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Piston type compressorRelated Patent Categories: Pumps, Three Or More Cylinders Arranged In Parallel, Radial, Or Conical Relationship With Rotary Transmission AxisPiston type compressor description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20060228229, Piston type compressor. Brief Patent Description - Full Patent Description - Patent Application Claims
BACKGROUND OF THE INVENTION [0001] The present invention relates to a piston type compressor having an oil separator for separating lubricating oil from discharged refrigerant gas. [0002] In a piston type compressor for a vehicle air conditioner, lubricating oil in the form of mist is mixed with refrigerant gas for flowing therewith within the compressor thereby to lubricate inner parts of the compressor. In such a compressor, the oil is contained in the discharged refrigerant gas. To prevent oil from being carried by the refrigerant gas to an external refrigerant circuit of the vehicle air conditioner, an oil separator is provided in a discharge-pressure region within the compressor for separating oil from the refrigerant gas. This is because the oil flowing with the refrigerant gas into the external refrigerant circuit tends to adhere to an inner wall surface of a heat exchanger in the external refrigerant circuit thereby to deteriorate the heat exchanging efficiency of the heat exchanger. A typical piston type compressor having an oil separator is disclosed, for example, in Japanese Patent Application Publication No. 2004-218601. [0003] The piston type compressor has such a structure in which oil separated from refrigerant gas by the oil separator returns into the compressor (specifically, returns into a compression chamber) in order to keep efficient lubrication of inner parts of the compressor. For this purpose, the oil separator and the interior of the compressor are in communication through an oil return passage. [0004] The oil return passage connects the oil separator with the compression chamber, so that there is a pressure differential between the oil separator and the compression chamber when the oil return passage connects the compression chamber that has just completed the suction stroke (namely, a suction-pressure region) with the oil separator (namely, a discharge-pressure region). [0005] If the cross-sectional area of the oil return passage is excessively large, not only the oil but high-pressure refrigerant gas discharged into the oil separator would flow back into the compression chamber and a large amount of refrigerant gas will leak from the oil separator to the compression chamber. For this reason, the oil return passage should be formed with an extremely small cross-sectional area or the oil return passage should have a throttle portion therein to provide a throttle function in the oil return passage, thereby preventing the refrigerant gas from flowing back. [0006] In the structure having a throttle with an extremely small cross-sectional area, however, foreign matters tend to clog the oil return passage and/or the throttle portion. If the foreign, matters clog the oil return passage and/or the throttle portion, the quantity of lubricating oil that returns into the compressor through the oil return passage will be decreased, with the result that efficient lubrication of the compressor cannot be performed. [0007] The present invention is directed to a piston type compressor that prevents the leakage of refrigerant gas from a discharge-pressure region to a suction-pressure region of the compressor and effectively returns lubricating oil to the suction-pressure region of the compressor. SUMMARY OF THE INVENTION [0008] In accordance with the present invention, a piston type compressor comprises a housing, a rotary shaft supported by the housing, a cam mounted on the rotary shaft. The housing is formed with a cylinder bore in which a piston is accommodated and a cam chamber in which the cam is accommodated. The housing is further provided with a discharge-pressure region and a suction-pressure region therein. The compressor further comprises an oil separator provided in the discharge-pressure region and an oil reservoir for storing lubricating oil from the oil separator. The rotary shaft is provided with a regulating means for regulating the axial movement of the rotary shaft and for forming a clearance between the regulating means and the valve plate assembly. The clearance is communicated with the oil reservoir through a communication hole formed in the valve plate assembly so that the clearance functions as a throttle in an oil return passage extending from the oil separator to the inside of the compressor. The rotary shaft may be provided with a rotary valve. A supply passage as a suction passage is formed in the rotary valve and in communication with the cam chamber in which a suction port is provided to be connected to an evaporator in an external refrigerant circuit. [0009] Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS [0010] The features of the present invention that are believed to be novel are set forth with particularity in the appended claims. The invention together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which: [0011] FIG. 1 is the longitudinal cross-sectional view of a piston type compressor according to an embodiment; and [0012] FIG. 2 is the partially enlarged cross-sectional view of a rotary valve around a closure cap. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0013] The following will describe a preferred embodiment of a piston type compressor according to the present invention with reference to FIGS. 1 and 2. Note that the double-headed arrow Y1 indicates the upper and lower sides of a piston type compressor 10 and the double-headed arrow Y2 indicates the front and rear sides of the compressor 10 in FIG. 1. [0014] Now referring to FIG. 1, the piston type compressor 10 includes a front housing 12 and a rear housing 13 connected to the rear end of the front housing 12. A cylinder block 11 is fixedly connected inside the front housing 12. A valve plate assembly 14 is interposed between the cylinder block 11 and the rear housing 13. The cylinder block 11, the rear housing 13 and the valve plate assembly 14 are fastened together by a plurality of bolts B (only one bolt B shown in FIG. 1). The front housing 12 and the rear housing 13 cooperate to form the housing assembly of the compressor 10. [0015] The housing assembly has a discharge chamber 18 formed between the rear housing 13 and the valve plate assembly 14 on the radially outer side in the rear housing 13. The rear housing 13 is provided with an oil separator S for separating lubricating oil contained in refrigerant gas. The oil separator S is in fluid communication with the discharge chamber 18 through a communication port 18a. Hence, the oil separator S is located in a discharge-pressure region of the compressor 10. [0016] The oil separator S includes an oil separation chamber 44 and an oil separation cylinder 45 accommodated in the oil separation chamber 44. The oil separation chamber 44 is in communication with the discharge chamber 18 through the communication port 18a. The communication port 18a is opened to the oil separation chamber 44 at a position which faces the outer peripheral surface of the oil separation cylinder 45. [0017] The oil separator S has a discharge hole 35 formed therein for allowing refrigerant gas from which lubricating oil has been separated to be discharged out from the compressor 10. The discharge chamber 18 is in communication with an external refrigerant circuit 26 through the discharge hole 35. The external refrigerant circuit 26 includes a condenser 27 for removing heat from refrigerant gas, an expansion valve 28 and an evaporator 29 for transferring ambient heat in vehicle compartment to refrigerant gas. The discharge hole 35 is in communication with the condenser 27. [0018] An oil reservoir T is formed at the center of the rear housing 13 between the rear housing 13 and the valve plate assembly 14. The oil reservoir T and the oil separation chamber 44 of the oil separator S are in communication through an oil passage 32, through which lubricating oil separated from refrigerant gas in the oil separator S is carried into the oil reservoir T for storage therein. [0019] The oil reservoir T is in communication with a shaft hole 20, or the like, at the center of the cylinder block 11 through a communication hole 46 formed in the valve plate assembly 14, so that the lubricating oil stored in the oil reservoir T flows back toward the cylinder block 11 through the communication hole 46. Additionally, the valve plate assembly 14 has discharge ports 14a and discharge valves 14b formed therein in association with the discharge chamber 18. The discharge valves 14b are operable to open and close the respective discharge ports 14a. In this embodiment, the discharge chamber 18, the oil separation chamber 44, the discharge hole 35, the oil reservoir T and the compression chamber 34 in discharge stroke form the discharge-pressure region of the compressor 10. [0020] A crank chamber 17, which serves as a cam chamber, is defined between the front housing 12 and the cylinder block 11. A rotary shaft 19 is rotatably supported in the crank chamber 17 by the cylinder block 11 and the front housing 12. The rotary shaft 19 is inserted at one end thereof into the shaft hole 20 formed in the cylinder block 11 and at the other end thereof into a shaft hole 21 formed in the front housing 12. The shaft hole 20 is located in alignment with the oil reservoir T through the valve plate assembly 14, and the communication hole 46 adjacent to the cylinder block 11 is opened to the shaft hole 20. Continue reading about Piston type compressor... Full patent description for Piston type compressor Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Piston type compressor patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Piston type compressor or other areas of interest. ### Previous Patent Application: Engine mounting frame Next Patent Application: Liquid pump Industry Class: Pumps ### FreshPatents.com Support Thank you for viewing the Piston type compressor patent info. IP-related news and info Results in 0.28852 seconds Other interesting Feshpatents.com categories: Software: Finance , AI , Databases , Development , Document , Navigation , Error 174 |
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