Refrigerant Compressor

Abstract

A hermetically encapsulated refrigerant compressor, comprising a hermetically sealed compressor housing, in the interior of which a piston-cylinder unit works which compresses a refrigerant, whose cylinder housing (3) is sealed by means of a valve plate (16) comprising a pressure bore (25) and an intake bore (15), and an intake duct and a pressure duct are provided through which refrigerant is drawn into the intake bore (15) via a suction valve and is compressed via a pressure valve from the pressure bore (25) into the pressure duct, with a muffler (11) preferably being arranged in the intake duct. A clamping element (18) is provided which clamps the valve plate (16) at least along a section of its circumference, preferably along the entire circumference, against the cylinder housing (3).

Description

BACKGROUND OF THE INVENTION

The present invention relates to a hermetically encapsulated refrigerant compressor, comprising a hermetically sealed compressor housing, in the interior of which a piston-cylinder unit works which compresses a refrigerant, whose cylinder housing is sealed by means of a valve plate comprising a pressure bore and an intake bore, and an intake duct and a pressure duct is provided through which refrigerant is drawn into the intake bore via a suction valve and is compressed via a pressure valve from the pressure bore into the pressure duct, with a muffler preferably being arranged in the intake duct.

Such refrigerant compressors have long been known and are predominantly used in refrigerators and cooling shelves. The annually produced number is accordingly very high.

DESCRIPTION OF THE PRIOR ART

In known refrigerant compressors, the valve plate sealing the cylinder housing is always screwed together with the cylinder housing in order to achieve the sealing of the cylinder space against the interior of the compressor housing. In order to achieve such sealing, a defined pressing pressure is required. In order to facilitate the sealing, sealing of the cylinder clearance is often provided which is arranged between the valve plate and the cylinder housing and assumes a sealing function.

The fastening of the valve plate to the cylinder housing is usually made through four screws which are each arranged in the four corner regions of the valve plate in order to achieve the most even pressing pressure.

The use of screws leads to a high amount of mounting work because on the one hand it is necessary to drill the threaded bores into the valve plate and the cylinder housing, and on the other hand it is necessary to screw in each screw individually into the provided bores. In the case of high piece numbers in which such refrigerant compressors are produced, this leads in summary to a high amount of time in production, which again entails high costs.

A compressor valve with a valve plate arranged on guide pillars is known from DE 32 21 554 A1, which is held in position by means of a spring steel leaf and is fastened to the end of the cylinder block by means of cap screws.

DE 38 13 539 A1 discloses an outlet valve arrangement of a hermetic refrigerant compressor, with a leaf valve of the intake duct resting on a lid-shaped retaining part which on its part is pretensioned by a clamping element. This clamping element projects with its end parts in recesses of the valve plate. This apparatus arrangement which is merely suitable for preliminary mounting of the valve components requires an even stronger pre-tensioning for fixing the retaining part, such that the cylinder head presses on the clamping element in the axial direction and the valve plate still requires a separate screw joint at its end sections in order to be fastened to the cylinder housing.

SUMMARY OF THE INVENTION

It is therefore the object of the present invention to avoid this disadvantage and to provide a refrigerant compressor of the kind mentioned above which can be mounted in a short period of time.

A further problem in known, screwed refrigerant compressors is the anharmonic, punctiform introduction of the sealing force into the valve plate.

It is also the goal of the present invention to provide a refrigerant compressor which has a substantially more harmonic introduction of force into the valve plate, while simultaneously offering an at least evenly remaining sealing effect between valve plate and cylinder housing.

This is achieved in accordance with the invention by the characterizing features of claim 1.

By providing a clamping element which clamps the valve plate to the cylinder housing at least along a section of its circumference, complex mounting by means of screws is no longer required on the one hand and there is a harmonic introduction of force into the valve plate on the other hand, thus providing secure sealing of the cylinder cavity against the interior of the compressor housing.

According to a preferred embodiment, the clamping element is substantially arranged in a J-shaped manner and in the form of an annulus, and is latched with an end section on an undercut provided on the cylinder housing, with the other end section of the clamping element forming a first clamping leg which presses the cylinder housing against the valve plate.

According to the characterizing features of claims 6 and 7, a carrier element forming the pressure valve in the form of a pressure leaf spring and/or a sealing element, which both rest in a planar manner on the valve plate, can be arranged between the clamping legs clamping the valve plate and the valve plate.

According to the characterizing features of claim 8, the cylinder housing comprises a shoulder in which the valve plate is sunk at least partly. According to one of the preferred embodiments as described in the characterizing features of claim 9, the surface of the valve plate averted from the piston is flush with the cylinder housing.

According to a further alternative embodiment as described in claim 10, the cylinder head is formed by the components forming the pressure duct or intake duct, and the clamping element comprises a further clamping leg, which pressure duct and intake duct press against the valve plate or into the suction or pressure bore.

According to the characterizing features of claim 11, a further clamping element is provided in another alternative embodiment which can be latched with the clamping element and clamps the cylinder head consisting of components forming the pressure duct or intake duct against the valve plate or into the intake bore and/or pressure bore.

The characterizing features of claims 12 and 13 describe alternative embodiments of the clamping element in connection with a conventional cylinder head in the form of a cylinder cover.

BRIEF DESCRIPTION OF THE DRAWINGS

A detailed description of the invention by reference to embodiments is provided below, wherein:

FIG. 1 shows a sectional view of a refrigerant converter according to the state of the art;

FIG. 2 shows a sectional view of a unit with cylinder housing and valve plate with the clamping element in accordance with the invention, shown in the direction of arrows DD of FIG. 4;

FIG. 2 a shows a detailed view of a unit with cylinder housing and valve plate, comprising the clamping element in accordance with the invention;

FIG. 3 shows an axonometric view of the unit with cylinder housing and valve plate according to FIG. 2;

FIG. 4 shows a top view of the unit with cylinder housing and valve plate according to FIGS. 3 and 4;

FIG. 5 shows an axonometric view of an alternative embodiment of the unit with cylinder housing and valve plate from FIGS. 2 to 4;

FIG. 6 shows a view of a further alternative unit with cylinder housing and valve plate, comprising the clamping element in accordance with the invention;

FIG. 7 shows a partially sectional view in the direction of arrows A of FIG. 6;

FIG. 8 shows a sectional view along the plane B of FIG. 6;

FIG. 9 shows a sectional view of an additional alternative unit with cylinder housing and valve plate, comprising the clamping element in accordance with the invention;

FIG. 10 shows an axonometric view of another unit with cylinder housing and valve plate, comprising the clamping element in accordance with the invention.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a sectional view through a hermetically encapsulated refrigerant compressor as is known from the state of the art. In the interior of a hermetically sealing compressor housing 1, a unit with cylinder housing and valve plate plus motor and piston is held elastically via springs 2.

The unit with cylinder housing and valve plate plus motor and piston substantially consists of a cylinder housing 3 and the piston 4 which performs a travel movement, and a crankshaft bearing 5 which is arranged perpendicularly to the cylinder axis 6. The crankshaft bearing 5 receives a crankshaft 7 and protrudes into a centric bore 8 of rotor 9 of an electromotor 10. A connecting-rod bearing 12 is situated at the upper end of the crankshaft 7, through which a connecting rod and subsequently the piston 4 is driven. The crankshaft 7 comprises a lubricating oil bore 13 and is fixed to rotor 9 in the area 14. The muffler 11 is arranged on the cylinder head, which muffler is to reduce the developed noise to a minimum during the intake process of the refrigerant.

The cylinder housing 3 is sealed on its face side by means of a valve plate 16, which in conventional refrigerant compressors is screwed together with the cylinder housing. A cylinder cover 17 is arranged adjacent to the valve plate 16 in refrigerant compressors according to the state of the art, which cover is provided with webs 28 (see FIG. 2) on its side facing the valve plate 16, which webs form a pressure duct in combination with the side walls of the cylinder cover 17 and the valve plate 16, through which compressed refrigerant pushed by the piston from the cylinder housing 3 is forwarded to pressure lines 29 and is conveyed from the hermetically sealed compressor housing 1. The cylinder cover 17 is usually also screwed together with the cylinder housing 3, so that the cylinder cover 17, the valve plate 16 and the cylinder housing 3 are all screwed together.

It is provided for in accordance with the invention that the connection between valve plate 16 and cylinder housing 3 is not made by means of a screwed joint, but by means of clamping.

FIG. 2 shows a sectional view of a known unit with cylinder housing 3 and valve plate 16, but with clamping according to the invention. The valve plate 16 and the cylinder cover 17 jointly delimit a pressure duct, through which compressed refrigerant is conveyed, namely via a pressure bore 25 and a pressure valve 33 into the pressure duct and further into the pressure line 29. The intake bore is not visible in this view.

In contrast to the unit with cylinder housing 3 and valve plate 16 which is shown in FIG. 1 and in which the cylinder cover 17 is screwed together with the valve plate 16 and the latter with the cylinder housing 3 (the screws are not shown in FIG. 1), the valve plate 16 is tightly clamped by means of a clamping element 18 onto cylinder housing 3 in the unit with cylinder housing 3 and valve plate 16 as is shown in FIG. 2.

For this purpose the cylinder housing 3 comprises an undercut 19 which can be latched together with an end section of the clamping element 18. The clamping element 18 itself comprises a first clamping leg 18a that clamps the valve plate 16 along its entire circumference against the cylinder housing 3 which for this purpose comprises a shoulder 27 in which the valve plate 16 is sunk at least partly but preferably entirely, as a result of which a centering of the valve plate is achieved simultaneously. Clamping occurs along a contact edge of the clamping leg 18a which has a circular, closed form, like the valve plate 16. It is obvious to the person skilled in the art however that the shape of the contact edge which finally causes the clamping of the valve plate 16 can be chosen at will. The clamping element 18 itself can also be chosen at will as long as it is ensured that clamping of the valve plate 16 against the cylinder housing 3 occurs with sufficient clamping force. Sufficient clamping force is ensured when it seals the cylinder cavity 20 against the interior of the compressor housing 1 enclosing the cylinder housing 3. This is achieved in practice by clamping along the circumference of the valve plate 16, with clamping along the entire circumference not being mandatory in accordance with the invention and it may be sufficient, depending on the clamping force, to clamp merely one section of the circumference of the valve plate 16 by means of the clamping legs 18a. The important aspect is however that clamping occurs along the circumference, i.e. in the circumferential region of the valve plate 16. In order to improve the sealing effect, a cylinder clearance seal 21 is provided in many cases.

Since the clamping element 18 is provided for clamping the valve plate 16 against the cylinder housing, a further clamping element 30 is provided in accordance with the invention which clamps the cylinder cover 17 against the valve plate 16. The further clamping element 30 is hooked for this purpose into two grooves or openings 31 which are provided on the clamping element 18 and are diametrically opposite of each other and traverses the cylinder cover 17 by simultaneously exerting a clamping force on the cylinder cover 17 in the region of the axis of the piston bore.

FIGS. 3 and 4 show two further views of the unit with cylinder housing 3 and valve plate 16 of FIG. 2. FIG. 4 shows the intake line 22 in addition to the pressure line 29.

FIG. 5 shows an axonometric view of an alternative embodiment of the unit with cylinder housing 3 and valve plate 16 of FIGS. 2 to 4. The clamping element 18 and the clamping element 30 are shown with an integral configuration. The two clamping elements 18 and 30 are welded together in a preferred embodiment. Moreover, the clamping element 18 clamps the valve plate merely along a section of the circumference, i.e. not over the entire circumference, with the clamping force being chosen in such a way that there is sufficient sealing of the cylinder cavity 20 against the interior of the compressor housing 1 which encloses the cylinder housing 3.

FIGS. 6, 7 and 8 show a further alternative embodiment of a unit with cylinder housing 3 and valve plate 16. The clamping element 18 is latched together again with an undercut 19 arranged on the cylinder housing 3. A first clamping leg 18a clamps the valve plate 16 along its entire circumference-against the cylinder housing 3 which for this purpose comprises a shoulder 27 in which the valve plate 16 is sunk at least partly. Clamping occurs preferably again along a contact edge of the clamping leg 18a.

In contrast to the unit with cylinder housing 3 and valve plate 16 as shown in FIG. 2 which comprises a conventional cylinder head in the form of a cylinder cover 17 and an intake duct (not shown in FIG. 2) fastened to the valve plate 16, the cylinder head shown in FIGS. 6, 7 and 8 consists of two components 23, 24 which are each arranged independently in such a way that it forms an independent flow duct for the refrigerant, with one flow duct 23 forming the pressure duct and the other flow duct 24 forming the intake duct, with the valve plate not being used as a sectional boundary of the pressure duct, as is the case in known refrigerant compressors according to FIG. 2. Accordingly, the pressure duct 23 is tightly connected with the pressure bore 25 provided in the valve plate 16 and the intake duct 24 is tightly connected with the intake bore 15 which is also provided in the valve plate 16. The component 24 forming the intake duct is further connected with the known muffler 11.

Whereas the intake duct was arranged as a separate flow duct in known refrigerant compressors, the arrangement of a separate flow duct for the compressed hot refrigerant in the form of a separate component 23 leads to the consequence that the use of a conventional cylinder cover as designated with reference numeral 17 in FIG. 1 and FIG. 2 is no longer necessary. Since when using conventional cylinder covers 17 the valve plate 16 was always in direct contact with the compressed refrigerant (because it was a component of the pressure duct) on its surface averted from the piston or at least was in direct contact with the component forming the pressure duct, the compressed hot refrigerant was not only able to emit its heat in conventional refrigerant compressors from the interior of the cylinder housing to the valve plate 16, but also from the outside, i.e. on the surface of valve plate 16 averted from the piston.

By providing two separate components 23, 24 which in their section directly adjacent to the valve plate 16 are guided away from the same in a substantially rectangular manner, the compressed hot refrigerant can immediately be transported away from the valve plate 16 without making contact with the valve plate 16 on its surface averted from the piston or only contacting this surface merely at a small section around the pressure bore 25, so that a heat transfer from the compressed hot refrigerant to the valve plate via said surface can be avoided. It can be provided that the pressure valve 33 in the form of a pressure leaf spring is arranged in the component 23.

An additional factor is that the two components 23, 24 can be made completely of plastic, so that also the heat transfer can virtually be prevented from said components to the valve plate.

In order to ensure a sufficiently tight connection between the pressure duct and the intake duct or the components 23, 24 with the intake bore 15 or pressure bore 25 in valve plate 16, it is provided for in accordance with the invention that the clamping element 18 comprises a further clamping leg 18b in addition to its first clamping leg 18a which clamps the valve plate 16 in the shoulder 27 of cylinder housing 3, which further clamping leg presses the two components 23, 24 against the valve plate 16 or in the pressure bore 25 or intake bore 15.

FIG. 9 shows an additional alternative unit with cylinder housing 3 and valve plate 16, with the clamping element 18 in accordance with the invention comprising two clamping sections 18a, 18b. Clamping section 18b latches together with a groove 26 on the component 23 forming the pressure duct and on the component 24 forming the intake duct (not shown).

Based on the embodiments it is clear to the person skilled in the art that the manner of the configuration of FIG. 10 shows an axonometric view of another alternative unit with cylinder housing 3 and valve plate 16, comprising the clamping element 18 in accordance with the invention, but with a new head group, i.e. with a component 23 forming the pressure duct and a component 24 forming the intake duct. In contrast to the unit with cylinder housing 3 and valve plate 16 as disclosed in FIGS. 6, 7, 8, the clamping of the components 23, 24 occurs here by means of a separate clamping element 30 which is latched into grooves or openings 31 arranged on the clamping element 18.

of the cylinder head, i.e. either with cylinder cover 17, as known so far, or instead with a head-group as described in the FIGS. 6 to 10, has no influence on the invention, because it is the object of the invention to clamp the valve plate 16 against the cylinder housing 3 in order to avoid the laborious screwing.

LIST OF REFERENCE NUMERALS

• • 1. Compressor housing
  • 2. Springs
  • 3. Cylinder housing
  • 4. Piston
  • 5. Crankshaft bearing
  • 6. Cylinder axis
  • 7. Crankshaft
  • 8. Centric bore
  • 9. Rotor
  • 10. Electromotor
  • 11. Muffler
  • 12. Connecting-rod bearing
  • 13. Lubricating oil bore
  • 14. Fixing area
  • 15. Intake bore
  • 16. Valve plate
  • 17. Cylinder cover
  • 18. Clamping element
  • 19. Undercut
  • 20. Cylinder cavity
  • 21. Cylinder clearance seal
  • 22. Intake line
  • 23. Component forming the pressure duct
  • 24. Component forming the intake duct
  • 25. Pressure bore
  • 26. Groove
  • 27. Shoulder
  • 28. Web
  • 29. Pressure line
  • 30. Clamping element
  • 31. Groove or opening
  • 32. Suction leaf spring
  • 33. Pressure leaf spring
  • 34. Gasket pressure side

Claims

1. A hermetically encapsulated refrigerant compressor, comprising a hermetically sealed compressor housing, in the interior of which a piston-cylinder unit works which compresses a refrigerant, whose cylinder housing (3) is sealed by means of a valve plate (16) comprising a pressure bore (25) and an intake bore (15), and an intake duct and a pressure duct are provided through which refrigerant is drawn into the intake bore (15) via a suction valve and is compressed via a pressure valve from the pressure bore (25) into the pressure duct, with a muffler (11) preferably being arranged in the intake duct, wherein a clamping element (18) is provided which clamps the valve plate (16) at least along a section of its circumference, preferably along the entire circumference, against the cylinder housing (3).

2. A hermetically encapsulated refrigerant compressor according to claim 1, wherein the clamping element (18) comprises a substantially J-shaped cross section.

3. A hermetically encapsulated refrigerant compressor according to claim 1, wherein the clamping element (18) is arranged in the form of an annulus.

4. A hermetically encapsulated refrigerant compressor according to claim 1, wherein undercuts (19) are provided on the cylinder housing (3) which can be latched together with an end section of the clamping element (18).

5. A hermetically encapsulated refrigerant compressor according to claim 4, wherein the other end section of the clamping element (18) forms a first clamping leg (18a) which clamps the valve plate (16) against the cylinder housing (3).

6. A hermetically encapsulated refrigerant compressor according to claim 5, wherein a carrier element forming the pressure valve (33)—preferably in the form of a pressure leaf spring—which rests in a planar manner on the valve plate (16) is arranged between the clamping legs (18a) and the valve plate (16).

7. A hermetically encapsulated refrigerant compressor according to claim 5, wherein a sealing element (34) which rests in a planar manner on the valve plate (16) is arranged between the valve plate (16) and the clamping legs (18a).

8. A hermetically encapsulated refrigerant compressor according to claim 1, wherein the cylinder housing comprises a shoulder (27) in which the valve plate (16) is sunk at least partly.

9. A hermetically encapsulated refrigerant compressor according to claim 1, wherein the surface of the valve plate (16) averted from the piston (4) is flush with the cylinder housing (13).

10. A hermetically encapsulated refrigerant compressor according to claim 5, wherein the clamping element (18) comprises at least one further clamping leg (18b) which clamps a component (23, 24) forming the pressure duct or intake duct against the valve plate (16) or in the intake bore (15) and/or the pressure bore (25).

11. A hermetically encapsulated refrigerant compressor according to claim 1, wherein a further clamping element (30) is provided which can be latched to the clamping element (18) and clamps the component (23, 24) forming the pressure duct or the intake duct against the valve plate (16) or in the intake bore (15) and/or the pressure bore (25).

12. A hermetically encapsulated refrigerant compressor according to claim 5, wherein the clamping element (18) comprises at least one further clamping leg (18b) which clamps the cylinder cover (17) against the valve plate (16).

13. A hermetically encapsulated refrigerant compressor according to claim 5, wherein a further clamping element (30) is provided which can be latched to the clamping element (18) and clamps the cylinder cover (17) against the valve plate (16).