Motor

Details Motor Motor

1999-04-13

2001-01-09

Mullins, Burton (Department: 2834)

Electrical generator or motor structure

Dynamoelectric

Rotary

C310S049030, C310S254100, C310S257000, C310S266000

Reexamination Certificate

active

06172440

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ultra-compact type motor with the high power output.
2. Related Background Art
A motor formed as a compact type motor is conventionally well known as, for example, a compact cylindrical step motor, as shown in
FIG. 16. A
stator
102
of the step motor is arranged in a manner that a stator coil
105
is coaxially wound on a bobbin
101
fixed and sandwiched in an axial direction between two stator yokes
106
, and stator gear teeth
106
a
and
106
b
are alternately disposed on the stator yoke
106
, on the inner peripheral surface of the bobbin
101
in the circumferential direction, and that the stator yoke
106
, integrated to the stator teeth
106
a
or
106
b
, is fixed to the case
103
.
A flange
115
and a bearing
108
are fixed to one of two sets of cases
103
and another bearing
108
is fixed to the outer part of the cases
103
. A rotor
109
includes a rotor magnet
111
fixed to a rotor shaft
110
and the rotor magnet
111
defines a radial gap portion together with the stator yoke
106
a
of the stator
102
. Further, the rotor shaft
110
is rotatably supported between two bearings
108
.
However, the above-mentioned conventional compact step motor has the disadvantage of having large outer dimensions since the case
103
, the bobbin
101
, the stator coil
105
, the stator yoke
106
and the like are coaxially disposed around the periphery of the rotor
109
. Further, the magnetic flux generated by energization of the stator
105
mainly passes through an end face
106
al
of the stator teeth
106
a
and an end face
106
bl
of the stator teeth
106
b
as shown in
FIG. 17
, so that it does not effectively act on the rotor magnet
111
, whereby the power output of the motor does not become higher.
The present inventors proposed a motor in which such problems had been overcome, as U.S. Pat. No. 5,831,356. The proposed motor has a cylindrical rotor comprised of a permanent magnet divided into equal parts in a circumferential direction and alternately polarized to different magnetic poles. A first coil, a rotor, and a second coil are disposed in an axial direction of the rotor in this order and a first outer magnetic pole and a second magnetic pole, which are excited by the first coil, are opposed to the outer and inner peripheral surfaces of the rotor, and a second outer magnetic pole and a second magnetic pole, which are excited by the second coil, are opposed to the outer and inner peripheral surfaces of the rotor. A rotary shaft that is a rotor shaft may be removed from within the cylindrical permanent magnet.
Thus configured motors may have a high power output and small outer dimensions. However, machining of the magnetic pole teeth is difficult because of the small diameter of an outer magnetic pole. Further, a small-diametered motor free from vibration and having a stable power output are required.
Thus, the present inventors recently proposed a motor in which the inner magnetic pole has a shape with improved machinability in U.S. patent application Ser. No. 08/994,994. Further, the present inventors proposed a rotor in which output transmission means, such as a gear and pulley, is easily mounted on a rotary shaft with a small diameter, in U.S. patent application Ser. No. 09/022,474. Furthermore, it has been required to obtain a stable and high power motor that is configured as an ultra-compact type motor.
SUMMARY OF THE INVENTION
Taking the above-mentioned problems into consideration, an object of the present invention is to provide an ultra-compact type motor configured in a manner that high power output can be stably obtained.
Another object of the present invention is to improve the output performance of a motor by setting the phase shift of a second polarized layer with respect to a first polarized layer of a magnet and the phase shift of a second stator with respect to a first stator.
Other objects of the present invention will become apparent from concrete examples described below.


REFERENCES:
patent: 4009406 (1977-02-01), Inariba
patent: 4754183 (1988-06-01), Gerber
patent: 4823038 (1989-04-01), Mizutani et al.
patent: 5283487 (1994-02-01), Oki et al.
patent: 5384506 (1995-01-01), Aoshima
patent: 5831356 (1998-11-01), Aoshima
patent: 5925945 (1999-07-01), Aoshima
patent: 5969453 (1999-10-01), Aoshima

Affiliated with

Also associated with

Rating

Motor does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Motor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Motor will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2547358