Cylinder block for a compressor, in particular swash plate compressor, and swash plate compressor

Abstract

A cylinder block (1) for a compressor has a central opening (3) for accommodating a drive shaft of a drive unit and defines a central axis of the cylinder block (1) with a plurality of cylinder bores (2) arranged around the central opening and each of the cylinder bores (2) adapted for accommodating a piston (14).The cylinder block (1) also has at least one stop (10) on a drive side of the cylinder block (1) with the stop (10) arranged within a triangular area which is delimited by the central opening (3) and the two adjacent cylinder bores (2).

Claims

1. A cylinder block (1) for a compressor having a central opening (3) for accommodating a drive shaft of a drive unit and defining a central axis of the cylinder block (1), the cylinder block (1) comprising a plurality of cylinder bores (2) arranged around the central opening (3) and with each of the cylinder bores (2) adapted for accommodating a piston (14), and at least one stop (10) on a drive side of the cylinder block (1), wherein the stop (10) is completely arranged within a triangular area which is delimited by the central opening (3) and the two adjacent cylinder bores (2), wherein the triangular area is delimited radially and inwardly by the central opening (3) and laterally by lines extending from the central axis through the center lines of two adjacent cylinder bores (2), and wherein a thickness of said stop is greater than a distance between said central opening (3) and said cylinder bores (2).

2. The cylinder block (1) of claim 1 wherein the stop (10) is in the form of a curved ridge concentric with the central axis (30).

3. The cylinder block (1) of claim 2 wherein the stop (10) extends, in a peripheral direction, up to the two adjacent cylinder bores (2).

4. The cylinder block (1) of claim 1 wherein the stop (10) is arranged close to the central opening (3).

5. The cylinder block (1) of claim 1 wherein the stop (10) extends, in a peripheral direction, up to the two adjacent cylinder bores (2).

6. The cylinder block (1) of claim 5 wherein the chamfer (12) is arranged with an angle of 15 degrees with respect to a plane which is parallel to the central axis.

7. The cylinder block (1) of claim 6 wherein the distance between adjacent stops (10) is half of the length of the stops (10).

8. The cylinder block (1) of claim 1 wherein opposite ends of the stop (10) are chamfered.

9. The cylinder block (1) of claim 1 wherein a stop (10) is provided between each pair of adjacent cylinder bores (2).

10. The cylinder block (1) of claim 1 wherein the outer end (11) of the stop (10) ends at a level which is below a level defined by the outer edge (5) of the cylinder block.

11. A swash plate compressor having a cylinder block (1) as defined in claim 1, and a drive unit comprising a swash plate (16) and extending into the central opening (3) of the cylinder block (1).

12. The cylinder block (1) of claim 1 wherein the stop (10) is arranged close to the central opening (3).

13. The cylinder block (1) of claim 1 wherein the stop (10) extends, in a peripheral direction, up to the two adjacent cylinder bores (2).

14. The cylinder block (1) of claim 1 wherein opposite ends of the stop (10) are chamfered.

15. The cylinder block (1) of claim 1 wherein the cylinder block (1) is casted such that the stop (10) is formed integrally with the cylinder block (1).

16. A cylinder block (1) for a compressor having a central opening (3) for accommodating a drive shaft of a drive unit and defining a central axis of the cylinder block (1), the cylinder block (1) comprising a plurality of cylinder bores (2) arranged around the central opening (3) and with each of the cylinder bores (2) adapted for accommodating a piston (14), and at least one stop (10) on a drive side of the cylinder block (1), wherein the stop (10) is completely arranged within a triangular area which is delimited by the central opening (3) and the two adjacent cylinder bores (2), wherein the triangular area is delimited radially and inwardly by the central opening (3) and laterally by lines extending from the central axis through the center lines of two adjacent cylinder bores (2), wherein the stop (10) is in the form of a curved ridge concentric with the central axis (30), and wherein the stop (10) extends, in a peripheral direction, up to the two adjacent cylinder bores (2).

17. The cylinder block (1) of claim 16 wherein opposite ends of the stop (10) are chamfered.

18. The cylinder block (1) of claim 16 wherein the cylinder block (1) is casted such that the stop (10) is formed integrally with the cylinder block (1).

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 shows in a perspective view a cylinder block according to the prior art,

(2) FIG. 2 in a perspective view a center portion of a cylinder block according to the invention,

(3) FIG. 3 a perspective view of a cylinder block according to the invention,

(4) FIG. 4 a top view of the cylinder block according to the invention,

(5) FIG. 5 a cross section through a stop of a cylinder block according to the invention,

(6) FIG. 6 a cross section through a swash plate compressor according to the invention during mounting, and

(7) FIG. 7 a schematic view of the process of mounting a piston to the cylinder block.

(8) In FIG. 1, a cylinder block 1 for a swash plate compressor is shown. It is a generally cylindrical part made from cast metal, for example an aluminum alloy, and comprises in this embodiment five cylinder bores 2 which are arranged concentrically around a central opening 3 which is provided for accommodating a drive shaft. Central opening 3 defines a central axis of cylinder block 1.

(9) The end face of cylinder block 1 which is visible in FIG. 1 is facing the swash plate and is therefore designated as drive side. The level at which the cylinder bores 2 end is referred to as end face 4. It is the same level at which central opening 3 ends. The circumferential portion 5 of cylinder block 1 protrudes over end face 4. In other words, end face 4 is recessed as compared to the uppermost level defined by cylinder block 1.

(10) On end face 4, a plurality of stops 6 is provided which are formed as small protruding ridges formed integrally with cylinder block 1. Each stop 6 is arranged at the place where the wall thickness between central opening 3 and the respective cylinder bore 2 is minimal. In other words, each stop is arranged at a position which lies between the central axis of cylinder block 1 and the central axis of the respective cylinder bore 2.

(11) The cylinder block according to the invention will now be described with reference to FIGS. 2 to 5. For elements known from FIG. 1, the same reference numerals are being used, and reference is made to the above comments.

(12) Cylinder block 1 according to the invention uses stops 10 which are arranged at a position where the wall thickness of the cylinder block 1, near the central opening 3, is larger as compared to the prior art design.

(13) As can be seen in FIGS. 2 to 4, each stop 10 according to the invention is provided in the generally triangular portion which is delimited by two adjacent cylinder bores 2 and the central opening 3.

(14) Such a triangular area allows the casting of the cylinder block. Such a triangular area allows a molding process of the cylinder block. This area allows also to create stops whose the width is enough for the molding process.

(15) In other words, each stop 10 is arranged within an area which is delimited radially inwardly by central opening 3, and laterally by lines extending from the central opening 3 to peripheral edges of two adjacent cylinder bores 2.

(16) Thus, the thickness of the stop is bigger than the thickness of the separating wall located between the central opening and a cylinder bore.

(17) The portion of end face 4 where the wall thickness between central opening 3 and the respective cylinder bore 2 is minimal, is kept free from stop 10. The distance between adjacent stops 10 in the region of the small wall thickness is approximately half of the length of each stop 10 in a peripheral direction.

(18) Each stop 10 is formed as a ridge integrally with cylinder block 1, and extending in a curved manner immediately adjacent to central opening 3 concentric with the central axis.

(19) Each stop 10 has two opposite ends 12, which can be also called lateral ends, which are formed as a chamfer. As can be seen in FIG. 5, each chamfer is inclined by an angle of 15 degrees with respect to a plane which is parallel to the central axis. So, two chamfers 12 are useful for guiding one piston 14 of the compressor into the respective cylinder bore. This can be seen in FIG. 7.

(20) In FIG. 6, the function of stops 10 can be seen. During a mounting process, the outer end 11 of each stop 10 can come into contact with the radial inner portions of a swash plate 16 such that the radially outer portions 18 used for driving pistons 14 is kept in a distance from end face 4 of cylinder block 1, thereby preventing any damage.