JPH01170342A - Differential type motor - Google Patents

Abstract

PURPOSE:To reduce the number of components and to decrease the thickness of a differential type motor by disposing a plurality of pairs of permanent magnets on a sun gear of the motor for rotating an output shaft by a planetary gear system to be engaged with two sun gears independently driven to be also used as a rotor. CONSTITUTION:A such gear 1 has teeth on its outer upper part and rotates around a shaft 15 in the bottom of a body 20 through bearings 16, 17. Eight permanent magnets are equally divided, magnetized and mounted on the lower side of the gear 1. Coil rows 3 are mounted at 60 deg. pitch oppositely to the magnets on the body 20. Planetary bears 5-7 are engaged with the sun gears 1, 2, and rotatably supported to shafts 11-13 secured to a disk at the lower end of an output shaft 10. The gear 2 is rotated around the shaft 10 through a bearing 18 at its center. Eight permanent magnets 9 are circumferentially equally divided, magnetized and mounted on the upper face of the gear 2, and coil rows 4 are mounted on the cover 21 of the body 20. The energizations of the rows 3, 4 are controlled. Thus, the shaft 10 is variably rotated from an extremely low speed to a high speed thereby reducing the number of components and its thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a differential motor that is particularly suitable for VTR reel motors and the like, and is capable of smoothly controlling the rotation speed from very low speeds to high speeds.

[Conventional technology]

Extremely wide speed control range, smooth even down to ultra-low speeds
Regarding this controllable differential motor I, for example, in the Proceedings of the 1986 Society for Precision Engineering Spring Conference, page 94, two motor units are arranged in series, and a cylindrical outer rotating shaft and It is described that the inner rotating shaft rotates two sun gears of a differential mechanism connected to one end.

[Problem that the invention seeks to solve]

However, it cannot be said that sufficient consideration has been given to the differential motors according to the above-mentioned conventional techniques in terms of structural simplicity, miniaturization, thinning, and cost reduction.

SUMMARY OF THE INVENTION An object of the present invention is to provide a differential type upper/lower having a simple structure, which can be easily reduced in size and thickness, and therefore at a low cost.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention includes two sun gears and independently controllable gears that drive these gears.
A drive means, a differential motor equipped with a differential mechanism that rotates the output shaft by a planetary gear thread that meshes with both sun gears and rotates with a CtV rotation speed difference between the two sun gears, in which both sun gears each have a plurality of permanent magnetic poles. It was decided that these sun gears themselves would also be used as the rotor of the electromagnetic drive means.

[Effect]

The two sun gears that make up the differential mechanism are also used as rotors for electromagnetically driving the sun gears, which simplifies the structure of the drive unit and reduces the number of parts. . Therefore, downsizing.

It is suitable for thinning and lowering costs, and since both sun gears can rotate at high speed while the output shaft can rotate at extremely low speed, it is possible to stably and smoothly control speeds from extremely low speeds to high speeds.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to the drawings. Fig. 1 is a plan view of a differential mechanism section according to an embodiment of the present invention, and Fig. 2 is a sectional view of the N embodiment.

A sun gear 1 constituting a rotor of one motor unit has teeth on the outside of its upper part as shown in FIG. This sun gear 1 has a bearing 1 at its center.
It is rotatably supported around a shaft 15 that is press-fitted upright into the bottom of the main body 20 through a 6.17% interposition. Permanent magnets 8 are identified below the sun gear 1 and are magnetized equally divided into eight poles (four pairs) in the circumferential direction to form permanent magnetic poles, and rotate integrally with the sun gear 1.

The coil array 3 is arranged on the main body 20 facing the lower surface of the permanent magnet 8.
It is fixedly placed. This coil row 3 is, for example,
Six of them are arranged in an annular shape with a 60 degree pinch, and by switching their energization, they form a motor unit that can rotate the sun gear 18 times like a normal motor.

The planetary gears 5, 6.7 are connected to the sun gear 1 as shown in FIG.
and the sun (internal gear) gear 2, and the shafts 11, 12, 13 are fixed to the lower end disk-shaped portion ζ of the output shaft 10, respectively.
It is rotatably supported.

The sun gear 2 is rotatably supported on the output shaft 10 via a bearing 18 at its center. On the other hand, the output shaft 10 is rotatably supported by a bearing 19 and a lid 21 of the main body 20.

In the thrust direction, the output shaft 10 is mounted on a shaft 15 . A ball 22 is inserted in the thrust direction of the sun gear 2 and the output shaft 10 to enable smooth rotation.

A permanent magnet 9 is fixed to the upper side of the sun gear 2 and is magnetized equally divided into 8 poles (4 pairs) in the circumferential direction to form permanent magnetic poles, similar to the permanent magnet 8, and is integrated with the sun gear 2. and rotate.

Inside the lid 21 fixed to the main pair 20, facing the permanent magnet 9, there is a coil array 4 that is exactly the same as the coil array 3.
is fixed, and by switching the energization of the coil array 4, the sun gear 2 can be rotated like a normal motor.

With the above configuration, if the energization of the coil array 3 and the coil array 4 is controlled, the output shaft 10 is connected to both sun gears by a differential mechanism consisting of the sun gear 1°, the sun gear 2, and the planetary gears 5, 6.7. Since the gears rotate due to the difference in rotation speed, the rotation speed can be easily and stably controlled from extremely low speeds to high speeds.

FIG. 3 shows another embodiment of the present invention, which is particularly designed to reduce the thickness of the device. The sun gear 1 is similar to the embodiment shown in FIG.
The bottom surface of the main body 20 is rotatably supported by a shaft 15 that is press-fitted in an upright position. A permanent magnet 8 is attached to the lower side of the sun gear 1 and is magnetized into eight poles to form permanent magnetic poles, and rotates integrally with the sun gear 1. A coil array 3 is fixedly arranged on the main body 20 so as to face the lower surface of the permanent magnet 8.

This coil array 3 is provided, for example, in an annular shape on six sides at a pitch of 60 degrees, and by switching the coils 3 to 3, the sun gear 1 can be rotated like a normal motor.

The planetary gears 5, 6.7 are similar to the sun gear 1 as in the previous embodiment.
The shafts 11, 12, and 13 mesh with the teeth cut on the outside of the annular sun gear 2 and the teeth cut on the inside of the annular sun gear 2, respectively. It is freely supported on the shaft.

The annular sun gear 2 is rotatably supported at its outer periphery inside the cylindrical portion of the main body 20 via balls 23 and 24. A permanent magnet 9 magnetized into eight equal poles ζ in the circumferential direction is fixed to the lower surface of the sun gear 2, and rotates outside the permanent magnet 8 integrally with the sun gear 2.

A coil array 4 is fixed to the bottom surface of the main body 20, facing the lower surface of the permanent magnet 9.
Similarly, for example, it is provided in an annular shape on 6 sides at a pitch of 60 degrees,
By switching IwL8, the sun gear 2 can be rotated like a normal motor.

The output shaft 10 is rotatably supported by the lid 21 of the main body 20 via a bearing 19, and is connected to both sun gears by a disk-shaped portion at the lower end into which the shafts 11, 12° 13 of the planetary gears 5, 6, 7 are implanted. It is driven at a rotation speed that is the difference between the rotation speeds.

In each of the above embodiments, the motor is described as a three-phase eight-pole DC motor, but it goes without saying that the motor may be similarly configured as a pulse motor or a two-phase eight-pole motor.

〔Effect of the invention〕

As explained above, according to the present invention, a motor unit can be configured with a relatively small number of parts, and a differential motor that is simple in structure, small in size, and inexpensive can be obtained.

[Brief explanation of the drawing]

Figure WX1 is a plan view of a differential mechanism section according to one embodiment of the present invention, Figure 2 is a sectional view of the same embodiment, and Figure 3 is a sectional view of another embodiment of the present invention. 1... External sun gear 2... Incisor sun gear 5.
4... Coil row 5, 6.7... Planetary gear 8,
9-...Permanent magnet 10...Output shaft/1 Agent Patent attorney Katsuo Ogawa (,'-7=1・γ
Pee 2- Figure 3 Figure\0

Claims (1)

[Claims] A differential mechanism that rotates an output shaft by means of one or two sun gears, drive means that drive these gears and can be controlled independently, and a planetary gear system that meshes with both sun gears and rotates based on the difference in rotation speed between the two sun gears. 1. A differential motor comprising: a plurality of pairs of permanent magnetic poles arranged on each of both sun gears, and the sun gears themselves also serving as a rotor of an electromagnetic drive means.