Inner rotor type electric motor

Abstract

To provide an inner rotor type electric motor having a simple configuration, in which a transmission part such as a brake or the like is installed.SOLUTION: An inner rotor type electric motor in which a transmission part is installed comprises: a rotor attached to a revolving shaft; a stator arranged spaced apart from the outer periphery of the rotor, in which a stator coil for generating a rotating magnetic field is stored; and a rotor coil that applies rotation force to the rotor by forming a magnetic field that interacts with the rotating magnetic field via current application. The transmission part comprises an armature that moves from an initial position during no current application to an operational position by applying a current to the rotor coil. The armature connects the rotor with the other member at one of the initial position and the operational position to release connection between the rotor and the other member at the other one of the initial position and the operational position.SELECTED DRAWING: Figure 5A

Description

Technical Field

[0001] This disclosure relates to an inner rotor type motor.

Background Art

[0002] In an inner rotor type motor in which stator coils are present on the outer periphery and a rotor provided inside the stator coils rotates, there is a motor that incorporates a brake in order to fix the rotor when the motor is not driven (for example, see Patent Document 1 below). In this motor, the rotor is fixed by a brake shoe when not driven.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the motor of Patent Document 1, the rotor itself is detached from the brake shoe by using the current flowing through the stator coil when the motor is driven. Therefore, when the motor is driven, it is necessary to hold the rotor at a position where the brake is not applied, and it is necessary to flow a large current that has nothing to do with the driving of the motor, and there is a problem that the efficiency of the motor cannot be improved. In Patent Document 1, although a part of the current flowing through the stator coil is used for the movement of the rotor, even if an independent electromagnetic brake is used, current supply is required for fixing / release, so the electrical efficiency cannot be improved. Also, a dedicated electromagnetic brake is required, which may cause a problem of increasing the size of the device.

Means for Solving the Problems

[0005] This disclosure The inner rotor type motor can be implemented in the following form. This inner rotor type motor includes a rotor attached to a rotating shaft, a stator spaced apart on the outer circumference of the rotor and housing a stator coil for generating a rotating magnetic field, a rotor coil that, when energized, forms a magnetic field that interacts with the rotating magnetic field, thereby acting a rotational force on the rotor, an inverter that controls the application of multiphase AC to the stator coil to generate the rotating magnetic field, and an armature that moves from an initial position when not energized to an operating position by switching the energization of the rotor coil on and off, the armature comprising a transmission unit that connects the rotor to other members at one of the initial position and the operating position, and releases the connection between the rotor and other members at the other of the initial position and the operating position, and the on / off switching of the energization of the rotor coil is performed by switching a DC current separate from the multiphase AC. In the following forms or application examples Implementation is also possible. It is Noh.

[0006] (1) One embodiment of the present disclosure is configured as an inner rotor type electric motor. This inner rotor type electric motor includes a rotor attached to a rotating shaft, a stator provided spaced apart on the outer circumference of the rotor and housing a stator coil for generating a rotating magnetic field, a rotor coil that, when energized, forms a magnetic field that interacts with the rotating magnetic field and thereby applies rotational force to the rotor, and an armature that moves from an initial position when not energized to an operating position when the rotor coil is energized, wherein the armature includes a transmission unit that connects the rotor to other members at one of the initial position and the operating position, and releases the connection between the rotor and other members at the other of the initial position and the operating position. In this way, the armature of the transmission unit can be operated by energizing the rotor coil, and the armature can be connected to and released from other members. For this reason, for example, a configuration in which the transmission unit operates as a brake or as a clutch can be adopted. (2) In the above configuration, the other members of the transmission unit are fixed members that are independent of the rotation of the rotor, and the armature of the transmission unit may be a brake that is coupled with the other members in the initial position to inhibit the rotation of the rotor, and allows the rotor to rotate in the operating position. In this way, the rotation of the rotor can be inhibited in the initial position where no power is supplied to the rotor coil, and no power is required for the braking operation. (3) In the above configuration, the brake may include a rotating member that rotates with the rotating shaft and is mounted to be movable in the axial direction of the rotating shaft, and the armature may be positioned in contact with an elastic member provided on the rotor, and when no power is supplied, it is held in the initial position by the biasing force of the elastic member and applies a braking force to the rotating member, and when power is supplied, the braking force on the rotating member is released at the operating position which is moved against the biasing force of the elastic member. In this way, the braking state when the rotor coil is not powered can be adjusted by adjusting the biasing force of the elastic member. (4) In the above configuration, the elastic member may be a spring having a predetermined free length and housed in a housing provided at the end of the rotor that is shallower than the free length, and the armature may be supported by the spring so as to be able to move along the axial direction of the rotation shaft. In this way, the above adjustment can be easily made by the free length of the spring. (5) In the above configuration, the armature may, in the initial position, bring the rotating member into contact with a part of the housing member surrounding the stator to apply the braking force. In this way, other members can be used in conjunction with a part of the housing member, and the configuration can be simplified. (6) In the above configuration, the other member may be a different rotating shaft from the rotating shaft, and the transmission unit may be a clutch that connects the rotor to the other rotating shaft when the armature is in the operating position, and disconnects the rotor from the other rotating shaft when the armature is in the initial position. In this way, the clutch can be disconnected when the rotor coil is not energized. (7) In the above configuration, the other rotating shaft may be used as a starter motor or alternator for an internal combustion engine, and may be a drive shaft for an internal combustion engine or a rotating shaft that is linked to the drive shaft. In this way, by controlling the energization to the rotor coil, it can be used as a starter motor to crank the internal combustion engine, or as an alternator to regenerate power using the power of the internal combustion engine. (8) In the above configuration, the rotor may be equipped with a claw-pole type rotor core. This allows for miniaturization of the electric motor and improves the efficiency of regenerative power generation. [Brief explanation of the drawing]

[0007] [Figure 1] This diagram shows a schematic cross-sectional view of the motor configuration of an inner rotor type electric motor as an embodiment of the motor. [Figure 2] A perspective view illustrating the shape of the rotor in the motor of the embodiment. [Figure 3]An explanatory diagram showing the structure of a pair of rotors. [Figure 4] A schematic diagram illustrating the electrical connections that drive a motor. [Figure 5A] A schematic diagram illustrating the state of the brake when it is not energized in the embodiment. [Figure 5B] A schematic diagram illustrating the state of the brake when it is energized in the embodiment. [Figure 6] An explanatory diagram illustrating the configuration of a rotating member that rotates together with the axis of rotation. [Figure 7] A schematic diagram illustrating the state of the brake when it is not energized in other configuration examples. [Figure 8] An explanatory diagram showing an example configuration in which the transmission unit is configured as a clutch. [Modes for carrying out the invention]

[0008] A. First Embodiment: (A1) Motor hardware configuration: As shown in Figure 1, the inner rotor type electric motor (hereinafter simply referred to as "motor") 10 comprises a housing 12 that houses the various components, a rotating shaft 20 rotatably mounted approximately at the center of the housing 12 by bearings 14 and 15, a rotor 30 attached to the rotating shaft 20, a stator 40 spaced apart on the outer circumference of the rotor 30 and housing a stator coil 41 for generating a rotating magnetic field, a rotor coil 32 that, when energized, forms a magnetic field that interacts with the rotating magnetic field, thereby applying rotational force to the rotor 30, and a brake 50 equipped with an armature 52 that moves from its initial position when not energized to an operating position when the rotor coil 32 is energized, all housed within the housing 12. In addition to the armature 52, the brake 50 includes a rotating member 54 mounted to be movable in the axial direction of the rotating shaft 20, and a fixed plate 55 that applies braking force to the rotation of the rotating member 54. The fixed plate 55 corresponds to a fixed member that is independent of the rotation of the rotor 30. Furthermore, the fixing plate 55 can be replaced with the housing 12. The configuration and function of the brake 50 will be explained in detail later.

[0009] The rotor 30 of the motor 10 in this embodiment is equipped with a so-called claw-pole type rotor core. Figure 2 is a perspective view illustrating the structure of the rotor 30. As shown in the figure, the rotor 30 has a structure in which claw-shaped rotor cores 31S and 30N are alternately arranged on the outside of the rotor coil 32. A pair of rotor cores 31S and rotor core 31N are shown in Figure 3. The rotor cores 31S and rotor core 31N are integrally formed by a common iron core 35, and when a DC current flows through the rotor coil 32 wound on the iron core 35, the iron core 35 is excited, and the rotor cores 31S and 30N, which are farther from the iron core 35, are polarized into S poles and N poles, respectively. The rotor 30 is equipped with six pairs of the rotor cores 31S and 30N shown in Figure 3, in the direction of the outer circumference. As a result, the claw-shaped rotor cores 31S and 30N are arranged alternately in groups of six in the outer circumference direction of the rotor 30, resulting in alternating S poles and N poles on the outer circumference of the rotor 30.

[0010] As shown in Figure 1, the rotor coil 32 is supplied with excitation power via brushes 25 and 26 that contact slip rings 21 and 22 provided on the rotating shaft 20. On the other hand, a three-phase alternating current is applied to the stator coil 41, which is wound in three phases on the stator 40 located outside the rotor 30. Due to the application of the three-phase alternating current, the magnetic field generated by the stator coil 41 appears to rotate in one direction. The interaction between this magnetic field on the stator 40 side and the S poles and N poles formed on the rotor cores 31S and 30N of the rotor 30 causes the rotor 30 to rotate together with the rotating shaft 20.

[0011] Figure 4 schematically shows the circuit configuration for driving the motor 10 by energizing the rotor coil 32 and stator coil 41. The DC output from the battery 61, which is the power source for the motor 10, is converted to three-phase AC by the inverter 71 of the control circuit 70 and applied to the three-phase stator coil 41 of the stator 40, which is connected in a star configuration. On the other hand, a predetermined DC voltage is applied to the rotor coil 32 of the rotor 30 via the DC-DC converter 72 of the control circuit 70. The rotor 30 rotates due to the energization of the stator coil 41 with three-phase AC by the control circuit 70.

[0012] (A2) Configuration of the Brake: FIG. 5A and FIG. 5B are explanatory diagrams schematically showing the enlarged configuration of the brake 50. FIG. 5A shows a state where the brake 50 is operating without power being supplied from the DC-DC converter 72 to the rotor coil 32, and FIG. 5B shows a state where the brake 50 is non-operating with power being supplied from the DC-DC converter 72 to the rotor coil 32. The on / off of the power supply from the DC-DC converter 72 is depicted as the on / off of the switch SW in FIGS. 5A and 5B as well as in Other diagrams However, in reality, the DC-DC converter 72 may be directly controlled to turn on / off the output. The armature 52 is separated from the rotating member 54 at the operating position, enabling the rotor 30 to rotate. At the initial position, the rotating member 54 is pressed against the fixed plate 55, inhibiting the rotation of the rotor 30.

[0013] Specifically, a plurality of accommodating portions 59 for mounting the spring 58 as an elastic member are provided at multiple locations on the surface (referred to as the side end face) 33 of the rotor core 31N facing the armature 52, and the spring 58 is mounted here. The depth of the accommodating portion 59 is shorter than the free length of the spring 58. Let the depth of the accommodating portion 59 be D, the free length of the spring 58 be L, the thickness of the armature 52 be W, and the distance from the side end face 33 of the rotor core 31N to the surface of the rotating member 54 be R. Then R << (L - D)+W This is the case. Therefore, in a state where the rotor coil 32 is not energized, the spring 58 is ΔL=(R - W)-(L - D) compressed by only this amount. With the force corresponding to this compression, the armature 52 presses the rotating member 54, and the rotating member 54 is pressed against the fixed plate 55. In this embodiment, the elastic member is the spring 58 which is a coil spring, but not limited to coil springs, leaf springs, helical springs, etc. can also be used. Instead of a spring, a compressible elastomer, etc. can also be used as an elastic member.

[0014] When the force pressing the rotating member 54 against the fixed plate 55 by a plurality of springs 58 is F, with the coefficient of friction between the rotating member 54 and the fixed plate 55 being μ, M = μ×F a static frictional force will occur, and thereby the rotating shaft 20 is held so as not to rotate. Of course, since the rotor coil 32 is not energized, the motor 10 itself does not rotate, and even when receiving a force from a driven member connected to the rotating shaft 20, such as a wheel or the like, the rotating shaft 20 does not rotate. That is, it is maintained in a braked state.

[0015] The rotating member 54 is coupled by a coupling portion 29 so as to be slidable in the axial direction with respect to the rotating shaft 20 and not rotatable. This state is shown in FIG. 6, which is an explanatory view seen from the axial direction of the rotating shaft 20. The coupling portion 29 has a rectangular cross-sectional shape perpendicular to the rotating shaft 20, and a sliding hole corresponding to the shape of the coupling portion 29 is formed in the central portion of the rotating member 54. For this reason, the rotating member 54 rotates together with the rotating shaft 20. On the other hand, the fitting between the sliding hole and the coupling portion 29 allows the rotating member 54 to slide in the axial direction. For this reason, when the armature 52 is pushed by the spring 58 and contacts the rotating member 54, the rotating member 54 moves in the axial direction of the rotating shaft 20 and is pressed against the fixed plate 55.

[0016] From this state, in order to start operating the motor 10, the DC-DC converter 72 of the control circuit 70 shown in Figure 4 is driven to supply current to the rotor coil 32. The magnetic field generated by the current flowing through the rotor coil 32 attracts the armature 52 to the rotor core 31N, as shown in Figure 5B. The magnetic flux generated by the magnetic field in the iron core 35 due to the energization of the rotor coil 32 passes through the rotor core 31N, as shown by the dashed line. A portion of this magnetic flux leaks out from the side end face 33 of the rotor core 31N and passes through the inside of the magnetic material armature 52, attracting the armature 52 to the side end face 33 of the rotor core 31N. As a result, the armature 52 moves towards the side end face 33 against the biasing force of the spring 58 and detaches from the rotating member 54. Therefore, the static frictional force between the rotating member 54 and the fixed plate 55 is also lost, and the rotating member 54 becomes rotatable together with the rotating shaft 20. When three-phase alternating current is applied to the stator coil 41 via the inverter 71, the rotor 30 rotates at a speed corresponding to the frequency of the three-phase alternating current.

[0017] As the frequency of the three-phase AC applied to the stator coil 41 is increased, the rotational speed of the rotating magnetic field also increases, and the rotational speed of the rotor 30 increases accordingly. If the back electromotive force generated in the stator coil 41 becomes high due to the high-speed rotation of the rotor 30, the DC-DC converter 72 can be controlled to reduce the current flowing to the rotor coil 32. On the other hand, to stop the rotation of the rotor 30, the rotational speed of the rotor 30 can be reduced by gradually decreasing the frequency of the three-phase AC applied to the stator coil 41, or by stopping the application of the three-phase AC to the stator coil 41 and reducing the rotation of the rotor 30 by the load. When the rotation of the rotor 30 has stopped, turning off the excitation current flowing to the rotor coil 32 causes the armature 52 to detach from the side end face 33 of the rotor core 31N, and the biasing force of the spring 58 presses the rotating member 54 against the fixed plate 55. As a result, the motor 10 is in a state where the brake 50 is applied. The rotational speed of the rotor 30 can be detected by a rotational speed detection sensor such as a Hall element, or it can be obtained by detecting the electromotive force generated in the stator coil 41.

[0018] If an emergency stop request is received for the motor 10, the emergency stop request is input to the control circuit 70, which then controls the inverter 71 and DC-DC converter 72 to turn off all power. In this case, the force attempting to rotate the rotor 30 is lost, and the armature 52 is further pressed against the rotating member 54 by the spring 58, so the rotation of the rotor 30 stops in a short time, and the motor 10 is in a state where the brake 50 is applied.

[0019] According to the motor 10 of the first embodiment described above, when the rotor coil 32 for driving the rotor 30 is not energized, the armature 52, due to the biasing force of the spring 58, contacts the rotating member 54 and presses it against the fixed plate 55, thereby preventing the rotation of the rotating shaft 20, which is joined at the joint 29 to rotate together with the rotating member 54. In other words, when the armature 52 is in its initial position, the motor 10 can be braked so that its rotating shaft 20 does not rotate. At this time, since no power is consumed in the operation of the brake 50, power saving can be achieved. Since no power is consumed in operating the brake 50, even if the battery 61 loses power due to discharge or the like as a result of leaving an automatic transport machine using this motor 10 stopped, the rotating shaft 20 of the motor 10 will be kept in a braked state by the brake 50.

[0020] On the other hand, when attempting to rotate the motor 10, the control circuit 70 controls the DC-DC converter 72 to supply a direct current to the rotor coil 32. A portion of the magnetic flux generated by the current flowing through the rotor coil 32 pulls the armature 52 against the biasing force of the spring 58 towards the side end face 33 (operating position) of the rotor core 31N, freeing the rotating member 54 and thus releasing the braking force of the brake 50. In this way, the motor 10 of this embodiment does not require the use of a dedicated coil or other actuator to release the brake 50. Moreover, since the brake is released by utilizing the configuration of an inner rotor type electric motor, which energizes the rotor coil 32 to rotate the rotor 30, the configuration can be simplified.

[0021] B. Second Embodiment: A second embodiment of the motor 10 will now be described. Figure 7 is an explanatory diagram showing the configuration of the rotor 30B provided in the motor 10 of the second embodiment. The figure shows the armature 52B in its initial position. The rotor 30B of the second embodiment has a configuration that is substantially the same as that of the first embodiment, except that the shape of the armature 52B and the shape of the side end face 33B of the rotor core 31N are different from those of the first embodiment.

[0022] The rotor 30B of the motor 10 in the second embodiment, as shown in the figure, has an armature 52B with a skirt portion 53 surrounding the rotating shaft 20, instead of the flat armature 52 of the first embodiment. The skirt portion 53 may be attached to the rotating shaft 20 by a strut bearing. The rotor 30B has an iron core 35B with a portion cut out corresponding to the skirt portion 53. In addition, a groove continuous in the circumferential direction is formed on the side end face 33B of the rotor core 31N, narrowing the magnetic path through which the magnetic flux passes. As a result, the magnetic flux formed by passing a DC current through the rotor coil 32 is guided from the skirt portion 53 and the inner circumferential projection 33i to the armature 52B, and from the outer circumferential projection 33o toward the claw-shaped tip of the rotor core 31N, so the armature 52B is strongly attracted to the rotor 30B. As a result, the amount of current that can be passed through the rotor coil 32 to operate 50B can be reduced. Other effects and benefits are the same as in the first embodiment.

[0023] C. Other embodiments: The motor 10 described above uses a structure with a claw-pole type rotor core as the rotor 30, but it is not necessarily limited to a claw-pole type rotor core. Any other form is acceptable as long as it is a structure that can form S / N magnetic poles on the rotor core by energizing. Also, in the above embodiment, the brakes 50 and 50B are provided on the N side of the rotor core 31N, which is the N pole, but they may also be provided on the S side of the rotor core 31S, which is the S pole, or on both sides. The stator coil 41 is a star-connected three-phase coil, but a delta connection may also be used. Furthermore, it is not limited to three phases, but a multi-phase coil of five or more phases may also be used.

[0024] The motor 10 using the claw-pole type rotor core used in the above embodiment can be used not only as an electric motor but also as a generator. For example, it can be used as a starter motor for a vehicle, as well as as an alternator. In this case, the armatures 52, 52B, etc., instead of brakes 50, 50B, constitute a clutch and are configured to switch the coupling between the rotating shaft 20 and the drive shaft of an internal combustion engine or the like. A specific example of the configuration is shown in Figure 8. The figure shows a combined example of a configuration in which the motor 10 is used as a starter and a configuration in which it is used as an alternator.

[0025] In this example, an electromagnetic clutch 90 is installed between the rotating shaft 20 of the motor 10 and another rotating shaft (hereinafter referred to as the output shaft) 120. A sprocket 101 is attached to the output shaft 120, and a power-transmitting chain belt 100 is installed between it and a sprocket 102 attached to the crankshaft 130 of an engine EG such as an internal combustion engine. Therefore, when the electromagnetic clutch 90 is engaged, the rotation of the motor 10 can crank the engine EG, or conversely, by operating the engine EG and rotating the crankshaft 130, the rotating shaft 20 of the motor 10 can be rotated, and the motor 10 can be used as a generator to regenerate electricity. The electromagnetic clutch 90 is installed on the output shaft 120 which is linked to the crankshaft 130, but the rotor 30 and rotating shaft 20 of the motor 10 may also be directly connected to the crankshaft 130.

[0026] Figure 8 will be used to explain the operation as a starter motor or alternator. The top row of the figure shows the state in which the engine EG is stopped and the motor 10 used as a starter motor or alternator is also stopped. In this state, the engine EG is stopped and no power is supplied to the rotor coil 32 of the motor 10. Therefore, the armature 52C is in its initial position and the electromagnetic clutch 90 is off, or unconnected. The armature 52C is in its initial position because it is held in place by a spring or the like provided on the electromagnetic clutch 90 side, at a distance from the side end of the rotor 30 of the motor 10, more specifically, from the side end of the rotor core.

[0027] The middle section of Figure 8 shows the state in which the engine EG is rotating and the motor 10, which is used as either a starter motor or an alternator, is also operating. In this state, whether the motor 10 is used as a starter motor or an alternator, the rotor coil 32 is energized. When used as a starter motor, three-phase AC is simultaneously applied to the stator coil 41, and the motor 10 rotates the rotor 30, causing the rotating shaft 20 to rotate as well. With the energization of the rotor coil 32, as in the first and second embodiments, the armature 52C is attracted to the rotor core 31N, and the electromagnetic clutch 90 connects the motor 10 to the rotor 30. As a result, the rotation of the rotor 30, which rotates together with the rotating shaft 20, is transmitted to the output shaft 120 via the electromagnetic clutch 90, and further rotates the crankshaft 130 via the chain belt 100. As a result, the crankshaft 130 is cranked and the engine EG is started.

[0028] On the other hand, when the motor 10 is used as an alternator, the rotor coil 32 is energized, but unlike when it is used as a starter motor, three-phase AC is not applied to the stator coil 41. In this case, the energization of the rotor coil 32 causes the armature 52C to be attracted to the rotor core 31N side, and the electromagnetic clutch 90 becomes engaged. As a result, the rotor 30 of the motor 10 is coupled to the output shaft 120 via the electromagnetic clutch 90, and further coupled to the crankshaft 130 via the chain belt 100. Therefore, when the engine EG is operated, the rotor 30 rotates together with the rotating shaft 20. At this time, the motor 10 operates as a generator, and the electromotive force generated in the stator coil 41 is converted to DC by the inverter 71 to charge the battery 61. In the figure, the hatching of the chain belt 100 indicates that the output shaft 120 on the output side of the electromagnetic clutch 90 and the crankshaft 130 of the engine EG are rotating.

[0029] The bottom row of the diagram shows the state where the motor 10 is stopped and not used as either a starter motor or an alternator, while the engine EG is running. In this state, the engine EG is running, and the electromagnetic clutch 90 is disengaged. In this state, the engine EG is running, the crankshaft 130 is rotating, and the output shaft 120 is also rotating. No power is supplied to the rotor coil 32 of the motor 10. Therefore, the armature 52C is in its initial position due to the spring, etc., and the electromagnetic clutch 90 is off, i.e., disengaged. In other words, when the motor 10 is used as a starter motor, the engine EG is running, so cranking by the starter motor is no longer necessary, and the electromagnetic clutch 90 is disengaged. Also, even when the motor 10 is used as an alternator, if, for example, the charge level (SOC) of the battery 61 is sufficiently high, power generation by the alternator is not necessary, and the electromagnetic clutch 90 may be disengaged. The bottom row of the diagram shows this state.

[0030] In the embodiment described above, the armature 52C is configured such that, in its initial position when the rotor coil 32 is not energized, the rotor 30 is not coupled to the output shaft 120, which is another component, and in the operating position, it forms an electromagnetic clutch 90 that couples the rotor 30 and the output shaft 120. As a result, whether or not the rotor 30 of the motor 10 is coupled to the crankshaft 130 of the engine EG can be switched on or off by turning the energization of the rotor coil of the rotor 30 on or off, and the motor 10 can be operated as a starter motor or as an alternator. In this embodiment as well, no new coils or other components are required to constitute the electromagnetic clutch 90, and the clutch can be turned on and off (connected or disconnected) by controlling the energization of the rotor coil provided on the rotor 30.

[0031] In the configuration shown in Figure 8, the electromagnetic clutch 90, which is the transmission unit, is in an off state (disconnected) when the rotor coil is not energized. However, it may also be configured to be on (connected) when the rotor coil is not energized and off (disconnected) when it is energized. Such a configuration can be easily achieved by supporting the armature 52C of the electromagnetic clutch 90 with a spring on the side end face of the rotor core, similar to the first and second embodiments. Conversely, the brake 50, which is the transmission unit in the first and second embodiments, may be configured to brake the rotors 30 and 30B when the rotor coil 32 is not energized and not brake when it is energized.

[0032] In each of the above embodiments, some of the configurations implemented by hardware may be replaced with software. At least some of the configurations implemented by software can also be implemented by discrete circuit configurations. Furthermore, if some or all of the functions of this disclosure are implemented by software, that software (computer program) can be provided in the form of being stored on a computer-readable recording medium. "Computer-readable recording medium" is not limited to portable recording media such as flexible disks and CD-ROMs, but also includes various internal storage devices within a computer such as RAM and ROM, and external storage devices fixed to a computer such as hard disks. In other words, "computer-readable recording medium" has a broad meaning that includes any recording medium on which data packets can be fixed rather than temporary.

[0033] This disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from its spirit. For example, the technical features in the embodiments corresponding to the technical features in each form described in the summary of the invention can be replaced or combined as appropriate in order to solve some or all of the above-described problems, or to achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate. [Explanation of symbols]

[0034] 10…Motor, 12…Case, 20…Rotating shaft, 21,22…Slip rings, 25,26…Brushes, 29…Coupling part, 30,30B…Rotor, 31N,31S…Rotor core, 32…Rotor coil, 33,33B…Side end face, 33i…Inner circumference projection, 33o…Outer circumference projection, 35,35B…Iron core, 40…Stator, 41…Stator coil, 50…Brake, 52,52B,52C…Armature, 53…Skirt part, 54…Rotating member, 55…Fixing plate, 58…Spring, 59…Recess, 61…Battery, 70…Control circuit, 71…Inverter, 72…DC-DC converter, 90…Electromagnetic clutch, 100…Chain belt, 101,102…Sprocket, 120…Output shaft, 130…Crankshaft

Claims

1. It is an inner rotor type electric motor, A rotor attached to the rotating shaft, A stator is provided spaced apart on the outer circumference of the rotor and houses stator coils for generating a rotating magnetic field. A rotor coil that, when energized, forms a magnetic field that interacts with the rotating magnetic field, thereby applying a rotational force to the rotor, An inverter that controls the application of multiphase alternating current to the stator coil to generate the rotating magnetic field, The armature is provided which moves from an initial position when de-energized to an operating position by switching the power supply to the rotor coil on and off, and the armature includes a transmission unit which connects the rotor to other members at one of the initial position and the operating position, and releases the connection between the rotor and other members at the other of the initial position and the operating position, Equipped with, An inner-rotor type electric motor in which the power supply to the rotor coil is switched on and off by switching a DC current, separate from the multiphase AC current, on and off.

2. The other members of the transmission unit are fixed members that are independent of the rotation of the rotor. The inner rotor type electric motor according to claim 1, wherein the armature of the transmission unit is a brake that, in the initial position, is coupled with the other member to inhibit the rotation of the rotor, and in the operating position, allows the rotor to rotate.

3. The brake comprises a rotating member that rotates together with the rotating shaft and is mounted to be movable in the axial direction of the rotating shaft, The armature is, It is positioned in contact with the elastic member provided on the rotor, When the current is not flowing, the elastic member is held in the initial position by its biasing force, and a braking force is applied to the rotating member. When the current is applied, the braking force on the rotating member is eliminated at the operating position, which is moved against the biasing force of the elastic member. The inner rotor type electric motor according to claim 2.

4. The elastic member is a spring having a predetermined free length and housed in a housing provided at the end of the rotor that is shallower than the free length. The armature is supported by the spring so that it can move along the axial direction of the rotation shaft. The inner rotor type electric motor according to claim 3.

5. The inner rotor type electric motor according to claim 3, wherein the armature, in the initial position, brings the rotating member into contact with a part of the housing member surrounding the stator to apply the braking force.

6. The aforementioned other member is a rotation axis different from the rotation axis, The inner rotor type electric motor according to claim 1, wherein the transmission unit is a clutch that connects the rotor to the other rotating shaft when the armature is in the operating position, and disconnects the rotor from the other rotating shaft when the armature is in the initial position.

7. An inner rotor type electric motor according to claim 6, Used as a starter motor or alternator for internal combustion engines. An inner rotor type electric motor, wherein the other rotating shaft is the drive shaft of an internal combustion engine or a rotating shaft linked to the drive shaft.

8. The inner rotor type electric motor according to any one of claims 1 to 7, wherein the rotor comprises a claw-pole type rotor core.

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