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] The present disclosure relates to inner rotor type electric motors. [Background technology]

[0002] Inner rotor type electric motors, in which a stator coil is present on the outer periphery and a rotor disposed inside the stator coil rotates, include a built-in brake to fix the rotor when the motor is not driven (see, for example, Patent Document 1 below). In this type of electric motor, the rotor is fixed by a brake shoe when the motor is not driven. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-210708 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the electric 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 electric motor is driven. Therefore, when the electric motor is driven, it is necessary to hold the rotor in a position where the brake is not applied, and a large current unrelated to the drive of the motor is required to flow, which causes a problem that the efficiency of the electric motor cannot be improved. In Patent Document 1, a part of the current flowing through the stator coil is used to move the rotor, but even if an independent electromagnetic brake is used, the supply of current is required for fixing / releasing, so the electrical efficiency cannot be improved. In addition, a dedicated electromagnetic brake is required, which may cause a problem that the device is likely to become large in size. [Means for solving the problem]

[0005] The present disclosure can be realized in the following forms or application examples.

[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 at a distance from the outer periphery of the rotor and housing a stator coil for generating a rotating magnetic field, a rotor coil that applies a rotational force to the rotor by forming a magnetic field that interacts with the rotating magnetic field when current is applied, and an armature that moves from an initial position when current is not applied to an operating position when current is applied to the rotor coil, and the armature includes a transmission unit that connects the rotor to another member at one of the initial position and the operating position, and releases the connection between the rotor and the other member at the other of the initial position and the operating position. In this way, the armature of the transmission unit can be operated by applying current to the rotor coil, and the connection and release between the armature and the other member can be performed. For this reason, for example, a configuration in which the transmission unit operates as a brake or a clutch can be adopted. (2) In the above configuration, the other member of the transmission part may be a fixed member that is not related to the rotation of the rotor, and the armature of the transmission part may be a brake that inhibits the rotation of the rotor by combining with the other member in the initial position and allows the rotor to rotate in the actuated position. In this way, the rotation of the rotor can be inhibited in the initial position where no current is applied to the rotor coil, and no power is required for the brake operation. (3) In the above configuration, the brake may include a rotating member that rotates with the rotating shaft and is attached so as to be movable in the axial direction of the rotating shaft, the armature is disposed at a position where it contacts an elastic member provided on the rotor, and when de-energized, the armature is held at the initial position by the biasing force of the elastic member to apply a braking force to the rotating member, and when energized, the armature is moved against the biasing force of the elastic member to the actuated position, thereby eliminating the application of the braking force to the rotating member. In this way, the braking state when the rotor coil is not energized 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 accommodated in a housing provided at an end of the rotor and shallower than the free length, and the armature may be supported by the spring so as to be movable along the axial direction of the rotating shaft. In this way, the above adjustment can be easily performed by adjusting the free length of the spring. (5) In the above configuration, the armature may apply the braking force by bringing the rotating member into contact with a part of a housing member surrounding the stator at the initial position. This allows another member to serve as a part of the housing member, thereby simplifying the configuration. (6) In the above configuration, the other member may be another rotating shaft different 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 motor may be used as a starter motor or an alternator for an internal combustion engine, and the other rotating shaft may be a drive shaft of the internal combustion engine or a rotating shaft interlocked with the drive shaft. In this way, by controlling the supply of electricity to the rotor coil, the motor can be used as a starter motor to crank the internal combustion engine, or as an alternator to perform regenerative power generation using the power of the internal combustion engine. (8) In the above configuration, the rotor may include a claw pole type rotor core. This allows the motor to be made smaller and the efficiency of regenerative power generation to be increased. [Brief description of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view illustrating a schematic configuration of a motor that is an inner rotor type electric motor according to an embodiment; [Diagram 2] 2 is a perspective view illustrating an example of a shape of a rotor in a motor according to an embodiment; FIG. [Diagram 3]FIG. 4 is an explanatory diagram showing the structure of a pair of rotors. [Figure 4] FIG. 4 is an explanatory diagram illustrating an electrical connection for driving a motor. [Figure 5A] FIG. 4 is an explanatory diagram illustrating a schematic diagram of a brake in a non-energized state in the embodiment. [Figure 5B] FIG. 4 is an explanatory diagram illustrating a brake in an embodiment when current is applied; [Figure 6] FIG. 4 is an explanatory diagram illustrating a configuration of a rotating member that rotates together with a rotating shaft. [Figure 7] FIG. 13 is an explanatory diagram illustrating a schematic diagram of a state in which a brake is not energized in another configuration example. [Figure 8] FIG. 13 is an explanatory diagram showing a configuration example in which the transmission unit is configured as a clutch. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] A. First embodiment: (A1) Motor hardware configuration: As shown in Fig. 1, an inner rotor type electric motor (hereinafter, simply referred to as a motor) 10 includes a housing 12 that accommodates various components, a rotating shaft 20 rotatably mounted at approximately the center of the housing 12 by bearings 14, 15, a rotor 30 attached to the rotating shaft 20, a stator 40 that is provided at a distance from the outer periphery of the rotor 30 and accommodates a stator coil 41 for generating a rotating magnetic field, a rotor coil 32 that applies a rotational force to the rotor 30 by forming a magnetic field that interacts with the rotating magnetic field when current is applied, and a brake 50 including an armature 52 that moves from an initial position when current is not applied to an operating position when current is applied to the rotor coil 32, all of which are accommodated within the housing 12. In addition to the armature 52, the brake 50 includes a rotating member 54 that is attached movably in the axial direction of the rotating shaft 20, and a fixed plate 55 that applies a braking force to the rotation of the rotating member 54. The fixed plate 55 corresponds to a fixed member that is not related to the rotation of the rotor 30. Also, the fixed plate 55 may be substituted by the housing 12. The structure and operation of the brake 50 will be described in detail later.

[0009] The rotor 30 of the motor 10 of this embodiment includes a so-called claw-pole type rotor core. FIG. 2 is a perspective view illustrating the structure of the rotor 30. As shown in the figure, the rotor 30 includes a structure in which claw-shaped rotor cores 31S, 30N are alternately arranged on the outside of a rotor coil 32. A pair of rotor cores 31S and 31N are shown in FIG. 3. The rotor cores 31S and 31N are integrally formed by a common iron core 35. When a direct current flows through the rotor coil 32 wound around the iron core 35, the iron core 35 is excited, and the rotor cores 31S and 30N farther from the iron core 35 are polarized to the south pole and the north pole, respectively. The rotor 30 includes six pairs of rotor cores 31S and 30N shown in FIG. 3 in the circumferential direction. As a result, six of each of the claw-shaped rotor cores 31S, 30N are arranged alternately in the outer circumferential direction of the rotor 30, and the outer periphery of the rotor 30 has alternating south poles and north poles.

[0010] As shown in Fig. 1, the rotor coil 32 is supplied with exciting power via brushes 25, 26 in contact with slip rings 21, 22 provided on the rotating shaft 20. On the other hand, a three-phase AC is applied to a stator coil 41 wound separately into three phases of a stator 40 provided on the outside of the rotor 30. When the three-phase AC is applied, the magnetic field generated by the stator coil 41 appears to rotate in one direction. The interaction between the magnetic field on the stator 40 side and the south and north poles formed on rotor cores 31S, 30N of the rotor 30 causes the rotor 30 to rotate together with the rotating shaft 20.

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

[0012] (A2) Brake configuration: 5A and 5B are explanatory diagrams showing an enlarged schematic configuration of the brake 50. FIG. 5A shows a state in which the rotor coil 32 is not energized from the DC-DC converter 72 and the brake 50 is in operation, and FIG. 5B shows a state in which the rotor coil 32 is energized from the DC-DC converter 72 and the brake 50 is in an inoperative state. The on / off of the energization from the DC-DC converter 72 is depicted as the on / off of a switch SW in FIGS. 5A and 5B and other drawings, but in reality, the output can be turned on / off by directly controlling the DC-DC converter 72. In the operating position, the armature 52 is separated from the rotating member 54 to enable the rotor 30 to rotate, and in the initial position, the armature 52 presses the rotating member 54 against the fixed plate 55 to inhibit the rotation of the rotor 30.

[0013] Specifically, a surface (called a side end surface) 33 of rotor core 31N facing armature 52 is provided with a plurality of accommodation portions 59 in which springs 58 serving as elastic members are attached, and springs 58 are attached to the accommodation portions 59. The depth of accommodation portions 59 is shorter than the free length of springs 58. If the depth of accommodation portions 59 is D, the free length of springs 58 is L, the thickness of armature 52 is W, and the distance from side end surface 33 of rotor core 31N to the surface of rotating member 54 is R, then R<<(LD)+W Therefore, when the rotor coil 32 is not energized, the spring 58 ΔL = (RW) - (LD) The armature 52 is compressed by a force corresponding to this compression, and the rotating member 54 is pressed against the fixed plate 55. In this embodiment, the elastic member is a spring 58 which is a coil spring, but it is not limited to a coil spring, and a leaf spring, a helical spring, or the like can also be used. Instead of a spring, a compressible elastomer or the like can also be used as the elastic member.

[0014] If the force with which the rotating member 54 is pressed against the fixed plate 55 by the multiple springs 58 is F, and the coefficient of friction between the rotating member 54 and the fixed plate 55 is μ, then M = μ × F This generates a static friction force, which holds the rotating shaft 20 so that it does not rotate. Since no current is applied to the rotor coil 32, the motor 10 itself does not rotate, and the rotating shaft 20 does not rotate even if it receives force from a driven member connected to the rotating shaft 20, such as a wheel. In other words, the brake is applied and the state is maintained.

[0015] The rotating member 54 is connected to the rotating shaft 20 by the connecting portion 29 so that it can slide in the axial direction but cannot rotate. This is shown in FIG. 6, which is an explanatory diagram of the rotating shaft 20 viewed from the axial direction. The connecting portion 29 has a rectangular cross section perpendicular to the rotating shaft 20, and a sliding hole corresponding to the shape of the connecting portion 29 is formed in the center of the rotating member 54. Therefore, the rotating member 54 rotates together with the rotating shaft 20. On the other hand, the fit between the sliding hole and the connecting portion 29 allows the rotating member 54 to slide in the axial direction. Therefore, when the armature 52 is pressed by the spring 58 and comes into contact with 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] In order to start the operation of the motor 10 from this state, when the DC-DC converter 72 of the control circuit 70 shown in FIG. 4 is driven to pass a current through 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 FIG. 5B. The magnetic flux generated by the magnetic field generated in the iron core 35 by the current passing through the rotor coil 32 passes through the rotor core 31N as shown by the dashed line, but a part of the magnetic flux leaks out from the side end surface 33 of the rotor core 31N and passes through the inside of the armature 52, which is a magnetic body, thereby attracting the armature 52 to the side end surface 33 of the rotor core 31N. As a result, the armature 52 moves toward the side end surface 33 against the biasing force of the spring 58 and is separated 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 a three-phase AC current is applied to the stator coil 41 via the inverter 71, the rotor 30 rotates at a rotation speed according to the frequency of the three-phase AC current.

[0017] When the frequency of the three-phase AC applied to the stator coil 41 is increased, the rotation speed of the rotating magnetic field also increases, and the number of rotations of the rotor 30 increases accordingly. When the rotor 30 rotates at high speed, and the back electromotive force generated in the stator coil 41 increases, the DC-DC converter 72 may be controlled to reduce the current flowing through the rotor coil 32. On the other hand, when the rotation of the rotor 30 is stopped, the frequency of the three-phase AC applied to the stator coil 41 may be gradually reduced to reduce the number of rotations of the rotor 30, or the application of the three-phase AC to the stator coil 41 may be stopped to reduce the rotation of the rotor 30 by a load. When the rotation of the rotor 30 stops, the excitation current flowing through the rotor coil 32 may be turned off, and the armature 52 may be released from the side end surface 33 of the rotor core 31N, and the urging force of the spring 58 may press the rotating member 54 against the fixed plate 55. As a result, the motor 10 is in a state in which the brake 50 is engaged. The rotation speed of the rotor 30 may be detected by a rotation speed detection sensor using a Hall element or the like, or may be obtained by detecting the electromotive force generated in the stator coil 41 .

[0018] When an emergency stop is requested for the motor 10, the emergency stop request is input to the control circuit 70, which then controls the inverter 71 and the DC-DC converter 72 to cut off all current. In this case, the force trying to rotate the rotor 30 is lost, and furthermore, the armature 52 is pressed against the rotating member 54 by the spring 58, so that within a short time, the rotation of the rotor 30 is stopped and the motor 10 enters a state in which 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 contacts the rotating member 54 by the biasing force of the spring 58 and presses it against the fixed plate 55, thereby preventing the rotation of the rotating shaft 20 joined at the joint 29 so as to rotate together with the rotating member 54. In other words, when the armature 52 is in the initial position, the motor 10 can be braked so that the rotating shaft 20 does not rotate. At this time, since no power is consumed to operate the brake 50, power saving can be achieved. Since no power is consumed to keep the brake 50 operating, even if an automatic conveyor using this motor 10 is left stopped and the power of the battery 61 is lost due to discharge or the like, the rotating shaft 20 of the motor 10 is kept in a braked state by the brake 50.

[0020] On the other hand, when the control circuit 70 controls the DC-DC converter 72 to pass a direct current through the rotor coil 32 in an attempt to rotate the motor 10, part of the magnetic flux generated by the current flowing through the rotor coil 32 attracts the armature 52 to the side end surface 33 (operating position) of the rotor core 31N against the biasing force of the spring 58, freeing the rotating member 54, i.e., releasing the braking applied by the brake 50. In this way, the motor 10 of this embodiment does not require the use of an actuator such as a dedicated coil to release the brake 50. Moreover, the brake is released by utilizing the configuration of an inner rotor type electric motor in which current is applied to the rotor coil 32 to rotate the rotor 30, thereby simplifying the configuration.

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

[0022] As shown in the figure, the rotor 30B of the motor 10 of the second embodiment includes an armature 52B having 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 includes an iron core 35B having a portion corresponding to the skirt portion 53 cut out. In addition, a groove that continues in the circumferential direction is formed on the side end surface 33B of the rotor core 31N, narrowing the magnetic path through which the magnetic flux passes. Therefore, the magnetic flux formed by passing a direct current through the rotor coil 32 is induced 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 that the armature 52B is strongly attracted to the rotor 30B. Therefore, the amount of current passed through the rotor coil 32 to operate 50B can be reduced. The other effects are the same as those of the first embodiment.

[0023] C. Other embodiments: The motor 10 described above uses a structure including a claw-pole rotor core as the rotor 30, but is not necessarily limited to a claw-pole rotor core. Any other structure may be used as long as it can form S / N magnetic poles in the rotor core by energizing it. In addition, in the above embodiment, the brakes 50, 50B are provided on the rotor core 31N side, which is the N pole, but they may be provided on the rotor core 31S side, 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. In addition, it is not limited to a three-phase coil, and 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 as a generator in addition to being used as an electric motor. For example, it can be used as a starter motor for a vehicle, as well as an alternator. In this case, the armatures 52, 52B, etc. form a clutch instead of the brakes 50, 50B, and are configured to turn on and off the connection between the rotating shaft 20 and the drive shaft of an internal combustion engine, etc. A specific configuration example is shown in FIG. 8. In the figure, a configuration example in which the motor 10 is used as a starter and a configuration example in which it is used as an alternator are shown together.

[0025] In this example, an electromagnetic clutch 90 is attached between the rotating shaft 20 of the motor 10 and another rotating shaft (hereinafter referred to as output shaft) 120. A sprocket 101 is attached to the output shaft 120, and a chain belt 100 for transmitting power is stretched between the output shaft 120 and a sprocket 102 attached to a crankshaft 130 of an engine EG such as an internal combustion engine. Therefore, when the electromagnetic clutch 90 is in a connected state, it is possible to crank the engine EG by rotating the motor 10, or conversely, to rotate the crankshaft 130 by operating the engine EG to rotate the rotating shaft 20 of the motor 10, and to use the motor 10 as a generator to regenerate electric power. The electromagnetic clutch 90 is provided on the output shaft 120 that is linked to the crankshaft 130, but the rotor 30 and the rotating shaft 20 of the motor 10 may be directly connected to the crankshaft 130.

[0026] The operation as a starter motor or alternator will be described with reference to FIG. 8. The top part of the figure shows a 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 current is passed through the rotor coil 32 of the motor 10. Therefore, the armature 52C is located in the initial position, and the electromagnetic clutch 90 is off, that is, in a non-connected state. The reason why the armature 52C is located in the initial position is that it is held at a position separated from the side end of the rotor 30 of the motor 10, more specifically, the side end of the rotor core, by a spring or the like provided on the electromagnetic clutch 90 side.

[0027] The middle part of FIG. 8 shows a state in which the engine EG is rotating and the motor 10 used as 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 the motor 10 is used as a starter motor, three-phase AC is simultaneously applied to the stator coil 41, and the motor 10 drives the rotor 30 to rotate, and the rotating shaft 20 also rotates. When the rotor coil 32 is energized, the armature 52C is attracted to the rotor core 31N, and the electromagnetic clutch 90 is connected to the rotor 30 of the motor 10, as in the first and second embodiments. As a result, the rotation of the rotor 30 rotating 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 cracked, 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 the motor 10 is used as a starter motor, three-phase AC is not applied to the stator coil 41. In this case, the rotor coil 32 is energized, so that the armature 52C is attracted toward the rotor core 31N, and the electromagnetic clutch 90 is engaged. As a result, the rotor 30 of the motor 10 is coupled to the output shaft 120 via the electromagnetic clutch 90, and is 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 part of the figure shows a state in which the engine EG is in operation and the motor 10 is stopped and is not used as a starter motor or an alternator. At this time, the engine EG is in operation and the electromagnetic clutch 90 is in a disengaged state. In this state, the engine EG is in operation, the crankshaft 130 rotates, and the output shaft 120 also rotates. The rotor coil 32 of the motor 10 is not energized. Therefore, the armature 52C is located in the initial position by a spring or the like, and the electromagnetic clutch 90 is off, that is, in a disengaged state. In other words, when the motor 10 is used as a starter motor, the engine EG is in an operating state, so cranking by the starter motor is no longer necessary, and the electromagnetic clutch 90 is in a disengaged state. Even when the motor 10 is used as an alternator, for example, when the charge level SOC of the battery 61 is sufficiently high, the electromagnetic clutch 90 may be in a disengaged state because power generation by the alternator is not necessary. The bottom part of the figure shows this state.

[0030] In the embodiment described above, the armature 52C constitutes an electromagnetic clutch 90 that, in an initial position where no current is applied to the rotor coil 32, does not connect the rotor 30 to the output shaft 120, which is another member, and connects the rotor 30 to the output shaft 120 in an actuated position. As a result, whether the rotor 30 of the motor 10 and the crankshaft 130 of the engine EG are connected can be switched by turning on and off the current to the rotor coil of the rotor 30, and the motor 10 can be operated as a starter motor or an alternator. In this embodiment, no new coil or the like that constitutes the electromagnetic clutch 90 is required, and the clutch can be turned on and off (connected and disconnected) by controlling the current to the rotor coil provided in the rotor 30.

[0031] In the embodiment shown in Fig. 8, the electromagnetic clutch 90, which is a transmission part, is off (disconnected state) when the rotor coil is not energized, but it may be on (connected state) when the rotor coil is not energized and off (disconnected state) when the rotor coil is energized. Such a configuration can be easily configured by supporting the armature 52C of the electromagnetic clutch 90 on the side end surface of the rotor core using a spring, as in the first and second embodiments. Conversely, the brake 50, which is a transmission part in the first and second embodiments, may brake the rotors 30, 30B when the rotor coil 32 is not energized and not brake when it is energized.

[0032] In each of the above embodiments, a part of the configuration realized by hardware may be replaced by software. At least a part of the configuration realized by software may be realized by a discrete circuit configuration. In addition, when a part or all of the functions of the present disclosure are realized by software, the software (computer program) can be provided in a form stored in a computer-readable recording medium. The term "computer-readable recording medium" is not limited to portable recording media such as flexible disks and CD-ROMs, but also includes internal storage devices in a computer such as various RAMs and ROMs, and external storage devices fixed to a computer such as a hard disk. In other words, the term "computer-readable recording medium" has a broad meaning including any recording medium to which a data packet can be fixed, not temporarily.

[0033] The present disclosure is not limited to the above-mentioned embodiment, and can be realized in various configurations without departing from the spirit of the present disclosure. For example, the technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention column can be appropriately replaced or combined to solve some or all of the above-mentioned problems or to achieve some or all of the above-mentioned effects. Furthermore, if the technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0034] 10...motor, 12...case, 20...rotating shaft, 21, 22...slip ring, 25, 26...brush, 29...coupling portion, 30, 30B...rotor, 31N, 31S...rotor core, 32...rotor coil, 33, 33B...side end surface, 33i...inner peripheral protrusion, 33o...outer peripheral protrusion, 35, 35B...iron core, 40...stator, 41...stator coil, 50...brake, 52, 52B, 52C...armature, 53...skirt portion, 54...rotating member, 55...fixed 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. An inner rotor type electric motor, A rotor attached to a rotating shaft; a stator that is provided on an outer periphery of the rotor at a distance and that houses 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 exerting a rotational force on the rotor; an armature that moves from an initial position when no current is applied to an operating position when current is applied to the rotor coil, the armature being a transmission section that connects the rotor to another member at one of the initial position and the operating position, and that disconnects the rotor from the other member at the other of the initial position and the operating position; An inner rotor type electric motor equipped with

2. the other member of the transmission part is a fixed member that is not related to rotation of the rotor, 2. The inner rotor type electric motor according to claim 1, wherein the armature of the transmission portion is a brake that inhibits rotation of the rotor by being coupled with the other member in the initial position and allows the rotor to rotate in the operating position.

3. The brake includes a rotating member that rotates together with the rotating shaft and is attached so as to be movable in the axial direction of the rotating shaft, The armature is The elastic member is disposed at a position where the elastic member is in contact with the rotor. When the current is not applied, the elastic member is biased to hold the rotating member at the initial position, thereby applying a braking force to the rotating member. When the current is applied, the braking force acting on the rotating member is released at the operating position to which the rotating member is moved against the biasing force of the elastic member.

3. The inner rotor type electric motor according to claim 2.

4. the elastic member is a spring having a predetermined free length and accommodated in an accommodating portion that is provided at an end of the rotor and is shallower than the free length, The armature is supported by the spring so as to be movable along the axial direction of the rotation shaft.

4. The inner rotor type electric motor according to claim 3.

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

6. the other member is a rotation shaft different from the rotation shaft, 2. 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 that disconnects the rotor from the other rotating shaft when the armature is in the initial position.

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

8. The inner rotor type electric motor according to claim 1 , wherein the rotor comprises a claw pole type rotor core.

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