Refrigerant Compressor
Disclosed is a compressor for hermetically sealed small refrigeration machines. Said compressor comprises a cylinder with a cylinder housing (4) and a piston that is guided in the piston bore of the cylinder and is used for compressing a working medium, the cylinder being closed in an axial direction by means of a cylinder head (1). According to the invention, a fastening element (2, 24, 25) is provided which fixes the cylinder head (1) to the cylinder housing (4) using contact pressure that is applied in the area of the axis of the piston bore. Said fastening element can be embodied as a clamp (2), a locking clip (24), or an elastically bendable fastening means (25) such as a rope (25). The clamp (2) can be provided with a base part (5) and lateral parts (6), for example, the base part (5) being disposed in front of the cylinder head (1) in an axial direction. Contact pressure is applied to the cylinder head (1) in an axial direction with the aid of the base part (5) while the lateral parts (6) are firmly anchored relative to the cylinder housing (4).
Applicants claim priority under 35 U.S.C. §119 of Austrian Application No. GM 138/2004 filed Feb. 26, 2004. Applicants also claim priority under 35 U.S.C. §365 of PCT/AT2005/000060 filed Feb. 24, 2005. The international application under PCT article 21(2) was not published in English.
BACKGROUND OF THE INVENTIONThe present invention relates to a compressor for hermetically encapsulated small-type refrigerating machines according to the preamble of claim 21.
DESCRIPTION OF THE PRIOR ARTCompressors of this kind comprise in the known manner a cylinder with a cylinder housing and a piston guided in the piston bore of the cylinder for compressing a working medium, with the cylinder being sealed with a cylinder head. Bolted connections are usually used for fastening the cylinder head to the cylinder housing.
The use of bolted connections comes with the disadvantage however that as a result of the forces which are introduced via the bolts into the cylinder housing, the cylindrical shape of the cylinder bore is negatively influenced. Bolted connections further always lead to additional assembly work because the bores for the bolts need to be placed at first in a purposeful way in order to ensure optical centering of the cylinder head relative to the cylinder housing. It would also be advantageous to replace the punctiform contact pressure caused by the bolted connections by a contact pressure which is constant over the entire sealing surface, as a result of which the sealing surface could also be reduced. It would further be advantageous to provide the introduction of the forces of the fastening means for the cylinder head on the cylinder housing in such a way that it is made especially in such regions of the cylinder head in which the highest loads occur by the piston force. The cylinder can thus be protected.
From U.S. Pat. No. 3,459,364 A a small-type refrigerating machine with a housing serving as fastening element is known, which housing first loosely encompasses the entire compressor structure, and is welded in this loose state. Afterwards, conical wedges are pushed between the housing and the cylinder head, thereby tensioning the housing which exerts a contact pressure on the cylinder head in axial direction in order to fasten the cylinder head to the cylinder housing.
SUMMARY OF THE INVENTIONIt is therefore the object of the present invention to fix the cylinder head to the cylinder housing in such a way that a negative impairment to the cylindrical shape of the cylinder bore is prevented. It is a further object of the present invention to reduce the amount of work and material involved in mounting, such that the use of bolts is omitted. The ability to easily center the cylinder head relative to the cylinder housing shall be ensured. An even contact pressure and a reduction of the sealing surfaces and thus a lower force of pressure for sealing the sealing surfaces at a surface pressing that remains the same are thus necessitated, as a result of which deformations are lower. Moreover, the introduction of forces of the fastening means for the cylinder head on the cylinder housing shall be provided in such a way that it is made especially in such areas of the cylinder head in which the highest loads occur by the piston force in order to thus load the cylinder head in a minimal way.
SOLUTION TO THE OBJECTThese objects are achieved by the characterizing features of claim 21.
A compressor for hermetically encapsulated small-type refrigerating machines comprises a cylinder with a cylinder housing and a piston guided in a piston bore of the cylinder for compressing a working medium, with the cylinder being sealed in an axial direction by a cylinder head. Furthermore, a fastening element is provided which fastens the cylinder head to the cylinder housing by a contact pressure exerted in the region of the axis of the piston bore. The fastening element comprises a base part and lateral parts, with the base part being arranged in the axial direction in front of the cylinder head and a contact pressure is exerted on the cylinder head in the axial direction with the help of the base part. According to the invention, the lateral parts are formed as legs which are laterally projecting from the base part, and which end sections spaced from the base part are latched on the cylinder housing or on bearing blocks which are rigidly connected with a supporting part of the compressor.
According to claim 22, the fastening element is a preferably U-shaped clamp which fastens the cylinder head to the cylinder housing. However, it would also be possible to provide more than one clamp. The base part of the clamp is appropriately chosen so wide that it fixes the cylinder head with an even contact pressure on the cylinder housing. According to claim 23, the base part is provided with configuration which is arched in the direction of the legs, which thus increases the pressure resilience of the base part.
If latching occurs by means of bearing blocks which are rigidly connected with a supporting part of the compressor, claim 24 provides as special embodiment that the bearing blocks are having at least one edge which are encompassed at least partly by the end sections of the legs.
According to claim 25, it is provided for forming a latching that the clamp encompasses the entire cylinder housing, with the cylinder housing having edges which are encompassed at least partly by the end regions of the legs. The use of bearing blocks can thus be omitted. According to claim 26, the latching is formed with the help of grooves in the cylinder housing. One end region of the legs engages into each of the grooves.
The base part of the clamp need not rest directly on the cylinder head. It is provided for according to claim 27 that the base part guides a pressing screw which exerts a contact pressure on the cylinder head in the axial direction. It is provided in accordance with claim 28, however, that the base part rests directly on the cylinder head and the lateral parts are anchored to bearing blocks fixedly joined to a supporting part of the compressor, with at least one of the lateral parts being configured as a screwed connection between base part and bearing block. In both variants is it possible to achieve a variable contact pressure of the cylinder head on the cylinder housing by a changed tightening of the screw.
Claim 29 provides an alternative embodiment of the fastening element in accordance with the invention, in which the fastening element is arranged as a locking clip. According to claim 30, the fastening element is arranged as a fastening element which exerts a tensile force and rests on the cylinder head and is fixed relative to the cylinder housing. It can especially concern a rope or a wire.
Claims 31 to 35 finally relate to the advantageous possibilities for fastening the valve plates of the cylinder head to the cylinder housing within the scope of using a clamp in accordance with the invention. According to claim 36, the contact pressure exerted by the fastening element in the area of the axis of the piston bore corresponds to an axial force of pressure of 1000 N to 10000 N, preferably 3000 N.
The invention is now explained in closer detail by reference to the enclosed drawings, wherein:
The cylinder head 1 can rest on the valve plate 16 or it can encompass the same entirely. In the first case it is obviously clear that a contact pressure exerted by the clamp 2 on the cylinder head 1 is transmitted directly onto the valve plate is and presses the same against the cylinder housing 4. In the second case, webs 21 will be provided within the cylinder head 1 which rest on the valve plate 16 and ensure a transmission of the contact pressure exerted by clamp 2. Such webs 21 can also be provided when the cylinder head 1 rests on the valve plate 16, as is shown in
In accordance with the invention, the fixing of the cylinder head 1 occurs relative to the cylinder housing 4 by means of a clamp 2. The clamp 2 comprises in one embodiment a base part 5 and laterally projecting resilient legs 6, with the base part 5 being provided with an arched configuration in the direction of legs 6 according to a preferred embodiment. This increases the flexural stiffness and thus the pressure resistance of the base part 5. In the mounted state, the base part 5 is aligned with respect to the cylinder head 1 in such a way that the arching of the base part rests with its convex side on the cylinder head 1. The base part 5 of the clamp 2 will be chosen in an appropriate manner with such a width that it fixes the cylinder head 1 with even contact pressure on the cylinder housing 4.
According to the embodiments shown in
According to the embodiment of
A further embodiment of the latched connection is shown in
The use of bearing blocks 3 can thus be omitted. The type of latched connection within the framework of this embodiment is shown especially clearly in
An embodiment comparable to
A further embodiment of the fastening element in accordance with the invention is shown in
Instead of the bolted connections 15 it would also possible to provide hook-like connections, as are shown in
A further embodiment of the fastening element in accordance with the invention is shown in
The valve plate 16 as mentioned above (not shown in
Such a twisting of the valve plate 16 in the step-like bore 17 during the operation of the compressor can also be prevented without such a nose 18 and without a notch. As is indicated in
The introduction of force or the contact pressure of the fastening elements 2, 24, 25 in accordance with the invention for the cylinder head 1 on the cylinder housing 4 is carried out in these embodiments in such a way that it is made especially in such regions of the cylinder head 1 in which the highest loads occur by the piston force, i.e. in the area of the axis of the piston bore. The way how this contact pressure of the fastening element 2, 24, 25 is produced by its different components is illustrated in
As is shown in the
Claims
1-20. (canceled)
21. A compressor for hermetically encapsulated small-type refrigerating machines, comprising a cylinder with a cylinder housing (4) and a piston guided in a piston bore of the cylinder for compressing a working medium, with the cylinder being sealed in an axial direction by a cylinder head (1), and a fastening element (2, 24, 25) is provided which fastens the cylinder head (1) to the cylinder housing (4) by a contact pressure exerted in the region of the axis of the piston bore, and the fastening element (2, 24, 25) comprises a base part (5) and lateral parts (6), with the base part (5) being arranged in the axial direction in front of the cylinder head (1) and a contact pressure is exerted on the cylinder head (1) in the axial direction with the help of the base part (5), wherein the lateral parts (6) are formed as legs (6) which are laterally projecting from the base part (5), and which end sections (7) spaced from the base part (5) are latched on the cylinder housing (4) or on bearing blocks (3) which are rigidly connected with a supporting part (9) of the compressor.
22. A compressor for hermetically encapsulated small-type refrigerating machines according to claim 21, wherein the fastening element (2, 24, 25) is a preferably ushaped clamp.
23. A compressor for hermetically encapsulated small-type refrigerating machines according to claim 21, wherein the base part is provided with an arched configuration in the direction of the legs (6).
24. A compressor for hermetically encapsulated small-type refrigerating machines according to claim 21, wherein the bearing blocks (3) each having at least one edge (12) which are encompassed at least partly by the end sections (7) of the legs (6).
25. A compressor for hermetically encapsulated small-type refrigerating machines according to claim 22, wherein for forming a latching the clamp (2) encompasses the entire cylinder housing (4), with the cylinder housing (4) having edges (13) which are encompassed at least partly by the end sections (7) of the legs (6).
26. A compressor for hermetically encapsulated small-type refrigerating machines according to claim 21, wherein the latching is formed with the help of grooves (8) in the cylinder housing (4) into which engage one end section (7) each of the legs (6).
27. A compressor for hermetically encapsulated small-type refrigerating machines according to claim 21, wherein the base part (5) guides a pressing screw (14) which exerts a contact pressure on the cylinder head (1) in the axial direction.
28. A compressor for hermetically encapsulated small-type refrigerating machines according to claim 21, wherein the base part (5) rests directly on the cylinder head (1) and the lateral parts (6) are anchored to bearing blocks (3) fixedly joined to a supporting part (9) of the compressor, with at least one of the lateral parts (6) being configured as a screwed connection between base part (5) and bearing block (3).
29. A compressor for hermetically encapsulated small-type refrigerating machines according to claim 21, wherein the fastening element (2, 24, 25) is a locking clip.
30. A compressor for hermetically encapsulated small-type refrigerating machines according to claim 29, wherein the fastening element (2,24,25) is a wire (25).
31. A compressor for hermetically encapsulated small-type refrigerating machines according to claim 21, with the cylinder head (1) comprising a valve plate (16), characterized in that the valve plate (16) is partly sunk into a bore (17) in the cylinder housing (4), which bore comprises a step.
32. A compressor for hermetically encapsulated small-type refrigerating machines according to claim 31, wherein the valve plate (16) comprises a radial nose (18) which engages in a respective radial notch (19) in the cylinder housing (4).
33. A compressor for hermetically encapsulated small-type refrigerating machines according to claim 30, wherein valve plate (16) as well as the cylinder housing (4) each comprise a radial notch (35, 36) into which a locking body (34) can be inserted with radial alignment of the notch (35) of the valve plate (16) with the notch (36) of the cylinder housing (4).
34. A compressor for hermetically encapsulated small-type refrigerating machines according to claim 33, wherein the cylinder head (1) can also comprise a radial notch (37) into which the locking body (34) can be inserted with overlapping alignment of the notch (35) of the valve plate (16) with the notch (37) of the cylinder head (1).
35. A compressor for hermetically encapsulated small-type refrigerating machines according to claim 30, wherein in addition to the valve plate (16) the cylinder head (1) is at least partly sunk into the bore (17) in the cylinder housing (1), which bore preferably comprises a step.
36. A compressor for hermetically encapsulated small-type refrigerating machines according to claim 21, wherein the contact pressure exerted by the fastening element (2, 24, 25) in the area of the axis of the piston bore corresponds to an axial force of pressure of 1000 N to 10000 N, preferably 3000 N.
Type: Application
Filed: Feb 24, 2005
Publication Date: May 8, 2008
Inventors: Meinhard Falch (Graz), Alfred Freiberger (Grosswilfersdorf), Gunther Zippl (Kukmirn)
Application Number: 10/590,758
International Classification: F04B 39/14 (20060101);