JP2008259364A - Variable field motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable field motor with a simple motor structure. <P>SOLUTION: This variable field motor includes: a rotor 5; a stator 7 which is coaxial with the rotor 5 and provided displaceably toward the rotation axis A of the rotor 5; stator moving means 11, 12 for displacing the stator 7 toward the rotation axis A. The stator moving means 11, 12 have an axial force transfer member 11 for transferring force, of which one end is connected to the stator 7, and axial force generating means 12 for displacing the other end of the axial force transfer member 11 so as to displace the stator toward the rotation axis A through the axial force transfer member 11. The axial force generating means 12 is provided in a position spaced from a motor body M including the stator 7 and the rotor 5. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a variable field motor, and more particularly to a variable field motor characterized by the configuration of a variable mechanism for a variable field.

2. Description of the Related Art In recent years, variable field motors that can adjust the field of a motor and obtain an appropriate rotation speed and torque in accordance with usage conditions have been used in electric vehicles. In general, a variable field motor is provided such that one of a stator or a rotor is movable with respect to the other, and a variable mechanism changes a field by changing a relative position between the stator and the rotor (for example, Patent Documents). 1).
Japanese Patent Application No. 2006-335502

  However, in the conventional variable field motor, as shown in FIG. 7, the variable mechanism portion is configured to include the actuator 100 and the feed screw 101, and these are provided integrally with the motor body including the stator and the rotor. When the vehicle is provided as an in-wheel motor, there is a problem that the unsprung load increases. In addition, the structure of the motor and the structure around the wheel are complicated, and there is a problem that the number of parts is large. Furthermore, there is a problem that it is difficult to take a dustproof and waterproof measure for the variable mechanism portion.

  The present invention has been made in view of the above-described problems, and when used as an in-wheel motor, the unsprung load of the vehicle can be reduced, and the motor structure and the structure around the wheel can be simplified. An object of the present invention is to provide a variable field motor capable of reducing the number of parts and facilitating dust prevention and waterproofing measures of the variable mechanism section.

  In order to solve the above-mentioned problems, the invention according to claim 1 of the present invention is a stator that is coaxial with the rotor 5 and is provided so as to be displaceable in the rotation axis direction A of the rotor 5. 7 and a variable field motor having stator moving means 11 and 12 for displacing the stator 7 in the rotation axis direction A. The stator moving means 11 and 12 are connected to the stator 7 at one end. An axial force transmission member 11 that transmits force in the axial direction, and a shaft that displaces the other end of the axial force transmission member so as to displace the stator in the rotational axis direction A via the axial force transmission member 11. The axial force generating means 12 is provided at a position separated from the motor body M including the stator 7 and the rotor 5.

  Further, the invention according to claim 2 of the present invention is the invention of claim 1, and is a biasing means (return spring 17) for returning the stator 7 to one of the displacement ends of the stator 7 in the rotational axis direction A. ), And the axial force transmission member 11 is a cable.

  According to the first aspect of the present invention, the axial force generating means, which is the driving force generating portion of the stator moving means serving as the variable mechanism portion that changes the field of the motor, is positioned away from the motor body including the stator and the rotor. Since it is provided, the weight of the motor main body can be reduced. Therefore, when the motor according to the present invention is used as an in-wheel motor, the unsprung weight is reduced, and the riding comfort and the running performance of the vehicle are improved. In addition, the number of parts of the motor main body is reduced, the structure of the motor main body is simplified, and the ease of assembly to the vehicle body is improved. In addition, since the structure around the wheel is simplified, the dust-proof and waterproof measures of the variable field motor become easy.

  According to the invention of claim 2, the stator is biased by the biasing means in a direction opposite to the force applied by the axial force generating means, and the stator position fluctuates due to slack of the axial force transmission member. And the stator position can be reliably determined. Therefore, the stator can be reliably moved to a predetermined position in response to abrupt stator movement control during manual and automatic control, and the reliability of the apparatus is improved.

  Further, since the cable can be bent, the stator moving means can be adapted to various device shapes by using the axial force transmission member as the cable. In addition, since the cable is lightweight, the unsprung weight of the motor body can be reduced. Further, when the motor to which the present invention is applied is mounted on the vehicle, it is possible to lengthen the cable in the vehicle body, and the selectivity of the installation position of the axial force generator in the vehicle body is increased. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view illustrating an example of drive wheels W of an electric vehicle to which the variable field motor according to the embodiment is applied. FIG. 2 is a side view seen from the XX direction of FIG. FIG. 3 is a partial cross-sectional view showing the motor type traction device according to the embodiment in a partially broken view. FIG. 4 is a partial cross-sectional view showing a manual traction device according to another embodiment with a part thereof broken. FIG. 5 is a schematic cross-sectional view showing an example of the drive wheel W of the electric vehicle to which the embodiment is applied, and shows a form after the embodiment of FIG. 1 is changed. FIG. 6 is a schematic cross-sectional view showing an example of drive wheels W of an electric vehicle to which a variable field motor according to another embodiment is applied.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the variable field motor according to the present embodiment is fixed to a knuckle 1 of a vehicle body as an in-wheel motor of an electric vehicle and constitutes a part of the wheel of the electric vehicle. A wheel support plate 2 is fixed to a knuckle 1 provided in the vehicle body, and a fixed support shaft 3 protrudes and is fixed to the wheel support plate 2. A rotor 5 is supported on the fixed support shaft 3 through a pair of bearings 4 a and 4 b so as to be rotatable with respect to the rotary shaft A, and is positioned in the direction of the shaft A by a fixed nut 21. Drive wheels W are attached to the outer periphery of the rotor 5 via wheels.

  The rotor 5 is formed with large and small boss portions 5a and 5b coaxially with the support shaft 3, and the space between the boss portions 5a and 5b is open to the knuckle 1 side (vehicle body side). A plurality of magnets 6 in which N and S poles are arranged in the circumferential direction are disposed on the inner peripheral surface of the large-diameter boss portion 5a. Moreover, the stator 7 is provided so that it may be received in the space by both boss | hub parts 5a * 5b.

  The stator 7 includes a core portion 8 that faces the magnet 6 and an annular member 9 that supports the core portion 8. The annular member 9 has an annular shape, the core portion 8 is fixed to the outer peripheral side, and the inner peripheral side is supported by the guide shaft 10 so as to be slidable in the direction of the axis A. The guide shaft 10 has an annular shape, is disposed so as to surround the outer peripheral side of the small-diameter boss portion 5 b via a gap, and one end is fixed to the wheel support plate 2. The core portion 8 includes a plurality of stator cores 8a fixed to the outer periphery of the annular member 9 and armature coils 8b wound around the stator cores 8a. The stator 7 and the rotor 5 thus configured form a motor body M. FIG. 2 is a side view seen from the XX direction in FIG. 1 and shows the motor body M formed as described above, except for the knuckle 1 and the drive wheels W. FIG.

  Stator moving means for moving the stator 7 in the direction in which the area where the stator 7 and the rotor 5 overlap in the axis A direction (area where the stator core 8a and the magnet 6 face each other) decreases, that is, in the direction a in which the stator 7 separates from the rotor 5, A motor 11 serving as an axial force generating means connected to the vehicle body at a distance from the motor main body M and connected to the other end of the cable 11 as a cable 11 serving as an axial force transmission member having one end connected to the annular member 9. It comprises a traction device 12 (see FIG. 3). The cable 11 includes an inner cable 11a and an outer case 11b that protects the inner cable 11a. The inner cable 11a and the outer case 11b in the present embodiment may be general-purpose products generally used as a brake cable for a motorcycle or a bicycle. The motor-type traction device 12 includes a motor 13, a drum 14 that rotates by a driving force of the motor, and a casing 15 that supports the motor 13 and the drum 14. One end of the outer case 11 b is fixed to the wheel support plate 2, and the other end is fixed to the casing 15 of the motor type traction device 12. One end of the inner cable 11 a is connected to the annular member 9, and the other end is fixed to the drum 14 of the motor type traction device 12. The inner cable 11 a is wound around the drum 14 by the rotational drive of the motor 13, and the stator 7 is pulled in the direction “a” of the axis A. The rotational drive of the motor 13 is determined by the control device of the variable field motor M according to the rotational speed of the variable field motor M and the running state of the automobile. The control method may be a known method and will not be described in detail.

  The motor type traction device 12 may be a manual type manual traction device 16 as shown in FIG. The manual traction device 16 includes a manual lever 18 for manual operation, a drum 19 fixed to one end of the manual lever 18, and a casing 20 that supports the manual lever 18 and the drum 19 in a tiltable manner. The other end of the inner cable 11 a having one end fixed to the stator 7 is fixed to the drum 19, and the outer case 11 b is fixed to the casing 20. When the manual lever 18 is tilted, the drum 19 is rotated to pull the inner cable 11 a and pull the stator 7. The manual traction device 16 is suitable for a race car of a solar car race that requires saving of power consumption, and can reduce the number of parts and the weight of the vehicle body.

  In the present embodiment, the cable 11 and the traction device 12 are used as the stator moving means, but the stator moving means can be replaced with other ones that have the same effect. For example, a push pull may be used instead of a cable. In addition, a rod or a feed screw may be used as an alternative to the cable, and a drive device such as an actuator may be provided at a position separated from the motor body in order to move the stator 7 via the rod or the feed screw.

  As shown in FIG. 1, a return spring 17 as an urging means is provided between the stator 7 and the wheel support plate 2, and the stator 7 is in the direction of the axis A and opposite to the direction a in which the stator 7 is detached from the rotor 5. Is biased in the direction b. FIG. 5 shows a side view after the stator 7 has moved in the direction a along the axis A. FIG. Originally, when the relative position between the stator 7 and the rotor 5 is deviated, the stator 7 is affected by the magnetic force acting between the stator core 8 a and the magnet 6, and the area where the stator core 8 a and the magnet 6 are opposed to each other. Is increased in the direction of increasing, that is, in the direction of direction b. However, when the stator 7 is vigorously moved in the direction a and the stator 7 moves too much, or when the traction force of the traction device 12 is suddenly loosened, the inner cable 11a is loosened, and the stator 7 The position of 7 may not be determined quickly and appropriately. In order to prevent these phenomena, the return spring 17 is always urged in the direction b to ensure the positioning of the stator 7. In this embodiment, the return spring 17 is provided so as to surround the guide shaft 10 and urge the stator 7 in a wide range. However, as shown in FIG. 6, the return spring is surrounded so as to surround the inner cable 11a. 22 may be provided.

  By configuring as described above, an in-wheel motor can be configured by separating the motor-type traction device as the stator moving means from the motor body M. Thereby, the number of parts around the motor M and the wheels is reduced, the structure is simplified, and the assembling property to the vehicle body is improved, so that the manufacturing cost can be reduced. Further, since the motor type traction device as the stator moving means is installed on the vehicle body, the unsprung load is reduced, and the riding comfort and the running performance of the vehicle are improved. In addition, since the structure is simple, it is easy to take dust-proof and waterproof measures.

  In this embodiment, the traction means 12 for applying a force in only one direction along the axis A to the stator 7 is used as the axial force generation means. However, the bidirectional force along the axis A is applied to the stator 7 as the axial force generation means. You may comprise so that the force of can be applied. For example, the stator moving means may be configured using an annular cable as the axial force transmitting means and using an apparatus capable of moving the cable in both directions in the axial direction as the axial force generating means. In such a case, the return spring 17 as the urging means can be omitted.

It is typical sectional drawing which shows the example of the drive wheel W of the electric vehicle to which the variable field motor which concerns on embodiment was applied. It is the side view seen from the XX direction of FIG. It is a fragmentary sectional view showing a motor type traction device concerning an embodiment partially fractured. It is a fragmentary sectional view which shows a manual traction device concerning other embodiments partially fractured. It is typical sectional drawing which shows the example of the drive wheel W of the electric vehicle to which embodiment was applied, Comprising: It is typical sectional drawing which shows the form after embodiment of FIG. 1 changed. It is typical sectional drawing which shows the example of the drive wheel W of the electric vehicle to which the variable field motor which concerns on other embodiment was applied. It is typical sectional drawing which shows the example of the drive wheel W of the electric vehicle to which the variable field motor which concerns on a prior art was applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Knuckle 2 Wheel support plate 3 Fixed support shaft 5 Rotor 5a Large diameter boss part 5b Small diameter boss part 6 Magnet 7 Stator 8 Core part 9 Annular member 10 Guide shaft 11a Inner cable 11b Outer case 12 Motor type traction device 16 Manual traction device 17・ 22 Return spring M Motor W Drive wheel A Rotating shaft

Claims (2)

The rotor,
A stator that is coaxial with the rotor and that is displaceable in the rotation axis direction of the rotor;
A variable field motor having stator moving means for displacing the stator in the rotation axis direction,
The stator moving means is
An axial force transmission member that transmits force in the axial direction connected to the stator at one end;
Axial force generating means for displacing the other end of the axial force transmission member so as to displace the stator in the rotational axis direction via the axial force transmission member;
The variable field motor according to claim 1, wherein the axial force generating means is provided at a position separated from a motor body including the stator and the rotor. Biasing means for returning the stator to any one of the displacement ends of the stator in the rotational axis direction;
The variable field motor according to claim 1, wherein the axial force transmission member is a cable.

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