U.S. patent number 3,887,303 [Application Number 05/107,681] was granted by the patent office on 1975-06-03 for hermetically sealed motor compressor.
This patent grant is currently assigned to Tokyo Shibaura Electric Co., Ltd.. Invention is credited to Tsuneo Koga, Kazuya Komiyama, Takashi Matsuzaka.
United States Patent |
3,887,303 |
Matsuzaka , et al. |
June 3, 1975 |
Hermetically sealed motor compressor
Abstract
A hermetically sealed motor compressor including a casing and a
compressor body received therein and provided with a frame having a
rim formed on the periphery, wherein there are formed notches in
the upper part of the rim and there are provided springs, the
bottom end of which is fitted into a socket in each notch and the
upper end of which is fixed to a spring hanger so as to suspend the
compressor body in the casing.
Inventors: |
Matsuzaka; Takashi (Fuji,
JA), Koga; Tsuneo (Fuji, JA), Komiyama;
Kazuya (Kamakura, JA) |
Assignee: |
Tokyo Shibaura Electric Co.,
Ltd. (Kawasaki-shi, JA)
|
Family
ID: |
14266990 |
Appl.
No.: |
05/107,681 |
Filed: |
January 19, 1971 |
Foreign Application Priority Data
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Oct 9, 1970 [JA] |
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45-100176 |
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Current U.S.
Class: |
417/363 |
Current CPC
Class: |
F04B
39/127 (20130101) |
Current International
Class: |
F04B
39/12 (20060101); F04b 017/00 (); F16f
015/00 () |
Field of
Search: |
;417/363,902
;248/15,20,21 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Freeh; William L.
Assistant Examiner: LaPointe; G. P.
Attorney, Agent or Firm: Flynn & Frishauf
Claims
What we claim is:
1. A hermetically sealed motor compressor including:
a hermetically sealed casing;
a compressor body housed in said casing and comprising a generally
cup-shaped frame having a generally circular rim extending downward
therefrom, said frame being provided at the upper portion thereof
with a plurality of substantially equally spaced notches for
causing the interior of said frame to communicate with the outside
thereof, the bottom of each of said notches constituting the
horizontally flat upper surface of said rim;
a plurality of generally L-shaped one piece spring hangers equal in
number to the number of said notches, each spring hanger comprising
a fitting portion fixed to said casing and an arm portion extending
inwardly of said casing from said fitting portion, said spring
hangers being disposed in said casing at a substantially equal
peripheral spacing and with the free ends of said arm portions
jointly defining an inscribed circle having a diameter larger than
the outside diameter of said frame;
a plurality of springs equal in number to the number of said
notches, each spring having the lower end portion thereof fitted
into a spring socket provided on the upper surface of the rim at
the respective notch, and having the upper end portion thereof
connected with the arm portion of the respective spring hanger by
means of said free end of said arm portion being inserted between
two adjacent coils of the upper end portion of the respective
spring; and
a substantially semicircular spring-engaging groove provided on at
least one of the upper and lower surfaces of the arm portion of
said spring hangers to receive one of the coils of its respective
spring.
2. The motor compressor according to claim 1 wherein said arm
portions of the spring hangers are inclined to the same extent as
the pitch angle of said spring with respect to a horizontal place
so as to suspend said spring substantially vertically.
3. The motor compressor according to claim 2 wherein the arm
portion of each of said spring hangers is provided on the upper
surface thereof with a substantially semicircular spring-engaging
groove for receiving the upper coil of said two adjacent coils of
the respective spring.
4. The motor compressor according to claim 3 wherein the arm
portion of each of said spring hangers is provided on the lower
surface thereof with a substantially semicircular spring-engaging
groove for receiving the lower coil of said two adjacent coils of
the respective spring.
5. The motor compressor according to claim 1 wherein the upper
surface of said rim defined by the bottom of said notch lies
substantially in a horizontal place including the gravitational
center of the compressor body.
6. The motor compressor according to claim 1 wherein said casing
has upper and lower parts, the fitting portions of said spring
hangers being fixed to the lower part of said casing.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a hermetically sealed motor
compressor having a compressor body elastically suspended in a
hermetically sealed casing. With compressor of such type, it is
desired that the frame supporting electrically driven members and
compressor part received in the casing be elastically suspended
therein.
Heretofore, the compressor body has been elastically suspended in a
casing by integrally forming projecting holders on the periphery of
the frame and stretching springs across the holders and the hangers
provided in the casing. With such a compressor, the spring holders
have to be disposed outside of the frame periphery due to
requirements for construction, presenting great difficulties in
rendering the compressor compact. Further with the conventional
compressor, the spring hanger assumes an L-form, one arm of which
is fixed to the inner wall of the sealed casing and the other arm
of which extends inward of the casing and is perforated with a
tapped hole. The spring is fitted to the spring hanger by being
inserted into the tapped hole. This fitting method often causes any
of the springs to fall off the tapped hole during compressor
operation, resulting in the occurrence of noises or compressor
failures. Said method has further drawbacks that the necessity of
screwing the spring into the spring hanger when the compressor body
is placed in the casing not only consumes a great deal of work but
also requires the spring hanger to be bored with a tapped hole,
unavoidably using a prominently extending horizontal arm.
Accordingly, the fitting of the compressor body into the casing
results in the bulkiness of the casing and compressor body and
further requires the frame of the compressor body to be provided
with an allowance or hole for insertion of the spring hangers so as
to facilitate the fitting or removal of the compressor body, thus
making its construction extremely complicated.
SUMMARY OF THE INVENTION
In a compressor according to the present invention there is bored a
screw hole n the upper part of each notch formed in the rim of a
compressor frame and the compressor body is elastically suspended
in the casing by causing the hangers fixed to the inner wall of the
casing to be clasped by springs. An object of the present invention
is to provide a hermetically sealed motor compressor which is made
compact by forming a spring fitting socket in the upper part of
each notch bored in the rim of the compressor frame.
Another object of the invention is to fit a spring into a cavity
formed in the upper side or both upper and under sides of the
extending arm of each spring hanger so as to prevent the spring
from falling off said arm.
Still another object of the invention is to incline the extending
arm by the pitch angle of the spring so as to fit it in an upright
position, and, under normal condition, cause the compressor body to
be only supported by the force vertically applied by the spring
along its axis.
A further object of the invention is to fit the spring to the
extending arm simply by causing said arm to be clasped by the
spring, thereby facilitating the fitting of the compressor body
into the casing.
BRIEF EXPLANATION OF THE DRAWINGS
FIG. 1 is a longitudinal sectional view of a hermetically sealed
motor compressor according to an embodiment of the present
invention;
FIG. 2 is a plan view of the frame of FIG. 1;
FIG. 3 is a side view with part of FIG. 2 shown in section;
FIG. 4 is a plan view of a spring hanger;
FIG. 5 is an elevational view of the same;
FIG. 6 is an elevational view of the same to which there are fitted
springs; and
FIG. 7 presents a spring hanger according to another embodiment of
the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, numeral 1 represents a hermetically sealed
casing which is formed by connecting upper and lower shells 1a and
1b with each other. A compressor body 2 comprises a cylinder 3, an
electric motor 4, a scotch yoke 5 for converting the rotation of
the electric motor 4 to a linear motion, a piston 6 made to slide
back and forth through the cylinder by the scotch yoke 5 and a
generally cylindrical frame 7 for suspending the electric motor 4
and rotatably supporting the shaft 8 of the electric motor 4.
The electric motor 4 consists of a rotor 9 through which the shaft
8 passes and a stator 10 fitted to the frame 7. As shown in FIGS. 2
and 3, the frame 7 assumes a generally cup-shaped form, and is
provided at the center with a cylindrical bracket 7a projecting
downward so as rotatably to support the shaft 8 of the electric
motor 4, and on the outer periphery with a rim 7b. Between the
bracket 7a and rim 7b is defined a cavity 7c, into which there are
received the rotor 9 and stator 10 of the electric motor 4
concentrically disposed with the shaft 8.
At the upper part of the rim 7b of the frame 7 are formed three or
more notches 12 spaced from each other at substantially equal
peripheral intervals. The upper surfaces 12a of the rim which are
defined by the bottoms of said notches 12 is made substantially
plain (or flat), and preferably disposed in a horizontal plane
including the gravitational center of the compressor body 2 or its
neighborhood. The outside of the frame 7 and cavity 7c communicate
with each other through the notches 12 to expel heat generated by
the electric motor 4 to the outside of the frame 7, thereby
preventing temperature rise therein. Those parts of the rim surface
12a where there are formed the notches 12 are each bored with a
spring socket 13, with at least the center of said spring socket 13
disposed inside of the outer periphery of the rim 7b. Into each
spring socket 13 is fitted the bottom end of a spring 11 having the
same pitch.
As shown in FIG. 1, the spring hangers 15 are fitted to the upper
part of the lower shell 1b to hold the springs 11, thereby causing
the compressor body 2 to be elastically suspended in the casing 1
by means of the springs 11. Numeral 14 denotes a cylindrical member
fitted to the bottom plate of the lower shell 1b. Into the
cylindrical member 14 is inserted the lower part of the shaft 8,
the outer wall of which abuts against the inner wall of said
cylindrical member 14 when the compressor body 2 rocks sidewise.
Accordingly, the cylindrical member 14 serves as a sort of stop
means for preventing the excess oscillation of the compressor body
2.
The spring hangers 15 are, as shown in FIGS. 4 and 5, L-shaped
members comprising of a fitting portion 15a and an arm portion 15b.
The fitting portion 15a is fixed to the upper part of the inner
wall of the lower shell 1b of the casing 1 by welding or other
means. Each arm portion 15b extends inward of the casing 1 (FIG.
1), and an imaginary inscribed circle defined by the free end face
of the arm portion 15b usually has a larger diameter than the outer
diameter of the frame 7. The upper surface of the arm portion 15b
is inclined by an angle .theta. corresponding to the pitch angle of
the spring 11 with respect to a horizontal plane. In said upper
surface is formed a semicircular spring engaging groove 16 by which
the arm portion 15b is clasped between two adjacent coils of the
spring 11 as illustrated in FIG. 6. The underside of the upper coil
is fitted into said spring engaging groove 16, and the upper side
of the lower coil is pressed against the underside of the arm
portion 15b. Accordingly, the easy fitting of the spring 11 to the
arm portion 15b facilitates the incorporation of the compressor
body 2 in the casing 1, permitting the arbitrary selection of its
fitted position therein. Further the tight fitting of the spring 11
into the spring engaging groove 16 prevents said spring 11 from
coming off the arm portion 15b, thereby eliminating the occurrence
of those noises or compressor failures which have heretofore
originated with such event.
The spring 11 is vertically held by the spring hanger 15 and, under
normal condition, the frame 7 is only suspended by a torsional
force applied by the spring 11 along its longitudinal direction,
offering the advantage of eliminating the possibility of any
lateral force being applied to the compressor body.
According to the embodiment of FIGS. 4 to 6, the upper part of each
notch 12 is perforated with a spring socket 13 into which the
spring is fitted. Accordingly, it is unnecessary to provide the
outer periphery of the rim 7 with a large projection to hold the
springs 11 or set them in place by screwing as is the case with the
prior art compressor. Even if such projection should be required,
it would only have to extend just a little, so that the casing 1
could be reduced in radius at least by that extent.
As mentioned above, the spring 11 is fitted to the spring hanger 15
by clasping the armed portion 15b by means of the spring engaging
groove 16 formed therein, so that said arm portion 15b has only to
extend inward just a little. Accordingly, said arm portion 15b does
not obstruct the insertion of the compressor body 2 into the casing
1 for assembly or its removal therefrom for repair, particularly
eliminating the necessity, as in the conventional compressor, of
providing the frame 7 with an allowance or hole to facilitate the
insertion or removal of the compressor body 2 by causing said
allowance to slide along the spring hangers or broadening the inner
diameter of the casing 1.
As described above, the present invention can render the compressor
body compact due to the use of the casing 1 of reduced size.
Further, the compressor body 2 is maintained in a horizontal plane
including its gravitational center or its neighborhood, so that if
the compressor body shakes, the moment of inertia will decrease
with respect to said gravitational center, minimizing the effect
exerted on the compressor body 2 by its oscillation.
FIG. 7 presents a spring hanger 15 according to another embodiment.
In this embodiment, there is formed a semicircular spring groove
117 also in the underside of an arm portion 115b corresponding to
the arm portion 15b of the embodiment of FIGS. 4 to 6. Formation of
the spring engaging grooves 116 and 117 in both the upper and under
sides of the arm portion 115b ensures the firmer clasp of the arm
portion 115b by the spring 11 than in the embodiment of FIGS. 4 to
6.
* * * * *