192 clutches and power-stop control – Clutches – Operators
Reexamination Certificate
2000-06-29
2002-04-16
Bonck, Rodney H. (Department: 3681)
192 clutches and power-stop control
Clutches
Operators
C192S084900, C335S296000
Reexamination Certificate
active
06371270
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electromagnetic clutch, and more specifically, to an electromagnetic clutch suitable for use in compressors.
2. Description of Related Art
An electromagnetic clutch is used as a power transmission for a compressor. For example, a known structure of a scroll-type compressor having an electromagnetic clutch is constructed as depicted in FIG.
17
. In
FIG. 17
, electromagnetic clutch
100
is assembled around cylindrical projected portion
121
a
of front housing
121
of scroll-type compressor
120
. Electromagnetic clutch
100
includes rotor
101
, which is mounted upon projected portion
121
a
via bearing
123
. Rotor
101
has inner cylindrical portion
101
a
, outer cylindrical portion
101
b
, and bottom portion
101
c
connecting the ends of cylindrical portions
101
a
and
101
b
. Containing space
101
d
is formed by portions
101
a
,
101
b
and
101
c
. Electromagnet device
102
is enclosed within containing space
101
d
of rotor
101
.
Armature
103
is provided facing one end of rotor
101
. Armature
103
is connected to stopper plate
105
via plate spring
104
. Stopper plate
105
is fixed to boss portion
106
via rivets
107
. Boss portion
106
is fixed to end portion
122
a
of drive shaft
122
by threaded nut
108
.
In electromagnetic clutch
100
, a rotational torque is transmitted from an external power source (not shown) to rotor
101
via a V belt (not shown). When electromagnet device
102
is not energized, because armature
103
is urged by plate spring
104
away from rotor
101
, even if rotor
101
rotates, armature
103
does not rotate. Therefore, the rotational torque of rotor
101
is not transmitted to drive shaft
122
. When electromagnet device
102
is energized, armature
103
is attracted to the end of rotor
101
by the attracting force generated by electromagnet device
102
, in opposition to the urging force applied by plate spring
104
. Therefore, rotor
101
and armature
103
are integrated, and rotated together. The rotational torque of rotor
101
is transmitted to drive shaft
122
through stopper plate
105
and boss portion
106
, thereby driving compressor
120
.
FIG. 18
depicts an inclined plate-type compressor as another type of compressor. In
FIG. 18
, electromagnetic clutch
110
is assembled around of cylindrical projected portion
131
a
of front housing
131
of inclined plate-type compressor
130
. Electromagnetic clutch
110
may have a structure similar to that depicted in FIG.
17
.
FIG. 19
depicts an example of the detailed structure of the electromagnet device depicted in
FIG. 17
or
18
. In
FIG. 19
, electromagnet device
102
has ring member
113
forming therein a containing chamber
113
a
. Ring-like plate
114
is provided on one end outer surface of ring member
113
for fixing ring member
113
on a front housing of a compressor. Coil bobbin
112
provided with coil element
111
is housed within containing chamber
113
a
of ring member
113
. Coil bobbin
112
is enclosed within containing chamber
113
a
by charging resin
115
, such as an epoxy resin into containing chamber
113
a
. Thus, in a known technology, a method for molding a resin is employed for preventing water or foreign material from entering into an electromagnetic clutch, including for ensuring the properties of vibration resistance, heat radiation resistance, and water proofing.
FIG. 20
depicts another example of the detailed structure of the electromagnet device depicted in
FIG. 17
or
18
. In
FIG. 20
, electromagnet device
102
′ has bobbin
116
formed as two separate parts. After coil element
111
is enclosed within the two parts of bobbin
116
, bobbin
116
is housed within containing chamber
113
a
of ring member
113
. Enclosed bobbin
116
then is fixed by caulked portions
117
formed at the partial inner edges of the opening portion of containing chamber
113
a.
In the known structure depicted in
FIG. 19
, however, because resin
115
for molding generally is a thermosetting resin, such as an epoxy resin, manufacturing electromagnet device
102
requires an expensive furnace for curing of the resin. Further, it takes a long period of time to cure the resin, thereby decreasing the productivity of manufacturing processes for such an electromagnetic clutch.
In the known structure depicted in
FIG. 20
, it is difficult to completely prevent water from entering into coil element
111
through a gap between the two parts of bobbin
116
. Therefore, there is a problem insulating coil element
111
.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an improved structure for an electromagnetic clutch that may increase the productivity of manufacturing processes by stopping use of a molding resin, and that may ensure the proper insulation of an electromagnet device.
To achieve the foregoing and other objects, an electromagnetic clutch according to the present invention is provided. The electromagnetic clutch includes an electromagnet device housed within a rotor. The electromagnet device comprises a ring member having a containing chamber, a coil member housed within the containing chamber of the ring member. The coil member comprises a bobbin and a coil element provided within the bobbin. The electromagnet device comprises a seal mechanism provided for enclosing the coil element within the containing chamber of the ring member in a sealed-off condition.
In the electromagnetic clutch, the seal mechanism comprises a seal plate to improve the seal formed between the bobbin and the ring member. The seal plate engages an engaging portion formed on an inner surface of the containing chamber of the ring member. The seal plate may comprise a side plate portion integral with the bobbin. Alternatively, the seal plate may comprise a resin plate provided separately from the bobbin.
The engaging portion may comprise a first groove formed on the inner surface of the containing chamber of the ring member. The first groove extends circumferentially about the ring member. Further, the engaging portion may comprise a stepped portion formed on the inner surface of the containing chamber of the ring member. The stepped portion extends circumferentially about the ring member.
The seal plate may have a projection extending circumferentially about the ring member. The projection engages the engaging portion formed on the inner surface of the containing chamber of the ring member. The projection may be brought into contact with the engaging portion. Further, the projection may be fitted into a second groove formed on the engaging portion. The second groove extends circumferentially about the ring member.
Further, the seal plate may have a V-shaped groove on its radial end surface, i.e., a radially outer end surface, or a radially inner end surface, or both. The seal plate may have a notch on its edge portion. The notch extends circumferentially about the seal plate.
The seal plate is fixed in the containing chamber of the ring member. For example, a part of the inner surface of the containing chamber of the ring member is crimped, and the seal plate is fixed in the containing chamber of the ring member by the crimping. Crimping may include the formation of a wave, bulge, crinkle, warp, or similar deformation in the ring member surface. A plurality of crimped portions may be disposed circumferentially about the ring member, or a crimped portion may extend continuously over the entire circumference of the ring member. The crimped portion, or portions, may be disposed on the inner surface of an outer cylindrical portion of the ring member, or an outer surface of an inner cylindrical portion of the ring member, or both.
An inner surface of of the containing chamber of the ring member positioned below the engaging portion, may be formed as a tapered surface causing a width of the containing chamber to gradually decrease.
The seal mechanism may comprise a protruded portion placed into contact with an inner su
Baker & Botts L.L.P.
Bonck Rodney H.
Sanden Corporation
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