JP2007189811A - Motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To switch an area in where a permanent magnet faces an armature coil in a motor with proper responsiveness. <P>SOLUTION: When an armature assembly 40 rotates in the left-hand direction (counterclockwise direction), a threadable mount between a female thread 64a of a female thread bearing member 64 and a male thread 50c is loosened, and friction between the threads is reduced, since the male thread 50c screwed to the female thread bearing member 64 rotates in the left-hand direction. The female thread bearing member 64 is held statically in an annular recess 62a in a bearing metal 62. Rotational movement is converted into linear movement, by screwing the female thread 64a and the male thread 50c. As a result, the armature assembly 40 moves in the right direction (Xb-direction) in parallel and the relative position between the armature coil 54 and the permanent magnet 30 is shifted, and the area in which the permanent magnet 30 faces the armature coil 54 is reduced and the region of effective magnetic field flux from the permanent magnet 30 is reduced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a motor, and more particularly to a motor configured to switch the rotational speed or rotational torque of a rotating shaft.

  For example, a permanent magnet field type DC motor having a brush is employed as a driving means for reciprocating a wiper that removes water droplets adhering to a front window of an automobile. In this type of motor, a permanent magnet is fixed to the inner wall of a housing, and an armature assembly (also referred to as an armature assembly) having a coil wound therein is rotatably supported. And in order to supply with electricity to the coil of an armature assembly, the 1st, 2nd brush (brush for low speed rotation) and the 3rd brush (brush for high speed rotation) which contact the commutator piece of an armature assembly are provided. ing.

  The third brush increases the rotational speed of the armature assembly by reducing the magnetic flux used in the armature assembly, and is arranged at a circumferential position (angle) different from the first and second brushes. Has been. By switching the energization to the third brush, the energization range of the armature coil is changed, thereby enabling the rotation speed of the armature assembly to be increased.

  However, in the conventional DC motor having the first to third brushes, every time the third brush for high speed straddles between the commutator pieces arranged in the circumferential direction in normal operation (low speed mode), the third brush Due to the induced electromotive force generated in the armature coil to be short-circuited, a large short-circuit current in the direction opposite to the energizing direction flowed instantaneously, and brush spark discharge was generated. The brush spark discharge causes electric noise (noise) and brush wear, and causes a rectification failure by the third brush.

  In addition, in order to solve such a problem, when the motor drive circuit is combined with a noise prevention coil (inductor), a capacitor, or the like, the number of parts and cost increase.

  In addition, when the magnet material is further miniaturized and a motor having a 4-pole 6-brush configuration is developed, it is physically difficult to secure an installation space for the third brush.

As a method for solving such a problem, the number of brushes is reduced by eliminating the third brush, and the armature assembly is translated between the armature coil and the permanent magnet fixed to the housing inner wall in the axial direction. A method has been proposed in which the effective magnetic flux amount from the permanent magnet is changed by changing the relative position (opposed area) to change the rotation speed of the armature coil (for example, see Patent Document 1).
JP-A-8-214522

  However, since the structure disclosed in Patent Document 1 is provided with armature driving means for translating the armature assembly in the axial direction, the rotational speed is reduced by transmission loss of the armature driving means. There is a problem that the responsiveness when switching is lowered.

  Furthermore, when the armature driving means is housed in the housing, there is a problem that the motor becomes large and it is difficult to cope with space saving.

  Therefore, in view of the above circumstances, the present invention provides a motor that solves the above problems by changing the effective magnetic flux from the permanent magnet by translating the armature assembly in the axial direction using the rotational force of the rotating shaft. The purpose is to provide.

  In order to solve the above problems, the present invention has the following means.

  The present invention relates to a housing, a permanent magnet that is fixed on the radially inner side of the housing and generates a field magnetic flux, a rotary shaft having a male screw, an armature core that is fixed to the outer periphery of the rotary shaft, An armature coil wound around the outer periphery, rotating in the radial direction of the permanent magnet and movable in the axial direction, and the inner peripheral surface of the through hole penetrating in the axial direction A female screw bearing member that has a female screw threadedly engaged with a male screw of the rotary shaft, and that translates the armature assembly in an axial direction corresponding to the rotational direction of the rotary shaft; and an outer peripheral surface fixed to the housing; The bearing includes a bearing that rotatably supports the female screw bearing member, and a rotation control means that enables or restricts relative rotation between the female screw bearing member and the bearing.

  Further, the rotation control means reverses the rotation direction of the armature assembly so that the male screw of the rotating shaft screwed to the female screw bearing member is driven in the axial direction and faces the permanent magnet. The number of rotations of the armature assembly is switched by changing the facing area.

  Further, the bearing restricts the rotation of the female screw bearing member due to friction with the female screw bearing member, and the movement of the armature assembly is restricted in the axial direction by the stopper, and the axial movement is stopped. Then, relative rotation with the female screw bearing member is allowed.

  According to the present invention, the male screw formed on the rotating shaft of the armature assembly is screwed to the female screw bearing member rotatably supported by the bearing, and the relative rotation between the female screw bearing member and the bearing is controlled by the rotation control means. Since it is possible or restricted, there is no need to provide a third brush as in the prior art, so that the rectification obstacle due to the third brush is eliminated and the armature assembly is directly pivoted using the rotational force of the rotating shaft. It is possible to drive in the direction, and there is no need to provide a driving means for translating the armature assembly in the axial direction. It becomes possible to plan.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 shows a first embodiment of a motor according to the present invention, and is a longitudinal sectional view showing a low-speed rotation mode in which an armature assembly is moved leftward. As shown in FIG. 1, the motor 10 includes a housing 20, a field permanent magnet 30 fixed inside the housing 20 in the radial direction, and an armature assembly 40.

  The housing 20 is configured by combining a storage case 22 that stores the armature assembly 40 and a lid member 26 that closes the storage chamber 24 of the storage case 22 from the right side. The storage case 22 is formed in a cylindrical shape, and a permanent magnet 30 is fixed to the inner wall at the center in the axial direction over the entire circumference.

  An armature assembly 40 is inserted into the inner circumference of the permanent magnet 30 so as to be rotatable in the circumferential direction and movable in the axial direction (Xa and Xb directions in FIG. 1). Since the storage chamber 24 of the storage case 22 stores the armature assembly 40 so as to be movable in the axial direction, a space having a size corresponding to the axial stroke of the armature assembly 40 is formed.

  Next, the configuration of the armature assembly 40 will be described. The armature assembly 40 includes a rotating shaft 50, an armature core 52 fixed to the rotating shaft 50, an armature coil 54 wound around the armature core 52, and a commutator 56.

  The armature core 52 and the armature coil 54 are attached so as to be close to and opposed to the inner peripheral surface of the permanent magnet 30 fixed to the inner wall of the storage chamber 24, and rotate on the radially inner side of the permanent magnet 30. And supported so as to be movable in the axial direction. In this embodiment, the armature core 52 and the armature coil 54 are formed so that the width dimension in the axial direction is the same as the width dimension L of the permanent magnet 30.

  Further, on the outer periphery of the commutator 56, the first brush 71 and the second brush 72 are supported by brush support members 74 and 76 so as to be in sliding contact with each other at an interval of 180 ° in the circumferential direction. The commutator 56 is formed to extend toward the left end 50 a of the rotary shaft 50, and has an axial length longer than an axial movement amount (stroke) of the armature assembly 40.

  Further, the first brush 71 and the second brush 72 are attached so as to maintain a state where they are in contact with the commutator 56 regardless of the movement position of the armature assembly 40. Accordingly, a current supplied to the first brush 71 or the second brush 72 from a drive circuit (not shown) flows through the armature coil 54, thereby generating a magnetic flux around the armature core 52. A rotational force that rotates the armature assembly 40 with respect to the field flux is generated.

  In the present embodiment, the first brush 71 and the second brush 72 are in contact with the commutator 56, and since the third brush is not provided as in the prior art, the commutation failure due to the third brush is eliminated. In addition, it is possible to eliminate a space problem when arranging the third brush in the case of quadrupolarization.

  The rotating shaft 50 has a left end (one end) 50a that extends through the center of the armature core 52 and extends in the Xa direction, and a right end (other end) 50b that extends in the Xb direction. A male screw 50 c is formed on the outer periphery of the left end 50 a of the rotating shaft 50. Since the male screw 50c is screwed into a female screw 64a formed on the inner periphery of the female screw bearing member 64, the male screw 50c can be translated in the axial direction (Xa direction or Xb direction) according to the rotation direction of the rotary shaft 50. It becomes possible.

  An output shaft 50d extending in the axial direction is integrally provided at the right end 50b of the rotating shaft 50. The output shaft 50d is inserted into the insertion hole 26c and protrudes to the outside of the lid member 26. The output shaft 50d is formed to have a length that protrudes a predetermined length even when the armature assembly 40 moves leftward (Xb direction). Has been. Since the motor 10 of this embodiment is used as a motor for driving a wiper of an automobile, the output shaft 50d of the rotary shaft 50 is connected to a drive shaft of a wiper drive mechanism (not shown).

  Further, a bearing support portion 28 communicating with the storage chamber 24 is provided at the left end portion of the storage case 22. The bearing support portion 28 supports a ball bearing 60 that contacts the end surface of the left end 50a of the rotating shaft 50 and a bearing metal 62 that rotatably supports the outer periphery of the left end 50a of the rotating shaft 50. The ball bearing 60 is held in a recess 28a formed by a dovetail groove formed on the inner wall of the bearing support 28 so as to coincide with the axis of the rotary shaft 50, and is in point contact with the end surface of the left end 50a of the rotary shaft 50. The rotary shaft 50 is provided so as to be rotatable and function as a stopper for restricting the movement position of the rotary shaft 50 in the Xa direction.

  The bearing metal 62 is formed in an annular shape, an outer peripheral surface is fixed to the stepped portion 28b of the bearing support portion 28, and an annular concave portion 62a in which the female screw bearing member 64 is slidably contacted is provided on the inner peripheral surface. The female screw bearing member 64 is supported so that its movement in the axial direction (Xa, Xb direction) is restricted and its rotation in the circumferential direction is allowed because the outer peripheral surface is fitted in the annular recess 62a. ing. The bearing metal 62 and the female screw bearing member 64 constitute a rotating shaft support mechanism that rotatably supports the left end 50a of the rotating shaft 50 and translates the rotating shaft 50 in the axial direction.

  The female screw bearing member 64 is an annular shape in which a female screw 64 a that engages with a male screw 50 c formed on the outer periphery of the left end 50 a of the rotating shaft 50 is formed on the inner peripheral surface, and an outer peripheral surface is formed on the inner periphery of the bearing metal 62. The recess 62a is fitted and held. Therefore, when the rotary shaft 50 rotates, an inner peripheral friction Fa is generated between the female screw 64a and the male screw 50c on the inner peripheral side of the female screw bearing member 64, and a bearing is provided on the outer peripheral side of the female screw bearing member 64. An outer peripheral friction Fb is generated between the metal 62 and the annular recess 62a.

  The frictional difference generated between the inner periphery and the outer periphery of the female screw bearing member 64 acts as a rotation control means that enables or restricts the relative rotation between the female screw bearing member 64 and the bearing metal 62. For example, when the relative relationship between the inner peripheral friction Fa and the outer peripheral friction Fb with respect to the female screw bearing member 64 is Fa <Fb, the female screw bearing member 64 is held stationary with respect to the annular recess 62 a of the bearing metal 62. When Fa> Fb, the female screw bearing member 64 is held in a rotating state with respect to the annular recess 62 a of the bearing metal 62.

  Therefore, when the outer peripheral friction Fb is larger than the inner peripheral friction Fa (Fa <Fb), the rotation of the female screw bearing member 64 is restricted. Therefore, when a rotational force is applied to the rotary shaft 50, the male screw 50c is screwed. The mating female screw bearing member 64 is restricted in rotation and can move the armature assembly 40 in the Xa direction or the Xb direction. Further, when the inner peripheral friction Fa is larger than the outer peripheral friction Fb (Fa> Fb), the female screw bearing member 64 can rotate integrally with the rotary shaft 50.

  The lid member 26 also supports a bearing metal 66 that rotatably supports the right end 50b of the rotary shaft 50. The bearing metal 66 is formed in a cylindrical shape, and an inner peripheral surface thereof is slidably contacted with an outer periphery of the right end 50 b of the rotary shaft 50, and an outer peripheral surface is formed so as to project into a cylindrical shape of the lid member 26. The step 26b of 26a is fitted and fixed. An insertion hole 26c that passes through the end of the right end 50b of the rotating shaft 50 passes through the end of the bearing support portion 26a in the axial direction.

  Furthermore, a C-shaped retaining ring (right stopper) 68 that is locked to the outer periphery of the right end 50b of the rotating shaft 50 is inserted into the hollow portion 26d formed inside the bearing support portion 26a, and A thrust washer 70 that abuts when the retaining ring 68 moves to the right (Xb direction) is inserted into the step portion of the hollow portion 26d.

  The amount of movement (stroke) of the armature assembly 40 in the axial direction is such that the end face of the left end 50a of the rotating shaft 50 is in the leftward moving limit position where the ball bearing 60 abuts and the retaining ring locked to the right end 50b of the rotating shaft 50. 68 is determined by the rightward movement limit position where the thrust washer 70 abuts.

  Here, the rotation drive and rotation speed switching operation of the motor 10 configured as described above will be described. FIG. 1 shows a low-speed rotation mode in which the left end 50a of the rotating shaft 50 is in contact with the ball bearing 60 and the armature assembly 40 moves in the Xa direction. In this low-speed rotation mode, the armature assembly 40 is rotated clockwise (clockwise). The rotation shaft 50 is supported by the bearing metal 62 at the left end 50a of the rotation shaft 50 and the bearing metal 66 at the right end 50b. It is supported.

  Since the left end 50a of the rotating shaft 50 is in contact with the ball bearing 60, when the armature assembly 40 is rotated clockwise (clockwise), the female screw 64a of the female screw bearing member 64 and the male screw 50c are screwed together. The relationship is tightened and the friction between the screws increases. That is, the relative relationship between the inner peripheral friction Fa and the outer peripheral friction Fb with respect to the female screw bearing member 64 is Fa> Fb. Therefore, the outer peripheral surface of the female screw bearing member 64 is allowed to rotate with respect to the annular recess 62 a of the bearing metal 62.

  Therefore, in a state where the left end 50a of the rotating shaft 50 is in contact with the ball bearing 60, a current from the drive circuit is supplied to the armature coil 54, and a clockwise (clockwise) rotational force with respect to the field flux of the permanent magnet 30 is generated. When applied, the female screw bearing member 64 rotates integrally with the rotary shaft 50. In this state, the armature coil 54 is close to and opposed to the permanent magnet 30 with the full axial width of the permanent magnet 30 (the entire range of the dimension L), and the full width of the permanent magnet 30 becomes an effective magnetic flux region, so that high torque Is obtained, but the rotational speed is low.

  Therefore, in the motor 10, the armature assembly 40 is rotationally driven clockwise (clockwise) to enter a low-speed rotation mode, and for example, an automobile wiper (not shown) can be driven at a low speed.

  Next, the operation for switching from the low speed rotation mode to the high speed rotation mode will be described. By reversing the flow direction of the current supplied from the drive circuit to the armature coil 54, a counterclockwise (counterclockwise) rotational force is generated in the armature assembly 40. In the low-speed rotation mode shown in FIG. 1, when a counterclockwise (counterclockwise) rotational force is applied to the armature assembly 40, the male screw 50c that engages with the female screw bearing member 64 rotates counterclockwise. The screwing relationship between the female screw 64a of the female screw bearing member 64 and the male screw 50c is loosened, and friction between the screws is reduced.

  Therefore, the relative relationship between the inner peripheral friction Fa and the outer peripheral friction Fb with respect to the female screw bearing member 64 is Fa <Fb, and the female screw bearing member 64 is held in a stationary state in the annular recess 62 a of the bearing metal 62. Therefore, since the rotational motion is converted into a linear motion by the screwing of the female screw 64a and the male screw 50c, the armature assembly 40 is translated in the right direction (Xb direction).

  FIG. 2 shows a high-speed rotation mode in which the armature assembly 40 has moved to the right. As shown in FIG. 2, the armature assembly 40 translates to the right (Xb direction) while rotating counterclockwise (counterclockwise), so that the armature coil 54 and the permanent magnet 30 are relative to each other. A position will shift | deviate and the opposing area of the armature coil 54 and the permanent magnet 30 will reduce. Thereby, the area | region of the effective field magnetic flux from the permanent magnet 30 reduces.

  Furthermore, when the armature assembly 40 is translated in the right direction (Xb direction), the C-shaped retaining ring 68 locked to the right end 50b of the rotating shaft 50 comes into contact with the thrust washer 70 of the bearing support portion 26a. When the movement of the armature assembly 40 to the right (Xb direction) is restricted by the thrust washer 70, the screwed relationship between the female screw 64a of the female screw bearing member 64 and the male screw 50c is tightened, and the friction between the screws is reduced. Increase. Therefore, the relative relationship between the inner peripheral friction Fa and the outer peripheral friction Fb with respect to the female screw bearing member 64 is Fa> Fb, and the female screw bearing member 64 rotates while slidingly contacting the annular recess 62a of the bearing metal 62.

  Therefore, in the armature assembly 40, when the retaining ring 68 contacts the thrust washer 70 and the movement to the right (Xb direction) is restricted, the female screw bearing member 64 rotates integrally with the rotary shaft 50. Thus, in a state where the facing area of the armature coil 54 with respect to the permanent magnet 30 is reduced, the resistance when the armature coil 54 cuts the magnetic flux from the permanent magnet 30 is reduced, and the armature assembly 40 rotates at high speed. To do.

  Therefore, in the motor 10, by rotating the armature assembly 40 counterclockwise (counterclockwise), the motor 10 enters a high-speed rotation mode, and for example, an automobile wiper (not shown) can be driven at high speed. .

  Furthermore, when switching from the high-speed rotation mode shown in FIG. 2 to the low-speed rotation mode, the armature assembly 40 is rotated clockwise (clockwise). When a clockwise (clockwise) rotational force is applied to the armature assembly 40, the male screw 50c that engages with the female screw bearing member 64 reversely rotates clockwise, so that the rotary shaft 50 is moved to the left (Xa direction). A driving force is generated in order to make a parallel movement.

  Thereby, the screwing relationship between the female screw bearing member 64 and the male screw 50c is loosened, and the friction between the screws is reduced. Therefore, the relative relationship between the inner peripheral friction Fa and the outer peripheral friction Fb with respect to the female screw bearing member 64 is Fa <Fb, and the female screw bearing member 64 is held in a stationary state in the annular recess 62 a of the bearing metal 62. Accordingly, since the rotational motion is converted into a linear motion by the screwing of the female screw 64a and the male screw 50c, the armature assembly 40 translates leftward (Xa direction) as shown in FIG.

  When the left end 50a of the rotating shaft 50 moves to the left (Xa direction) to a position where it abuts on the ball bearing 60, the relative relationship between the inner peripheral friction Fa and the outer peripheral friction Fb with respect to the female screw bearing member 64 as described above. Becomes Fa> Fb. Therefore, when a clockwise (clockwise) rotational force is applied, the female screw bearing member 64 rotates integrally with the rotary shaft 50. In this state, since the armature coil 54 is close to and opposed to the permanent magnet 30 with the full axial width of the permanent magnet 30 (the entire range of the dimension L), the rotational speed is low.

  Therefore, in the motor 10 of this embodiment, it is possible to switch from the low-speed rotation mode to the high-speed rotation mode or from the high-speed rotation mode to the low-speed rotation mode by switching the rotation direction of the armature assembly 40. There is no loss and the responsiveness of the switching operation is improved. In addition, since the motor 10 is configured to move the armature assembly 40 in the axial direction by utilizing the rotation of the rotary shaft 50, a driving means for moving the armature assembly 40 in the axial direction is specially provided. There is no need, it becomes a compact configuration, and it is possible to meet demands for miniaturization and space saving.

  In the present embodiment, the case where the motor 10 is used as a wiper driving motor has been described. However, the use of the motor 10 is not limited to this, and any motor can be used as long as it is a device for switching the number of revolutions or a device for switching torque. Of course, it can be applied to other fields. For example, when the motor 10 is used as a power window motor, it is possible to perform an operation for opening the window at a high speed rotation and an operation for closing the window at a low speed rotation. It becomes possible to switch speed and direction of operation.

  FIG. 3 is a longitudinal sectional view showing a low-speed rotation mode in which the armature assembly 40 according to the second embodiment moves leftward. In FIG. 3, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The motor 80 is provided with output shafts 50 d and 50 e at both ends of the rotating shaft 50. The output shafts 50d and 50e are inserted through the insertion holes 26c and 28c of the bearing support portions 26a and 28, respectively. Retaining rings 68a and 68b are engaged with the left end 50a and the right end 50b of the rotary shaft 50, and thrust washers 70a and 70b are provided at the step portions of the hollow portions 26d and 28d.

  Therefore, the amount of movement (stroke) in the axial direction of the armature assembly 40 is such that the stop ring 68a locked to the left end 50a of the rotating shaft 50 is in the leftward moving limit position where the thrust ring 70a abuts against the thrust washer 70a. The retaining ring 68b latched by 50b is determined by the rightward movement limit position where it abuts against the thrust washer 70b.

  Here, the rotation drive and rotation speed switching operation of the motor 80 configured as described above will be described. FIG. 3 shows a low-speed rotation mode in which the retaining ring 68a locked to the left end 50a of the rotating shaft 50 is in contact with the thrust washer 70a and the armature assembly 40 moves in the Xa direction. In this low speed rotation mode, the armature assembly 40 is rotated clockwise (clockwise).

  Since the retaining ring 68a at the left end 50a is in contact with the thrust washer 70a, when the armature assembly 40 is rotated clockwise (clockwise), the female screw 64a of the female screw bearing member 64 and the male screw 50c are screwed together. The relationship is tightened and the friction between the screws increases. That is, since the relative relationship between the inner peripheral friction Fa and the outer peripheral friction Fb with respect to the female screw bearing member 64 is Fa> Fb, the outer peripheral surface of the female screw bearing member 64 rotates with respect to the annular recess 62 a of the bearing metal 62. .

  Therefore, in a state where the retaining ring 68a at the left end 50a is in contact with the thrust washer 70a, the current from the drive circuit is supplied to the armature coil 54, and the clockwise (clockwise) rotational force with respect to the field flux of the permanent magnet 30 is generated. When applied, the female screw bearing member 64 rotates integrally with the rotary shaft 50.

  In this state, the armature coil 54 is close to and opposed to the permanent magnet 30 with the full axial width of the permanent magnet 30 (the entire range of the dimension L), and the full width of the permanent magnet 30 becomes an effective magnetic flux region, so that high torque Is obtained, but the rotational speed is low. Therefore, the motor 80 is in the low-speed rotation mode by rotating the armature assembly 40 clockwise (clockwise).

  Next, the operation for switching from the low speed rotation mode to the high speed rotation mode will be described. By reversing the flow direction of the current supplied from the drive circuit to the armature coil 54, a counterclockwise (counterclockwise) rotational force is generated in the armature assembly 40. In the low-speed rotation mode shown in FIG. 1, when a counterclockwise (counterclockwise) rotational force is applied to the armature assembly 40, the male screw 50c that engages with the female screw bearing member 64 rotates counterclockwise. The screwing relationship between the female screw 64a of the female screw bearing member 64 and the male screw 50c is loosened, and friction between the screws is reduced.

  Therefore, the relative relationship between the inner peripheral friction Fa and the outer peripheral friction Fb with respect to the female screw bearing member 64 is Fa <Fb, and the female screw bearing member 64 is held in a stationary state in the annular recess 62 a of the bearing metal 62. Therefore, since the rotational motion is converted into a linear motion by the screwing of the female screw 64a and the male screw 50c, the armature assembly 40 is translated in the right direction (Xb direction).

  FIG. 4 shows a high-speed rotation mode in which the armature assembly 40 of the second embodiment is moved to the right. As shown in FIG. 2, the armature assembly 40 translates to the right (Xb direction) while rotating counterclockwise (counterclockwise), so that the armature coil 54 and the permanent magnet 30 are relative to each other. A position will shift | deviate and the opposing area of the armature coil 54 and the permanent magnet 30 will reduce. Thereby, the area | region of the effective field magnetic flux from the permanent magnet 30 reduces.

  Further, when the armature assembly 40 is translated to the right (Xb direction), the C-shaped retaining ring 68b locked to the right end 50b of the rotating shaft 50 comes into contact with the thrust washer 70b of the bearing support portion 26a. When the movement of the armature assembly 40 to the right (Xb direction) is restricted by the thrust washer 70b, the screwing relationship between the female screw 64a of the female screw bearing member 64 and the male screw 50c is tightened, and the friction between the screws is reduced. Increase. Therefore, the relative relationship between the inner peripheral friction Fa and the outer peripheral friction Fb with respect to the female screw bearing member 64 is Fa> Fb, and the female screw bearing member 64 rotates while slidingly contacting the annular recess 62 a of the bearing metal 62.

  Therefore, in the armature assembly 40, when the retaining ring 68a abuts against the thrust washer 70a and the movement to the right (Xb direction) is restricted, the female screw bearing member 64 rotates integrally with the rotary shaft 50. Thus, in a state where the facing area of the armature coil 54 with respect to the permanent magnet 30 is reduced, the resistance when the armature coil 54 cuts the magnetic flux from the permanent magnet 30 is reduced, and the armature assembly 40 rotates at high speed. To do. Therefore, the motor 80 is in the high-speed rotation mode by rotationally driving the armature assembly 40 counterclockwise (counterclockwise).

  Furthermore, when switching from the high-speed rotation mode shown in FIG. 4 to the low-speed rotation mode, the armature assembly 40 is rotated clockwise (clockwise). When a clockwise (clockwise) rotational force is applied to the armature assembly 40, the screwed relationship between the female screw bearing member 64 and the male screw 50c is loosened, and friction between the screws is reduced.

  Therefore, the relative relationship between the inner peripheral friction Fa and the outer peripheral friction Fb with respect to the female screw bearing member 64 is Fa <Fb, and the female screw bearing member 64 is held in a stationary state in the annular recess 62 a of the bearing metal 62. Therefore, since the rotational motion is converted into a linear motion by screwing the female screw 64a and the male screw 50c, the armature assembly 40 translates leftward (Xa direction) as shown in FIG.

  When the C-shaped retaining ring 68b locked to the right end 50b of the rotating shaft 50 moves to the left (Xa direction) to a position where it abuts against the thrust washer 70b of the bearing support portion 26a, as described above, the female screw bearing The relative relationship between the inner peripheral friction Fa and the outer peripheral friction Fb with respect to the member 64 is Fa> Fb. Therefore, when a clockwise (clockwise) rotational force is applied, the female screw bearing member 64 rotates integrally with the rotary shaft 50. In this state, since the armature coil 54 is close to and opposed to the permanent magnet 30 with the full axial width of the permanent magnet 30 (the entire range of the dimension L), the rotational speed is low.

  Therefore, in the motor 80 of the present embodiment, the same effect as the motor 10 of the first embodiment can be obtained, and the output shafts 50d and 50e at both ends of the rotating shaft 50 can be connected to the drive shafts of different devices. Thus, each device can be driven at different rotational speeds or different torques. Further, by switching the rotation direction of the armature assembly 40, the low speed rotation mode can be switched to the high speed rotation mode, or the high speed rotation mode can be switched to the low speed rotation mode, and the driven system path can be selected.

  For example, when the high-rotation pump and the low-rotation pump are arranged on both sides of the motor 80, one of the pumps can be driven depending on the moving direction of the rotary shaft 50. Accordingly, the fluid supply amount can be switched by switching the rotation direction of the armature assembly 40 according to the above.

  In addition, in the said Example, it is needless to say that it can use for all uses other than a motor vehicle only as an example of the example of application of this invention.

  Of course, in the above embodiment, the screwing of the rotary shaft 50 and the female screw bearing member 64 may be a ball screw.

1 is a longitudinal sectional view illustrating a first embodiment of a motor according to the present invention and illustrating a low-speed rotation mode in which an armature assembly is moved leftward. FIG. It is a longitudinal cross-sectional view which shows the high-speed rotation mode which the armature assembly 40 moved to the right. It is a longitudinal cross-sectional view which shows the low speed rotation mode which the armature assembly 40 of Example 2 moved to the left. It is a longitudinal cross-sectional view which shows the high-speed rotation mode which the armature assembly 40 of Example 2 moved rightward.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,80 Motor 20 Housing 22 Storage case 24 Storage chamber 26 Cover member 30 Permanent magnet 40 Armature assembly 50 Rotating shaft 50c Male screw 50d, 50e Output shaft 52 Armature core 54 Armature coil 56 Commutator 60 Ball bearing 62 Bearing metal 64 Female thread bearing member 64a Female thread 68, 68a, 68b Retaining ring 70, 70a, 70b Thrust washer 71 First brush 72 Second brush

Claims (3)

A housing;
A permanent magnet that is fixed on the radially inner side of the housing and generates a field flux;
A rotating shaft having a male screw; an armature core fixed to the outer periphery of the rotating shaft; an armature coil wound around the outer periphery of the armature core; and rotating on a radially inner side of the permanent magnet; An armature assembly movable in a direction;
A female screw bearing member having a female screw threadedly engaged with a male screw of the rotating shaft on the inner peripheral surface of the through hole penetrating in the axial direction, and translating the armature assembly in the axial direction corresponding to the rotating direction of the rotating shaft When,
A bearing having an outer peripheral surface fixed to the housing, and an inner peripheral surface rotatably supporting the female screw bearing member;
Rotation control means for enabling or restricting relative rotation between the female screw bearing member and the bearing;
A motor comprising:   The rotation control means reverses the rotation direction of the armature assembly so that the male screw of the rotary shaft screwed to the female screw bearing member is driven in the axial direction, and the armature coil facing the permanent magnet is driven. The motor according to claim 1, wherein the rotation speed of the armature assembly is switched by changing the facing area. The bearing restricts the rotation of the female screw bearing member due to friction with the female screw bearing member, and when the armature assembly is restricted from moving in the axial direction by a stopper, the axial movement is stopped. The motor according to claim 1, wherein relative rotation with the female screw bearing member is allowed.

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