Refrigerant scroll compressor for motor vehicle air conditioning systems

Abstract

A refrigerant scroll compressor for a motor vehicle air conditioning system having a fixed scroll, an orbiting scroll engaging with the fixed scroll, wherein the fixed scroll and the orbiting scroll cooperate to compress a refrigerant gas. An intermediate pressure chamber is disposed adjacent the orbiting scroll, an oil return duct provides fluid communication between the intermediate pressure chamber and a high pressure area of the refrigerant scroll compressor, and at least one intermediate pressure duct is formed in one of the orbiting scroll and fixed scroll and is in fluid communication with the intermediate pressure chamber.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims priority to German Non-Provisional Patent Application Serial No. DE 10 2012 104 045.1 filed May 9, 2012, hereby incorporated herein by reference in its entirety.FIELD OF THE INVENTION[0002]The invention relates to a refrigerant scroll compressor for vehicle air-conditioning systems and in this context particularly a design with efficient oil recirculation within the refrigerant circuit while controlling the intermediate pressure level optimally.BACKGROUND OF THE INVENTION[0003]The use of refrigerant scroll compressors in motor vehicle air-conditioning systems is highly desirable, since this type of compressor has a robust structural design and can also be produced and used cost-effectively. Scroll compressors moreover operate radially to the inside, which results in a relatively short axial installation length for the compressor. An electrical refrigerant compressor can thus be designed without requiring any additio...

AI Technical Summary

Benefits of technology

[0008]The purpose of the invention consists in providing a refrigerant scroll compressor for motor vehicle air-conditioning systems which ensures a stable oil return and where the sealing force for sealing the fixed scroll to the orbiting scroll can moreover be well controlled.

[0011]According to another embodiment of the invention, the intermediate pressure duct is arranged in the orbiting scroll and is furthermore preferably formed on the bottom of the orbiting scroll. It has been shown that the intermediate pressure duct can be designed particularly cost-effectively as an intermediate pressure bore.

[0014]The relatively large flow area for the refrigerant gas compared to the flow area for the oil return results in that the resulting sealing force can be well controlled, and therefore it essentially operates independently of the oil return.

[0015]A further advantageous embodiment of the invention is realized in that an intermediate pressure duct is formed in each of the chambers of the scroll compressor in areas which have the same functions at the same pressure level. This will increase the functional reliability of the compressor, since if an intermediate pressure duct fails due to plugging or the like, the lubrication still continues through the second duct. During normal operation without interference, the same lubricating characteristics are obtained for both scrolls. Viewed overall, this therefore improves the redundancy of lubricating the scrolls.

[0016]By using the conceptual implementation of the invention, the disadvantage of the prior art of the inaccurate and complicated control and management of the intermediate pressure by a mixture of refrigerant oil and refrigerant gas by means of the oil return can be overcome effectively in terms of design by providing the intermediate pressure duct. Refrigerant gas flows almost exclusively through the intermediate pressure duct, and it is thus possible to obtain a stable intermediate pressure in the intermediate pressure chamber.

[0018]Another embodiment is that the intermediate pressure for generating the axial sealing force between the orbiting and the fixed scroll can be well controlled and managed. The higher intermediate pressure ensures a stable sealing function during the compression of the refrigerant gas between the scrolls.

Problems solved by technology

Scroll compressors moreover operate radially to the inside, which results in a relatively short axial installation length for the compressor.

A known problem with refrigerant scroll compressors consists of the fact that the oil return must be designed for process safety and at the same time must be able to develop a sufficient sealing force with reference to the orbiting scroll by controlling the intermediate pressure.

This design from the prior art has the disadvantage, however, that the oil return and the intermediate pressure can only be poorly controlled.

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