JPH02275146A - Wave motion gearing - Google Patents

Abstract

PURPOSE:To eliminate sliding sections out of a wave motion generator, and thereby eliminate countermeasures for wear resistance by making up the wave motion generator out of a means generating a rotating magnetic field, and of a magnetic field which is hermetically enclosed in such a way as to be capable of being moved around the circumference of the rotating magnetic field. CONSTITUTION:Only paired electromagnets for example, 9a and 9b which are faced with each other in the direction of diameter, are magnetized first out of electromagnets within a member in a circular shape. This causes magnetized fluid 7 to be attracted only to the circumference of the electromagnets 9a and 9b while a flexspline 3 is being formed into an ellipse wherein the dimension connecting the electromagnets 9a and 9b results in its major axis. In the second place, when said paired electromagnets 9 which are faced with each other is for example, magnetized continuously clockwise so as to let a rotating magnetic field be formed, a magnetic body together with the magnetic field is moved along the circumference of a member 8 in a circular shape as the magnetic field is moved clockwise. By this constitution, it appears that the ellipse formed by the flexspline 3 would be rotated clockwise, the meshing position of a circular spline 2 with the flexspline 3 is moved, the output can thereby be obtained with no sliding section developed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a wave gear device, and particularly to a wave gear device equipped with a wave generator using a magnetic fluid.

[Conventional technology]

As a wave generator of a conventional wave gear device, one consisting of an elliptical plate and a flexible bearing fitted around the outside of the plate has often been used.

[Problem to be solved by the invention]

However, this wave generator has many sliding parts, such as the elliptical plate and the flexible bearing, and the flexible bearing and the flexspline, which causes the problem of fretting corrosion (fine movement wear). Ta.

Various lubrication methods have been proposed to solve this problem, but even if these methods are used, a new lubrication mechanism must be provided, which complicates the structure of the wave gear device. .

The present invention has been made in view of this point, and an object of the present invention is to provide a wave gear device that eliminates the problem of wear by eliminating sliding parts in the wave generator and does not require lubrication as a wear countermeasure. shall be.

[Means to solve the problem]

To achieve this object, the wave generator of the wave gear device according to the present invention is characterized in that it comprises means for generating a rotating magnetic field and a magnetic fluid sealed so as to be movable around the rotating magnetic field. .

[For production]

According to the above-described configuration of the present invention, when a magnetic field is generated, the magnetic fluid is attracted around the magnetic field, and the flexspline is deformed into a non-circular shape (in many cases, an elliptical shape). Then, when the magnetic field is rotated, the magnetic fluid also moves as the magnetic field rotates, making it possible to partially engage the flexspline with the circular spline without creating a sliding part.

〔Example〕

FIG. 1 and FIG. 2 show an embodiment of a strain wave gear device according to the present invention. FIG. 1 is a sectional view taken along a plane passing through the axis of the flexspline, and FIG. 2 is a sectional view taken along line X--X in FIG. 1.

The wave gearing device 1 consists of a circular spline 2, a flexspline 3, and a wave generator 4 that bends the flexspline 3 into a forward shape and engages the circular spline 2 at two points. The wave generator 4 is connected to the output shaft 5.The wave generator 4 includes a rotating magnetic field generating means 6 and a magnetic fluid 7 that can move around the rotating magnetic field generating means 6.The rotating magnetic field generating means 6 includes a disk-shaped member. 8, 12 electromagnets 9 are arranged radially at approximately equal intervals around the axis of the flexspline 3.The magnetic fluid 7 is sealed by a disc-shaped member 8 and a sealing material 10. , can be moved around the disc-shaped member 8 along the circumference of the disc-shaped member 8.

This wave gear device 1 operates as follows.

First, the electromagnet 9 incorporated inside the disc-shaped member 8
Among them, only a pair of electromagnets facing each other in the diametrical direction of the disc-shaped member 8, for example, electromagnets 9a and 9b shown in FIG. 2, are magnetized. As a result, the magnetic fluid 7 is attracted only around the electromagnets 9a and 9b, and the flexspline 3 is attracted only around the electromagnets 9a and 9b.
, 9b is deformed into an ellipse whose major axis is the diameter connecting 9b.

Next, a pair of electromagnets 9 facing each other in the diametrical direction of the disc-shaped member 8 are continuously magnetized, for example, in a clockwise direction to form a rotating magnetic field. As the magnetic field moves clockwise, the magnetic fluid also moves along the circumference of the disc-shaped member 8 together with the magnetic field. For this reason, the ellipse formed by the flexspline 3 appears to have rotated clockwise, the meshing position between the circular spline 2 and the flexspline 3 moves, and the gap between the circular spline 3 and the flexspline 2 moves. causes a relative rotation. This movement can be taken out as an output from the output shaft 5.

The scope of the present invention is not limited to the above examples, and various changes can be made within the scope of the invention described in the claims, and these are also included within the scope of the present invention. It is something that will be done.

For example, in the above-mentioned embodiment, a wave gear device in which the circular spline 2 is an internal gear and the flexspline 3 is an external gear is given as an example, but in the present invention, the circular spline 2 is an external gear and the flexspline 3 is an external gear. It is also applicable to wave gear devices in the form of internal gears.

In addition to forming the rotating magnetic field by arranging electromagnets in a circular shape and sequentially magnetizing them as in the embodiment, it is also possible to form the rotating magnetic field by, for example, rotating a permanent magnet.

When forming a rotating magnetic field using electromagnets, the number of electromagnets is arbitrary, but it is most preferable that the number be a multiple of four.

〔Effect of the invention〕

According to the present invention, it is possible to eliminate the sliding portion in the wave generator of the wave gear device. Accordingly, the problem of wear is eliminated, and lubrication as a measure against wear is no longer necessary.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a wave gear device according to the present invention, and FIG. 2 is a sectional view taken along the line X--X in FIG. 1. [Explanation of symbols] 1... Wave gear device 3... Flex spline 5... Output shaft 7... Magnetic fluid 9... Electromagnet 2... Circular spline 4... Wave generator 6...・Rotating magnetic field generating means ・Disc-shaped member 10 ・Sealing material Figure 1 x 2 Figure 2

Claims (1)

[Claims] A wave gear device comprising a circular spline, a flex spline, and a wave generator that bends the flex spline non-circularly and partially meshes with the circular spline, wherein the wave generator includes a rotating magnetic field generating means, and a rotating magnetic field generating means. A wave gear device comprising a magnetic fluid sealed so as to be movable around a generating means.