JP4613527B2 - Axial type motor - Google Patents

Description

  The present invention relates to an axial type motor, and more particularly to an axial type motor capable of changing a gap amount between a rotor and a stator.

  A conventional example of this type of axial motor is disclosed in Patent Document 1 below. In Patent Document 1, a support bar having a carved rack is attached to a stator in a state of being parallel and offset with respect to a rotor rotation axis, and a pinion is engaged with the rack. By rotating the pinion, the rack is driven and the stator moves in the rotor rotation axis direction (axial direction). As a result, the gap amount between the rotor and the stator is changed, and the magnetic flux interlinking from the permanent magnet of the rotor to the coil of the stator is changed.

JP 2002-247822 A

  In Patent Document 1, the amount of gap between the rotor and the stator is changed by rotating the pinion. However, a dedicated actuator for generating a rotational force in the pinion and its control device are required. Therefore, in patent document 1, there exists a problem that the whole apparatus will enlarge.

  An object of the present invention is to provide an axial type motor that can change the gap amount between a rotor and a stator without increasing the size of the apparatus.

An axial type motor according to the present invention is configured to change a gap amount between a rotor rotatable around a rotation axis, a stator disposed opposite to the rotor in the rotation axis direction, and the rotor and the stator in the rotation axis direction. An axial type motor having a moving mechanism that supports the stator in a state of being movable in the direction of the rotation axis. supporting, by the rotational force acting between the rotor and the stator, the stator is the gap amount is moved to the rotation axis direction while rotating along the thread is changed to the moving mechanism, the moving mechanism stator further comprising, when changing the gap amount needed to release the stator by fixing mechanism fixable securing mechanism against To.

  In the present invention, the stator is supported by the moving mechanism with a screw whose central axis substantially coincides with the rotation axis. Then, the rotational force acting between the rotor and the stator causes the stator to rotate along the screw and move in the direction of the rotation axis with respect to the moving mechanism, so that the gap between the rotor and the stator in the direction of the rotation axis. The amount changes. In this way, since the amount of gap between the rotor and the stator can be changed using the rotational force acting between the rotor and the stator, a dedicated force is required to generate the driving force that changes the amount of gap. There is no need to add an actuator and its controller. Therefore, according to the present invention, the gap amount between the rotor and the stator can be changed without increasing the size of the apparatus.

Furthermore, Oite the present invention, the stator further comprising a lockable securing mechanism to the moving mechanism, when changing the gap amount releases the fixation of the stator by fixing mechanism. In this way, the stator can be reliably fixed when the stator is not moved .

In the axial type motor according to the present invention, the gap amount may be changed by causing a current to flow through a coil disposed in the stator so as to apply a rotational force to the rotor . In this way, the amount of gap between the rotor and the stator can be controlled by controlling the current flowing through the stator coil .

  In the axial type motor according to the present invention, the moving mechanism may include a shaft in which the screw is provided on an outer peripheral portion and a center portion of the stator is supported by the screw. In this way, it is possible to reduce the size of the moving mechanism for rotating the stator around the rotation axis and moving the stator in the direction of the rotation axis.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

  1 to 3 are diagrams showing an outline of a configuration of an axial motor according to an embodiment of the present invention, FIG. 1 shows an outline of a perspective view, FIG. 2 shows an overview of an internal configuration, and FIG. 3 shows a stator. The figure explaining the electrical connection to the coil of is shown. The axial type motor according to this embodiment includes a rotor 10, a stator 12, a moving mechanism 14, and a fixing mechanism 16.

  The rotor 10 has a substantially disk shape and can rotate around a rotation axis. Although not shown in FIGS. 1 and 2, permanent magnets are arranged on the rotor 10 in the circumferential direction.

  The stator 12 has a substantially disk shape, and is disposed opposite to the rotor 10 in the rotor rotation axis direction (axial direction). And the stator 12 is supported by the moving mechanism 14 of the structure mentioned later. Although not shown in FIGS. 1 and 2, coils 22 formed by winding a conductive wire around teeth that protrude toward the rotor 10 are arranged in the stator 12 in the circumferential direction. Thereby, the magnetic flux from the permanent magnet of the rotor 10 can be linked to the coil 22 of the stator 12.

  The control device 30 calculates the d-axis current command value and the q-axis current command value, and controls the drive of the inverter 32 based on the d-axis current command value and the q-axis current command value. Control the current flow. The direct current voltage from the battery 36 is converted into alternating current by the inverter 32, and alternating current is supplied to the coil 22 of the stator 12. Torque for rotating the rotor 10 can be generated by the interaction between the rotating magnetic field generated by the alternating current supplied to the coil 22 and the magnetic field generated by the permanent magnet of the rotor 10.

  The moving mechanism 14 supports the stator 12 in a state where the stator 12 can be rotated around the rotor rotation axis and moved in the rotor rotation axis direction. For example, as shown in FIGS. 1 and 2, the moving mechanism 14 can be realized by a shaft made of a nonmagnetic material in which a screw 20 is provided on the outer peripheral portion. The central axis of the screw 20 (the central axis of the shaft 14) substantially coincides with the rotor rotation axis. The center portion of the stator 12 is also threaded, and the stator 12 is supported on the shaft 14 by the screw 20 at the center portion. The shaft 14 is fixed with respect to a rotational movement around the central axis and a translational movement in the central axis direction by being fixed to a housing (not shown). The rotor 10 is supported by the shaft 14 via a bearing 24 at the center thereof in a state where the movement in the direction of the rotation axis is restricted and the rotor 10 can rotate around the rotation axis.

  When the stator 12 rotates along the screw 20 with respect to the shaft 14, the stator 12 moves relative to the shaft 14 in the rotor rotation axis direction. Thereby, the gap amount between the rotor 10 and the stator 12 in the rotor rotation axis direction changes, and the number of magnetic fluxes linked from the permanent magnet of the rotor 10 to the coil 22 of the stator 12 changes. A screw 20 is cut on the outer peripheral surface of the shaft 14 so that the gap amount increases when the stator 12 rotates clockwise as viewed from the lower side of FIG.

  The fixing mechanism 16 can fix the stator 12 to the shaft 14 (housing). For example, as shown in FIG. 2, the fixing mechanism 16 here can be realized by a brake that is disposed inside the stator 12 and that can fasten the shaft 14 at the outer periphery thereof. The brake 16 is fixed with respect to translational movement in the rotor rotation axis direction with respect to the stator 12. The operation of the brake 16, that is, the fixing of the stator 12 and the shaft 14 can be performed by, for example, hydraulic pressure supplied to the oil chamber 26 from a hydraulic actuator (not shown). Note that the hydraulic actuator here is for driving the brake 16, so that the apparatus is not increased in size.

  In the axial type motor according to the present embodiment, the gap amount between the rotor 10 and the stator 12 in the rotor rotation axis direction can be changed, and the magnetic flux interlinking from the permanent magnet of the rotor 10 to the coil 22 of the stator 12. The number can be changed. Here, when the gap amount between the rotor 10 and the stator 12 is not changed, the stator 12 is fixed to the moving mechanism (shaft) 14 by operating the fixing mechanism (brake) 16.

  On the other hand, the gap amount between the rotor 10 and the stator 12 is increased as follows. First, the fixing of the stator 12 by the fixing mechanism (brake) 16 is released. And the control apparatus 30 controls the electric current sent through the coil 22 of the stator 12 so that a negative torque generate | occur | produces in the rotor 10 (q-axis current command value is negative). However, when viewed from the stator 12 side (lower side in FIG. 2), the clockwise direction is the positive direction and the counterclockwise direction is the negative direction. As shown in FIG. 4, the stator 12 receives a reaction force from the rotor 10, thereby rotating in the positive direction along the screw 20 (clockwise when viewed from the lower side in FIG. 2) and moving away from the rotor 10. Move to. As a result, the gap amount between the rotor 10 and the stator 12 increases.

  Here, an attractive force due to a magnetic force acts between the rotor 10 and the stator 12, and in order to increase the gap amount between the rotor 10 and the stator 12, the stator 10 is repelled by the attractive force. 12 must be moved in the direction of the rotor rotation axis. However, in the present embodiment, the driving force necessary to change the gap amount can be reduced by moving the stator 12 along the screw 20 in the direction of the rotor rotation axis. In order to reduce the driving force required to change the gap amount, it is preferable to set the pitch of the screws 20 small.

  When reducing the gap amount between the rotor 10 and the stator 12, the control device 30 generates a positive torque in the rotor 10 in a state where the fixing of the stator 12 by the fixing mechanism (brake) 16 is released. Thus, the current flowing through the coil 22 of the stator 12 is controlled (q-axis current command value is positive). As shown in FIG. 5, the stator 12 receives a reaction force from the rotor 10, thereby rotating in the negative direction (counterclockwise when viewed from the lower side in FIG. 2) along the screw 20 and approaching the rotor 10. Move in the direction. As a result, the gap amount between the rotor 10 and the stator 12 is reduced. After the gap amount is changed by the operation described above, the stator 12 is fixed to the moving mechanism (shaft) 14 by operating the fixing mechanism (brake) 16.

  As an example of gap amount control in the present embodiment, during low load operation, the amount of gap between the rotor 10 and the stator 12 is increased by the current control of the coil 22 described above, so that the rotor 10 becomes permanent. The number of magnetic fluxes linked from the magnet to the coil 22 of the stator 12 is reduced. Thereby, the efficiency at the time of low load operation can be improved. On the other hand, when the driving torque of the rotor 10 is required, the amount of gap between the rotor 10 and the stator 12 is reduced by the current control of the coil 22 described above, so that the permanent magnet of the rotor 10 is changed from the permanent magnet of the rotor 10. The number of magnetic fluxes linked to the coil 22 is increased.

  As described above, in the present embodiment, by passing an electric current through the coil 22 of the stator 12 so that torque is applied to the rotor 10, the stator 12 is rotated along the screw 20 and the rotor rotational axis direction (axial) Direction). Thus, since the gap amount between the rotor 10 and the stator 12 can be changed by using the torque acting between the rotor 10 and the stator 12, a driving force for changing the gap amount is generated. Therefore, it is not necessary to add a dedicated actuator and its control device. Therefore, according to the present embodiment, the gap amount between the rotor 10 and the stator 12 can be changed without increasing the size of the apparatus, and the number of flux linkages from the permanent magnet of the rotor 10 to the stator 12 can be changed. Can be changed.

  Further, in the present embodiment, the driving force necessary for changing the gap amount between the rotor 10 and the stator 12 is obtained by moving the stator 12 along the screw 20 in the rotor rotation axis direction. Can be small.

  Further, in the present embodiment, the stator 12 is supported around the center of the shaft 12 via the screw 20 provided on the outer periphery of the shaft 14, thereby rotating the stator 12 around the rotor rotation axis and the rotor rotation axis direction. It is possible to reduce the size of the moving mechanism 14 for moving to the right.

  Further, when the stator 12 is not moved in the rotor rotation axis direction, the stator 12 is fixed by the fixing mechanism (brake) 16, so that the stator 12 is securely fixed when the gap amount between the rotor 10 and the stator 12 is not changed. can do.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to such embodiment at all, and it can implement with a various form in the range which does not deviate from the summary of this invention. Of course.

It is a perspective view showing the outline of the composition of the axial type motor concerning the embodiment of the present invention. It is a figure which shows the outline of the internal structure of the axial type motor which concerns on embodiment of this invention. It is a figure explaining the example of the electrical connection to the coil of a stator. It is a figure explaining operation | movement of the axial type motor which concerns on embodiment of this invention. It is a figure explaining operation | movement of the axial type motor which concerns on embodiment of this invention.

Explanation of symbols

  10 rotor, 12 stator, 14 moving mechanism (shaft), 16 fixing mechanism (brake), 20 screw, 22 coil, 24 bearing, 30 control device, 32 inverter, 36 battery.

Claims (3)

A rotor rotatable around a rotation axis;
A stator disposed opposite to the rotor in the rotational axis direction;
A moving mechanism that supports the stator in a movable state in the direction of the rotation axis so that the gap amount between the rotor and the stator in the direction of the rotation axis can be changed;
An axial motor having
The moving mechanism supports the stator with a screw whose central axis substantially coincides with the rotation axis,
Due to the rotational force acting between the rotor and the stator, the stator rotates along the screw with respect to the moving mechanism and moves in the direction of the rotation axis, thereby changing the gap amount .
A fixing mechanism capable of fixing the stator to the moving mechanism;
When changing the gap amount, the stator is released from being fixed by the fixing mechanism . The axial type motor according to claim 1,
An axial type motor characterized in that the gap amount is changed by passing an electric current through a coil disposed in a stator so that a rotational force is applied to a rotor. An axial type motor according to claim 1 or 2,
An axial type motor characterized in that the moving mechanism includes a shaft in which the screw is provided on an outer peripheral portion and a central portion of the stator is supported by the screw .

Images