JPS59222666A - Magnet coupling - Google Patents

Abstract

PURPOSE:To prevent the occurrence of energy loss due to yielding of an eddy current, by a method wherein an amorphous film used for a magnetic shield is adhered to the outer periphery of an externally-rolling yoke. CONSTITUTION:An externally-rolling rotor 3, provided at the inner periphery of a externally-rolling yoke 1 with an outer magnet 2 with plural poles, in which an N-pole and an S-pole are aligned alternately, is extended from a drive source. An internally-rolling rotor 6, provided at the outer periphery of an internally- rolling yoke 4 with an inner magnet 5, corresponding to the outer magnet 2 in which N-poles and S-poles are alternately aligned on the outer periphery of an internally-rolling yoke 4 disposed in a hollow part at the axis of the externally- rolling yoke 1, is extended from a follower object. An amorphous film 8 with high permeability is firmly adhered to the outer periphery of the externally-rolling yoke 1. This causes magnetic flux, leaking through the externally-rolling yoke 1, to leak in the amorphous film 8, but since the amorphous film 8 is extremely high in permeability, the leak-in phous film 8 is extremely high in permeability, the leak-in magnetic flux is returned from the inside of the amorphous film 8 to the externally-rolling yoke 1 agains.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a magnetic coupling used to transmit power using magnetic force.

(b) Prior art Conventionally, as this type of magnetic coupling, the first
As shown in the figure, an outer rotor C has a plurality of outer magnets b provided on the inner periphery of an outer rotor yoke a, and an inner rotor C has a plurality of outer magnets b provided on the inner periphery of an outer rotor yoke a, and an inner rotor d is provided in an axial hollow part of the outer rotor yoke a. There is an inner rotor f having a plurality of inner magnets e corresponding to the outer magnets b on the outer periphery of the inner rotor yoke d. In such a device, the outer rotor yoke a is generally made of a high-strength material such as iron. Note that g is a fixed housing surrounding the magnetic coupling.

However, in such a device, the high-strength material such as iron has low magnetic permeability, and increasing the thickness of the outer yoke a is limited due to space constraints, so the magnetic flux A from the outer yoke a is limited.
leaks out and enters the housing g, and the leaked magnetic flux A generates an eddy current B in the housing g as the outer rotating yoke a rotates, resulting in energy loss. And, as the rotation speed of the outer rotor a increases, this inconvenience becomes too large to be ignored.

In order to eliminate these inconveniences, it is conceivable to form the outer rotation yoke using permalloy or the like having high magnetic permeability. But 1. (-Malloy and the like have low tensile strength, so they have a weak force to resist centrifugal stress, and when an outer rotor yoke formed of 7Nl+-Malloy and the like is rotated at high speed, the outer rotor yoke will break.

(c) Purpose The present invention was made with attention to the above circumstances, and
Even if it is rotated at high speed, it will not break (,Moreover, (・14
The purpose of this invention is to provide a magnetic force/knob ring that can suppress energy loss due to the generation of eddy currents, which can lead to complicated and large-sized construction.

(D) Structure In order to achieve the above object, the present invention forms the outer rotation yoke from a high-strength fourth material as in the past, and the outer rotation 1. It is characterized by having an amorphous thin film for magnetic shielding applied to the outer periphery of the yoke.

(e) Examples Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

As shown in FIGS. 2 and 3, a plurality of external magnets 2 with NS poles arranged alternately are provided on the inner periphery of an outer rotor yoke 1 made of a high-strength material such as iron. An external rotating rotor 3 is extended from a drive source (not shown), and NS poles are arranged alternately on the outer periphery of an internal rotating yoke 4 disposed in the axial hollow part of the external rotating yoke 1. Inner magnet 5 corresponds to magnet 2...
The inner rotor 6 provided with . is extended from a driven object (not shown). Note that 7 is l-Using.

With such magnetic force and knob ring, an amorphous thin film 8 having high magnetic permeability is closely adhered to the outer periphery of the outer rotary yoke 1. The amorphous thin film 8 is adhered by applying an adhesive 9 to one surface of the amorphous thin film 8 and applying the adhesive 9 (FIG. 4).
. As the amorphous thin film 8, for example, Fe-8i-
B amorphous tape or the like is used.

``If it is like this, when the outer rotor 3 rotates by receiving a rotational force from a drive source (not shown), the outer rotor yoke 1 and the outer magnet 2... rotate integrally. Since the inner magnets 5 and . 5 and transmits the rotation to a driven object (not shown).

At this time, as shown in FIG. 5, the magnetic flux A leaking from the outer rotor yoke 1 leaks into the amorphous thin film 8, but since the amorphous thin film 8 has extremely high magnetic permeability, the increased magnetic flux A flows through the amorphous thin film 8. 8 and is returned to the inside of the abduction yoke 1 again. Therefore, the disadvantage that the magnetic flux A leaks into the housing 7 and generates eddy currents, which causes energy loss, as in the conventional case, is reduced. Further, since the outer rotor yoke 1 is conventionally made of a high-strength material such as iron, there is no problem that the outer rotor yoke 1 will break when rotated at high speed, unlike when the outer rotor yoke is made of permalloy or the like. Moreover, since the above effect can be achieved with a simple structure in which the amorphous thin film 8 is adhered to the outer periphery of the outer rotor yoke 1 using the adhesive 9, the structure does not become complicated, and the thickness of the outer rotor yoke 1 is reduced. There is no need to significantly increase the size of the magnetic coupling (therefore, there is no need to increase the size of the magnetic coupling).

It should be noted that the present invention is of course not limited to the above embodiments, and the inner periphery of the outer rotation yoke and the outer periphery of the inner rotation yoke are not limited to circular cross-sections, but polygonal cross-sections that facilitate the attachment of magnets. It may be.

In addition, various modifications can be made without departing from the spirit of the present invention.

(f) Effects As explained above, the present invention has a simple structure in which an amorphous thin film is coated on the outer periphery of the abduction yoke. It is possible to provide a magnetic coupling that can reduce leakage of magnetic flux and suppress energy loss due to eddy current generation while maintaining high strength of the yoke.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a conventional example, FIGS. 2 to 5 show an embodiment of the present invention, FIG. 2 is a sectional view, FIG. 3 is a sectional view taken along line 11 in FIG. The figure is a perspective view showing the main parts.
The figure is an explanatory diagram of the action. 1... Abduction yoke 2... Outer magnet 3...
- External rotor 4... Inner rotor yoke 5... Inner magnet 6... Inner rotor 8... Amorphous thin film agent Patent attorney Hiroshi Akazawa Figure 2 - -. Figure 4 Figure 5ゝ\l'

Claims (1)

[Claims] The outer rotor has a plurality of outer magnets arranged on the inner periphery of the outer yoke, and an inner yoke arranged in the axial hollow part of the outer yoke. A magnetic coupling comprising an inner rotor provided with a plurality of corresponding inner magnets, the outer rotor yoke being formed of a high-strength material, and an amorphous material for magnetic shielding on the outer periphery of the outer rotor yoke. A magnetic coupling characterized by having a thin film coated on it.