WO2007080481A1

WO2007080481A1 - Reciprocating compressor with piston guide

Info

Publication number: WO2007080481A1
Application number: PCT/IB2007/000043
Authority: WO
Inventors: Frank Obrist; Peter Kuhn; Stefan Kröss
Original assignee: Obrist Engineering Gmbh
Priority date: 2006-01-08
Filing date: 2007-01-08
Publication date: 2007-07-19
Also published as: CN101365878B; DE112007000085A5; KR20080082005A; DE102006001173A1; CN101365878A

Abstract

The invention relates to a reciprocating compressor, especially for compressing refrigerants in a refrigerant circuit. Said compressor has a compressor housing (2, 2', 2'') in which at least one compression cylinder (3, 3', 3'') is arranged which is delimited on a first side by a cylinder head arrangement (4) and in which a piston (5, 5') is received so as to be translationally movable. The piston can be actuated by means of a power transmission element, especially via a wobble plate or pivoting plate in the area of the piston base (5b, 5b'). The piston is associated with a piston back (5c, 5c') on which the piston is supported and guided during operation. The piston (5, 5') is associated with a slide rail (8, 8', 8'') that extends substantially parallel to the piston axis (3a, 3a') and that has a distance to the compressor housing (2b) in the radial direction and/or at an angle to the piston axis and/or at an angle to the drive axis (2c, 2c', 2c'') of the power transmission element. The compressor according to the invention is used in refrigerant circuits, especially in air-conditioning systems.

Description

Reciprocating compressor with a piston guide

The present invention relates to a reciprocating compressor, in particular for compressing refrigerant in a refrigerant circuit with a compressor housing in which at least one compression cylinder is arranged, which is bounded on a first side via a cylinder head assembly and in which ■ a piston is mounted translationally movable, wherein the Piston by means of a power transmission element, in particular by means of a wobble or swash plate in the region of a piston foot is controlled and wherein the piston is associated with a piston back, on which the piston is designed supportable during operation.

The object of the invention is to provide a cost-producible reciprocating compressor of the type mentioned in such a way that a rotational movement of the piston and in particular a rattling of the piston is reliably avoided.

This object is achieved by a reciprocating compressor with the features of claim 1. In such a reciprocating compressor piston is associated with a slide, which can be inserted or inserted into a housing part of the compressor housing. is set and which extends approximately parallel to the piston axis and in the radial direction and / or transverse to the piston axis and / or transversely to the drive axis of the reciprocating compressor has a distance from the compressor housing. The slide is designed for this purpose as independent of the compressor housing, separate component and preferably has a flat sliding surface, which is associated with a corresponding Kolbengleitfläche in the region of the piston back. The sliding surface of the slide rail and the Kolbengleitfläche are arranged parallel to each other and serve as a one-way slide bearing over which forces in the direction of the circumference of the preferably circular-cylindrical running compressor housing are transferable, preferably both the Kolbengleitfläche and the sliding surface of the slide with a radial distance from the compressor housing are designed transversely to the piston axis and / or transversely to the drive axis of the power transmission element. A bearing of the slide on the compressor housing is preferably carried out via a resilient support and / or a extending in the direction of the piston axis bracket. The latter holder may be integral with both a portion of the compressor housing and integral with the slide rail.

In an embodiment of the invention, the piston is associated with two slide rails, which engage around at least a portion of the piston back. Both slides each have a sliding surface, wherein each sliding surface is associated with a corresponding Kolbengleitfläche. The sliding surfaces of the slide rails are preferably arranged parallel to one another, alternatively they have an acute angle. With the help of the two slide rails, the piston can be secured in two directions against unwanted rotations. In a further embodiment of the invention, a nose arranged in the region of the piston back is provided, which slides in operation along a slide rail. The nose can be dimensioned such that an optimum with the lowest possible frictional forces and sufficient guiding property and low mass of the piston can be achieved.

In a further embodiment of the invention, a plurality of slide rails, in particular slide rails of adjacent pistons are connected to each other or made in one piece. In a preferred manner, a slide rail thus serves to support two adjacent pistons, which proves to be advantageous in particular when using a plurality of pistons arranged on a common circular line.

In a further embodiment of the invention, a plurality of pistons is assigned a common cage extending in the circumferential direction along the inside of the compressor housing, on which a plurality of slide rails are fixed. Such a cage is used in a preferred manner for simultaneous guidance of all pistons of the compressor, resulting in a substantial balance of forces in the circumferential direction. The cage is preferably made in one piece and inserted into the compressor housing, wherein the cage is supported and / or fixed to an upper part of the compressor housing and / or on a lower part of the compressor housing.

In a further embodiment of the invention, the cage is made of a metallic sheet metal semifinished product, wherein the material of the cage selected similar to the material of the piston, in particular in the form of an aluminum alloy. That way are several slides by bending provided on the sheet metal blank straps produced. It is further preferred to produce the slide rails of the same material as the piston.

In a further embodiment of the invention, the cage and / or individual slide rails are fixed to an upper part of the compressor housing in particular on a cylinder head assembly and in particular have a distance from a lower part of the compressor housing. Preferably, a one-piece design of at least one slide rail is provided with a removable from a lower housing part of the compressor housing cylinder head assembly, wherein the lower housing part is made substantially cylindrical and surrounds the piston in the region of a drive chamber.

Further features and combinations of features of the invention will become apparent from the following description in which preferred embodiments of the invention are illustrated by the drawings.

Show this

1 is a schematic representation of a longitudinal section through a first reciprocating compressor,

2 shows a cross section through the first Hubkolbenkom- pressor according to FIG. 1 in the direction of the line II-II,

3 is a perspective view of a second reciprocating compressor, Fig. 4 is a longitudinal section through the second reciprocating compressor of FIG. 3 along the line IV-IV and

Fig. 5 is a perspective view of a housing part of a third reciprocating compressor.

A reciprocating compressor 1 according to the invention comprises in a generally known manner a multi-part compressor housing 2, which consists essentially of an upper part 2a and a lower part 2b. In the upper part 2a of the compressor housing, a plurality of compression cylinders 3 are arranged in a circle around a common axis 2c (drive axis). On a first side, the upper part 2a is closed in a manner not shown with the aid of a cylinder head assembly 4. In particular, a plurality of inlet and outlet valves are positioned in the cylinder head arrangement 4, via which refrigerant can be supplied and discharged to the reciprocating compressor 1. On a second side, the lower part 2b connects to the upper part 2a, wherein in the lower part 2b of the so-called drive chamber 2d is formed, in which a drive shaft is mounted, which drives a power transmission element not shown in detail in the form of a swash plate.

In the compression cylinders 3, a piston is mounted in each case translationally displaceable. A piston 5 essentially comprises a circular-cylindrical piston head 5a, a piston foot 5b and a piston back 5c. A piston is executable in a generally known manner, so that the details of its design and its function need not be discussed in detail. The mounted on the common drive shaft, serving as a force transmission element pivot plate engages via sliding blocks on the piston 5b of each piston and sets a rotational movement of the drive shaft in the translational movement of the piston 5 to. For this purpose, the swash plate is arranged at a variable angle inclined to the drive axis, resulting, inter alia, on the piston 5 acting tilting forces and torques.

The piston 5 is associated with a cage 7, which has a substantially circular cylindrical basic shape with a diameter which is made slightly smaller than the inner diameter of the compressor housing 2, 2b in the region of the drive chamber 2d. The cage 7 essentially comprises an annular band 7a, which is preferably inserted at a small radial distance from the lower part 2b of the compressor housing 2 in this. At several, individual attachment points of the cage 7 via integrally with the cage running, slightly resilient or rigid brackets 6 is fixed to the upper part 2a. Advantageously, the cage 7 is made slightly resilient with low mass. In addition, the cage can be supported on the lower part 2b via further holders. The cage is preferably made of a metallic sheet metal semi-finished product, in particular of a perforated plate, a grid or a film.

Per piston 7 two slides 8 are provided on the cage. The slide rails 8 are carried out in an advantageous manner as projecting from the cage 7 tabs. The slide rails 8 and the cage 7 are preferably produced in one piece, the tabs protruding in a simple manner from the material of the cage. are bent. The material selected is preferably the same material from which the pistons 5 or their piston backs 5c are made. In particular, aluminum wrought or cast alloys or alternatively iron, nickel, magnesium or titanium alloys are suitable.

As can be seen from Fig. 2, a nose 5d is provided on the piston 5 in the region of the piston back 5c, which has two in the direction of ümfangs the compressor housing 2 facing piston sliding surfaces 5e. The piston sliding surfaces 5e are oriented parallel to respective corresponding sliding surfaces 8a of the slide rails 8. Thus, the two slide rails 8 surround the nose 5d with little play, so that a support of the piston 5 transversely to the direction of the translational movement and thus effectively prevents rotation of the piston 5 about its axis.

In FIGS. 3 and 4, the upper housing part 2a 'of a second reciprocating compressor V according to the invention is shown schematically.

In the upper part 2a 'of the compressor housing, which may be designed in particular as a cylinder head arrangement, in turn a plurality of compression cylinders 3' are arranged in a circle around a common axis 2c 'around. In the compression cylinders 3 'is in each case a piston 5' mounted translationally displaceable. For simplicity, only one piston is shown in Figs. 3 and 4. A piston 5 'in turn comprises a circular-cylindrical piston head 5a', a piston foot 5b 'and a piston back 5c'. A drive of the pistons 5 'takes place again via a force transmission element, which acts on the piston base 5b' and performs a translational motion. tion of the piston parallel to the main axis 2c 'of the compressor 1' forces. Not shown is an approximately cylindrical or cup-shaped housing lower part, which surrounds the piston and a drive chamber in an annular manner. Housing lower part and housing upper part 2a 'are placed flush with each other in the region of their end faces.

The piston 5 'are each associated with two parallelepiped slide rails 8' with preferably rectangular cross-section which engage around the respective piston back 5c 'on two opposite piston slide surfaces 5e'. The slide rails are preferably made in one piece with the housing upper part or fixed to this, so that the slide rails are fixed to each other on the housing top and can be used with the help of the housing upper part in the housing base. The slide rails in the assembled state, as well as the pistons 5 'in a direction transverse to the main axis 2c' of the compressor 1 ', i. in particular in the radial direction at a distance to the surrounding housing lower part of the compressor. As a result, rotations of the pistons 5 'are effectively avoided in a manner which is simple to implement and at the same time a transmission of vibrations to the compressor housing 2' or, in particular, to the housing lower part is reduced.

To achieve a particularly low-friction guidance of the piston 5c 'are on the slide rails 8' in pairs opposing sliding surfaces 8a 'is provided which correspond to the Kolbengleitflächen 5e'. The slide rails 8 'are formed substantially dimensionally stable and preferably in one piece with the upper part 2a' and in particular made of a light metal alloy or steel, so that a movement of the piston in the circumferential direction safely limited becomes. Preferably, the slide rails 8 'are made in one piece with the piston guides or piston liners.

In a modified embodiment, the slide rails 8 'made of a low-friction plastic, for example made of Teflon and positively fixed to the housing upper part 2a'. In a further modified embodiment, the sliding surfaces 8a 'and / or the piston sliding surfaces 5e' are provided with a friction-reducing coating. In a further modified embodiment, the sliding surfaces 8a 'and the piston sliding surfaces 5e' have corresponding surface structures, via which an additional guidance of the pistons in the radial direction can be achieved. In a further modified embodiment, the housing upper part is provided with stiffening and / or heat transfer ribs. In a further modified embodiment, a damping element, in particular in the form of a seal, is provided between the upper part of the housing and the lower part of the housing.

FIG. 5 shows a housing part 2 "of a third exemplary embodiment of a reciprocating compressor 1" according to the invention. The housing part 2 '' integrally comprises both an upper part 2a '' and a lower part 2b ''. In the region of the lower part 2b '' slide rails 8 '' are provided, which are fixed via neck-like brackets 9 with a distance transverse to the drive shaft 2c '' of the compressor on the lower part 2b ''. Optionally, the slide rails 8 '' frontally on the upper part 2a '' set.

Sliding surfaces 8a '' extend both approximately in the radial and in the axial direction of the compressor housing 2 '', engage in operation on the piston back of not shown, in compression cylinders 3 '' mounted piston and prevent movement of the piston transverse to the drive shaft 2c ''. Preferably, a significant distance is provided between the sliding surfaces 8a '' and the cylindrical inner surface Z of the housing part 2 '', so that the piston can be kept at a distance from the inner surface Z.

It is understood that the features encompassed in the described exemplary embodiments can each be transferred to similar or modified exemplary embodiments, so that further combinations of features result.

Claims

claims

1) reciprocating compressor, in particular for the compression of refrigerant in a refrigerant circuit with a compressor housing (2, 2 ', 2''^' ), in which at least one compression cylinder (3, 3 ', 3'') is arranged, on a first Side over a cylinder head assembly (4) is limited and in which a piston (5, 5 ') is mounted translationally movable, wherein the piston by means of a power transmission element, in particular by means of a wobble or swash plate in the region of a piston foot (5b, 5b') controlled is and wherein the piston is associated with a piston back (5c, 5c '), on which the piston is guided in support during operation, characterized in that the piston (5, 5') has a slide rail (8, 8 ', 8'') is assigned, which is used or inserted into a housing part (2b) of the compressor housing and the

- Has approximately parallel to the piston axis (3a, 3a ') and in the radial direction and / or transversely to the piston axis and / or transversely to the drive axle (2c, 2c', 2c '') of the force transmission element at a distance from the housing part (2b) ,

2.) Hubkolbenkorαpressor according to claim 1, characterized in that the piston two slide rails (8, 8 ', 8' ') are associated, which engage around at least a portion of the piston back (5c, 5d).

3.) reciprocating compressor according to one of claims 1 and 2, characterized in that in the region of the piston back (5c) arranged nose (5d) is provided, which slides in operation on a slide rail (8, 8 ', 8 ") along.

4.) reciprocating compressor according to one of claims 1 to 3, characterized in that a plurality of slide rails (8), in particular slide rails of adjacent pistons (5) are interconnected or designed in one piece.

5.) reciprocating compressor according to one of claims 1 to 4, characterized in that a plurality of pistons (5) is associated with a common, along the inside of the compressor housing (2b) extending cage (7) on which a plurality of slide rails (8) are fixed ,

6.) reciprocating compressor according to claim 5, characterized in that the cage (7) is made of a metallic sheet metal semi-finished, wherein the material of the cage (7) similar to the material of the piston (5), in particular selected from an aluminum alloy. Reciprocating compressor according to one of claims 1 to 6, characterized in that the cage (7) and / or individual slide rails (8, 8 ', 8'') on an upper part (2a, 2a') of the compressor housing (2, 2 ', 2 ''), in particular are fixed to a cylinder head assembly and in particular a distance from a lower part (2b, 2b '') of the compressor housing.