JPH0578700B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a gear reduction device, and more particularly to a gear reduction device that uses a planetary gear mechanism and can obtain a high reduction ratio.

[Prior art]

Generally, when the reduction ratio of a gear reduction device is high, such as a reduction ratio of about 1/60, the number of gears increases in the case of a gear reduction device consisting of a normal gear mechanism, and the reduction mechanism becomes There is a problem that the installation space becomes large. In order to eliminate such problems, the applicant of the present application previously proposed a gear reduction device that can obtain a high reduction ratio using a planetary gear mechanism as shown in FIG. (Japanese Patent Application No. 58-158499) That is, a stepping motor 10 as a rotational drive source is provided with a drive shaft 12.
2 is provided with a pinion 14 as a sun gear. A fixed internal gear 16 is arranged around the pinion 14 and coaxially with the pinion 14. A plurality of first planetary gears 18 are meshed with the pinion 14 and the fixed internal gear 16. Further, an output rotating internal gear 20 is arranged concentrically with the fixed internal gear 16. This rotating internal gear 20 is pivotally supported by a frame 22 via a shaft 24. The pinion 14 and this rotating internal gear 20 have a plurality of second
The planetary gears 26 are in mesh with each other. This first planetary gear 18 is provided with a shaft 28 , and the second planetary gear 26 is further provided with a shaft 30 , and this shaft 28 is provided with a shaft 28 .
8 and 30 are pivotally supported by a retainer 32 as a common arm member.

However, in the gear reduction device shown in FIG. 1, the shaft 12 of the pinion 14 and the shaft 24 of the output rotary internal gear 20 are configured as separate shafts, so it is difficult to align the shafts 12 and 24. This made it difficult to assemble the gear reduction gear. If the alignment between the shafts 12 and 24 is neglected, it will naturally occur that the second
There is a possibility that the rotation and revolution of the planetary gear 26 may not be smooth.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a gear reduction device that is made into a unit and that does not require centering work.

[Structure of the invention]

In order to achieve the above object, the present invention fixes a sun gear to the drive shaft of a motor, and pivots an output rotary internal gear that meshes with a planetary gear to the drive shaft of the motor, thereby connecting the drive shaft of the motor to the sun gear. It is characterized by having a common shaft with the output rotating internal gear.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the gear reduction device according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 2 is a sectional view of the gear reduction device according to the present invention,
FIG. 3 is a plan view thereof. In FIG. 2, a stepping motor 34 as a rotational drive source is provided with a drive shaft 36, and this drive shaft 36 is provided with a pinion 38 as a sun gear. A fixed internal gear 40 is arranged around this pinion 38 and concentrically with the pinion 38 . This fixed internal gear 40 is formed on a flange 42, and this flange 42 is fixed to a collar 44 formed integrally with the case of the motor 34 via screws 46. Flange 4
Centering of the drive shaft 36 of No. 2 is performed by using the bearing case 48 of the drive shaft 36 as a guide surface and fitting the hole 50 of the flange 42 into the bearing case 48.

A plurality of first planetary gears 52 are meshed between the pinion 38 and the fixed internal gear 40. Further, an output rotating internal gear 54 is installed concentrically with the fixed internal gear 40.
is arranged, and this rotating internal gear 54 is connected to the output member 5
5 is engraved. The output member 55 is pivotally supported above the drive shaft 36 of the motor 34. A plurality of second planetary gears 56 are meshed between the pinion 38 and the rotary internal gear 54. The output member 55 is prevented from coming off from the drive shaft 36 via a retaining ring 58.

This first planetary gear 52 is provided with a shaft 60, and the second planetary gear 56 is further provided with a shaft 62, and these shafts 60, 62 are pivoted to a thin plate ring-shaped retainer 64 as a common arm member. supported.
The inside of the retainer 64 is supported on a ring-shaped seat 66 formed on the flange 42, and the upper end surface of the second planetary gear 56 is in contact with a seat 68 formed on the lower surface of the output member 55. Seat 66 and catch 6
8 restricts the vertical movement of the retainer 64. Furthermore, a stepped portion 70 is formed on the flange 42, and this stepped portion 70 restricts movement of the retainer 64 in the left-right direction in FIG. Further, a ring-shaped groove 72 formed by the seat 66 and the stepped portion 70 is used as a grease reservoir.

The flange 42 has three arc-shaped guides 73 as shown in FIG. 3, and the flange 42 also has two long holes 75 on both sides for frame attachment.
It is formed in places.

The gear reduction device configured as described above has a motor 3.
It can be configured as a single unit with 4. That is, first, the pinion 38 is press-fitted and attached to the drive shaft 36 of the motor 34, and in this state, the flange 42 is guided by the bearing case 48, and the drive shaft 3 is attached.
It is attached to a flange 44 integral with the case of the motor 34 with screws 46 while centering it with respect to 6. Next, a retainer 64 with the shafts 60, 62 planted thereon is placed, and the shafts 60, 62 planted on this retainer 64 are
The first and second planetary gears 52 and 56 are connected to the pinion 3.
8. Attach while meshing with the internal gear 40. Thereafter, the output member 55 is fitted onto the drive shaft 36 while the output rotary internal gear 54 meshes with the second planetary gear 56, and is attached to the drive shaft 36 with a retaining ring 58. The gear reduction device configured in this manner is integrated with the motor 34 into a unit, and can be attached to the frame 74, for example, via screws 76. At this time, the gear reduction gear unit can be inserted into the frame 74 using the guide 73 as a guide member. Note that external gears 78 and 80 are formed on the output member 55, and can transmit the rotational force of the motor 34 at a reduced speed via a gear transmission mechanism (not shown).

The operation of the embodiment according to the present invention constructed as described above is as follows. First, the pinion 38 provided on the drive shaft 36 of the motor 34 transmits its rotational force to the first planetary gear 52.
rotates while meshing with both the pinion 38 and the fixed internal gear 40, and also revolves around the pinion 38 to rotate the retainer 64. On the other hand, the second planetary gear 56 meshes with the pinion 38 and the rotating internal gear 54, and further engages with the retainer 64.
It rotates under the influence of the rotation of the first planetary gear 52, revolves around the pinion 38 at the same speed as the first planetary gear 52, and transmits its rotational force to the rotating internal gear 54.

In this embodiment, a case has been described in which the first and second planetary gears are composed of a plurality of pieces, but the number of the first and second planetary gears may be one piece each. Further, in this embodiment, a case has been described in which the rotational drive source is a stepping motor, but it is needless to say that this is not limited to a stepping motor.

According to the embodiment, since the rotational force of the motor 34 is transmitted to the output member 55 using the planetary gear mechanism, the rotational force can be transmitted at a high reduction ratio even though the installation space is small. Also, a pinion 38 as a sun gear and a rotating internal gear 54 for output.
Since the pinion 38 and the rotating internal gear 54 are supported by the drive shaft 36 of the motor 34 as a common shaft, the troublesome work of aligning the pinion 38 and the rotary internal gear 54 becomes unnecessary.

〔Effect of the invention〕

As explained above, according to the gear reduction device according to the present invention, the drive shaft of the motor is used as a common shaft, the sun gear is fixed, and the output rotary internal gear that meshes with the planetary gears is pivoted to the drive shaft of the motor. This eliminates the need for troublesome centering work between the sun gear and the output rotary internal gear.

In the present invention, since the first and second planetary gears are pivotally supported by the arm member via the first and second shafts arranged in parallel, the gear reduction device can be formed in a thin shape.

Further, in the present invention, since the external gear is formed on the outer periphery of the output rotary internal gear to reduce the rotational speed of the motor, an even thinner gear reduction device can be obtained.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the structure of a gear reduction device using a conventional planetary gear mechanism, FIG. 2 is a cross-sectional view showing the structure of a first embodiment of the present invention, and FIG.
FIG. 3 is a plan view of the embodiment. 34... Motor, 36... Drive shaft, 38... Pinion as sun gear, 40... Fixed internal gear, 42... Flange, 52... First planetary gear, 54... Rotating internal gear for output Gear, 56...2nd
Planetary gear, 74...frame.

Claims (1)

[Scope of Claims] 1. A sun gear fixed to the drive shaft of the motor; a fixed internal gear disposed around the sun gear concentrically with the sun gear and fixed to the casing side of the motor; an output rotating internal gear disposed concentrically with the gear; a first planetary gear meshing with the sun gear and meshing with the fixed internal gear; a first planetary gear meshing with the sun gear and the rotating internal gear; a second planetary gear meshing with each other; a first planetary gear arranged in parallel with each other so that the first and second planetary gears can revolve around the sun gear at the same speed;
an arm member pivotally supported via a second shaft; A gear reduction device characterized in that an external gear is formed on the outer periphery of a gear to reduce the rotational speed of a motor.