Electric motor

Abstract

This electric motor is provided with an inner periphery side rotor, an outer periphery side rotor, and a rotating device that can change a relative phase between these rotors by rotating at least one of them about a rotational axis thereof. The rotating device is provided with a first member integrally and rotatably provided to the outer periphery side rotor, and a second member integrally fixed on an inside of the inner periphery side rotor which together with the first member defines a pressure chamber on the inside of the inner periphery side rotor. The rotating device changes a relative phase between the inner periphery side rotor and the outer periphery side rotor by supplying a hydraulic fluid to the pressure chamber. The rotating device is further provided with a linking passage that leaks the hydraulic fluid supplied to the pressure chamber to an outside of the pressure chamber.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of an essential portion of an electric motor according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view showing an inner periphery side rotor, an outer periphery side rotor, and a rotating mechanism of the electric motor.

FIG. 3 is an elevation view showing the inner periphery side rotor, the outer periphery side rotor, without a drive plate in front, indicating a strong magnetic field state of the rotating mechanism of the electric motor. This figure shows a passage groove of the drive plate in front by two-dotted lines.

FIG. 4 is an elevation view showing the inner periphery side rotor, the outer periphery side rotor, without the drive plate in front showing a weak magnetic field state of the rotating mechanism of the electric motor. This figure shows the passage groove of the drive plate in front by two-dotted lines.

FIG. 5 is an elevation view showing the inner periphery side rotor, the outer periphery side rotor, without the drive plate in front showing the strong magnetic field state of the rotating mechanism of the electric motor. This figure shows the passage groove of the drive plate at the back by two-dotted lines.

FIG. 6 is a part perspective view that shows the inner periphery side rotor without the drive plate in front showing the weak magnetic field state of a vane rotor of the electric motor. This figure shows the passage groove of the drive plate in front by two-dotted lines.

FIG. 7A schematically shows the strong magnetic field state of permanent magnets of the inner periphery side rotor and permanent magnets of the outer periphery side rotor disposed in an unlike-pole facing arrangement. FIG. 7B schematically shows the weak magnetic field state of the poles of the permanent magnets of the inner periphery side rotor and the permanent magnets of the outer periphery side rotor disposed in a like-pole facing arrangement.

FIG. 8 is a graph showing the induced voltage in the strong magnetic field state and the weak magnetic field state shown in FIG. 7.

FIG. 9A is a graph showing a relationship between the electric current and torque of the electric motor that vary in response to the induced voltage constant Ke. FIG. 9B is a graph showing the relationship between the revolution speed and the field weakening loss of the electric motor that vary in response to the induced voltage constant Ke.

FIG. 10 shows the operable region for revolution speed and torque of the electric motor that varies in response to the induced voltage constant.

FIG. 11A is a graph showing the relationship between the electric current and the revolution speed of the electric motor that vary in response to the induced voltage constant Ke. FIG. 11B is a graph showing the relationship between the revolution speed and the output of the electric motor that vary in response to the induced voltage constant Ke.

FIG. 12A shows the distribution of operable regions and efficiency for the revolution speed and the torque of the electric motor that vary in response to the induced voltage constant Ke in one example. FIG. 12B shows the distribution of operable regions and efficiency for the revolution speed and the torque of the electric motor that vary in response to the induced voltage constant Ke in the second comparative example.

FIG. 13 is a cross-sectional view of an essential portion of an electric motor according to a second embodiment of the present invention.

FIG. 14 is an elevation view showing an inner periphery side rotor and an outer periphery side rotor, without a drive plate in front, indicating the weak magnetic field state of a rotating mechanism of the electric motor.

FIG. 15A and FIG. 15B show the around of bolt connected parts of the outer periphery side rotor and the drive plate of the electric motor. FIG. 15A shows a partially enlarged cross-sectional view before assembly of the electric motor, while FIG. 15B shows a partially enlarged cross-sectional view after assembly of the electric motor.

FIG. 16 is an elevation view showing the inner periphery side rotor and the outer periphery side rotor, without the drive plate in front, and indicating the strong magnetic field state of the rotating mechanism of the electric motor.

FIG. 17A schematically shows the strong magnetic field state of permanent magnets of the inner periphery side rotor and permanent magnets of the outer periphery side rotor disposed in an unlike-pole facing arrangement. FIG. 17B shows a schematic view of the weak magnetic field state in which the poles of permanent magnets of the inner periphery side rotor and the permanent magnets of the outer periphery side rotor are disposed in a like-pole facing arrangement.

FIG. 18 is a graph showing the induced voltage in the strong magnetic field state and the weak magnetic field state shown in FIG. 17A and FIG. 17B.

FIG. 19A is a graph showing the relationship between the electric current and the torque of the electric motor that vary in response to the induced voltage constant Ke. FIG. 19B is a graph showing the relationship between the revolution speed and the field weakening loss of the electric motor that vary in response to the induced voltage constant Ke.

FIG. 20 shows an operable region for the revolution speed and the torque of the electric motor that varies in response to the induced voltage constant.

FIG. 21A is a graph showing the relationship between the electric current and the revolution speed of the electric motor that vary in response to the induced voltage constant Ke. FIG. 21B is a graph showing the relationship between the revolution speed and the output of the electric motor that vary in response to the induced voltage constant Ke.

FIG. 22A shows the distribution of operable regions and efficiency for revolution speed and torque of the electric motor that vary in response to the induced voltage constant Ke in the embodiment. FIG. 22B shows the distribution of operable regions and efficiency for revolution speed and torque of the electric motor that vary in response to the induced voltage constant Ke in the second comparative example.

FIG. 23 is a cross-sectional view of an essential portion of an electric motor according to a third embodiment of the present invention.

FIG. 24 is an elevation view showing an inner periphery side rotor and an outer periphery side rotor, without a drive plate in front, and indicating the weak magnetic field state of the rotating mechanism of the electric motor.

FIG. 25 is an exploded perspective view showing the inner periphery side rotor, the outer periphery side rotor, and the rotating mechanism of the electric motor.

FIG. 26 is an elevation view showing the inner periphery side rotor and the outer periphery side rotor, without the drive plate in front indicating the strong magnetic field state of the rotating mechanism of the electric motor.

FIG. 27A shows a schematic view of the strong magnetic field state of permanent magnets of the inner periphery side rotor and permanent magnets of the outer periphery side rotor disposed in an unlike-pole facing arrangement. FIG. 27B shows a schematic view of the weak magnetic field state in which the poles of permanent magnets of the inner periphery side rotor and permanent magnets of the outer periphery side rotor are disposed in a like-pole facing arrangement.

FIG. 28 is a graph showing the induced voltage in the strong magnetic field state and the weak magnetic field state shown in FIG. 27A.

FIG. 29A is a graph showing the relationship between the electric current and torque of the electric motor that vary in response to the induced voltage constant Ke. FIG. 29B is a graph showing the relationship between the revolution speed and the field weakening loss of the electric motor that vary in response to the induced voltage constant Ke.

FIG. 30 shows the operable region for revolution speed and the torque of the electric motor that varies in response to the induced voltage constant.

FIG. 31A is a graph showing the relationship between the electric current and the revolution speed of the electric motor that vary in response to the induced voltage constant Ke. FIG. 31B is a graph showing the relationship between the revolution speed and the output of the electric motor that vary in response to the induced voltage constant Ke.

FIG. 32A shows the distribution of operable regions and the efficiency for revolution speed and torque of the electric motor that vary in response to the induced voltage constant Ke in the embodiment. FIG. 32B shows the distribution of operable regions and the efficiency for the revolution speed and the torque of the electric motor that vary in response to the induced voltage constant Ke in the second comparative example.

Claims

1. An electric motor comprising: an inner periphery side rotor provided with inner peripheral permanent magnets disposed along a circumferential direction thereof;an outer periphery side rotor provided with outer peripheral permanent magnets disposed along a circumferential direction thereof such that a rotational axis thereof is coaxial with a rotational axis of the inner periphery side rotor; anda rotating device that can change a relative phase between the inner periphery side rotor and the outer periphery side rotor by rotating at least the inner periphery side rotor or the outer periphery side rotor about the rotational axis, whereinthe rotating device:is provided with a first member integrally and rotatably provided to the outer periphery side rotor, and a second member integrally fixed on an inside of the inner periphery side rotor which together with the first member defines a pressure chamber on the inside of the inner periphery side rotor;changes the relative phase between the inner periphery side rotor and the outer periphery side rotor by supplying a hydraulic fluid to the pressure chamber; andis further provided with a linking passage that leaks the hydraulic fluid supplied to the pressure chamber to an outside of the pressure chamber.

2. The electric motor according to claim 1, wherein: the linking passage is a through hole from the pressure chamber provided in the second member to an outer periphery; anda flow passage that links the through hole is formed between the inner periphery side rotor and the second member.

3. The electric motor according to claim 2, wherein: the first member is a vane rotor which is installed integrally with the outer periphery side rotor, is disposed on the inside of the inner periphery side rotor, and has multiple blades;the second member is a housing with multiple grooves, which together with the blades defines the pressure chamber and is integrally installed on the inside of the inner periphery side rotor while rotatably housing the blades of the vane rotor; andthe through holes linking the flow passage are formed in each of the multiple pressure chambers.

4. The electric motor according to claim 3, wherein: the flow passage is formed in a spiral shape extending along the circumferential direction, and links to the through holes formed in each of the multiple pressure chambers; andan end of the flow passage opens to an end face of the inner periphery side rotor.

5. The electric motor according to claim 1, wherein: the first member is a vane rotor which is disposed on the inside of the inner periphery side rotor, and is integrally installed with the outer periphery side rotor;the second member is a housing with multiple grooves, which together with the vane rotor defines the pressure chamber and is integrally installed on the inside of the inner periphery side rotor while rotatably housing the blades of the vane rotor;the inner periphery side rotor is rotatably disposed in the circumferential direction in a space between the surrounding outer periphery side rotor, the vane rotor and two end plates, by fixing the end plates that transmit the drive force of the outer periphery side rotor to an output shaft on the sides of the two ends in the axial direction of the outer periphery side rotor and the vane rotor; andthrough holes are formed laterally in a gap between the outer periphery side rotor and the inner periphery side rotor in the end plates.

6. The electric motor according to claim 1, wherein the linking passage is a fluid passage that links the pressure chamber, and a gap between the inner periphery side rotor and the outer periphery side rotor.

7. The electric motor according to claim 6, wherein notches are formed in the wall of the pressure chamber that enable the fluid passage to remain always open to the pressure chamber regardless of the relative position of the vane rotor.

8. The electric motor according to claim 7, wherein the fluid passage is formed in the end plate.

9. The electric motor according to claim 8, wherein a second fluid passage is formed in the end plate extending from the gap to the outer periphery side rotor.

10. The electric motor according to claim 9, wherein the second fluid passage is formed in both end plates of the pair of end plates, and a phase in the circumferential direction of the second fluid passage installed in one of the end plates differ from a phase in the circumferential direction of the second fluid passage installed in the another end plate.