Magnetic ring

Details Magnetic ring Magnetic ring

1999-07-09

2001-03-06

Enad, Elvin (Department: 2834)

Electrical generator or motor structure

Dynamoelectric

Rotary

C310S049540

Reexamination Certificate

active

06198185

ABSTRACT:

The present invention is concerned with a magnetic ring intended to serve as a signal generator for a sensor sensitive to a magnetic field. Magnetic rings of this type, usually, are mounted, for example, on driving shafts of electromotors to determine the number of revolutions or the angular position thereof. For that purpose, the magnetic ring must be held on the shaft in a non-rotating manner. However, it cannot be directly forced onto the shaft because the magnetic material is brittle and would burst when forced onto the shaft. Consequently, the provision of additional fasteners is required.
It is suggested, for example, according to DE 37 32 958 C2 to use a fastener formed of a plastic sleeve of a T-shaped profile which carries the magnetic ring together with a back circuit sleeve on the cylindrical circumferential face extending in the axial direction, and on the front face thereof extending in the radial direction. To secure the said unit on the shaft, the plastic sleeve, the back circuit sleeve and the magnetic ring along with the shaft are coated, by spraying, with a plastic material.
It is readily apparent that this way of procedure is rather complex.
It is, therefore, suggested by the invention to spray the magnetic ring onto an annular disc, with the outer rim of the said annular disc being embraced by the magnet while at least certain sections of the interior thereof are exposed, with the exposed inner rim, at least in part, being located on a circle the diameter of which is only little less than the diameter of the shaft to which the magnetic ring is to be mounted.
The inwardly protruding sections of the annular disc form resilient holding elements capable of being forced onto the shaft, thereby holding the magnetic ring on the shaft in a non-rotating manner and locked against displacement, provided that the holding forces are selected correspondingly large, with the compression forces being applied to the annular disc rather than to the magnetic ring. Preferably, the inner rim of the disc, except for two recesses, is located on a circle, with the sections of the inner rim disposed in the recesses, being embraced by the magnet.
The recesses are in the form of segments the centers of which conform to the center of the circle formed by the remainder of the inner rim.
The embodiment so far described wherein the inwardly protruding sections of the annular disc comprise segment-shaped recesses, is intended for use at a place having a smooth surface. The recesses are required to enable the remaining bridges to bend in the axial direction.
However, the shaft can also be provided with some circumferentially distributed longitudinal grooves cut into the material, with the material extracted being piled up to form a longitudinal bridge along the groove. Now, if the annular disc is forced onto the said bridges, a firm foothold is formed; in addition, the provision of segmented recesses in the annular disc can be foregone.
The disc, preferably, is made of a non-magnetic metal, e.g. hard brass or a beryllium alloy.
A magnetic ring of the afore-described type is produced by spray-coating the premanufactured annular disc with a magnetizable material—as described—and by subsequently magnetizing the sprayed-on magnetic material in the desired way.


REFERENCES:
patent: 2432819 (1947-12-01), Schumacker
patent: 4049984 (1977-09-01), Ishii et al.
patent: 4336517 (1982-06-01), Kobayashi et al.
patent: 4492906 (1985-01-01), Goto et al.
patent: 4710659 (1987-12-01), Takano et al.
patent: 5019796 (1991-05-01), Lee et al.
patent: 5081756 (1992-01-01), Abe et al.
patent: 5293125 (1994-03-01), Griffen et al.
patent: 5563463 (1996-10-01), Stark
patent: 5565721 (1996-10-01), Knappe
patent: 5608277 (1997-03-01), Emery et al.
patent: 1 043 540 (1958-11-01), None
patent: 76 28 220 U (1978-08-01), None
patent: 86 14 601 U (1986-09-01), None
patent: 37 18 047 (1987-12-01), None
patent: 36 22 312 (1988-01-01), None
patent: 36 36 039 (1988-04-01), None
patent: 37 32 958 (1989-04-01), None
patent: 92 16 750 U (1994-05-01), None
patent: 0 213 732 (1987-03-01), None
patent: 0 640 838 (1995-03-01), None
patent: WO 85/04934 (1985-11-01), None
patent: WO 97/46850 (1997-12-01), None
Patent Abstracts of Japan, E-353, vol. 9, No. 270 (Oct. 26, 1985) (concerning 60-116110 by S. Kojima).
Patent Abstracts of Japan, E-417, vol. 10, No. 192 (Jul. 5, 1986) (concerning 61-35501 by Y. Hirabayashi).
Patent Abstracts of Japan, (Jul. 1987) (concerning 62-40706 by K. Tsunemi).
Patent Abstracts of Japan, P-685, vol. 12, No. 104 (Apr. 6, 1988) (concerning 62-237315 by T. Abe).
Patent Abstracts of Japan, P-758, vol. 12, No. 341 (Sep. 13, 1988) (concerning 63-101708 by T. Yokoyama).
Patent Abstracts of Japan, P-993, vol. 14, No. 31, (Jan. 22, 1990) (concerning 1-269013 by Y. Asami).
Patent Abstracts of Japan, (concerning 07037715 by M. Yoshihiko and K. Kotoji and published on Feb. 7, 1995).
International Search Report of Oct. 15, 1996.
International Search Report of Dec. 11, 1996.
Merriam Webster's Collegiate Dictionary, tenth edition, p. 376, 1997.

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