JP2013031240A - Motor unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor unit which has a reverse rotation prevention structure without increasing the size of the unit and the number of components.SOLUTION: A biasing mechanism constituting a reverse rotation prevention structure includes: a first helical tooth portion 422 formed on a first gear 42; a second helical tooth portion 441 engaged with the first helical tooth portion 422 and formed on a second gear 44; and load application means 50 for applying a load to rotation of the first gear 42. When a synchronous motor 10 is reversely rotated, the biasing mechanism biases the first gear 42 on the side of a reverse rotation prevention member 43 in the axial direction due to thrust force caused by engagement of helical teeth of the first helical tooth portion 422 and the second helical tooth portion 441 and the load of the load application means 50.

Description

  The present invention relates to a motor unit, and more particularly to a motor unit having a reverse rotation prevention structure for preventing reverse rotation of a synchronous motor as a drive source.

  The following Patent Document 1 describes a device including a reverse rotation prevention body (5) for preventing reverse rotation of a motor. In this device, the reverse rotation preventing body rotates in the same direction as the gear (14) by the frictional force generated by the elastic body (16). When the motor rotates in reverse, the anti-reverse body contacts the anti-reverse piece (6). The reverse rotation of the motor is blocked by the contact between the reverse rotation prevention body and the reverse rotation prevention piece.

  On the other hand, Patent Document 2 described below describes a device that prevents reverse rotation of a motor using a worm (66) and a worm gear (78a) meshing with the worm (66). In this apparatus, when the motor rotates in the reverse direction, the output shaft (64) of the motor is moved to one side in the axial direction by the worm and the worm gear meshing therewith. When the output shaft moves to one side, the locking pin (74) provided on the output shaft engages with the locking piece (76). The reverse rotation of the motor is prevented by the engagement between the locking pin and the locking piece.

Japanese Utility Model Publication No. 6-41372 Japanese Patent Laid-Open No. 2002-266953

  However, when the structure for preventing the reverse rotation of the motor as in Patent Document 1 is adopted, an urging member that generates a frictional force such as an elastic body is required separately, which increases the number of parts and increases the size of the apparatus. End up. In addition, when the structure for preventing reverse rotation of the motor as in Patent Document 2 is adopted, it is necessary to provide the rotor with a structure for preventing reverse rotation such as a worm or a locking pin, or to move the rotor in the axial direction. As in Patent Document 1, the apparatus is increased in size.

  In view of the above problems, the problem to be solved by the present invention is to provide a motor unit having a reverse rotation prevention structure that does not cause an increase in the size of the device or an increase in the number of parts.

  In order to solve the above-described problems, the present invention provides a motor unit including a reverse rotation prevention structure that uses a synchronous motor as a drive source, and prevents the reverse rotation of the synchronous motor by a certain amount or more to prevent normal rotation. The surface of the first gear is in surface contact with the first gear, the power of the synchronous motor being transmitted and rotating about an axis parallel to the synchronous motor and movable in the axial direction of the first gear. When the synchronous motor rotates in the reverse direction, the reverse rotation preventing member that rotates in the rotation direction of the first gear by the frictional force generated by the rotation rotates in the rotation direction of the first gear that receives the power of the reverse motor. The reverse rotation preventing contact portion provided on the rotor of the synchronous motor that contacts the reverse rotation preventing member and prevents further reverse rotation of the synchronous motor; An urging mechanism that urges the gear toward the reverse rotation preventing member side in the axial direction, the urging mechanism including a first helical tooth portion formed on the first gear, A second helical gear portion formed on a second gear meshing with the helical gear portion, and load applying means for applying a load to the rotation of the first gear, wherein the synchronous motor is reversely rotated. When the first helical gear portion and the second helical gear portion are engaged with each other and the thrust force generated by the load of the load applying means causes the first gear to move along its axis. The gist is to bias the reverse rotation preventing member in the direction.

  In the motor unit, the first gear is prevented from reverse rotation by utilizing the thrust force generated by the meshing of the first and second helical teeth and the load of the load applying means. Energize to the member side. That is, it is not necessary to separately provide a biasing member or the like that biases the first gear toward the reverse rotation preventing member. Therefore, it can be set as the motor unit provided with the reverse rotation prevention structure which does not cause the increase in a number of parts, or the enlargement of an apparatus.

  In this case, grease may be interposed between the axial end face of the first gear and the reverse rotation preventing member.

  When the first gear and the reverse rotation preventing member are in surface contact with each other through the grease in this way, the reverse rotation preventing member is in contact with the first gear due to the viscosity of the grease. That is, the biasing force of the biasing mechanism that biases the first gear, that is, the thrust force generated in the first gear can be reduced by the amount of viscosity of the grease. If the thrust force can be reduced in this way, the torsion angle (inclination angle) of the first helical gear and the second helical gear meshing with the first helical gear can be reduced. Transmission loss of power (rotational power) between the two gears is suppressed.

  Further, the first helical tooth portion of the first gear or the other tooth portion may be directly meshed with the tooth portion of the gear that rotates integrally with the rotor of the synchronous motor.

  In this way, if the tooth portion of the first gear is directly meshed with the tooth portion of the gear rotating integrally with the rotor of the synchronous motor, the power is immediately transmitted to the first gear when the synchronous motor is reversed. Therefore, the reverse rotation preventing member immediately rotates. Therefore, the reverse synchronous motor can be immediately forward rotated.

  In this case, the load applying means may be a centrifugal brake that rotates by the rotation of the first gear.

  The centrifugal brake does not function unless the rotational speed is not less than a predetermined value. As described above, since the tooth portion of the first gear is directly meshed with the tooth portion of the gear that rotates integrally with the rotor of the synchronous motor, the reduction ratio from the synchronous motor to the first gear is small. Therefore, a speed increasing mechanism from the first gear to the centrifugal brake for rotating the centrifugal brake at a rotation speed equal to or higher than a predetermined value is simplified.

  In addition, the synchronous motor and the first gear only have to be rotated in opposite directions.

  As described above, the reverse rotation preventing member rotates in the same direction as the first gear. Therefore, for example, when the rotational directions of the synchronous motor and the first gear are the same and the angular speeds of the anti-reverse contact part and the reverse-prevention member are close, until the reverse-prevention contact part and the reverse-prevention member abut (forward rotation) It may take a long time to switch. However, if the rotation direction of the synchronous motor and the first gear is reversed, when the synchronous motor rotates in the reverse direction, the reverse rotation prevention contact portion and the reverse rotation prevention member immediately contact (less than one rotation). That is, the synchronous motor can be quickly rotated forward.

  A first transmission train having one or a plurality of power transmission members for transmitting the power of the synchronous motor to the driven body, and the transmission of power by the first transmission train in a “continuous” state or a “disconnected” state; A clutch means for switching to the second gear, a second transmission train having the first gear and the second gear for transmitting the power of the synchronous motor to the clutch means, and the second gear in one of its axial directions. An urging member that urges toward the side, and when the motor is driven, the second gear is configured such that the first helical tooth portion and the second helical tooth portion have helical teeth. Due to the thrust force generated by the meshing and the load of the load applying means, it moves to the other side in the axial direction against the urging force of the urging member while rotating, and the first transmission via the clutch means Set the power transmission by the row to the `` join '' state On the other hand, when the motor stops from the driving state, the second gear moves to one side in the axial direction while rotating against the load of the load applying means by the urging force of the urging member, Any configuration may be employed as long as the transmission of power by the first transmission train is set to the “joining” state via the clutch means.

  Thrust force is generated in the first gear by the engagement between the first helical tooth portion and the second helical tooth portion and the load applying means. Therefore, the opposite thrust force is generated in the second gear. In the above configuration, the thrust force generated in the second gear is used to “join” or “disconnect” the clutch means for switching whether or not to transmit the power of the motor to the driven body. That is, according to the above configuration, not only the reverse rotation preventing structure is operated by the meshing and load applying means of the first and second helical gears, but also the first transmission train is “joined”. The clutch means for “disengaging” can also be operated.

  Further, in this case, the rotor of the synchronous motor rotatably supported on the fixed shaft has a first rotor gear meshing with a driving side tooth portion of the first gear, and the first transmission train is A second rotor gear rotatably supported by the fixed shaft and movable in the axial direction thereof, and when the second rotor gear is located at a first position on the rotor side, The rotor gear engages with the second rotor gear, and the rotation of the rotor causes the rotor gears to rotate integrally, while the second rotor gear is positioned at a second position away from the rotor. When doing so, it is sufficient if the rotation of the rotor is not transmitted to the second rotor gear.

  With this configuration, it is possible to switch whether or not the motor power is transmitted to the second rotor gear (first transmission train) without moving the rotor in the axial direction.

  The second gear is a tooth portion meshed with the second helical gear portion and a power transmission member that drives the load applying means, and has the same axis as the second helical gear portion. It is only necessary that the second gear tooth portion that rotates in the right direction is a compound gear that is integrally formed with the driven tooth portion having a smaller diameter than the second helical gear portion.

  With this configuration, even if the second gear moves in the axial direction, the driven tooth portion of the second gear does not interfere with the first helical tooth portion of the first gear.

  In the motor unit according to the present invention, the first gear is prevented from rotating reversely by the thrust force generated by the meshing of the first and second helical teeth and the load of the load applying means. Since the structure is on the member side, there is no increase in the number of parts or an increase in the size of the apparatus.

It is the figure which showed the whole motor unit (state which removed the case) concerning this embodiment. It is the figure which looked at the power system (the 1st transmission line and the 2nd transmission line) of the motor unit shown in Drawing 1 from the upper part. FIG. 3 is a cross-sectional view (hatching is omitted) cut along a transmission line (A-A line shown in FIG. 2) of the motor unit shown in FIG. 1. FIG. 2 is an exploded view of the motor unit shown in FIG. 1 and is a view for explaining structures of a first gear, a reverse rotation preventing member, a first rotor gear, a second rotor gear, and the like included in the motor unit. FIG. 2 is an exploded view of the motor unit shown in FIG. 1, in which a first gear meshes with a first rotor gear and a second gear meshes with a first gear (extracted). is there. It is a schematic diagram for demonstrating the function of the reverse rotation prevention structure with which the motor unit shown in FIG. 1 is provided. It is the figure which decomposed | disassembled and showed the 1st rotor gearwheel and 2nd rotor gearwheel which the motor unit shown in FIG. 1 has. FIG. 2 is a view of the first transmission train of the motor unit shown in FIG. 1 as viewed from one direction (the configuration of the second transmission train other than the case and the lower motor gear is omitted). FIG. 9 is a view of the first transmission train of the motor unit shown in FIG. 1 as viewed from a direction different from FIG. 8 (the configuration of the second transmission train other than the case and the lower motor gear is omitted). It is the figure which decomposed | disassembled the planetary gear mechanism with which the motor unit shown in FIG. It is the figure which decomposed | disassembled the planetary gear mechanism with which the motor unit shown in FIG. It is the figure which looked at the 2nd transmission line of the motor unit shown in FIG. 1 from one direction (The structure of a case, a 1st transmission line, etc. are deleted). FIG. 13 is a view of the second transmission train of the motor unit shown in FIG. 1 as viewed from a direction different from that of FIG. 12 (the configuration of the case and the first transmission train is deleted). It is the figure which showed the relationship between the rotational speed of a drum and the braking force in the load provision means which the motor unit concerning this embodiment has. It is a system diagram for demonstrating the power system of the motor unit concerning this embodiment.

  Hereinafter, embodiments of the present invention will be described in detail. In addition, the upper and lower in the following description shall mean the upper and lower in FIG. The “original position” refers to the position of each constituent member in a state where the synchronous motor 10 is not driven.

(Reverse prevention structure)
The motor unit 1 according to the present embodiment is a unit that uses a synchronous motor 10 (for example, a two-phase AC synchronous motor) as a drive source, and prevents a certain amount of reverse rotation (rotation in the wrong direction) of the synchronous motor 10. Equipped with a reverse rotation prevention structure that rotates forward (rotates in the correct direction). This reverse rotation prevention structure includes a first gear 42, a reverse rotation prevention member 43, a reverse rotation prevention contact portion 411, and an urging mechanism.

  The first gear 42 is a gear that rotates around an axis parallel to the synchronous motor 10 to which the power of the synchronous motor 10 is transmitted. In the present embodiment, the first gear 42 is a compound gear having a first helical tooth portion 422 and a driving side tooth portion 421. The first helical tooth portion 422 is a portion formed in a “helical tooth” having a helical tooth shape, and is an element constituting an urging mechanism. The driving side tooth portion 421 is a spur gear portion having a larger diameter than the first helical tooth portion 422 that rotates integrally with the rotor 11. The driving side tooth portion 421 meshes with the first rotor gear 41. Therefore, the first gear 42 rotates in the direction opposite to the rotation direction of the synchronous motor 10 as the first rotor gear 41 rotates.

  The first gear 42 is supported by a first gear support shaft 85 fixed to the base 84 so as to be rotatable and movable in the axial direction. As shown in FIG. 3, when the first gear 42 is assembled at a predetermined position, the upper end surface of the first gear 42 is in a state of being close to the inner bottom surface of the upper case 81 constituting the case 80. That is, the upward movement of the first gear 42 in the axial direction is restricted by the upper case 81. As will be described later, when the motor unit 1 is used as an actuator that drives a valve body that opens and closes the drain of the washing machine, the motor unit 1 is such that the axial direction of the first gear support shaft 85 is vertical. The reverse rotation preventing member 43 is attached to the washing machine so that the upper side of the first gear 41, that is, the upper direction in FIG.

  The reverse rotation preventing member 43 is a plate-like member disposed on the lower surface of the first gear 42 (drive side tooth portion 421), and has a circular main body portion 431 and an abutment projecting outward from the main body portion 431. Part 432 and rotation preventing part 433. The reverse rotation preventing member 43 is supported by the first gear support shaft 85 at the center of the main body 431 so as to be rotatable and movable in the axial direction. The contact portion 432 of the reverse rotation preventing member 43 is a portion that contacts the reverse rotation prevention contact portion 411 when the synchronous motor 10 rotates reversely. The rotation prevention part 433 is a part that contacts the stopper part 841 when the synchronous motor 10 rotates forward. Grease is interposed between the upper surface of the reverse rotation preventing member 43 and the lower surface of the first gear 42. In the present embodiment, an annular recess 4311 is formed on the upper surface of the main body portion 431 of the reverse rotation preventing member 43, and grease is held in the recess.

  The reverse rotation prevention abutting portion 411 is a protrusion formed on the rotor 11 of the synchronous motor 10 and is located below the first rotor gear 41. That is, when the rotor 11 rotates, the reverse rotation preventing contact portion 411 rotates around the rotation axis. In the present embodiment, two reverse rotation preventing contact portions 411 are formed at intervals of 180 degrees in the circumferential direction. The reverse rotation prevention contact portion 411 contacts the contact portion 432 of the reverse rotation prevention member 43 when the synchronous motor 10 rotates reversely.

  The urging mechanism is configured to urge the first gear 42 downward (on the reverse rotation prevention member 43 side) when the synchronous motor 10 rotates in reverse, and the first helical gear 422 and the second helical gear. The tooth portion 441 and load applying means 50 that applies a load to the rotation of the first gear 42 are provided.

  As described above, the first helical tooth portion 422 is a helical tooth portion formed on the first gear 42 that is a compound gear. The second helical tooth portion 441 is a helical tooth portion formed on the second gear 44 that meshes with the first helical tooth portion 422. The second gear 44 is a compound gear having a second helical gear portion 441 and a driven side tooth portion 442 (worm wheel portion) which is a spur gear portion having a smaller diameter than the second helical gear portion 441. The second gear support shaft 86 fixed to the base 84 is supported so as to be rotatable and movable in the axial direction.

  The load applying means 50 includes a worm (gear) portion 51 and a load portion 52 that is a so-called centrifugal brake. The worm portion 51 meshes with the output side gear portion of the second gear 44. The output side gear portion and the worm portion 51 constitute a speed increasing gear mechanism. Therefore, the rotation of the second gear 44 is increased and transmitted to the worm portion 51.

  The load portion 52, which is a centrifugal brake, has a weight provided on a rotating disk fixed to the tip of the worm portion so as to be movable in the radial direction. When the rotational speed reaches a certain level or more, it moves against the inner peripheral surface of the drum 83 fixed to the case 80. The centrifugal force applied to the weight increases as the rotational speed increases, and the braking force for stopping the rotation due to the friction between the weight and the drum 83 also increases. Specifically, as shown in FIG. 14, the rotational speed of the drum 83 increases, and the braking force that suddenly stops the rotation after the weight and the drum 83 come into contact with each other increases.

  The load applying means 50 configured as described above rotates when the second gear 44 rotates, and applies a load to the rotation of the second gear 44. Since the first helical tooth portion 422 of the first gear 42 meshes with the second helical tooth portion 441 of the second gear 44, a load is also applied to the rotation of the first gear 42. . That is, the first gear 42 is subjected to a load in the direction opposite to the rotation direction, and the first helical gear 422 is engaged with the second helical gear 441. A thrust force is generated in the gear 42. The thrust force is set to be downward in the axial direction when the synchronous motor 10 is reversely rotated (direction indicated by X in FIGS. 3 and 5) and upward in the axial direction when the synchronous motor 10 is normally rotated. (The direction of the helical teeth of the first helical tooth portion 422 and the second helical tooth portion 441 is set). That is, when the synchronous motor 10 rotates in the reverse direction, the urging mechanism is configured so that the first helical tooth portion 422 and the second helical tooth portion 441 mesh with each other and the load applied by the load applying means 50. The first gear 42 is urged toward the reverse rotation prevention member 43 (downward in the axial direction (X direction)) by the thrust force generated in the gear.

  The reverse-hand prevention structure having the above configuration functions as follows. When the synchronous motor 10 rotates in the reverse direction, as described above, the first gear 42 is urged downward in the axial direction by the meshing of the helical teeth of the second helical tooth portion 441 and the load of the load applying means 50. The That is, the first gear 42 is in a state of being pressed by the reverse rotation preventing member 43, and the lower surface (one axial end surface) of the first gear 42 and the upper surface of the reverse rotation preventing member 43 are in surface contact. The reverse rotation preventing member 43 rotates in the same direction as the first gear 42 due to the frictional force caused by the surface contact and the viscosity of the grease interposed therebetween. In the present embodiment, since the drive side tooth portion 421 of the first gear 42 meshes with the first rotor gear 41, the first gear 42 and the reverse rotation preventing member 43 that rotates together with the first gear 42 rotate the synchronous motor 10. (See FIG. 6A). The contact portion 432 of the anti-reverse rotation member 43 rotated in this direction moves to a position overlapping the rotation trajectory T of the outer edge of the reverse rotation prevention contact portion 411 of the synchronous motor 10 (rotates in a direction approaching the synchronous motor 10) and is synchronized. It contacts the reverse rotation prevention contact portion 411 of the motor 10 (see FIG. 6B). The rotation of the synchronous motor 10 is corrected to normal rotation by the impact at the time of contact. The reverse rotation of the synchronous motor 10 is corrected to normal rotation by the function of the reverse rotation prevention structure.

  When the rotation of the synchronous motor 10 is switched to normal rotation, the rotation direction of the first gear 42 having the drive side tooth portion 421 meshed with the first rotor gear 41 is also switched (forward rotation). When the rotation direction of the first gear 42 is switched, an axially upward thrust force is generated in the first gear 42. As a result, when the first gear 42 and the reverse rotation prevention member 43 are separated, the first gear 42 rotates independently (separately from the reverse rotation prevention member 43). However, the reverse rotation preventing member 43 may rotate (forward rotation) in the same direction as the first gear 42 in a state where the reverse rotation preventing member 43 is attached to the first gear 42 due to the viscosity of the grease. In the base 84, a stopper portion 841 is erected at a position where the base 84 enters the rotation locus of the rotation preventing portion 433 of the reverse rotation preventing member 43 that rotates in the forward direction. That is, when the reverse rotation preventing member 43 is rotated forward, the rotation preventing portion 433 comes into contact with the stopper portion 841 and the rotation of the reverse rotation preventing member 43 is blocked (see FIG. 6C). Accordingly, the reverse rotation preventing member 43 is prevented from continuing to rotate together with the first gear 42 that normally rotates, and the contact portion 432 does not enter the rotation locus T of the outer edge of the reverse rotation prevention contact portion 411. Since grease is interposed between the first gear 42 and the reverse rotation preventing member 43, the reverse rotation preventing member 43 does not become a resistance of the first gear 42 that rotates normally.

  When the synchronous motor 10 rotates forward, for example, when the abutting portion 432 enters the rotation trajectory T of the outer edge of the anti-reverse preventing abutting portion 411, the abutting portion 432 of the anti-reverse preventing member 43 prevents the reverse rotation. It is conceivable that the contact portion 411 contacts, but in this case, the contact portion 432 of the anti-reverse member 43 is repelled by the rotating anti-reverse contact portion 411 and the anti-reverse member 43 rotates until the two do not contact each other. Therefore, the drive of the synchronous motor 10 (rotation of the rotor 11) is not affected.

(Configuration other than reverse prevention structure)
The motor unit 1 having such a reverse rotation prevention structure is a motor actuator that drives the driven body 90. Hereinafter, the configuration of the motor actuator will be described. As shown in FIG. 15, the power system of the motor unit 1 includes an output system (first transmission train) for transmitting the power of the synchronous motor 10 to the driven body 90, and a clutch operating system (second system) for operating the clutch means. Transmission train). The clutch means switches the transmission of power by the output system between the “joining” state and the “disconnecting” state. That is, if the clutch means is in the “joining” state, the power of the synchronous motor 10 is transmitted to the driven body 90 through the output system. If the clutch means is in the “disengaged” state, the output system is disconnected, and the power of the synchronous motor 10 is not transmitted to the driven body 90. In the present embodiment, the synchronization for driving the driven body 90 as the power of the clutch operating system for operating the clutch means in this way (transmission of power by the first transmission train is set to the “joining” state). A part of the power of the motor 10 is used.

  The motor unit includes a first transmission train that transmits the power of the synchronous motor 10 that is a drive source to the driven body 90, and a clutch that switches the transmission of the power by the first transmission train to a “continuous” state or a “disconnected” state. Means, a second transmission train for transmitting the power of the synchronous motor 10 to the clutch means, and a load applying means 50. These are accommodated in a case 80 composed of an upper case 81 and a lower case (except for pulleys and wires).

  The first transmission train constitutes an output system that transmits the power of the synchronous motor 10 to the driven body 90. The first transmission train includes the second rotor gear 21, the input side gear 22 meshing with the second rotor gear 21, and the rotation of the input side gear 22 when the clutch means is in the "joint" state. A rotating output side gear 23; a composite gear meshing with the output side gear 23; a cam gear meshing with the composite gear; a pulley rotating integrally with the cam gear; and a wire wound up by rotation of the pulley. . The input side gear 22 and the output side gear 23 are also gears constituting clutch means (differential gear mechanism based on a planetary gear train) whose details will be described later.

  The second rotor gear 21 is a spur gear supported so as to be rotatable on the same axis as the synchronous motor 10 and movable in the axial direction. It is supported on the first rotor gear 41 that rotates integrally with the rotor 11 (at the front end side of the rotating shaft). The second rotor gear 21 is urged upward in the axial direction by a coil spring 28. On the lower surface of the second rotor gear 21, an upper engagement portion 212 that engages with the lower engagement portion 412 of the first rotor gear 41 when the second rotor gear 21 is positioned on the rotor 11 side (lower side). Is formed. The position of the second rotor gear 21 in a state where the lower engagement portion 412 and the upper engagement portion 212 are engaged is referred to as a first position. The position of the second rotor gear 21 in a state where the lower engagement portion 412 and the upper engagement portion 212 are not engaged is referred to as a second position.

  An input side gear 22 meshes with the second rotor gear 21. The input side gear 22 is one gear constituting a planetary gear train and is a so-called sun gear. The input side gear 22 has a relatively large diameter large diameter tooth portion 221 and a relatively small diameter small diameter tooth portion 222. The large-diameter tooth portion 221 of the input side gear 22 meshes with the second rotor gear 21, and the input side gear 22 rotates as the second rotor gear 21 rotates. Further, a locked projection 233 is formed on the upper surface of the input side gear 22. An input side gear lock projection 62 of the sector lever 60 described later acts on the locked projection 233.

  The power of the synchronous motor 10 is transmitted to the output side gear 23 via the second rotor gear 21. The output side gear 23 in this embodiment corresponds to the three planetary gears 231 and the planetary support gear 232 that are gears constituting the planetary gear train. The planetary gear 231 is rotatably supported by three planetary gear support shafts that protrude from the upper end surface of the planetary support gear 232 and are provided at equal intervals in the circumferential direction. A retaining ring 233 is fixed to the upper end of the planetary gear support shaft to prevent the planetary gear 231 from falling off. The planetary support gear 232 has a gear portion 2321 on the side opposite to the surface to which the planetary gear 231 is attached. The planetary gear 231 meshes with the small diameter tooth portion 222 of the input side gear 22. Although details will be described later, when the clutch means is in the “joining” state, the planetary gear 231 revolves around the small-diameter tooth portion 222 of the input side gear 22 as the input side gear 22 rotates. With the revolution of the planetary gear 231, the planetary support gear 232 that supports the planetary gear 231 rotates. In this way, power is transmitted from the input side gear 22 to the output side gear 23.

  The compound gear 24 meshes with the planetary support gear 232 (output side gear 23). Specifically, the compound gear 24 has a relatively small diameter tooth portion 241 and a relatively large diameter tooth portion 242, and the large diameter tooth portion 242 meshes with the gear portion 2321 of the planetary support gear 232. doing. As a result, the compound gear 24 rotates as the planetary support gear 232 rotates.

  A cam gear 25 meshes with the compound gear 24. Specifically, the gear portion 251 of the cam gear 25 meshes with the small diameter tooth portion 241 of the compound gear 24. As a result, the cam gear 25 rotates as the compound gear 24 rotates. A cam groove 252 is formed on the upper end surface of the portion where the gear portion 251 is formed on the outer periphery. The sector lever 60 is engaged with the cam groove 252. This configuration and its operation will be described later.

  A pulley 26 is fixed to the cam gear 25. The fixing method is not particularly limited as long as the pulley 26 rotates integrally with the cam gear 25. Thereby, the pulley 26 rotates with the rotation of the cam gear 25. The pulley 26 is exposed outside the case. A wire groove 261 is formed on the outer periphery of the pulley 26.

  One end of a wire 27 is fixed to the pulley 26. The fixing method is not particularly limited as long as it can reliably prevent the wire 27 from falling off. When the pulley 26 rotates in the direction in which the wire 27 is drawn, the wire 27 is wound up so as to fit into the wire groove 261 of the pulley 26. A driven body 90 (for example, a valve body that opens and closes the drain port) is fixed to the other end side of the wire 27, and the driven body 90 is always returned to the original position (position where the valve body is closed). A load in the direction of pulling, that is, the direction of pulling out the wire 27 is acting. When the wire 27 is wound around the pulley 26, the driven body 90 performs a predetermined operation. That is, when the wire 27 is wound around the pulley 26, the power of the synchronous motor 10 is transmitted to the driven body 90 via the first transmission train. In addition, in order to operate the driven body 90 accurately, the wire 27 is formed of a non-stretchable material.

  The clutch means plays a role of switching the power transmission (output system) by the first transmission train to the “joining” state or the “disconnection” state. The operation of the clutch means in the present embodiment is the planetary gear train having the input side gear 22 (sun gear), the output side gear 23 (planetary gear 231 and planetary support gear 232), and the fixed gear 31 (ring gear) (see FIG. 10 and FIG. 11).

  As already described, the input side gear 22 meshes with the second rotor gear 21 and rotates as the second rotor gear 21 rotates. Three planetary gears 231 arranged at equal intervals in the circumferential direction mesh with the small-diameter tooth portion 222 of the input side gear 22. The planetary gear 231 is supported on the planetary support gear 232. The planetary support gear 232 rotates with the revolution of the planetary gear 231.

  The fixed gear 31 that is a ring gear constituting the planetary gear train has an outer tooth portion 311 and an inner tooth portion 312. The external tooth portion 311 of the fixed gear 31 is located below the large-diameter tooth portion 221 of the input side gear 22 and meshes with a lock gear 47 that is one gear constituting a second transmission train described later. . That is, when the rotation of the lock gear 47 is blocked, the rotation of the fixed gear 31 is blocked. The internal gear portion 312 of the fixed gear 31 meshes with the three planetary gears 231.

  In the clutch means having such a configuration, whether or not the planetary gear 231 revolves and the planetary support gear 232 rotates depends on whether or not the rotation of the fixed gear 31 is blocked. In the case where the rotation of the fixed gear 31 is blocked, when the input side gear 22 rotates, the internal tooth portion 312 of the fixed gear 31 does not move. Therefore, the small diameter tooth of the input side gear 22 along the internal tooth portion 312. The planetary gear 231 meshing with the portion 222 revolves and the planetary support gear 232 rotates. On the other hand, when the rotation of the fixed gear 31 is not blocked, even if the input side gear 22 rotates and the planetary gear 231 tries to revolve, the fixed gear 31 rotates idly, so that the planetary support gear 232 does not rotate.

  That is, if the rotation of the fixed gear 31 is prevented, the first transmission train is in the “join” state, and if the rotation of the fixed gear 31 is not blocked, the first transmission train is in the “disconnected” state. . If the first transmission train is in the “joining” state by the clutch means, that is, if the output system is in the “joining” state, the power of the synchronous motor 10 is transmitted to the driven body 90 via the first transmission train. On the other hand, if the first transmission train is in the “disconnected” state by the clutch means, that is, if the output system is in the “disconnected” state, the power of the synchronous motor 10 is disconnected by the clutch means (the input gear 22 and the output gear 23 are And is not transmitted to the driven body 90.

  The second transmission train constitutes a clutch operating system that transmits the power of the synchronous motor 10 to the clutch means. The second transmission train includes a first rotor gear 41, a first gear 42 meshing with the first rotor gear 41, a second gear 44 meshing with the first gear 42, and a second gear. It has a lock lever 45 that is pushed down when 44 moves downward in the axial direction, and a lock gear 47 that is locked by the pushed down lock lever 45.

  The first rotor gear 41 is a spur gear formed integrally with the rotor 11 of the synchronous motor 10. It is provided under the second rotor gear 21 described above (on the main body side of the synchronous motor 10). A lower engagement portion 412 that engages with the upper engagement portion 212 formed on the lower surface of the second rotor gear 21 described above is formed on the upper surface of the first rotor gear 41. The second rotor gear 21 is moved to the rotor 11 side by an inclined cam of the sector lever 60 described later, and the upper engagement portion 212 of the second rotor gear 21 and the lower engagement portion 412 of the first rotor gear 41 are moved. When in the engaged state (the second rotor gear 21 is in the first position), the second rotor gear 21 and the first rotor gear 41 rotate integrally. That is, the power of the synchronous motor 10 is also transmitted to the second rotor gear 21.

  A first gear 42 meshes with the first rotor gear 41. The first gear 42 is supported by the first gear support shaft 85 so as to be rotatable and movable in the axial direction, and has a smaller diameter than the drive side tooth portion 421 and the drive side tooth portion 421. A first helical tooth portion 422; The first helical tooth portion 422 is a portion formed into a “helical tooth” as described above. The first gear 42 has a drive-side tooth portion 421 meshed with the first rotor gear 41. Therefore, the first gear 42 rotates as the first rotor gear 41 rotates.

  A second gear 44 meshes with the first gear 42. The second gear 44 includes a second helical tooth portion 441 having a relatively large diameter and a driven side tooth portion 442 having a relatively small diameter. The second gear 44 is supported by the second gear support shaft 86 so as to be rotatable and movable in the axial direction. As described above, the second helical tooth portion 441 is a portion formed into a “helical tooth”. The driven side tooth portion 442 is a so-called worm wheel portion that meshes with the worm portion 51 included in the load applying means 50. The driven tooth portion 442 may be a helical tooth or a spur gear.

  In the second gear 44, the second helical gear 441 is engaged with the first helical gear 422 of the first gear 42. Therefore, the second gear 44 rotates as the first gear 42 rotates. When the synchronous motor 10 rotates in the forward direction, a load in the direction opposite to the rotation direction is applied to the second gear 44 by the load applying means 50, so that a downward thrust force in the axial direction is generated. Therefore, when the first gear 42 rotates, the second gear 44 moves downward in the axial direction while rotating.

  The lock lever 45 is a flat plate-like member and is disposed under the second gear 44. Specifically, it is supported by a second gear support shaft 86 that is the same as the second gear 44 and is movable in the axial direction. The lock lever 45 is formed with a recess (not shown), and this recess is engaged with a not-shown protrusion formed along the axial direction inside the side wall of the lower case 82. Due to the engagement between the convex portion and the concave portion, the lock lever 45 is supported by the second gear support shaft 86 while being prevented from rotating and movable in the axial direction. At one end portion of the lock lever 45, a lock portion 451 is formed that is thicker than the other portions. A biasing member 46 (coil spring) that biases the lock lever 45 upward is disposed below the lock lever 45. Due to the urging member 46, the lock lever 45 is positioned above the locked portion 471 of the lock gear 47 during normal times (when the synchronous motor 10 is not driven). Further, since the second gear 44 is disposed on the lock lever 45, the second gear 44 is also urged upward in the axial direction. The urging force of the urging member 46 is smaller than the axially downward thrust force generated in the second gear 44 when the second gear 44 rotates as the first gear 42 rotates. That is, when the second gear 44 rotates, the second gear 44 moves downward in the axial direction against the biasing force of the biasing member 46. When the second gear 44 moves downward in the axial direction, the lock lever 45 underneath also moves downward. The lock portion 451 of the lock lever 45 moved downward is positioned at substantially the same height as the locked portion 471 of the lock gear 47.

  The lock gear 47 includes a locked portion 471 and a lock tooth portion 472 on a flat plate on which the locked portion 471 is formed. The locked portion 471 is formed so as to protrude outward from the circular flat plate. When the lock lever 45 moves downward, the lock portion 451 of the lock lever 45 and the locked portion 471 of the lock gear 47 are positioned so as to face each other, so that the rotation of the lock gear 47 is at a predetermined position (the lock portion 451 and the locked portion). At a position where the 471 is in contact). On the other hand, the lock tooth portion 472 meshes with the external tooth portion 311 of the fixed gear 31. Accordingly, when the rotation of the lock gear 47 is blocked, the rotation of the fixed gear 31 meshing with the lock gear 47 is also blocked. In the present embodiment, the lock gear 47 has a brake portion 473 that is a centrifugal brake. The brake unit 473 applies a load in a direction that prevents the lock gear 47 from rotating, and prevents the lock gear 47 from rotating at a higher speed than necessary. The effect | action of this brake part 473 is mentioned later.

  The worm part 51 is a so-called worm (gear) part. The worm portion 51 extending in the direction orthogonal to the axial direction of the second gear 44 meshes with the driven side tooth portion 442 (worm wheel portion). The worm part 51 is one line, and the driven side tooth part 442 and the worm part 51 constitute a speed increasing gear mechanism (when the driven side tooth part 442 rotates by one tooth, the worm part 51 makes one rotation). Therefore, the rotation of the second gear 44 is increased and transmitted to the worm portion 51.

  A sector lever 60 is disposed on the compound gear 24. The sector lever 60 is rotatably supported on the same shaft as the shaft on which the compound gear 24 is rotatably supported. An engaging protrusion 61 is formed on the lower surface of the sector lever 60. The engaging protrusion 61 is engaged with a cam groove 252 formed on the upper surface of the cam gear 25. Similarly, a second rotor gear lock protrusion 62 and an inclined cam (not shown) are formed from the lower surface of the sector lever 60. Although details of the engaging protrusion 61, the cam groove 252, the second rotor gear lock protrusion 62, and the inclined cam are omitted, the function of each member is as follows. The sector lever 60 moves in conjunction with the operation of the cam gear 25 by the engagement protrusion 61 that engages with the cam groove 252. When the sector lever 60 moves to a predetermined position (the wire 27 is wound up to a predetermined position), the second rotor gear lock projection 62 acts on the locked projection 211 of the second rotor gear 21, and the second rotor gear 21. Prevent rotation. At the same time, the second rotor gear 21 pressed downward in the axial direction by the inclined cam is released and moved upward in the axial direction by the coil spring (the second rotor gear 21 is located at the second position). As a result, the engagement between the upper engagement portion 212 of the second rotor gear 21 and the lower engagement portion 412 of the first rotor gear 41 is released. That is, the power of the synchronous motor 10 is not transmitted to the second rotor gear 21. (See operation description below).

(Operation of motor unit)
The normal operation of the motor unit 1 having the above configuration will be described. In the following description, the power of the synchronous motor 10 is transmitted to the driven body 90 in the original position. 1) The power transmission operation and the transmission of the power of the synchronous motor 10 are cut off to return the driven body 90 to the original position. ) The explanation will be divided into the power cut-off operation.

1) Power transmission operation Synchronous motor from a state where the driven body 90 is in the original position (a state where the wire 27 is not wound around the pulley 26, that is, a state where the power of the synchronous motor 10 does not act on the driven body 90) When 10 is driven in one direction (forward rotation), the second rotor gear 21 and the first rotor gear 41 rotate. At this time, when the synchronous motor 10 rotates in the reverse direction, the above-described reverse rotation prevention structure works, and the synchronous motor 10 immediately rotates forward. When the synchronous motor 10 is driven, the rotation of the first rotor gear 41 causes the first gear 42 having the drive-side tooth portion 421 that meshes with the first rotor gear 41 to rotate.

  When the first gear 42 rotates, the second gear 44 having the second helical gear portion 441 that meshes with the first helical gear portion 422 of the first gear 42 rotates. The second gear 44 has a driven side tooth portion 442 (worm wheel portion) meshed with the worm portion 51 of the load applying means 50, and the load portion of the load applying means 50 is rotated by the rotation of the second gear 44. 52 also rotates. When the load unit 52 rotates and its speed increases, a load (torque) is generated in a direction in which the rotation is stopped. The load is transmitted from the worm portion 51 to the second gear 44 having the driven side tooth portion 442 and the first gear 42 meshing with the second gear 44. In this way, the first gear 42 and the second gear 44 are subjected to loads opposite to their rotational directions.

  As described above, the transmission of power between the first gear 42 and the second gear 44 is based on the meshing of the “helical teeth”. Therefore, the second gear 44 that has received a load opposite to the rotation direction from the load applying means 50 receives a downward thrust force in the axial direction due to the rotation of the first gear 42. In other words, the second gear 44 moves downward in the axial direction while rotating by a load opposite to the meshing of the “helical teeth” and the rotation direction. Further, as described above, the first gear 42 receives axially upward thrust force.

  In the present embodiment, since the meshing between the second gear 44 and the load applying means 50 is also based on “helical teeth”, a large axial downward thrust force is generated with respect to the second gear 44. That is, the load generated by the load portion 52 is transmitted to the second gear 44 by meshing between the worm portion 51 and the driven side tooth portion 442, and therefore the axial downward thrust force due to the transmission of the load is also the second. Is generated in the gear 44.

  When the second gear 44 moves downward in the axial direction, the lock lever 45 disposed below the second gear 44 moves downward in the axial direction against the biasing force of the biasing member 46. When the lock lever 45 is pushed down in this way, the lock portion 451 provided on the lock lever 45 is substantially the same height as the locked portion 471 of the lock gear 47 and faces the lock gear 47 in the circumferential direction. To position. Accordingly, in this state, the rotation of the lock gear 47 is prevented by the lock portion 451 of the lock lever 45. That is, the lock gear 47 is prevented from rotating.

  The lock gear 47 has its lock tooth portion 472 meshed with the external tooth portion 311 of the fixed gear 31 constituting the planetary gear train of the clutch means. Therefore, when the rotation of the lock gear 47 is blocked, the rotation of the fixed gear 31 is also blocked. As a result, the transmission of power by the first transmission train by the clutch means is in the “joint” state, and the power of the synchronous motor 10 can be transmitted to the driven body 90 through the first transmission train. In this way, the second gear 44 moves downward in the axial direction thereof, thereby bringing the power transmission by the first transmission train into the “joining” state via the clutch means.

  On the other hand, the second rotor gear 21 that rotates together with the first rotor gear 41 by driving the synchronous motor 10 meshes with the large-diameter tooth portion 221 of the input side gear 22 (sun gear) that constitutes the planetary gear train. . Accordingly, the input side gear 22 rotates with the rotation of the second rotor gear 21.

  Three planetary gears 231 constituting the output side gear 23 are meshed with the outside of the small-diameter tooth portion 222 of the input side gear 22. An inner tooth portion 312 of the fixed gear 31 meshes with the outside of the planetary gears 231 arranged at equal intervals in the circumferential direction. As described above, the fixed gear 31 is prevented from rotating by the lock gear 47. Therefore, when the input side gear 22 rotates, the planetary gear 231 revolves around the small diameter tooth portion 222. When the planetary gear 231 revolves, the planetary support gear 232 that supports the planetary gear 231 rotates. That is, all the rotational power of the input side gear 22 is transmitted to the output side gear 23.

  If the input side gear 22 rotates when the rotation of the fixed gear 31 is not blocked, the fixed gear 31 rotates idle via the planetary gear 231. Since the power transmission train after the planetary support gear 232 includes a load on the transmission train itself and a load on the driven body 90, all the rotational power of the input side gear 22 is transmitted to the fixed gear 31 side. It is. As described above, in the present embodiment, the “transmission” state and the “disconnection” state of the first transmission train by the clutch means are switched by the differential gear mechanism using the planetary gear train.

  The gear portion 2321 of the planetary support gear 232 meshes with the large-diameter tooth portion 242 of the compound gear 24. Therefore, the compound gear 24 rotates as the planetary support gear 232 rotates.

  The gear portion 251 of the cam gear 25 meshes with the small diameter tooth portion 241 of the compound gear 24. Therefore, the cam gear 25 rotates with the rotation of the compound gear 24.

  When the cam gear 25 rotates, the pulley 26 fixed to the upper end of the cam gear 25 rotates. When the pulley 26 rotates, the wire 27 fixed to the pulley 26 is wound up along the wire groove 261. Since the driven body 90 is fixed to the tip of the wire 27, the driven body 90 operates to be pulled up by the wire 27. For example, when the driven body 90 is a valve body that opens and closes the drain port of the washing machine, the valve body is pulled up by the wire 27 so that the drain port is opened and drainage is started.

  Thus, the rotational power of the synchronous motor 10 is transmitted to the driven body 90 via the first transmission train. The first transmission train is put into the “engaged” state by the clutch means, but a part of the rotational power of the synchronous motor 10 is also used for the power to put the clutch means in the “joined” state.

  The winding of the wire 27 by the pulley 26 is stopped as follows. When the cam gear 25 rotates to a predetermined position (when the wire 27 is wound up by a predetermined amount), the sector lever 60 having the engagement protrusion 61 that engages with the cam groove 252 rotates in a direction away from the cam gear 25. When the sector lever 60 rotates in this manner, the input side gear lock protrusion 62 of the sector lever 60 contacts the locked protrusion 223 of the input side gear 22 from the circumferential direction. As a result, the input side gear 22 is prevented from rotating. Also, the second rotor gear 21 pressed downward in the axial direction by the inclined cam of the sector lever 60 is released and moved upward in the axial direction by the coil spring (the second rotor gear 21 is positioned at the second position). To do). As a result, the upper engagement portion 212 of the second rotor gear 21 and the lower engagement portion 412 of the first rotor gear 41 are disengaged, and the power of the synchronous motor 10 is transmitted to the second rotor gear 21. It will be in a state that is not. When the rotation of the input side gear 22 stops, the operation of each member constituting the first transmission train also stops. That is, the winding of the wire 27 by the pulley 26 is stopped, and the pulley 26 is held at the winding position (when the driven body 90 is a valve body that opens and closes the drain of the washing machine, the drain is opened). Is maintained). Thus, in the state where the drain opening is maintained, the synchronous motor 10 continues to be driven, but the power is not transmitted to the second rotor gear 21 (first transmission train). Therefore, the load applied to the synchronous motor 10 is small, and the power consumption can be reduced.

  In this way, the power transmission operation for transmitting the power of the synchronous motor 10 to the driven body 90 is completed.

2) Power cut-off operation When the driven body 90 is returned to the original position after the power transmission operation is completed, the drive of the synchronous motor 10 is stopped (the energization to the synchronous motor 10 is stopped). Then, since the rotation of the first rotor gear 41 and the first gear 42 is stopped, the rotation of the second gear 44 is also stopped. When the rotation of the second gear 44 is stopped, the axial downward thrust force with respect to the second gear 44 generated by the engagement of the “helical teeth” and the load applied by the load applying means 50 disappears. Since the second gear 44 is urged upward in the axial direction by the urging member 46 together with the lock lever 45 arranged thereunder, the second gear 44 rotates while the second gear 44 rotates in the axial direction. Move upward and return to the original position. Of course, the lock lever 45 also moves in this direction and returns to the original position. Since the force of the biasing member 46 to return the second gear 44 to the original position is small, the rotation speed of the second gear 44 and the load portion 52 is low, and the weight of the load portion 52 contacts the drum 83. do not do. Therefore, the magnitude of the load acting on the second gear 44 by the load applying means 50 does not increase, and the second gear 44 returns smoothly to the original position.

  When the lock lever 45 is moved upward by the biasing member 46, the height direction position of the lock portion 451 of the lock lever 45 becomes higher than the height direction position of the locked portion 471 of the lock gear 47. Specifically, the lock portion 451 and the locked portion 471 are positioned so as not to overlap in the circumferential direction. Therefore, the state in which the rotation of the lock gear 47 is prevented is eliminated, and the lock gear 47 can be freely rotated. That is, the fixed gear 31 of the clutch means (planetary gear train) can freely rotate, that is, the clutch means is in the “disengaged” state. In this way, the second gear 44 moves upward in the axial direction thereof, thereby bringing the power transmission by the first transmission train into the “disconnected” state via the clutch means.

  The driven body 90 is always going to return to the original position by an external load acting on itself. For example, when the driven body 90 is a valve body that opens and closes a drain port of a washing machine, and the valve body is operated in a direction to open the drain port by driving the motor unit 1, the valve body always opens the drain port. It is biased in the closing direction. Therefore, when the clutch means that can freely rotate the fixed gear 31 is in the “disengaged” state, the load applied to the driven body 90 reverses the first transmission train so that the output side gear 23 (planet support) To the gear 232). The energy based on the load applied to the driven body 90 thus transmitted is output (consumed) by the idling of the output side gear 23 because the clutch means is in the “disengaged” state. Thereby, the driven body 90 returns to the original position.

  Further, when the cam gear 25 returns to the original position, the sector lever 60 having the engagement protrusion 61 that engages with the cam groove 252 rotates in a direction approaching the cam gear 25. When the sector lever 60 rotates in this way, the input side gear lock projection 62 of the sector lever 60 is separated from the locked projection 223 of the input side gear 22. As a result, the input side gear 22 is allowed to rotate. In addition, the second rotor gear 21 urged upward in the axial direction by the coil spring is pressed against the inclined cam and moves downward in the axial direction (the second rotor gear 21 is located at the first position). . As a result, the upper engagement portion 212 of the second rotor gear 21 and the lower engagement portion 412 of the first rotor gear 41 are engaged, and the power of the synchronous motor 10 is also transmitted to the second rotor gear 21. It becomes a state.

  At this time, the brake portion 473 of the lock gear 47 brakes the operation of the driven body 90 to return to the original position, and softens the impact applied to the first transmission train. Therefore, it is possible to prevent the power transmission member constituting the first transmission train from being damaged. In addition, when the driven body 90 returns to the original position, an impact sound that collides with each other (when the driven body 90 is a valve body that opens and closes the drain port of the washing machine, the valve body is connected to the drain port. (Impact sound that collides with the surroundings) can be reduced.

  Thus, when the synchronous motor 10 is stopped, the lock of the fixed gear 31 constituting the planetary gear train is released by the action of the urging member 46, and the clutch means places the first transmission train in the “disconnected” state. Thereby, the driven body 90 returns to the original position.

(Effect of this embodiment)
According to the motor unit 1 according to the present embodiment described above, the following operational effects are achieved. In the motor unit 1 according to this embodiment, the thrust force generated by the meshing of the helical teeth of the first helical tooth portion 422 and the second helical tooth portion 441 and the load of the load applying means 50 is utilized. The first gear 42 is urged toward the reverse rotation preventing member 43 side (lower side). That is, it is not necessary to separately provide a biasing member or the like that biases the first gear 42 toward the reverse rotation prevention member 43. Therefore, it can be set as the motor unit 1 provided with the reverse rotation prevention structure which does not cause the increase in a number of parts, or the enlargement of an apparatus.

  Further, a thrust force is generated in the first gear 42 by the meshing of the first helical gear 422 and the second helical gear 441 and the load applying means 50. Therefore, the opposite thrust force is also generated in the second gear 44. In the present embodiment, using the thrust force generated in the second gear 44, the clutch means for switching whether or not to transmit the power of the synchronous motor 10 to the driven body 90 is "joined" or "disconnected". Is.

  That is, in the motor unit 1 according to the present embodiment, the reverse rotation preventing structure is operated by the engagement of the first helical gear 422 and the second helical gear 441 and the load applying means 50, and the first The clutch means for “joining” and “disconnecting” the transmission train can also be operated. As described above, the motor unit 1 uses the thrust force generated in the first gear 42 and the second gear 44 engaged therewith by the meshing and load applying means 50 of the helical teeth to make the reverse rotation preventing function function. In addition, it is excellent in that it is used for operating the clutch means.

  In the present embodiment, since the grease is interposed between the axial end surface (lower surface) of the first gear 42 and the reverse rotation prevention member 43 (upper surface), the reverse rotation prevention member 43 is caused by the viscosity of the grease. The first gear 42 is attached. Further, when the reverse rotation preventing member 43 is in contact with the first gear 42, the reverse rotation preventing member 43 is moved to the first gear due to the viscosity of the grease without the biasing force of the biasing mechanism that biases the first gear 42. Rotates in the same direction as the gear 42. That is, the urging force of the urging mechanism that urges the first gear 42 is such that the reverse rotation preventing member 43 is attached to the first gear 42 by moving the first gear 42 to the reverse rotation preventing member 43 side. If you have the power to do. If such grease viscosity acts, the urging force of the urging mechanism that urges the first gear 42, that is, the thrust force generated in the first gear 42 can be reduced. If the thrust force can be reduced in this way, the twist angle (inclination angle) of the first helical tooth portion 422 and the second helical tooth meshing with the first helical tooth portion 422 can be reduced. And transmission loss of power (rotational power) between the second gear 44 and the second gear 44 are suppressed.

  In the present embodiment, the drive-side tooth portion 421 of the first gear 42 is directly meshed with the first rotor gear 41 of the synchronous motor 10. Accordingly, when the synchronous motor 10 rotates in the reverse direction, the power is immediately transmitted to the first gear 42, so that the reverse rotation preventing member 43 immediately rotates. Therefore, the reverse synchronous motor 10 can be immediately forward rotated. Further, since the contact portion 432 of the reverse rotation prevention member 43 moves to a position overlapping the rotation locus T of the reverse rotation prevention contact portion 411 while the rotational speed of the synchronous motor 10 is low, the contact portion 432 of the reverse rotation prevention member 43 and The force applied to the reverse rotation preventing contact portion 411 is small, and these members can be made small.

  In the present embodiment, a centrifugal brake that rotates by the rotation of the first gear 42 is employed as the load applying means 50. As described above, this centrifugal brake does not function at all unless the rotation speed of the load portion 52 is equal to or higher than a predetermined value. On the other hand, in the motor unit 1 according to the present embodiment, the drive-side tooth portion 421 of the first gear 42 is directly meshed with the first rotor gear 41 of the synchronous motor 10. The reduction ratio to the gear 42 is small. Therefore, the speed increasing mechanism from the first gear 42 to the centrifugal brake for rotating the centrifugal brake (load unit 52) at a rotational speed equal to or higher than a predetermined value is simple (constructing a multi-stage speed increasing mechanism, No need to increase the speed of the centrifugal brake). For example, as in the present embodiment, a speed increasing mechanism from the first gear 42 to the centrifugal brake can be configured by meshing the worm wheel portion (driven side tooth portion 442) and the worm portion 51.

  In the present embodiment, the rotation directions of the synchronous motor 10 and the first gear 42 are opposite. For example, when the rotation directions of the synchronous motor 10 and the first gear 42 are the same and the angular speeds of the reverse rotation prevention contact portion 411 and the reverse rotation prevention member 43 are close, until the reverse rotation prevention contact portion 411 and the reverse rotation prevention member 43 contact each other. The time (until switching to normal rotation) may be longer. However, if the rotation directions of the synchronous motor 10 and the first gear 42 are opposite, when the synchronous motor 10 is reversely rotated, the reverse rotation prevention contact portion 411 and the reverse rotation prevention member 43 are immediately contacted (less than one rotation). . That is, the synchronous motor 10 can be quickly rotated forward.

  In the present embodiment, the upward movement of the first gear 42 in the axial direction is regulated by the upper case 81. However, since there is a risk that assembly may become difficult due to molding errors and deformation of the upper case 81, assembly errors of other members, and the like, these errors may occur between the upper case 81 and the end face of the first gear 42. Therefore, there is a possibility that the first gear 42 moves in a direction away from the reverse rotation prevention member 43 by the amount of the clearance set. However, the motor unit 1 according to the present embodiment can reliably urge the first gear 42 toward the reverse rotation preventing member 43 by the urging mechanism.

  In the present embodiment, when the second rotor gear 21 is located at the first position on the rotor 11 side, the first rotor gear 41 and the second rotor gear 21 are engaged, and the rotation of the rotor 11 When both the rotor gears 41 and 21 rotate integrally, the rotation of the rotor 11 is transmitted to the second rotor gear 21 when the second rotor gear 21 is positioned at the second position away from the rotor 11. It is a configuration that is not. Therefore, it is possible to switch whether or not the motor power is transmitted to the second rotor gear 21 (first transmission train) without moving the rotor 11 in the axial direction.

  In the present embodiment, the second gear 44 is a second helical tooth portion 441 and a tooth portion meshed with a power transmission member that drives the load applying means 50, and the second helical tooth portion. This is a composite gear in which a driven side tooth portion 442 having a smaller diameter than the second helical tooth portion 441 rotating around the same axis as the shaft 441 is integrally formed. Therefore, even if the second gear 44 moves in the axial direction, the driven tooth portion 442 of the second gear 44 and the first helical tooth portion 422 of the first gear 42 do not interfere with each other.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

  For example, in the above-described embodiment, the centrifugal brake is used for the load unit 50. However, the load unit 50 may be configured to increase the braking force as the rotational speed of the worm unit 51 increases. For example, a braking force may be obtained by a generator in which a magnet is fixed to the tip of the worm portion 51 and a coil is disposed around the magnet.

DESCRIPTION OF SYMBOLS 1 Motor unit 10 Synchronous motor 11 Rotor 21 Second rotor gear 41 First rotor gear 411 Reverse rotation prevention contact portion 412 Lower engagement portion 42 First gear 421 Drive side tooth portion 422 First helical tooth portion 43 Anti-reverse member 44 Second gear 441 Second helical tooth 442 Driven side tooth 50 Load applying means

Claims (8)

A motor unit having a reverse rotation prevention structure that uses a synchronous motor as a drive source and prevents the synchronous motor from rotating more than a certain amount and reversely rotates.
The reversal prevention structure is
A first gear that is transmitted around the axis parallel to the synchronous motor to which the power of the synchronous motor is transmitted and is movable in the axial direction;
An anti-reverse member that rotates in the rotational direction of the first gear by frictional force caused by surface contact with one axial end surface of the first gear;
When the synchronous motor is reversely rotated, the synchronous motor is in contact with the reverse rotation preventing member that rotates in the rotation direction of the first gear that receives the power of the reverse rotating motor, and prevents further reverse rotation of the synchronous motor. An anti-reverse contact portion provided on the rotor of the motor;
An urging mechanism that urges the first gear toward the reverse rotation preventing member in the axial direction when the synchronous motor rotates in reverse.
The biasing mechanism is
A first helical tooth portion formed on the first gear;
A second helical tooth portion formed on a second gear meshing with the first helical tooth portion;
Load applying means for applying a load to the rotation of the first gear,
When the synchronous motor rotates in the reverse direction, the first helical tooth portion and the second helical tooth portion engage with each other and the thrust force generated by the load of the load applying means causes the first The motor unit is biased toward the reverse rotation preventing member side in the axial direction.   2. The motor unit according to claim 1, wherein grease is interposed between an axial end surface of the first gear and the reverse rotation preventing member.   The first helical tooth portion or the other tooth portion of the first gear is directly meshed with a tooth portion of a gear that rotates integrally with a rotor of the synchronous motor. The motor unit according to claim 1 or claim 2.   The motor unit according to claim 3, wherein the load applying unit is a centrifugal brake that rotates by rotation of the first gear.   The motor unit according to any one of claims 1 to 4, wherein the synchronous motor and the first gear have rotation directions opposite to each other. A first transmission train having one or more power transmission members for transmitting the power of the synchronous motor to a driven body;
Clutch means for switching the transmission of power by the first transmission train to a "continuous" state or a "disconnected"state;
A second transmission train having the first gear and the second gear for transmitting the power of the synchronous motor to the clutch means;
A biasing member that biases the second gear toward one side in the axial direction thereof; and
When the motor is driven, the second gear is caused by the thrust force generated by the meshing of the first and second helical teeth and the load applying means. , While rotating, against the urging force of the urging member to move to the other side in the axial direction, while making the transmission of power by the first transmission train through the clutch means in a "joining" state,
When the motor stops from the driving state, the second gear moves to one side in the axial direction while rotating against the load of the load applying means by the urging force of the urging member, and the clutch means 6. The motor unit according to claim 1, wherein transmission of power by the first transmission train is set to a “disconnected” state via the motor. The rotor of the synchronous motor rotatably supported on the fixed shaft has a first rotor gear that meshes with a driving side tooth portion of the first gear,
The first transmission train has a second rotor gear rotatably supported by the fixed shaft and movable in the axial direction thereof,
When the second rotor gear is located at the first position on the rotor side, the first rotor gear and the second rotor gear are engaged with each other, and both rotor gears are integrally formed by the rotation of the rotor. While rotating
7. The motor unit according to claim 6, wherein when the second rotor gear is located at a second position on the side away from the rotor, the rotation of the rotor is not transmitted to the second rotor gear. .   The second gear is a tooth portion meshed with the second helical gear portion and a power transmission member that drives the load applying means, and rotates around the same axis as the second helical gear portion. 8. The motor unit according to claim 6, wherein the second toothed tooth portion is a compound gear integrally formed with a driven side tooth portion having a diameter smaller than that of the second helical tooth portion.

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