Electrical generator or motor structure – Dynamoelectric – Rotary
Reexamination Certificate
2002-01-10
2004-03-16
Nguyen, Tran (Department: 2834)
Electrical generator or motor structure
Dynamoelectric
Rotary
C310S156780, C310S156820
Reexamination Certificate
active
06707216
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a single phase line start permanent magnet synchronous motor, and particularly, to a single phase line start permanent magnet synchronous motor by which a driving efficiency can be improved, a structure can be compact, and a manufacturing cost can be reduced.
2. Description of the Background Art
Generally, a brushless direct current motor is used as a fan motor for a refrigerator, a microwave oven, a humidifier, and a small electric fan because the brushless direct current motor has a simple structure and costs a little.
The brushless direct current motor has relatively higher efficiency than that of an alternating current motor, a speed of the motor can be changed by controlling an applied electric power, and has high reliability and long life span.
FIG. 1
is a partially cross-sectional view showing a conventional brushless direct current motor in longitudinal direction,
FIG. 2
is a rear elevation view showing the conventional brushless direct current motor, and
FIG. 3
is a front view showing a stator core of the conventional brushless direct current motor.
As shown therein, the brushless direct current motor comprises: a rotor
111
; a stator
121
for receiving the rotor
111
with a certain air gap therebetween; a PCB (Printed Circuit Board)
136
for forming a drive circuit; and a PCB cover
137
coupled to one side of the stator
121
for receiving the PCB
136
.
The rotor
111
is formed to have circular cross section using a permanent magnet, and a rotary shaft
112
is coupled to the shaft of the rotor
111
as a single body.
In addition, a pair of bearing housings
113
including bearings
115
for supporting the rotary shaft
112
are coupled to both sides of the rotor
111
along with a direction of shaft line of the rotary shaft
112
.
Also, as shown in
FIGS. 1 and 3
, the stator
121
comprises: a first stator core
122
including a first pole-shoe
123
and a second pole-shoe
125
, which are facing each other with a predetermined air gap, formed as a single body; a second stator core
132
coupled to one side of the first stator core
122
as a single body; and a bobbin
133
, on which a coil
135
is wound a plurality of times, coupled in an inner space
138
formed by coupling the first stator core
122
and the second stator core
132
as penetrating the inner space
138
.
In addition, the first stator core
122
and the second stator core
132
are fixed and coupled as a single body with each other by insulatingly stacking a plurality of steel sheets. And a first detent groove
127
and a second detent groove
129
, which are apart from an outer diameter surface in a radial direction, and extended as a predetermined width via a circumferential direction for starting the rotor
111
, are formed on the first stator core
122
respectively.
On the other hand, a PCB cover
137
for receiving the PCB
136
is disposed on one side of the bobbin
133
via the rotary shaft line direction of the rotor
111
, and a sensor receiving part
139
is formed on the PCB cover
137
so as to receive and support a position sensor (not shown) which is disposed between the bobbin
133
and the rotor
111
for sensing a rotary position of the rotor
111
(see FIG.
1
).
In the above brushless direct current motor, the first detent groove
127
and the second detent groove
129
are formed on the first pole-shoe
123
and on the second pole-shoe
125
so that the rotor
111
is not disposed on a position where an electric torque is zero for starting the rotor
111
. However, the air gap is enlarged by forming the detent grooves, and then an effective magnetic flux is reduced and an efficiency of the motor is lowered.
Also, an additional direct current supplying device (not shown) which has a large volume and costs high should be disposed in order to drive the motor making the utility alternating current as an input power, and a drive circuit for driving the rotor
111
and the position sensor (not shown) for sensing the position of the rotor
111
are should be included, a volume and price of the motor are increased.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide a single phase line start permanent magnet synchronous motor by which a driving efficiency of the motor can be improved, a structure of the motor is compact, and a manufacturing expense can be reduced.
To achieve the object of the present invention, as embodied and broadly described herein, there is provided a single phase line start permanent magnet synchronous motor comprising: a rotary shaft; a rotor core coupled on outer circumferential surface of the rotary core so as to be rotatable; a plurality of permanent magnets fixedly inserted into the rotor core in rotary shaft direction and disposed so as to be apart from each other in circumferential direction; a rotor including a secondary conductor fixedly inserted between protruded parts of the rotor core in rotating shaft line direction; a stator located on an outer circumferential surface of the rotor with a predetermined air gap therebetween; bearings for supporting both end parts of the rotary shaft in shaft line direction of the rotary shaft so as to support the rotary shaft; a first housing, through which the rotary shaft is penetrated, coupled to the outer circumferential surface of the stator for receiving bearing on one side among those bearings; and a second housing, through which the rotary shaft penetrates, coupled on one side of the first housing for receiving the bearing on the other side among the bearings.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
REFERENCES:
patent: 4506181 (1985-03-01), Jones et al.
patent: 4924130 (1990-05-01), Fratta
patent: 5067166 (1991-11-01), Ito
patent: 5510662 (1996-04-01), Tanimoto et al.
Cho Kwan Yeul
Han Seung Do
Kim Yoon Hyeo
Shin Hyoun Jeong
Birch & Stewart Kolasch & Birch, LLP
LG Electronics Inc.
Nguyen Tran
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