Variable magnetic field rotary electric machine

Abstract

The application provides a variable magnetic field rotating electric machine, which comprises a stator fixed in a casing, a rotor, and a rotor shaft, wherein the rotor is sleeved on the rotor shaft, the front end of the rotor shaft is provided with an output gear, and the output gear is engaged with a second gear to generate an axial force when transmitting power, the axial force acts on the rotor shaft to make the rotor shaft axially move together with the rotor, and the axial position of the rotor relative to the stator is changed. The variable magnetic field rotating electric machine of the application utilizes the axial force generated when the output gear arranged on the rotor shaft is engaged with other gears to transmit power to push the rotor shaft to axially move, change the relative position of the rotor and the stator, weaken the magnetic flux and back electromotive force, and thus increase the maximum rotating speed.

Description

[TECHNICAL FIELD]

[0001] The present application relates to a variable magnetic field rotating electric machine. [BACKGROUND]

[0002] The existing permanent magnet drive motor for vehicle requires wide constant power area. However, when the motor speed increases to a certain speed, the back electromotive force is equal to the power supply voltage, then the speed is difficult to further increase, and the performance of the system is greatly limited.

[0003] In the existing variable magnetic field motor, for example, the rotor is axially moved out of the stator, or the stator is moved to reduce the overlapping part with the rotor core, which can reduce the magnetic flux and thus reduce the back electromotive force, so that the increase of the rotating speed is possible.

[0004] However, in the known variable magnetic field motor, in order to realize the axial movement of the rotor or the stator, a large axial force needs to be overcome, a large moving actuator needs to be provided, and a large amount of energy needs to be consumed. Therefore, it is also expected to provide a small high-performance variable magnetic field rotating electric machine. [SUMMARY]

[0005] In order to overcome the problems existing in the prior art, the present application provides a variable magnetic field rotating electric machine.

[0006] The variable magnetic field rotating electric machine of the present application comprises a stator fixed in a housing, a rotor, and a rotor shaft, wherein the rotor is sleeved on the rotor shaft, the front end of the rotor shaft is provided with an output gear, the output gear is engaged and driven with a second gear to generate an axial force, the axial force acts on the rotor shaft to move the rotor shaft and the rotor axially together, and the axial position of the rotor relative to the stator is changed.

[0007] Preferably, the rotor has two limit positions, i.e. a first position with minimum magnetic flux and a second position with maximum magnetic flux, and the rotor moves steplessly between the first position and the second position under the action of the axial force.

[0008] Preferably, the first position is set according to the maximum rotating speed of the variable magnetic field rotating electric machine, and the second position is set according to the maximum torque of the variable magnetic field rotating electric machine.

[0009] Preferably, when the rotating speed of the rotor is zero, the rotor is located at the first position, and as the output torque of the variable magnetic field rotating electric machine increases, the rotor moves from the first position to the second position; when the rotating speed of the rotor increases to the maximum output power of the variable magnetic field rotating electric machine, as the output torque of the variable magnetic field rotating electric machine decreases, the rotor moves from the second position to the first position.

[0010] Preferably, the rotating shaft is supported on the housing by a bearing, and the rotor sleeve is arranged on the rotating shaft and can drive the rotating shaft to rotate and can move axially on the rotating shaft.

[0011] Preferably, an oil chamber and a spring are provided between the rotating shaft and the rotor shaft, and the damping force generated by the oil in the oil chamber, the spring force generated by the spring and the axial force jointly determine the axial position of the rotor shaft relative to the rotating shaft.

[0012] Preferably, the oil chamber includes a first oil chamber and a second oil chamber connected through a damping hole.

[0013] Preferably, the tooth width of the output gear is equal to the sum of the axial movement distance of the rotor shaft and the tooth width of the second gear.

[0014] Preferably, it also includes: an axial position sensor, which is installed between the casing and the rotor shaft and is used to detect the axial position of the rotor shaft.

[0015] Preferably, it also includes: a rotor position sensor, which is installed between the casing and the rotating shaft and is used to detect the angular position of the rotor.

[0016] Compared with the prior art, the variable magnetic field rotating motor of the present invention utilizes the axial force generated when the output gear installed on the rotor shaft engages with other gears to move the rotor shaft, thereby changing the relative position of the rotor and stator, weakening the magnetic flux and back electromotive force, and thus increasing the maximum speed. [Brief Description of the Drawings]

[0017] Figure 1 is a schematic structural diagram of a variable magnetic field rotating motor according to a specific embodiment of the present invention;

[0018] Figure 2 1 is a schematic diagram of output characteristics of a variable magnetic field rotating motor according to a specific embodiment of the present invention;

[0019] Figure 3 is a structural schematic diagram of a variable magnetic field rotating electrical machine according to another specific embodiment of the present invention, wherein the rotor moves to a first position;

[0020] Figure 4 yes Figure 3 A schematic structural diagram of a variable magnetic field rotating electrical machine according to a specific embodiment is shown, wherein the rotor moves to a second position. [Specific implementation method]

[0021] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0022] As shown in Figure 1 Variable magnetic field rotating electric machine 100, comprising: stator 11, fixed in the housing (not shown); rotor 12; rotor shaft 13, rotor 12 is set on the rotor shaft 13, the front end of the rotor shaft 13 is provided with output gear 131, the output gear 131 is engaged with the second gear 14 to produce axial force, the axial force acts on the rotor shaft 13 to make the rotor shaft 13 move axially with the rotor 12, change the axial position of the rotor 12 relative to the stator 11.

[0023] The axial force generated by the gear engagement does not need external energy, so as to push the rotor shaft 13 to move axially with the rotor 12, change the axial position of the rotor 12 relative to the stator 11, reduce the magnetic flux, so as to improve the maximum speed, expand the constant power area, and obtain a small high-performance variable magnetic field rotating electric machine.

[0024] As shown in Figure 2 Preferably, the rotor 12 has two limit positions, i.e. the first position P1 with the minimum magnetic flux and the second position P2 with the maximum magnetic flux, and the rotor 12 moves steplessly between the first position P1 and the second position P2 under the action of the axial force. The rotor 12 can also move in segments between the first position P1 and the second position P2 under the action of the axial force, i.e. a plurality of positions are also arranged between the first position P1 and the second position P2, and the rotor 12 moves to these positions, which can be selected according to specific conditions, and is not limited thereto.

[0025] Preferably, the first position P1 is set according to the maximum speed n max of the variable magnetic field rotating electric machine 100; and the second position P2 is set according to the maximum torque T max of the variable magnetic field rotating electric machine 100. When the core of the rotor 12 is completely axially coincident with the core of the stator 11, this is the position with the maximum magnetic flux, and the maximum torque required can be realized. When the core of the rotor 12 is partially axially coincident with the core of the stator 11, for example 50%, the maximum speed can be increased to twice that of the complete coincidence, which can be selected according to specific conditions, and is not limited thereto.

[0026] Preferably, when the speed of the rotor 12 is zero, the rotor 12 is located at the first position P1, and as the output torque of the variable magnetic field rotating electric machine 100 increases, the rotor 12 moves from the first position P1 to the second position P2; when the speed of the rotor 12 increases to the maximum output power of the variable magnetic field rotating electric machine 100, as the output torque of the variable magnetic field rotating electric machine 100 decreases, the rotor 12 moves from the second position P2 to the first position P1.

[0027] For example, when the vehicle starts to accelerate, the rotor 12 is at rest, the rotor 12 is at the first position P1, as the accelerator pedal is pressed, the output torque of the variable magnetic field rotating electric machine 100 gradually increases, the axial force of the output gear 131 also gradually increases, the rotor 12 moves from the first position P1 to the second position P2, when the rotor 12 moves to the second position P2, the torque reaches the maximum torque T max When the rotor 12 increases to the maximum output power P max of the variable magnetic field rotating electric machine 100, that is, enters the constant power area, as the output torque decreases, the axial force also decreases, the rotor 12 moves from the second position P2 to the first position P1, the decrease of the magnetic flux makes the back electromotive force decrease, when the rotor 12 reaches the first position P1, the speed increases to the maximum speed n max .

[0028] When the accelerator pedal is kept at a certain opening, the rotor 12 is kept at a certain position P between the first position P1 and the second position P2, and the speed increases to the maximum output power P max of the variable magnetic field rotating electric machine 100, the output torque decreases, the rotor 12 moves to the first position P1 until it reaches the first position P1, and the maximum speed n max .

[0029] It should be made, other types of variable magnetic field rotating electric machine 100 output characteristics are also possible, can be set according to actual needs, and not limited to this.

[0030] As Figure 3 And Figure 4 Also includes: the rotating shaft 15 is supported by the bearing on the shell (not shown), the rotor shaft 13 is sleeved on the rotating shaft 15, and can drive the rotating shaft 15 to rotate together, and can move axially on the rotating shaft 15. The rotor shaft 13 is rotating and axially moving, for this, the rotating shaft 15 is provided, which is supported by the bearing on the shell, and the rotor shaft 13 is sleeved on the rotating shaft, not only drives the rotating shaft 15 to rotate, but also can move axially on the rotating shaft 15, so as to realize the support of the axially moving rotor shaft 13, but not limited to this.

[0031] Preferably, an oil chamber 16 and a spring 17 are further arranged between the rotating shaft 15 and the rotor shaft 13, the damping force generated by the oil in the oil chamber 16 and the spring force generated by the spring 17 together determine the axial position of the rotor shaft 13 relative to the rotating shaft 15 with the axial force of the output gear 131. The oil chamber 16 is arranged axially on the rotor shaft 13 or the rotating shaft 15 and is sealed by a sealing ring at both ends. The oil chamber 16 is filled with oil, which provides the required axial damping force when the rotor shaft 13 moves axially relative to the rotating shaft 15, limits the speed of movement, avoids oscillation, and filters out the fluctuation part of the axial force of the output gear 131. Other methods of generating damping force are also possible and not limited thereto.

[0032] The spring 17 arranged on the rotating shaft 15 abuts against the limiting block on the rotating shaft 15 at one end and abuts against the rotor shaft 13 at the other end, providing an elastic thrust force that acts with the axial force of the output gear 131 to determine the axial position of the rotor shaft 13 relative to the rotating shaft 15. The spring 17 can be a cylindrical coil spring, which can have a constant pitch or a variable pitch, i.e., a spring with variable characteristics, and other types of springs are also possible and not limited thereto.

[0033] Preferably, the oil chamber 16 includes a first oil chamber 161 and a second oil chamber 162 that are connected by a damping hole 163. A boss can be arranged on the rotating shaft 15 to divide the oil chamber into the first oil chamber and the second oil chamber, and an annular gap is left between the top of the boss and the rotor shaft 13 as the damping hole 163, through which the oil can pass from the first oil chamber 161 to the second oil chamber 162 or vice versa when the rotor shaft 13 moves relative to the rotating shaft 15, thereby providing a damping force. The size of the damping hole 163 can be set according to actual needs, and other methods that can provide the required damping force are also possible and not limited thereto.

[0034] Preferably, the tooth width of the output gear 131 is equal to the sum of the axial movement distance of the rotor shaft 13 and the tooth width of the second gear 14. The tooth width of a pair of meshing gears is usually set according to the maximum load capacity. However, since the output gear 131 moves axially with the rotor shaft 13, the tooth width of the output gear 131 is equal to the tooth width of the second gear 14 plus the axial movement distance of the rotor shaft 13, but not limited thereto. For example, the width of the second gear 14 can be determined according to the load capacity, and when the output gear 131 moves axially to the first position P1, the speed of the motor is high and the torque is small at this time, so the tooth width of the second gear 14 does not need to correspond to the load capacity, and the tooth width of the second gear 14 can be selected as 2 / 3-1 / 2 according to the actual situation, plus the axial movement distance of the rotor shaft 13 as the tooth width of the output gear 131, which can reduce the axial length and the volume.

[0035] Preferably, further comprising: an axial position sensor (not shown) arranged between the housing and the rotor shaft 13 for detecting the axial position of the rotor shaft 13. The axial position sensor can be a Hall position sensor, but is not limited thereto.

[0036] Preferably, further comprising: a rotor position sensor (not shown) arranged between the housing and the rotor shaft 15 for detecting the angular position of the rotor 13. The rotor position sensor can be a resolver, but is not limited thereto.

[0037] The above-described embodiments of the present application are not intended to define the scope of the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall fall within the scope of the claims of the present application.

Claims

1. A variable magnetic field rotating electrical machine, characterized in that: include: The stator is fixed in the casing; rotor; a rotor shaft, wherein the rotor is sleeved on the rotor shaft, and an output gear is provided at the front end of the rotor shaft. When the output gear is engaged with the second gear for transmission, an axial force is generated. The axial force acts on the rotor shaft to cause the rotor shaft to move axially with the rotor, thereby changing the axial position of the rotor relative to the stator; It also includes: a rotating shaft, which is supported on the housing by bearings, and an oil chamber and a spring are provided between the rotating shaft and the rotor shaft. The damping force generated by the oil in the oil chamber, the spring force generated by the spring, and the axial force jointly determine the axial position of the rotor shaft relative to the rotating shaft.

2. A variable magnetic field rotating electrical machine according to claim 1, characterized in that: The rotor has two extreme positions, namely a first position where the magnetic flux is minimum and a second position where the magnetic flux is maximum. The rotor moves steplessly between the first position and the second position under the action of the axial force.

3. The variable magnetic field rotating electrical machine according to claim 2, characterized in that: The first position is set according to the maximum speed of the variable magnetic field rotating motor; The second position is set according to the maximum torque of the variable magnetic field rotating electric machine.

4. A variable magnetic field rotating electrical machine according to claim 3, characterized in that: When the rotor speed is zero, the rotor is located at the first position, and as the output torque of the variable magnetic field rotating motor increases, the rotor moves from the first position to the second position; when the rotor speed increases until the output power of the variable magnetic field rotating motor reaches a maximum value, as the output torque of the variable magnetic field rotating motor decreases, the rotor moves from the second position to the first position.

5. The variable magnetic field rotating electrical machine according to claim 1, characterized in that: The oil chamber includes a first oil chamber and a second oil chamber which are communicated through a damping hole.

6. The variable magnetic field rotating electrical machine according to claim 1, characterized in that: The tooth width of the output gear is equal to the sum of the axial movement distance of the rotor shaft and the tooth width of the second gear.

7. The variable magnetic field rotating electrical machine according to claim 1, characterized in that: It also includes: an axial position sensor, which is installed between the casing and the rotor shaft and is used to detect the axial position of the rotor shaft.

8. The variable magnetic field rotating electrical machine according to claim 1, characterized in that: It also includes: a rotor position sensor, which is installed between the casing and the rotating shaft and is used to detect the angular position of the rotor.

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