Swash plate compressor

Details Swash plate compressor Swash plate compressor

2001-09-19

2003-06-10

Look, Edward K. (Department: 3745)

Expansible chamber devices

Displacement control of plural cylinders arranged in...

Parallel cylinders

C092S071000

Reexamination Certificate

active

06575079

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a swash plate compressor, and more particularly, to a swash plate compressor having an improved structure for preventing rotation of a race in the compressor.
2. Description of the Related Art
In an air conditioning apparatus for an automobile, a typical compressor enables refrigerant to continuously circulate by sucking heat exchange medium vaporized in an evaporator, compressing the sucked heat exchange medium, and pumping the compressed heat exchange medium. The compressor is classified into various types such as a swash plate type, a scroll type, a rotary type, and a wobble plate type based on a driving method.
FIG. 1
shows an example of a swash plate type compressor
100
. Referring to the drawing, the swash plate type compressor
100
includes a plurality of pistons
112
installed in a cylinder block
111
to be inserted therein and a drive shaft
113
is installed at the central portion of the cylinder block
111
. A boss
112
a
having a shoe pocket (not shown) for accommodating a shoe (not shown) to facilitate smooth sliding of the pistons
112
with respect to a swash plate
114
is formed in the middle portion of each of the pistons
112
. Since the swash plate
114
coupled to the drive shaft
113
is inserted in the boss
112
a
, when the swash plate
114
rotates, the pistons
112
can sequentially reciprocate in the lengthwise direction of the cylinder block
111
.
A thrust bearing
120
is installed so that rotational movements of the swash plate
114
is converted to reciprocating movements of the pistons
112
at both sides of the swash plate
12
.
Races
121
a
and
121
b
are interposed between the swash plate
114
and the thrust bearing
120
, and a thrust surface
111
c
(see
FIG. 2A
) and the thrust bearing
120
, respectively, at both sides of the thrust bearing
120
. The races
121
a
and
121
b
guide needle type rollers
120
a
in the thrust bearing
120
.
A valve plate
115
where suction holes
115
a
and discharge holes
115
b
are formed is installed at both sides of the cylinder block
111
. A thin plate type suction reed
116
for opening and shutting the suction holes
115
a
and an discharge reed
117
for opening and shutting the discharge holes
115
b
are installed at both sides of the valve plate
115
. A front head
118
and a rear head
119
are installed at both sides of the cylinder block
111
where the suction reed
116
and the discharge reed
117
are installed.
In the typical swash plate type compressor having the above structure, when the drive shaft
113
is rotated by a predetermined driving means (not shown), the swash plate
114
installed at the drive shaft
113
rotates so that the pistons
112
radially arranged at the cylinder block
111
are reciprocated. As the pistons
112
reciprocate, heat exchange medium is sucked and discharged while being compressed. Here, the suction reed
116
and the discharge reed
117
open and shut the suction holes
115
a
and the discharge holes
115
b
, respectively, by the pressure of the sucked or compressed heat exchange medium.
However, during the operation of the above swash plate type compressor
100
, when an impact is generated by an instantaneous thrusting force, the races
121
a
and
121
b
are elastically deformed and absorb the impact. Here, by the instantaneous elastic deformation by the impact, an insertion phenomenon that the thrust bearing
120
is instantaneously inserted between the races
121
a
and
121
b
and the cylinder block
11
occurs. Then, the roller
120
a
in the thrust bearing
120
does not rotate due to the insertion phenomenon and the race
121
b
rotates together with the thrust surface
111
c
of the cylinder block
111
while making friction therebetween.
Meanwhile, the race
121
a
at the right contacting a thrust surface of the swash plate
114
hardly generates rotation and abrasion due to the rotation. This is because the right race
121
a
contacts the thrust surface of the swash plate
114
in a large area while the left race
121
b
contact the thrust surface
111
c
of the cylinder block
111
in a small area.
Due to the above phenomenon, the thrust surface
111
c
of the cylinder block formed of a relatively softer material is excessively abraded so that the gap between the swash plate
114
and the cylinder block
111
is generated and parts subordinately affected generate noise inside the compressor. Also, since the performance of the races
121
a
and
121
b
guiding the roller
120
a
of the thrust bearing
120
deteriorates, the thrust bearing
120
cannot properly absorb an impact and generates noise and further the thrust bearing
120
itself is damaged. Furthermore, as the swash plate
114
freely moves, the suction reed
116
is damaged as the pistons
112
apply impacts to the suction reed
116
.
To solve the above problem, an swash plate type compressor is disclosed in Japanese Utility Model Publication No. 57-134370 (published on Aug. 21, 1982). In this swash plate type compressor, a protrusion for preventing rotation which is bent toward a cylinder block is installed at the outer circumferential surface of a race. The rotation preventing protrusion is inserted in a bore formed in the cylinder block to prevent the rotation of the race.
However, in the above swash plate compressor, since only one rotation prevention protrusion is provided, directivity is produced when the cylinder block and the race are coupled together and assembly thereof becomes difficult. Thus, when misassembly occurs, the piston may be damaged. Also, since there is an accommodating structure in which the protrusion of the race is inserted into the bore, excessive movements of the race may generate noise and as the inner surface of the bore and the protrusion may collide, foreign materials may be generated.
SUMMARY OF THE INVENTION
To solve the above-described problems, it is an object of the present invention to provide a swash plate type compressor having a race on the outer circumference surface of which at least two protrusions for preventing rotation are formed, so that, when the race is coupled to the cylinder block, the accommodating structure for preventing rotation by distributing a rotational force of the race and assembly thereof is improved.
To achieve the above object, there is provided a swash plate type compressor comprising a drive shaft rotated by a driving source, a swash plate fixedly installed at the drive shaft, a piston reciprocated by the swash plate, a cylinder bore, where the piston is installed to be capable of sliding, for guiding reciprocation of the piston, a thrust bearing supporting a thrust force generated the swash plate and the drive shaft, a race having a protrusion for preventing rotation radially formed at an outer circumference thereof, and a cylinder block having a protrusion fixing means for preventing rotation of the race by fixing the protrusion of the race. Thus, abrasion due to rotational friction between the flat surface of the race and the thrust surface of the cylinder block can be prevented.
It is preferred in the present invention that the protrusion fixing means is at least one pair of protrusion stoppers formed to face each other around a drive shaft insertion hole of the cylinder block.
It is preferred in the present invention that the protrusion fixing means is at least a protrusion insertion hole formed around the drive shaft insertion hole of the cylinder block.
It is preferred in the present invention that at least two protrusions for preventing rotation are fixedly supported at the protrusion fixing means of the cylinder block.
It is preferred in the present invention that the protrusion for preventing rotation is formed at an identical interval.


REFERENCES:
patent: 5937735 (1999-08-01), Shimizu et al.
patent: 57134370 (1982-08-01), None

Affiliated with

Also associated with

Rating

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

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

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3098600