U.S. patent application number 11/791036 was filed with the patent office on 2008-06-26 for small refrigerant compressor.
This patent application is currently assigned to ACC AUSTRIA GMBH. Invention is credited to Hans Peter Schoegler.
Application Number | 20080152514 11/791036 |
Document ID | / |
Family ID | 35508885 |
Filed Date | 2008-06-26 |
United States Patent
Application |
20080152514 |
Kind Code |
A1 |
Schoegler; Hans Peter |
June 26, 2008 |
Small Refrigerant Compressor
Abstract
The invention relates to a compressor for hermetically sealed
small refrigeration machines, comprising a cylinder with a cylinder
housing and a piston that is guided in the piston bore of the
cylinder and that compresses a working medium. The cylinder is
sealed by a disc-type valve plate in the axial direction, a
cylinder cover lying against or being surrounded by the plate.
According to the invention, the cylinder housing comprises axial
extensions facing towards the cylinder cover and located in the
peripheral area of the cover. A first axial section of the axial
extensions lies against the cylinder cover in the contact region
between the cylinder cover and the valve plate and a second axial
section surrounds the cylinder cover with a small degree of
play.
Inventors: |
Schoegler; Hans Peter;
(Styria, AT) |
Correspondence
Address: |
COLLARD & ROE, P.C.
1077 NORTHERN BOULEVARD
ROSLYN
NY
11576
US
|
Assignee: |
ACC AUSTRIA GMBH
Furstenfeld
AT
|
Family ID: |
35508885 |
Appl. No.: |
11/791036 |
Filed: |
November 25, 2005 |
PCT Filed: |
November 25, 2005 |
PCT NO: |
PCT/EP05/56234 |
371 Date: |
May 17, 2007 |
Current U.S.
Class: |
417/415 |
Current CPC
Class: |
F04B 39/125 20130101;
F04B 39/102 20130101 |
Class at
Publication: |
417/415 |
International
Class: |
F04B 39/12 20060101
F04B039/12 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 25, 2004 |
AT |
GM 857/2004 |
Claims
1. A compressor for hermetically encapsulated small refrigerators,
which has a cylinder having a cylinder housing (I) and a piston
(2), which is guided in the piston bore of the cylinder, for
compressing an operating medium, the cylinder being terminated in
an axial direction using a disk-shaped valve plate (6), against
which a cylinder cover (8) presses or which it encloses, wherein
the cylinder housing (71) has axial projections (10) in the
direction of the cylinder cover (8), which are situated around the
circumference of the cylinder cover (8), the axial projections (10)
pressing against the cylinder cover (8) in a first axial section
(11) in the contact area of the cylinder cover (8) with the valve
plate (6) and enclosing the cylinder cover (8) with slight play in
a second axial section (12).
2. The compressor for hermetically encapsulated small refrigerators
according to claim 1, wherein the second axial section (12)
projects beyond the cylinder cover (8).
3. The compressor for hermetically encapsulated small refrigerators
according to claim 1, wherein inwardly projecting retention nubs
(13) are provided in the end section of the particular second axial
sections (12).
4. The compressor for hermetically encapsulated small refrigerators
according to claim 1, wherein a fastening element (9) is provided
which attaches the cylinder cover (8) to the cylinder housing (1)
by a contact pressure exerted in the area of the axis of the piston
bore.
5. The compressor for hermetically encapsulated small refrigerators
according to claim 4, wherein the fastening element (9) is a spring
element (9).
6. The compressor for hermetically encapsulated small refrigerators
according to claim 3, wherein the spring element (9) is a spring
washer (9), whose sections facing away from the cylinder cover (8)
are supported on the retention nubs (13).
7. The compressor for hermetically encapsulated small refrigerators
according to claim 1, wherein an insulating material is located
between the cylinder cover (8) and the particular second axial
sections (12) of the projections (10).
8. The compressor for hermetically encapsulated small refrigerators
according to claim 1, wherein the axial projections (10) enclose
the cylinder cover (8) essentially completely.
9. The compressor for hermetically encapsulated small refrigerators
according to claim 1, wherein the axial projections (10) are
implemented in one piece with the cylinder housing (1) and
essentially represent extensions of the cylinder housing (1).
Description
AREA OF THE INVENTION
[0001] The present invention relates to a compressor for
hermetically encapsulated small refrigerators, which has a cylinder
having a cylinder housing and a piston guided in the cylinder bore
of the cylinder for compressing an operating medium, the cylinder
being terminated in an axial direction using a disk-shaped valve
plate, against which a cylinder cover presses or which it encloses,
according to the preamble of Claim 1.
PRIOR ART
[0002] Compressors of this type are well-known according to the
prior art. Screw connections are typically used for fastening the
cylinder cover and/or the valve plate to the cylinder housing.
However, the disadvantage is displayed when screw connections are
used that because of the tension which acts on the cylinder
housing, the cylindrical shape of the cylinder bore is negatively
influenced. Furthermore, screw connections always require increased
mounting effort, because first the holes for the screws must be
placed in a targeted way to ensure optimum centering of the
cylinder cover in relation to the cylinder housing. In addition, it
would be advantageous to replace the punctual contact pressure
produced by screw connections with a constant contact pressure over
the entire seal area, by which the seal area and/or the required
contact pressure may also be reduced. Furthermore, it would be
advantageous to implement the force introduction of the fasteners
for the cylinder cover on the cylinder housing in such a way that
it is performed especially in those areas of the cylinder cover in
which the largest loads due to the piston force also occur.
Protection of the cylinder cover may thus be caused.
[0003] For example, a cylinder head configuration for piston
compressors, which comprises a multipart valve assembly and an
intake noise damper, is previously known from DE 102 44 565 A1.
Asymmetrically oriented projections which project radially into the
cylinder head bore, which engage upon insertion into the housing in
corresponding grooves of the valve assembly and the cylinder head
cover, are used for orienting the individual parts. The cylinder
head cover is attached to the housing in a typical way using a
peripheral flange and fastening bolts.
DESCRIPTION OF THE INVENTION
[0004] It is therefore the object of the present invention to fix
the cylinder cover to the cylinder housing in such a way that a
negative impairment of the cylindrical shape of the cylinder bore
is avoided. Furthermore, it is the object of the present invention
to reduce the mounting and material outlay by dispensing with the
use of screws. The ability to center the cylinder cover easily in
relation to the cylinder housing is to be ensured and uniform
contact pressure and reduction of the seal area and/or the required
contact pressure are to be made possible. Furthermore, the force
introduction of the fasteners for the cylinder cover on the
cylinder housing is to be implemented in such a way that it occurs
in particular in those areas of the cylinder cover in which the
largest loads due to the piston force also occur, to thus protect
the cylinder cover in the best possible way.
[0005] A further object of the present invention comprises reducing
the heat emission of the cylinder into the interior of the
compressor. Reducing this heat emission into the interior of the
compressor also causes a performance increase of the compressor,
because the heat arising due to the compression of the operating
medium in the cylinder is dissipated more rapidly and the
thermodynamic efficiency is thus improved.
[0006] These objects are achieved by the characterizing features of
Claim 1.
[0007] Claim 1 relates to a compressor according to the species and
provides that the cylinder housing has axial projections in the
direction of the cylinder cover which are situated around the
circumference of the cylinder cover, the axial projections pressing
against the cylinder cover in a first axial section in the contact
area of the cylinder cover with the valve plate and enclosing the
cylinder cover with slight play in a second axial section. Because
the axial projections in a first axial section press against the
cylinder cover in the contact area of the cylinder cover with the
valve plate, centering of the valve plate and the cylinder cover is
achieved. Screw connections for centering the valve plate and the
cylinder cover may be dispensed with. Fastening elements may be
provided for the axial contact pressure in this way, which do not
have a primarily centering effect, but rather solely have to ensure
an axial contact pressure. Fastening elements of this type are
described in the subclaims. Because the axial projections also
enclose the cylinder cover with slight play in a second axial
section, an insulating effect is achieved, because the air layer
between the cylinder cover and the second axial sections reduces
the heat emission into the interior of the compressor.
[0008] In Claim 2, the second axial section projects beyond the
cylinder cover. In this way, on one hand, the insulating effect is
improved and, on the other hand, the installation of fasteners for
fixing the cylinder cover to the cylinder housing is made easier.
The latter is also achieved by the features of Claim 3, according
to which retention nubs which project radially inward are provided
in the end section of the particular second axial sections.
[0009] Claim 4 relates to a preferred embodiment, in which a
fastening element is provided, which attaches the cylinder cover to
the cylinder housing by a contact pressure exerted in the area of
the axis of the piston bore. According to Claim 5, this is a spring
element. According to claim 6, this spring element may be
implemented as a spring washer, whose sections facing away from the
cylinder cover are supported on the retention nubs.
[0010] As noted, the insulating effect is achieved by the air layer
between the cylinder cover and the second axial sections. To
improve this insulating effect, according to Claim 7, an insulating
material may be located between the cylinder cover and the
particular second axial sections of the projections. However, the
insulating effect may also be improved if, according to Claim 8,
the axial projections essentially completely enclose the cylinder
cover. The formulation "essentially" relates in particular to the
fact that openings are typically provided for the supply and
removal of the operating medium to be compressed, for example.
[0011] Claim 9 allows an embodiment of the axial projections of the
cylinder housing according to the present invention having an
especially simple construction.
BRIEF DESCRIPTION OF THE FIGURES
[0012] The present invention is explained in greater detail in the
following on the basis of the attached figures.
[0013] FIG. 1 shows a section through the cylinder of a compressor
according to the present invention along line A-A visible in FIG.
2,
[0014] FIG. 2 shows a view of the cylinder of a compressor
according to the present invention from above, and
[0015] FIG. 3 shows a perspective view of the cylinder of a
compressor according to the present invention.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0016] FIG. 1 shows a section through the cylinder of a compressor
according to the present invention along line A-A shown in FIG. 2,
in which the relative configuration of cylinder cover 8, cylinder
housing 1, and the projections 10 according to the present
invention is visible. The individual components are only shown
schematically in this case, and the cylinder cover 8 may thus also
be implemented as an assembly. However, to understand the present
invention, it is solely decisive that the cylinder cover 8 has a
seal area 7 as the contact area to the valve plate 6. The axial
section in which the cylinder cover 8, the valve plate 6, and/or
the seal area 7 are incident on one another is also referred to in
the following as the contact area of the cylinder cover 8 with the
valve plate 6. A piston 2 is guided inside the cylinder housing 1
using a connecting rod 3 to compress an operating medium. The
piston bore of the cylinder is terminated using the disk-shaped
valve plate 6, the valve plate 6 pressing against the cylinder
housing 1 via a dead space seal 5.
[0017] The valve plate 6 and the cylinder cover 8 are to be
fastened to the cylinder housing. As already described, screw
connections are typically used for this purpose. However, if screw
connections are used, the disadvantage is displayed that because of
the tension which acts on the cylinder housing 1, the cylindrical
shape of the cylinder bore is negatively influenced. Furthermore,
screw connections always cause increased mounting effort, because
firstly the holes for the screws must be placed in a targeted way
to ensure optimum centering of the cylinder cover 8 in relation to
the cylinder housing 1. In addition, it would be advantageous to
replace the punctual contact pressure caused by the screw
connections by a constant contact pressure over the entire seal
area 5 and/or 7, by which the seal area and/or the required contact
pressure may also be reduced. Furthermore, it would be advantageous
to implement the force introduction of the fasteners for the
cylinder cover 8 on the cylinder housing 1 in such a way that it
occurs in particular in those areas of the cylinder cover 8 in
which the largest loads due to the piston force also arise. The
cylinder cover 8 may thus be protected.
[0018] Therefore, according to the present invention, the cylinder
housing 1 has axial projections 10 in the direction of the cylinder
cover 8, which are situated around the circumference of the
cylinder cover 8, the axial projections 10 pressing against the
cylinder cover 8 in a first axial section 11 in the contact area of
the cylinder cover 8 with the valve plate 6 and enclosing the
cylinder cover 1 with slight play in a second axial section 12.
Because the axial projections 10 press against the cylinder cover 8
in a first axial section 11, which is in the contact area of the
cylinder cover 8 with the valve plate 6, centering of the valve
plate 6 and the cylinder cover 8 is achieved. Screw connections for
centering the valve plate 6 and the cylinder cover 8 may be
dispensed with. In this way, fastening elements 9 may be provided
for the axial contact pressure which do not have a primary
centering effect, but rather only have to ensure an axial contact
pressure. For example, a spring element 9, in particular a spring
washer 9, may be provided as a fastening element 9, as will be
explained in greater detail in the following. Because the axial
projections 10 in a second axial section 12 also enclose the
cylinder cover 8 with slight play, an insulating effect is
achieved, because the air layer between the cylinder cover 8 and
the second axial sections 12 reduces the heat emission into the
interior of the compressor. The play is preferably 0.1 to 10
mm.
[0019] In Claim 2, the second axial section projects beyond the
cylinder cover. In this way, on one hand the insulating effect is
improved, and, in addition, the installation of fasteners for
fixing the cylinder cover to the cylinder housing is made easier.
The latter is also achieved by the features of Claim 3, according
to which inwardly projecting retention nubs are provided in the end
section of the particular second axial sections.
[0020] As a shown in FIG. 1, the second axial section 12 projects
beyond the cylinder cover 8 according to a preferred embodiment. In
this way, on one hand, the insulating effect is improved and, on
the other hand, the installation of the spring element 9 is made
easier, which compensates for settling of the dead space seal 5 and
the cylinder cover seal 7 because of a lower spring stiffness than
the screws known from the prior art, to fix the cylinder cover 8 to
the cylinder housing 1. For this purpose, inwardly projecting
retention nubs 13 may also be provided in the end section of the
particular second axial sections 12, on which the spring washer 9
is supported in its sections facing away from the cylinder cover 8.
The retention nubs 13 are also visible in FIGS. 2 and 3, from which
it may also be seen that in this case the valve plate 6 and the
cylinder cover 8 must have radial recesses around their
circumferences corresponding to the retention nubs 13 to allow
their insertion between the axial projections 10.
[0021] As noted, the insulating effect is achieved by the air layer
between the cylinder cover 8 and the second axial sections 12. To
improve this insulating effect, an insulating material may be
located between the cylinder cover 8 and the particular second
axial sections 12 of the projections 10 (not visible in FIGS. 1
through 3). However, the insulating effect may also be improved if
the axial projections 10 enclose the cylinder cover 8 essentially
completely. The formulation "essentially" relates in particular to
the fact that typically openings 14 are provided for the supply and
removal of the operating medium to be compressed, for example.
[0022] An embodiment of the axial projections 10 of the cylinder
housing 1 according to the present invention having an especially
simple construction may be achieved if the axial projections 10 are
implemented in one piece with the cylinder housing 1 and
essentially represent extensions of the cylinder housing 1, as
shown in FIGS. 1 through 3.
[0023] Therefore, fixing of the cylinder cover 8 on the cylinder
housing 1 is achieved by the measures according to the present
invention without negatively impairing the cylindrical shape of the
cylinder bore. The mounting and material outlay is reduced by
dispensing with the use of screws. The measures according to the
present invention additionally allow easy ability to center the
cylinder cover 8 in relation to the cylinder housing 1 and ensure a
uniform contact pressure while simultaneously reducing the seal
area and/or the contact pressure. Furthermore, the force
introduction of the fasteners 9 for the cylinder cover 8 on the
cylinder housing 1 may be implemented in such a way that it occurs
in particular in those areas of the cylinder cover 8 in which the
largest loads due to the piston force also arise, in order to thus
protect the cylinder cover 8 as well as possible.
[0024] A further advantage of the present invention is that the
heat emission of the cylinder into the interior of the compressor
is reduced. A reduction of this heat emission into the interior of
the compressor also causes a performance increase of the
compressor, because the heat arising due to the compression of the
operating medium in the cylinder is dissipated more rapidly and the
thermodynamic efficiency is thus improved.
* * * * *