JP6693829B2 - Power transmission device - Google Patents

Description

  The present invention relates to a power transmission device that operates various members using a rotation of a motor as a drive source.

  For example, in a vehicle-mounted display device in which a movable display panel is moved up and down by a power transmission device, main components of the power transmission device including a motor and a gear train are integrated in advance as a drive unit, and this drive unit is A method of increasing the assembly workability by handling them as one component is widely adopted.

  Conventionally, as described in Patent Document 1, a drive gear is fixed to an output shaft of a motor in advance, and the motor is elastically attached to a chassis on a fixed side via a vibration isolation member such as a vibration isolation rubber. A power transmission device has been proposed in which a recess formed in the central portion of a drive gear is supported and inserted into and held by a fixed shaft provided in a chassis, and the drive gear is meshed with a driven gear that is axially supported by the chassis. There is.

  In the power transmission device configured as described above, since the motor is elastically supported by the chassis via the vibration isolating member, it is possible to reduce the transmission of the vibration generated by the driving of the motor to the chassis, Since the tip of the drive gear that is fixed to the output shaft of the motor is held by the fixed shaft, the vibration of the motor itself appears as a swivel motion around the fixed shaft, and the meshing of the drive gear and the driven gear can be stabilized. it can.

JP, 7-107697, A

  According to the power transmission device disclosed in Patent Document 1, since the motor is elastically supported, the vibration transmission from the motor to the chassis is reduced, and the drive gear does not swing largely even though the motor is elastically supported. The engagement between the drive gear fixed to the output shaft of the motor and the driven gear pivotally supported on the chassis side is stable, and it is possible to exert some effect in reducing both vibration and noise. However, since the vibration of the motor itself appears as a pivoting movement (pivot movement) around the engagement point between the drive gear and the fixed shaft, the meshing state of the tooth portion of the drive gear with the tooth portion of the driven gear slightly changes. In particular, when the torque largely fluctuates during the reverse rotation of the motor, the backlash between the teeth of the drive gear and the driven gear becomes large, which causes a noise.

  The present invention has been made in view of such circumstances of the conventional art, and an object thereof is to provide a power transmission device capable of reliably reducing both vibration and noise.

In order to achieve the above object, a power transmission device of the present invention includes a drive unit having a motor and a rotation output body that rotates using the motor as a drive source, a chassis that elastically supports the drive unit, and the rotation output body. includes a drive gear that is driven to rotate, the elastic coupling for connecting the drive gear and the rotary output member, and a driven gear meshed with the drive gear is rotatably supported on said chassis, a by the drive The unit has a movable base that supports the motor, and a final stage gear of a gear train mounted on the movable base is the rotation output body .

In the power transmission device configured as described above, since the drive unit including the motor and the rotation output member is elastically supported by the chassis via the damper or the like, the vibration generated by driving the motor is transmitted to the chassis. In addition, since the elastic shaft coupling can absorb the vibration of the rotation output body on the drive unit side and transmit the torque to the drive gear on the chassis side, the engagement between the drive gear and the driven gear can be stabilized. The generation of abnormal noise can be reduced. Further, since the drive unit has a movable base that supports the motor, and the final stage gear of the gear train mounted on this movable base is the rotation output body, it is possible to mount the motor and the gear train on the movable base. It can be handled as one part.

  In the above configuration, the drive gear may be directly supported on the chassis, but further includes a moving base that rotatably supports the drive gear and an elastic member that biases the moving base in one direction. If the drive gear is engaged with the driven gear by receiving the urging force of the elastic member, the backlash between the teeth of the drive gear and the driven gear will always be zero, so the generation of abnormal noise is reliably prevented. can do.

  Further, in the above structure, the elastic shaft coupling is made of coupling rubber having a plurality of engaging recesses on the outer peripheral surface, and the engaging recesses are fitted to the protrusions provided on the respective facing surfaces of the rotation output body and the drive gear. This is preferable because the power transmission device can be easily assembled.

  According to the present invention, both vibration and noise can be reliably reduced in the power transmission device that transmits the rotational force of the motor mounted on the drive unit side to the driven gear that is axially supported on the chassis side.

It is a perspective view showing the important section of the in-vehicle display device in which the power transmission device concerning the example of the 1st embodiment was carried. It is a top view of the power transmission device concerning the example of a 1st embodiment. It is a perspective view of the power transmission device concerning a 1st embodiment example. It is a perspective view which removes some chassis and a movable base from FIG. It is an exploded perspective view of the power transmission device concerning a 1st embodiment example. It is the perspective view seen from the arrow A direction of FIG. It is explanatory drawing which shows typically the power transmission device which concerns on an example of 1st Embodiment. It is an explanation showing typically a power transmission device concerning a 2nd embodiment example.

  An embodiment of the invention will be described with reference to the drawings. As shown in FIG. 1, a power transmission device 2 according to the first embodiment is mounted on an inner bottom surface of a box-shaped chassis 1 having an open top surface. A display panel (not shown) and the like are incorporated in the chassis 1. The chassis 1 constitutes a housing of a movable display panel provided in a vehicle-mounted display device, and the movable display panel is moved up and down between a use position and a storage position by a power transmission device 2.

  As shown in FIGS. 2 to 5, the power transmission device 2 includes a movable base 3 formed by bending a metal plate, and a motor 4 fixed to a standing wall 3 a of the movable base 3 with screws. , A worm gear 5 fixed to the rotation shaft of the motor 4, a worm wheel 6 that meshes with the worm gear 5, a large-diameter gear 7 that is a rotation output member that meshes with the worm wheel 6, and rotates in conjunction with the large-diameter gear 7. Small gear 8 which is a driving gear, an elastic shaft coupling 9 interposed between the large gear 7 and the small gear 8, and a driven gear 10 which is rotatably supported by the chassis 1 and meshes with the small gear 8. And a moving base 11 that rotatably supports the small diameter gear 8 and a tension spring 12 that elastically biases the small diameter gear 8 toward the driven gear 10.

  The side plate 3b and the top plate 3c are integrated with the movable base 3 by using screws, and the worm wheel 6 and the large-diameter gear 7 are rotatably supported on the inner bottom surface of the movable base 3. The worm gear 5, the worm wheel 6, and the large-diameter gear 7 constitute a reduction gear train, and the reduction gear train and the motor 4 are incorporated into the movable base 3 and integrated to form a drive unit U (Fig. 3). As shown in FIG. 6, a plurality of positions of the top plate 3c of the movable base 3 are fixed to the boss 1a protruding from the bottom surface of the chassis 1 with screws 14 via dampers 13 made of ring-shaped vibration-proof rubber. Thus, the entire drive unit U including the motor 4 and the reduction gear train such as the large-diameter gear 7 is elastically supported by the chassis 1 via the damper 13.

  A support plate 1b is screwed to the chassis 1 so as to cover the drive unit U, and a central portion of the moving base 11 is rotatably supported by the support plate 1b. The small-diameter gear 8 is rotatably supported on the front end side of the moving base 11, and the small-diameter gear 8 is pulled by hooking both ends of the tension spring 12 on the rear end side of the moving base 11 and the support plate 1b. Due to the elastic force of the spring 12, the spring 12 is always urged in the direction in which it comes into pressure contact with the teeth of the driven gear 10.

  The large-diameter gear 7 and the small-diameter gear 8 are arranged on substantially the same axis, two projections 7a are provided on the upper surface of the large-diameter gear 7 at 180-degree opposite positions, and two projections 7a are provided on the lower surface of the small-diameter gear 8. The protrusions 8a are provided at 180-degree facing positions. The elastic shaft coupling 9 is made of a cross-shaped coupling rubber having four engaging recesses 9a on its outer peripheral surface. The elastic shaft coupling 9 is a large-diameter gear with the engaging recesses 9a fitted in the protrusions 7a, 8a. 7 and the small-diameter gear 8 are provided on opposite surfaces. At this time, the number of the protrusions 7a and 8a provided on the large-diameter gear 7 and the small-diameter gear 8 may be two or more. In that case, the engaging recess 9a of the elastic shaft coupling 9 is adjusted to the number of the protrusions 7a and 8a. Should be increased.

  With such a configuration, when the motor 4 mounted on the drive unit U side rotates, the rotation of the large diameter gear 7 at the output end is transmitted to the small diameter gear 8 arranged on the chassis 1 side via the elastic shaft coupling 9. After being transmitted, it is transmitted to the driven gear 10 that meshes with the small diameter gear 8. Although not shown, the driven gear 10 is engaged with the components of the lifting mechanism, and the movable display panel including the chassis 1 is moved up and down by the lifting mechanism.

  FIG. 7 is an explanatory view schematically showing the positional relationship of the power transmission device 2 configured as described above. As shown in FIG. 7, in the power transmission device 2 according to the first embodiment, the motor 4 and the large Since the drive unit U having the radial gear 7 and the like is elastically supported by the chassis 1 via the damper 13, it is possible to prevent the vibration generated due to the driving of the motor 4 from being transmitted to the chassis 1 and becoming a resonance sound. .. Further, even when the drive unit U vibrates due to the driving of the motor 4, this vibration is absorbed by the elastic shaft coupling 9 provided between the large diameter gear 7 and the small diameter gear 8. The vibration of the large diameter gear 7 can be absorbed by the elastic shaft coupling 9, and the torque can be transmitted to the small diameter gear 8 on the chassis 1 side. Therefore, the tooth portion of the small-diameter gear 8 can be stably meshed with the tooth portion of the driven gear 10 axially supported by the chassis 1, and the generation of abnormal noise due to the deterioration of the meshing of the both is reduced. be able to.

  Moreover, in the power transmission device 2 according to the first embodiment, the small-diameter gear 8 is axially supported by the moving base 11 rotatably supported by the supporting plate 1b integral with the chassis 1, and the moving base 11 and the supporting plate 1b are supported. Since the small-diameter gear 8 is biased in the rotation axis direction of the driven gear 10 by the elastic force of the tension spring 12 installed between them, the backlash between the teeth of the small-diameter gear 8 and the driven gear 10 is always zero. Therefore, it is possible to reliably prevent abnormal noise generated from the tooth portions of the small diameter gear 8 and the driven gear 10.

  Further, in the power transmission device 2 according to the first embodiment, a plurality of engaging recesses 9a are formed on the outer peripheral surface of the elastic shaft coupling 9 made of coupling rubber, and these engaging recesses 9a are formed into the large diameter gear 7. And the projections 7a, 8a provided on the opposing surfaces of the small diameter gear 8 and the small diameter gear 8, the elastic shaft coupling 9 is interposed between the large diameter gear 7 on the drive unit U side and the small diameter gear 8 on the chassis 1 side. Therefore, the assembly work of the power transmission device 2 can be easily performed.

  FIG. 8 is an explanatory view schematically showing the positional relationship of the power transmission device 20 according to the second embodiment. As shown in FIG. 8, the second embodiment differs from the first embodiment described above. The point is that the small-diameter gear 8 that meshes with the driven gear 10 is directly supported by the chassis 1, and the other configurations are basically the same.

  Also in the power transmission device 20 according to the second embodiment configured as described above, since the drive unit U having the motor 4, the large-diameter gear 7 and the like is elastically supported by the chassis 1 via the damper 13, It is possible to prevent the vibration generated due to the driving of No. 4 from being transmitted to the chassis 1 and becoming a resonance sound. Further, even when the drive unit U vibrates due to the driving of the motor 4, this vibration is absorbed by the elastic shaft coupling 9 provided between the large diameter gear 7 and the small diameter gear 8. The vibration of the large diameter gear 7 can be absorbed by the elastic shaft coupling 9, and the torque can be transmitted to the small diameter gear 8 on the chassis 1 side. Therefore, the tooth portion of the small-diameter gear 8 can be stably meshed with the tooth portion of the driven gear 10 axially supported by the chassis 1, and the generation of abnormal noise due to the deterioration of the meshing of the both is reduced. be able to.

  In each of the above embodiments, the worm gear 5 fixed to the rotation shaft of the motor 4 is transmitted to the large-diameter gear 7 serving as a rotation output body via the worm wheel 6, but is mounted on the drive unit U. The gear train from the motor 4 to the large-diameter gear 7 is not limited to this. For example, another gear such as a helical gear or a bevel gear is fixed to the rotation shaft of the motor 4, and one or more gears are provided. It may be transmitted to the rotary output body of the final stage gear via a gear.

1 Chassis 1a Boss 1b Support plate 2,20 Power transmission device 3 Movable base 3b Side plate 3c Top plate 4 Motor 5 Worm gear 6 Worm wheel 7 Large diameter gear (rotation output body)
7a protrusion 8 small diameter gear (drive gear)
8a Protrusion 9 Elastic shaft coupling 9a Engagement recess 10 Driven gear (driven gear)
11 Moving base 12 Tension spring (elastic member)
13 Damper U drive unit

Claims (3)

A drive unit having a motor and a rotation output body that rotates using the motor as a drive source;
A chassis that elastically supports the drive unit,
A drive gear rotationally driven by the rotation output body,
An elastic shaft coupling that connects the rotation output body and the drive gear,
A driven gear that is rotatably supported by the chassis and meshes with the drive gear,
Equipped with
The drive unit has a movable base that supports the motor, and a final stage gear of a gear train mounted on the movable base is the rotation output body .   2. The moving base for rotatably supporting the drive gear, and an elastic member for urging the moving base in one direction according to claim 1, wherein the drive gear receives the urging force of the elastic member. A power transmission device which is meshed with the driven gear.   3. The elastic shaft coupling according to claim 1, wherein the elastic shaft coupling is made of a coupling rubber having a plurality of engaging recesses on an outer peripheral surface thereof, and the protrusions are provided on the protrusions provided on the respective facing surfaces of the rotation output body and the drive gear. A power transmission device characterized in that the engaging recesses are fitted.