U.S. patent application number 10/781300 was filed with the patent office on 2005-04-28 for hermetic compressor.
This patent application is currently assigned to SAMSUNG GWANG JU ELECTRONICS CO., LTD.. Invention is credited to Lee, Sung Tae.
Application Number | 20050089416 10/781300 |
Document ID | / |
Family ID | 34511112 |
Filed Date | 2005-04-28 |
United States Patent
Application |
20050089416 |
Kind Code |
A1 |
Lee, Sung Tae |
April 28, 2005 |
Hermetic compressor
Abstract
A hermetic compressor, in which a plurality of oil slots are
formed on a bearing seat that seats a thrust bearing therein.
During an operation of the hermetic compressor, oil flows through
the plurality of oil slots while hydraulically supporting a lower
surface of the thrust bearing upward. Therefore, even when an
impact is applied from a piston to a rotating shaft during a
refrigerant compressing operation of the piston in a compression
chamber, the impact load imposed on the thrust bearing is evenly
distributed along a junction between a lower race and all balls of
the thrust bearing, because the oil hydraulically supports the
lower race of the thrust bearing upward. The thrust bearing thus
smoothly rotates and effectively supports the rotation of an
eccentric part of the rotating shaft. Therefore, the hermetic
compressor reduces vibration of the balls and the lower race of the
thrust bearing, and attenuates noise caused by the vibration. The
hermetic compressor further has improved operational
efficiency.
Inventors: |
Lee, Sung Tae;
(Gwangju-City, KR) |
Correspondence
Address: |
Ladas & Parry
26 West 61st Street
New York
NY
10023
US
|
Assignee: |
SAMSUNG GWANG JU ELECTRONICS CO.,
LTD.
|
Family ID: |
34511112 |
Appl. No.: |
10/781300 |
Filed: |
February 18, 2004 |
Current U.S.
Class: |
417/415 ;
417/410.1; 417/902 |
Current CPC
Class: |
F04B 39/122 20130101;
F04B 39/0246 20130101 |
Class at
Publication: |
417/415 ;
417/410.1; 417/902 |
International
Class: |
F01C 001/02; F01C
001/063 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 27, 2003 |
KR |
2003-75214 |
Claims
What is claimed is:
1. A hermetic compressor, comprising: a hollow frame; a rotating
shaft placed in a hollowed part of the frame so as to rotate
relative to the frame; an eccentric part provided on the rotating
shaft so as to eccentrically rotate; a piston to rectilinearly
move, in response to an eccentric rotation of the eccentric part; a
cylinder provided on an upper end of the hollow frame so as to
allow the piston to compress a fluid in the cylinder; a bearing
seat provided on an upper end of the hollowed part of the frame; a
thrust bearing seated in the bearing seat so as to support the
eccentric part; an oil path provided in the rotating shaft so as to
guide oil upward; an oil discharge hole to communicate with the oil
path, thus discharging the oil to an outer surface of the rotating
shaft; and an oil slot provided in the bearing seat, thus allowing
the oil discharged from the oil discharge hole to flow through the
oil slot.
2. The hermetic compressor according to claim 1, wherein the oil
slot extends on a bottom surface of the bearing seat in a radial
direction.
3. The hermetic compressor according to claim 2, wherein the
bearing seat comprises an inclined surface which is formed around
the bottom surface of the bearing seat while being inclined upward
and outward, with a diameter of the inclined surface increasing in
an outward direction from an inside edge to an outside edge of the
inclined surface.
4. The hermetic compressor according to claim 3, wherein the oil
slot extends to the inclined surface of the bearing seat and to an
edge of the hollowed part of the frame, thus having extension slot
parts with predetermined lengths.
5. The hermetic compressor according to claim 2, wherein the oil
slot comprises a plurality of oil slots which are formed on the
bearing seat while being spaced apart from each other at
predetermined angular intervals.
6. The hermetic compressor according to claim 2, wherein the oil
slot is widened at an oil inlet of the oil slot.
7. The hermetic compressor according to claim 2, wherein the oil
slot is shaped in a helical manner, with a width of the oil slot
reducing in a direction from an oil inlet to an oil outlet of the
oil slot.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Korean Patent
Application No. 2003-75214, filed Oct. 27, 2003 in the Korean
Intellectual Property Office, the disclosure of which is
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates, in general, to hermetic
compressors and, more particularly, to a hermetic compressor which
uses a bearing to execute a smooth operation between moving parts
of the hermetic compressor.
[0004] 2. Description of the Related Art
[0005] Generally, compressors are machines that compress a
substance, such as a gas refrigerant, to reduce a volume and thus
increase a pressure of the substance or change a phase of the
substance. As an example of the compressors, hermetic compressors
are typically used in refrigeration systems to compress a gas
refrigerant within a hermetic compression chamber while converting
a rotating motion into a rectilinear motion, prior to discharging
the compressed refrigerant to a condenser.
[0006] Conventional hermetic compressors having the above-mentioned
use have a hermetic casing. The hermetic casing is fabricated with
upper and lower casing parts assembled into a single body, and has
a compression unit and a drive unit therein. The compression unit
draws and then compresses a gas refrigerant, while the drive unit
generates a drive power to operate the compression unit.
[0007] In the conventional hermetic compressors, the compression
unit has a cylinder block which is integrated with a frame and
defines a compression chamber therein, and a cylinder head which is
mounted to the cylinder block. The cylinder head has both a suction
chamber to draw the gas refrigerant into the compression chamber
and an exhaust chamber to release the compressed refrigerant from
the compression chamber to an outside of the hermetic casing. The
conventional hermetic compressors further include a piston which is
received in the compression chamber to execute a rectilinear
reciprocating motion in the compression chamber.
[0008] The drive unit is placed under the compression unit in the
hermetic casing, and includes a stator along which an
electromagnetic field is generated when electricity is applied to
the stator. The drive unit further includes a rotor which rotates
by the electromagnetic field generated along the stator, and a
rotating shaft which axially penetrates a center of the rotor so as
to rotate along with the rotor.
[0009] The rotating shaft is set in a bore of the frame, with an
eccentric part provided at an upper end of the rotating shaft. The
frame has a bearing seat at an upper end of the bore, and a thrust
bearing is seated in the bearing seat of the frame, thus supporting
the eccentric part of the rotating shaft.
[0010] The above-mentioned conventional hermetic compressor is
problematic as follows. When an impact is applied to the rotating
shaft during a refrigerant compressing operation of the piston in
the compression chamber, the impact is concentrated on a ball of
the thrust bearing. The ball of the thrust bearing is thus
overloaded, so that the thrust bearing cannot smoothly rotate and
thereby cannot effectively support a rotation of the eccentric part
of the rotating shaft.
[0011] In a detailed description, because the load imposed on the
thrust bearing is unevenly distributed on all balls of the thrust
bearing, friction between the balls and a lower race of the thrust
bearing increases. The conventional hermetic compressor thus
generates noise, and has reduced operational efficiency.
SUMMARY OF THE INVENTION
[0012] Accordingly, it is an aspect of the present invention to
provide a hermetic compressor, which has an improved bearing seat
structure to seat a thrust bearing therein while allowing the
thrust bearing to smoothly rotate, regardless of a load imposed on
the thrust bearing during an operation of the hermetic compressor,
thus effectively supporting a rotation of a rotating shaft of a
drive unit.
[0013] Additional aspects and/or advantages of the invention will
be set forth in part in the description which follows and, in part,
will be obvious from the description, or may be learned by practice
of the invention.
[0014] The above and/or other aspects are achieved by providing a
hermetic compressor, including: a hollow frame; a rotating shaft
placed in a hollowed part of the frame so as to rotate relative to
the frame; an eccentric part provided on the rotating shaft as to
eccentrically rotate; a piston to rectilinearly move, in response
to an eccentric rotation of the eccentric part; a cylinder provided
on an upper end of the hollow frame so as to allow the piston to
compress a fluid in the cylinder; a bearing seat provided on an
upper end of the hollowed part of the frame; a thrust bearing
seated in the bearing seat so as to support the eccentric part; an
oil path provided in the rotating shaft so as to guide oil upward;
an oil discharge hole to communicate with the oil path, thus
discharging the oil to an outer surface of the rotating shaft; and
an oil slot provided in the bearing seat, thus allowing the oil
discharged from the oil discharge hole to flow through the oil
slot.
[0015] The oil slot may extend on a bottom surface of the bearing
seat in a radial direction.
[0016] The bearing seat may include an inclined surface which is
formed around the bottom surface of the bearing seat while being
inclined upward and outward, with a diameter of the inclined
surface increasing in an outward direction from an inside edge to
an outside edge of the inclined surface.
[0017] The oil slot may extend to the inclined surface of the
bearing seat and to an edge of the hollowed part of the frame, thus
having extension slot parts with predetermined lengths.
[0018] The oil slot may comprise a plurality of oil slots which are
formed on the bearing seat while being spaced apart from each other
at predetermined angular intervals.
[0019] The oil slot may be widened at an oil inlet of the oil
slot.
[0020] The oil slot may be shaped in a helical manner, with a width
of the oil slot reducing in a direction from an oil inlet to an oil
outlet of the oil slot.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] These and other aspects and advantages of the invention will
become apparent and more readily appreciated from the following
description of the preferred embodiments, taken in conjunction with
the accompanying drawings of which:
[0022] FIG. 1 is a side sectional view showing a construction of a
hermetic compressor, according to the present invention;
[0023] FIG. 2 is an exploded perspective view of a frame of the
hermetic compressor, according to a first embodiment of the present
invention;
[0024] FIG. 3 is a plan view showing a shape of an oil slot of the
frame of FIG. 2; and
[0025] FIGS. 4 and 5 are plan views respectively showing shapes of
oil slots, according to second and third embodiments of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] Reference will now be made in detail to the present
preferred embodiments of the present invention, examples of which
are illustrated in the accompanying drawings, wherein like
reference numerals refer to like elements throughout. The
embodiments are described below in order to explain the present
invention by referring to the figures.
[0027] FIG. 1 is a side sectional view showing a construction of a
hermetic compressor, according to the present invention.
[0028] As shown in FIG. 1, the hermetic compressor according to the
present invention includes a hermetic casing 10 which is fabricated
with upper and lower casing parts 11 and 12 assembled into a
hermetic single body. The hermetic compressor further includes a
compression unit 20 to draw and compress a gas refrigerant, and a
drive unit 30 to drive the compression unit 20.
[0029] In the hermetic compressor, the compression unit 20 has a
cylinder block 22 which is integrated with a frame 21 and defines a
compression chamber 22a therein, and a cylinder head 23 which is
mounted to the cylinder block 22. The cylinder head 23 has both a
suction chamber 23a to draw the gas refrigerant into the
compression chamber 22a and an exhaust chamber 23b to release the
compressed refrigerant from the compression chamber 22a to an
outside of the hermetic casing 10. The hermetic compressor further
includes a piston 24 which is received in the compression chamber
22a to execute a rectilinear reciprocating motion in the
compression chamber 22a.
[0030] The hermetic compressor further includes a valve plate 25.
The valve plate 25 is interposed between the cylinder block 22 and
the cylinder head 23 to control flows of the refrigerant drawn into
and discharged from the compression chamber 22a.
[0031] The drive unit 30 is placed under the compression unit 20 in
the hermetic casing 10, and includes a stator 31 along which an
electromagnetic field is generated when electricity is applied to
the stator 31. The drive unit 30 further includes a rotor 32 which
rotates by the electromagnetic field generated along the stator 31,
and a rotating shaft 33 which axially penetrates a center of the
rotor 32 so as to rotate along with the rotor 32.
[0032] The rotating shaft 33 has an eccentric part 34 which is
provided at an upper end of the rotating shaft 33 to eccentrically
rotate. The eccentric part 34 of the rotating shaft 33 includes a
balance weight 34a to allow the rotating shaft 33 to rotate while
keeping balance thereof regardless of the eccentric part 34, and an
eccentric shaft 34b which extends upward from the balance weight
34a to a predetermined length and eccentrically rotates during a
rotation of the rotating shaft 33. The piston 24 is connected to
the eccentric shaft 34b of the eccentric part 34 through a
connecting rod 35, so that the eccentric rotation of the eccentric
shaft 34b is converted into a rectilinear reciprocation of the
piston 24 by the connecting rod 35. Therefore, when the eccentric
part 34 rotates along with the rotating shaft 33, the piston 24
rectilinearly reciprocates in the compression chamber 22a. The
rotating shaft 33 is set in a bore 21a of the frame 21. The frame
21 has an annular bearing seat 40 around an upper end of the bore
21a, and a thrust bearing 50 is seated in the bearing seat 40 of
the frame 21, thus supporting the eccentric part 34 of the rotating
shaft 33. The thrust bearing 50 includes a plurality of balls 51
which are supported between upper and lower races 52 and 53.
[0033] The rotating shaft 33 has an oil path 33a. The oil path 33a
extends through the rotating shaft 33 from a lower end of the
rotating shaft 33 to the eccentric shaft 34b, thus drawing and
guiding oil L to the eccentric shaft 34b. The rotating shaft 33
further includes a spiral oil groove 33b. The spiral oil groove 33b
is formed around an outer surface of the rotating shaft 33 from a
position where the rotating shaft 33 is in sliding contact with the
frame 21. The spiral oil groove 33b communicates with the oil path
33a via both an oil suction hole 33d and an oil discharge hole 33c
which are respectively provided at upper and lower ends of the
spiral oil groove 33b.
[0034] Therefore, the oil L is drawn from a bottom of the hermetic
casing 10 into the oil path 33a of the rotating shaft 33, and flows
upward to a predetermined height along the oil path 33a, prior to
being discharged from the oil path 33a to the spiral oil groove 33b
through the oil discharge hole 33c. The discharged oil, thereafter,
flows along the spiral oil groove 33b, thus forming lubrication
layers in the junction gaps between the rotating shaft 33 and the
frame 21 and between the rotating shaft 33 and the thrust bearing
50.
[0035] The hermetic compressor of the present invention further
includes a plurality of oil slots 43 which are formed on the
bearing seat 40 while being spaced apart from each other at regular
angular intervals, as shown in FIG. 2.
[0036] The bearing seat 40 includes an annular bottom surface 41,
with an annular inclined surface 42 which is formed around the
annular bottom surface 41 while being inclined upward and outward.
Thus, a diameter of the annular inclined surface 42 gradually
increases in an outward direction from an inside edge to an outside
edge of the annular inclined surface 42. Each of the oil slots 43
extends from a predetermined portion of the annular inclined
surface 42 to an edge of the upper end of the bore 21a, so that
each of the oil slots 43 has an upper extension slot part 45 with
an oil outlet and a lower extension slot part 44 with an oil
inlet.
[0037] Due to the plurality of oil slots 43, the oil L flows under
a lower surface of the thrust bearing 50, thus the oil L
hydraulically supports the lower race 53 of the thrust bearing
50.
[0038] In the present invention, shapes of the oil slots 43 may be
alternately designed without affecting the functioning of the
invention, as shown in FIGS. 3, 4 and 5.
[0039] In a first embodiment of the present invention, the oil
slots 43 are formed on the bearing seat 40 such that each of the
oil slots 43 extends in a radial direction while having a constant
width, as shown in FIG. 3. In a second embodiment of the present
invention, the oil slots 43 are formed to respectively have widened
oil inlets 43a, as shown in FIG. 4. In a third embodiment of the
present invention, the oil slots 43 are shaped in a helical manner,
with a width of each of the oil slots 43 gradually reducing in a
direction from the oil inlet 43a to the oil outlet 43b, as shown in
FIG. 5. In the second and third embodiments of the present
invention, the oil L is smoothly introduced into the oil slots 43,
during an operation of the hermetic compressor.
[0040] The operation and effect of the hermetic compressor
according to the present invention will be described herein
below.
[0041] When the hermetic compressor is powered on, an
electromagnetic field is generated along the stator 31, and the
rotor 32 rotates by the electromagnetic field generated along the
stator 31. In the above state, the rotating shaft 33 that axially
penetrates the center of the rotor 32 rotates along with the rotor
32. Because the piston 24 is connected to the eccentric shaft 34b
of the eccentric part 34 through the connecting rod 35, the piston
24 rectilinearly reciprocates within the compression chamber 22a by
the rotation of the rotating shaft 33, thus drawing the refrigerant
into the compression chamber 22a and compressing the refrigerant,
prior to discharging the refrigerant from the compression chamber
22a.
[0042] During the rotation of the rotating shaft 33, the oil L
flows upward along the oil path 33a of the rotating shaft 33. In
the above state, a part of the oil L is discharged from the oil
path 33a to the spiral oil groove 33b through the oil discharge
hole 33c. The discharged oil, thereafter, flows along the spiral
oil groove 33b while lubricating the rotating shaft 33 and the
thrust bearing 50. The oil L further flows through the plurality of
oil slots 43 which are placed under the lower surface of the thrust
bearing 50, thus the oil L hydraulically supports the lower race 53
of the thrust bearing 50 upward.
[0043] Therefore, even when an impact is applied to the rotating
shaft 33 during a refrigerant compressing operation of the piston
24 in the compression chamber 22a, the impact load imposed on the
thrust bearing 50 is evenly distributed along a junction between
the lower race 53 and the all balls 51 of the thrust bearing 50,
because the oil L hydraulically supports the lower race 53 of the
thrust bearing 50 upward. The thrust bearing 50 thus smoothly
rotates and thereby effectively supports the rotation of the
eccentric part 34 of the rotating shaft 33.
[0044] The hermetic compressor of the present invention thus
reduces vibration of the balls 51 and the lower race 53 of the
thrust bearing 50, and attenuates noise caused by the vibration.
The hermetic compressor further has improved operational
efficiency.
[0045] As apparent from the above description, the present
invention provides a hermetic compressor, in which a plurality of
oil slots are formed on a bearing seat that seats a thrust bearing
therein. During an operation of the hermetic compressor, oil flows
through the plurality of oil slots while hydraulically supporting a
lower surface of the thrust bearing upward.
[0046] Therefore, even when an impact is applied from a piston to a
rotating shaft during a refrigerant compressing operation of the
piston in a compression chamber, the impact load imposed on the
thrust bearing is evenly distributed along a junction between a
lower race and all balls of the thrust bearing, because the oil
hydraulically supports the lower race of the thrust bearing upward.
The thrust bearing thus smoothly rotates and effectively supports
the rotation of an eccentric part of the rotating shaft. Therefore,
the hermetic compressor of the present invention reduces vibration
of the balls and the lower race of the thrust bearing, and
attenuates noise caused by the vibration. The hermetic compressor
further has improved operational efficiency.
[0047] Although a few preferred embodiments of the present
invention have been shown and described, it would be appreciated by
those skilled in the art that changes may be made in these
embodiments without departing from the principles and spirit of the
invention, the scope of which is defined in the claims and their
equivalents.
* * * * *