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Valve mounting arrangement for a refrigeration compressor

Valve mounting arrangement for a refrigeration compressor description/claims

The present invention refers to an arrangement for mounting a valve, which is not of the single piece type, in a refrigeration compressor, such as that used in small refrigeration systems.

The energetic efficiency of the refrigeration compressors is mostly attributed to the good performance of their valves in the control of the gas flow.

In the reciprocating refrigeration compressors, the compression of the refrigerant gas is achieved by movement of the piston, which is driven by a driving means, such as a mechanism of the connecting rod-crankshaft type, or by a linear motor. The piston reciprocates inside the compression chamber and, at the moment it begins to return from the upper dead point to the lower dead point, in its suction stroke, it draws the refrigerant gas from the suction line of the refrigeration system to which the compressor is coupled (that is, coming from the evaporator of the refrigeration system). Subsequently, when said piston returns from the lower dead point, in its compression stroke, it compresses the refrigerant gas which, under high pressure (of condensation), flows through the discharge system and returns to the refrigeration system to which the compressor is coupled.

Reciprocating refrigeration compressors use one way valves to control the gas flow during operation thereof. The valve systems contained in the head are responsible for regulating the flowrate and optimizing the dynamics of the gas flow during the suction and discharge of refrigerant gas in relation to the compression cylinder. A suction valve controls the gas flow coming from the suction line connected to the low pressure side of the refrigeration system and which is drawn into the interior of the compression cylinder, while a discharge valve controls the already compressed gas flow to be directed to the high pressure side of the refrigeration system.

The suction valve is designed to be responsible not only for regulating the gas flow during the suction, but also in order that its opening and closing pendular movement be synchronized with the displacement of the piston. Actually, for a better performance in the compression cycle, it is desired to anticipate the opening of the suction valve (in relation to the arrival of the piston at the upper dead point), in order to increase the volumetric efficiency.

The suction and discharge valves generally comprise one or more passage orifices and vanes that are fixed by one of the ends thereof, so that, when a pressure differential is established through the valve, the vane moves, allowing the passage of gas in the required preferential direction.

There are countless embodiments of suction valve systems adopted in reciprocating compressors, regarding the project of the obturator, of the valve seat, of the gas passage orifice and also the way the valve is attached.

In the construction in which the suction valve is of the single-piece type, made of a laminar plate to be mounted to the valve plate, the suction valve is usually dimensioned to have its lateral movement restricted by head screws (FIG. 1), which attach the single-piece suction valve to both the valve plate and the head. This construction minimizes possible lateral and transverse movements which may alter the positioning of the suction valve when mounted to the valve plate. In spite of this advantage, said construction presents a high cost due to the raw material that is consumed in the production of said suction valve. Furthermore, such construction requires additional machining operations of the faces of the blank valve plate.

In a known prior art arrangement for mounting a single-piece suction valve, the latter is substituted by a valve that is not constructed in a single-piece, or valve element, which is lodged in a recess produced in the valve plate (FIG. 2), the fixation of said valve element to the valve plate being achieved by mechanically interlocking said parts, generally by riveting or spot welding.

Nevertheless, although not presenting the constructive deficiencies of the single-piece suction valve, said solution has the disadvantage of requiring an additional process for mounting the valve plate assembly, which is required to guarantee the correct positioning of the valve element in the recess.

Thus, it is an object of the present invention to provide a valve mounting arrangement for a refrigeration compressor, which allows providing and maintaining, in a simple and reliable manner, the positioning of a valve element on the valve plate.

Another object of the present invention is to provide an arrangement as cited above, which reduces the process steps of mounting the valve element on the valve plate.

An additional object is to provide an arrangement as cited above, which has a reduced cost.

These and other objects are achieved through a valve mounting arrangement for a compressor of the type that presents a cylinder defining, in its interior, a compression chamber having an end closed by a valve plate provided with at least one suction orifice and at least one discharge orifice, each being selectively closed by a respective valve element having a mounting end portion attached to an adjacent face of the valve plate; a bending median portion; and a sealing end portion operatively associated with the respective orifice on the valve plate, said mounting arrangement comprising: a receiving recess provided on the valve plate to lodge the mounting end portion of the valve element; a first retaining means to be seated and secured against said adjacent face of the valve plate, so as to retain the mounting end portion of the valve element in the interior of the receiving recess; and at least one of the parts of: at least one orientation projection, carried by at least one of the parts of receiving recess of the valve plate and mounting end portion of the valve element and to be fitted into a respective orientation recess provided in the other of said parts; and a second retaining means provided between the receiving recess and the mounting end portion of the valve element, so as to avoid the latter from moving outwardly from the receiving recess of the valve plate, before mounting the first retaining means.

The objects of the present invention are further achieved with a valve mounting arrangement for a refrigeration compressor of the type described above and which comprises: a receiving recess provided on the valve plate to lodge the mounting end portion of the valve element, said receiving recess presenting a contour similar to and surrounding the contour of said mounting end portion, so that the latter is tightly disposed in said receiving recess; a first retaining means to be seated and secured against said adjacent face of the valve plate, so as to retain the mounting end portion of the valve element in the interior of the receiving recess; and at least one of the parts of: at least one orientation projection carried by at least one of the parts of receiving recess of the valve plate and mounting end portion of the valve element and to be fitted into a respective orientation recess provided in the other of said parts; and a second retaining means provided between the receiving recess and the mounting end portion of the valve element, so as to avoid the latter from moving outwardly from the receiving recess of the valve plate, before mounting the first retaining means.

• Provisional Patent
• Utility Patent

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