JPH0532833U - Shaft coupling - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a new non-backlash type shaft coupling that has a simple structure, can be made lightweight, and can be easily attached and detached. [Structure] A pair of circular hubs 11 and 12 having central holes 13 and 14 fitted into a shaft and having facing surfaces 11a and 12a facing each other are faced to each other, and
When the opposing surfaces 11a, 12a of the above are divided by the radial reference line A at equal intervals, the projections 15, 16 which are divided so as to be located at the equal distance H from the reference line A are provided in every one of the divisions 18,
A space L is formed between the protrusions 15 and 16 when the protrusions 15 and 16 of the circular hubs 11 and 12 are alternately positioned, and at least the protrusions 15 and 16 of the circular hubs 11 and 12 are formed.
It is a shaft coupling formed of permanent magnets whose surfaces repel each other.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a non-backlash, small-sized shaft joint that can be used for high precision, such as a shaft joint used for a rotary encoder.

[0002]

[Prior Art]

 Non-backlash is an essential requirement for shaft couplings for precision positioning devices such as rotary encoders. The most common non-backlash type shaft coupling is a disk coupling. The disc coupling is a flexible element that is made by stacking and stacking square, hexagonal, octagonal, or donut-shaped thin metal plates depending on the number of bolts used, and using them as a pair of circular hubs on the same pitch circle diameter. Bolted to. Non-backlash can be achieved because the connecting part of each part can have a structure without play. There are also non-backlash shaft couplings that use links or diaphragms instead of discs.

[0003]

[Problems to be solved by the device]

 The flexible coupling element such as the disc coupling described above that is connected by bolts has a complicated shape, and there is a problem that it takes time to attach and detach. From the standpoint of mounting and dismounting, there is a parallel staggered type (Oldham) shaft coupling. An intermediate plate with key-shaped protrusions that cross each other in a cross shape is fitted between circular hubs with one-character grooves. Assembly is extremely simple, but there is backlash due to the gap between the keys. ..

The present invention has been made in view of the above problems of the prior art, and its object is to have a simple structure and reduce weight, and to be easily attached and detached. However, it is intended to provide a new non-backlash type shaft coupling.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the shaft coupling according to the present invention comprises a pair of circular hubs having a central hole to be fitted into the shaft and having facing surfaces facing each other, and the facing surfaces of the circular hubs are radially spaced. Providing protrusions that are partitioned so that they are located equidistant from the reference line in every step of dividing by the reference line, and when the protrusions of each circular hub are alternately positioned, a space is formed between the protrusions. Thus, at least the protruding surface of each circular hub is formed of permanent magnets that repel each other.

[0006]

[Action]

 Since the protrusions on one circular hub and the protrusions on the other circular hub are located alternately, and both protrusions are made of repulsive permanent magnets, they try to maintain a constant position where the repulsive forces are balanced, which causes backlash. do not do.

[0007]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an assembly view of a shaft coupling according to the present invention. FIG. 1 (a) is a front view and FIG. 1 (b) is a sectional view taken along line XX. FIG. 2 is a part view of each circular hub. The same (a) is a front view of one circular hub, the same (b) is a side view of one circular hub, and the same (c) is the other circular hub. A side view and the same (d) are front views of the other circular hub.

In FIG. 2, one circular hub 11 and the other circular hub 12 have central holes 13 and 14 into which shafts are fitted, and projections 15 and 16 are provided on the facing surfaces 11 a and 12 a of both hubs 11 and 12, respectively. It is projected. The projections 15 and 16 position the facing surfaces 11a and 12a in fan-shaped sections 17 and 18 which are sectioned by equally spaced radial reference lines A having a circumferential angle of 60 degrees. The side surfaces of the projections 15 and 16 are partitioned at equal distances parallel to the radial reference line A by a distance H 2, and the outer circumferences of the projections 15 and 16 are smaller than the outer diameter of the circular hub and are fan-shaped sections 17 and 18. It is a similar figure. Further, the projections 15 and 16 are provided so as to project every other sectoral section 17 and 18. Although the circular hub 11 on one side and the circular hub 12 on the other side have the same shape, at the time of assembly, the phases of the protrusions 15 and 16 are shifted by 60 degrees so that they are alternately positioned. .

The circular hubs 11 and 12 described above are made of a permanent magnet, which is a magnetic material having a high coercive force, and the protrusions 15 and 16 thereof are combinations of S poles and S poles or N poles and N poles. There is. Ferrite and rare earth cobalt are used as the material of this permanent magnet. For example, it can be manufactured by a method in which ferrite is processed into a shape of a circular hub with protrusions and magnetized. It is also possible to manufacture it by forming only the protrusion with a permanent magnet and implanting it in a circular hub. Further, it is also possible to manufacture by attaching a plate-shaped permanent magnet to the surfaces of the protrusions 15 and 16.

In FIG. 1, the above-mentioned circular hubs 11 and 12 with protrusions are positioned so that the protrusions 15 and 16 are inserted into each other, whereby the assembly is completed. Installation and removal is extremely easy. Then, a space having a parallel interval L is formed between the protrusions 15 and 16, and the repulsive force F is generated because they have the same S pole or N pole. The positions of the projections 15 and 16 on which the repulsive force F is balanced are uniquely determined, and backlash does not occur even if the rotation direction changes. The magnitude of the repulsive force F that determines the rigidity of the shaft coupling can be adjusted by the magnitude of the interval L, the material of the permanent magnet, the degree of magnetization, the projection size, and the projecting shape.

FIG. 3 is an assembly view of another shaft coupling, in which (a) is a front view and (b) is a YY sectional view. The difference from FIG. 1 is that the outer circumferences of the protrusions 19 and 20 are substantially equal to the outer diameters of the circular hubs 11 and 12, and the N poles or the S poles repel each other. The others are the same as in FIG. In addition, in a usage example in which the magnetic lines of force of the permanent magnets such as the protrusions 19 and 20 may leak to the outside and cause magnetic interference in, for example, a rotary encoder, the magnetic shield 21 is fitted on the outer circumference of the circular hubs 11 and 12. And it can trap the magnetism. As the magnetic shield 21, steel, aromatic polyamide, resin sleeve containing polyester stem fiber, simple resin sleeve, or the like can be used.

[0012]

[Effect of the device]

 In the shaft coupling according to the present invention, the protrusions of one circular hub and the protrusions of the other circular hub are located alternately, and are formed of permanent magnets that repel both protrusions. You can maintain the rigidity by repulsive force and achieve non-backlash. The assembly is completed by inserting both protrusions alternately, so it is extremely easy to install and remove. Furthermore, the simple structure makes it possible to reduce the weight and eliminates the need for maintenance such as element exchange due to stress strain, unlike the flexible element of the disc coupling.

[Brief description of drawings]

FIG. 1 is an assembly view of a shaft coupling of the present invention.

FIG. 2 is a component diagram of each circular hub.

FIG. 3 is an assembly diagram of another shaft coupling.

[Explanation of symbols]

 11,12 Circular hub 11a, 12a Opposing surface 13,14 Central axis 15,16,19,20 Protrusion 17,18 Division A Reference line H Distance L Space

Claims (1)

[Scope of utility model registration request] 1. A pair of circular hubs having a central hole to be fitted into a shaft and having facing surfaces facing each other are faced to each other,
When the facing surface of each circular hub is divided by radial reference lines at equal intervals, a protrusion is provided in every other division so that it is positioned equidistant from the reference line, and the protrusions on each circular hub are alternately positioned. A shaft coupling formed so that a space is formed between the protrusions when the protrusions are made, and at least the protrusion surfaces of each circular hub are formed of permanent magnets that repel each other.