mechanism is used to push the sliding sleeve to slide on the rotating shaft.

2. The variable power electric drive system according to claim 1, characterized in that: The pushing mechanism includes a main body, an electromagnetic coil, a push ring and a push plate. The main body is fixedly sleeved on the rotating shaft, the electromagnetic coil is arranged in the first annular cavity of the main body, the push ring is arranged in the second annular cavity of the main body, and the electromagnetic coil is located on the outside of the push ring; the push plate is located on the side of the main body close to the rotor core, and one end of the push ring close to the rotor core passes through the main body and is connected to the push plate. A through hole is provided on the push plate for the rotating shaft to pass through, and the through hole is matched with the rotating shaft gap; the sliding sleeve is connected to the side of the push plate close to the rotor core.

3. The variable power electric drive system according to claim 2, characterized in that: A fixing ring for connecting with the rotor core is arranged on one side of the push plate close to the rotor core.

4. The variable power electric drive system according to claim 2, characterized in that: An annular protrusion is provided on the side of the push ring away from the rotor core, and the annular protrusion is used to block and connect with the side of the second annular cavity away from the rotor core.

5. The variable power electric drive system according to claim 2, characterized in that: A limiting portion is arranged on the outer circumferential surface of the push ring, and an end surface of the limiting portion close to the push plate is used to block with the limiting surface of the second annular cavity, and a gap is provided between the limiting surface and an end surface of the limiting portion close to the push plate.

6. The variable power electric drive system according to claim 5, characterized in that: The limiting portion is an annular structure.

7. The variable power electric drive system according to claim 1, characterized in that: There are two pushing mechanisms, one of which is arranged on the rotating shaft between the rear end cover and the sliding sleeve, and the other is arranged on the rotating shaft between the reducer input shaft and the sliding sleeve.

8. The variable power electric drive system according to any one of claims 1 to 7, characterized in that: The rotating shaft is spline-connected to the input shaft of the reducer.

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