Abstract: The piston is provided with a pair of radial holes opened to an external circumferential recess and lodging and retaining one respective end of a pin, to which is coupled a driving mechanism to reciprocate the piston inside a cylinder. The radial holes are completely sealed in order that the axial extension of a bottom radial gap provided by a bottom bearing surface of the piston work together with the axial extension of a top radial gap provided by a top bearing surface to provide the required leakage restriction of the refrigerant gas and also the required bearing of the piston inside the cylinder. The axial extension of each of the top bearing surface and of the bottom bearing surface is insufficient to provide by itself said required leakage restriction of the refrigerant gas.

Abstract: The present invention relates to a flow rate control system in refrigeration circuits, to a method for controlling a refrigeration system and to a refrigeration system properly speaking, which may include, for example, from a domestic refrigerator to an air conditioning system. In particular, the present invention is directed to a solution for the loss of efficiency in the expansion valve (17), when the system load varies, making the expansion valve (17) operate below its nominal capacity and, therefore, at low efficiency. One of the ways to achieve the objectives of the present invention is through a flow rate control system in refrigeration circuits comprising a hermetic compressor fluidly connected to a closed circuit (20).

Abstract: The piston is provided with a pair of radial holes opened to an external circumferential recess and lodging and retaining one respective end of a pin, to which is coupled a driving mechanism to reciprocate the piston inside a cylinder. The radial holes are completely sealed in order that the axial extension of a bottom radial gap provided by a bottom bearing surface of the piston work together with the axial extension of a top radial gap provided by a top bearing surface to provide the required leakage restriction of the refrigerant gas and also the required bearing of the piston inside the cylinder. The axial extension of each of the top bearing surface and of the bottom bearing surface is insufficient to provide by itself said required leakage restriction of the refrigerant gas.

Abstract: A mounting arrangement for the piston of a reciprocating hermetic compressor, comprising: a cylinder (1), inside which is defined a compression chamber (C); and a piston (10) provided with a pair of radial holes (11), each lodging and retaining one end of a pin (20), to which is coupled a driving mechanism of the compressor to reciprocate the piston (10) inside the cylinder (1), said radial holes (11) being completely sealed in relation to the radial gaps (15) of the bearing surfaces (10a, 10b) of the piston (10), so that both radial gaps (15) operate as means for restraining the leakage of refrigerant gas outwardly and inwardly in relation to the compression chamber (C).

Abstract: The fixation arrangement of the present invention is applied to a compressor of the type which comprises a shell (1) inferiorly defining an oil sump (3) and housing: a crankshaft (4) journalled in a cylinder block (2) and carrying a rotor (6) formed by a stack of annular laminations; and an oil pump (10) comprising a tubular sleeve (20), which is superiorly mounted to the rotor (6) and inferiorly immersed in the oil sump (3), and a pump shaft (30). The fixation arrangement comprises at least one retention element (40) radially and axially locked around the tubular sleeve (20) and having a radially outer locking portion (41), which is seated and radially forced against a respective confronting circumferential extension (6c) defined between two consecutive annular laminations, in order to axially lock the tubular sleeve (20) to the rotor (6).

Abstract: Oil pump for hermetic refrigerating compressor comprising a tubular sleeve having an upper portion affixed to at least one of the parts of crankshaft and rotor, and a lower portion having a lower end immersed in the lubricant oil, said tubular sleeve being provided with an inner surface presenting, along at least part of its longitudinal extension, at least one helical groove upwardly extending from the lower end; and a pump body disposed inside the tubular sleeve and defining, with the adjacent helical groove of the tubular sleeve, a lubricant oil ascending channel, said pump body presenting a lower end portion mounted to one of the parts of shell, cylinder block and stator, so as to be freely displaced within the tubular sleeve, in radial directions orthogonal to the crankshaft and rotatively locked in relation to the rotor.

Abstract: A piston-and-cylinder assembly, used in cooling sys terns that may include, for example, refrigerators, air-conditioning systems and the like. In order to solve the problems of volumetric loss (or of cooling capacity) of compressors in general, according to the present invention, one foresees configuring the cylinder (11) of the compression chamber in such a manner that the friction will be as low as possible in the phase in which the gas being compresses still does not exert a significant force onto the piston (10) top and will only have a significant effect during the phase in which the gas to be compressed exerts a greater force onto the piston (10), a moment when the volumetric loss impairs the efficiency of the compressor.

Abstract: The present invention relates to a control system for protection against breakage of the lubricating-oil film in the bearings of hermetic compressors, as well as to a control method that has the objective of guaranteeing that a variable-capacity compressor should be maintained above a minimum rotation in order to prevent the oil film close to the respective bearing from breaking. One of the forms of achieving the objectives of the present invention is by means of a control system for protection against break of the lubricating-oil film in bearings of hermetic compressors, a microprocessor (10) actuating a set of switches (SW2M) selectively, so as to generate a rotation at the motor-compressor assembly (20, 21), the compressor (21) having a minimum rotation (RPMmin) of the compressor (21) so that the oil film will not be broken.

Abstract: The fixation arrangement of the present invention is applied to a compressor of the type which comprises a shell (1) inferiorly defining an oil sump (3) and housing: a crankshaft (4) journalled in a cylinder block (2) and carrying a rotor (6) formed by a stack of annular laminations; and an oil pump (10) comprising a tubular sleeve (20), which is superiorly mounted to the rotor (6) and inferiorly immersed in the oil sump (3), and a pump shaft (30). The fixation arrangement comprises at least one retention element (40) radially and axially locked around the tubular sleeve (20) and having a radially outer locking portion (41), which is seated and radially forced against a respective confronting circumferential extension (6c) defined between two consecutive annular laminations, in order to axially lock the tubular sleeve (20) to the rotor (6).

Abstract: A piston-and-cylinder assembly, used in cooling sys terns that may include, for example, refrigerators, air-conditioning systems and the like. In order to solve the problems of volumetric loss (or of cooling capacity) of compressors in general, according to the present invention, one foresees configuring the cylinder (11) of the compression chamber in such a manner that the friction will be as low as possible in the phase in which the gas being compresses still does not exert a significant force onto the piston (10) top and will only have a significant effect during the phase in which the gas to be compressed exerts a greater force onto the piston (10), a moment when the volumetric loss impairs the efficiency of the compressor.

Abstract: Oil pump for hermetic refrigerating compressor comprising a tubular sleeve having an upper portion affixed to at least one of the parts of crankshaft and rotor, and a lower portion having a lower end immersed in the lubricant oil, said tubular sleeve being provided with an inner surface presenting, along at least part of its longitudinal extension, at least one helical groove upwardly extending from the lower end; and a pump body disposed inside the tubular sleeve and defining, with the adjacent helical groove of the tubular sleeve, a lubricant oil ascending channel, said pump body presenting a lower end portion mounted to one of the parts of shell, cylinder block and stator, so as to be freely displaced within the tubular sleeve, in radial directions orthogonal to the crankshaft and rotatively locked in relation to the rotor.

Abstract: The present invention relates to a flow rate control system in refrigeration circuits, to a method for controlling a refrigeration system and to a refrigeration system properly speaking, which may include, for example, from a domestic refrigerator to an air conditioning system. In particular, the present invention is directed to a solution for the loss of efficiency in the expansion valve (17), when the system load varies, making the expansion valve (17) operate below its nominal capacity and, therefore, at low efficiency. One of the ways to achieve the objectives of the present invention is through a flow rate control system in refrigeration circuits comprising a hermetic compressor fluidly connected to a closed circuit (20).

Abstract: The present invention relates to a control system for protection against breakage of the lubricating-oil film in the bearings of hermetic compressors, as well as to a control method that has the objective of guaranteeing that a variable-capacity compressor should be maintained above a minimum rotation in order to prevent the oil film close to the respective bearing from breaking. One of the forms of achieving the objectives of the present invention is by means of a control system for protection against break of the lubricating-oil film in bearings of hermetic compressors, a microprocessor (10) actuating a set of switches (SW2M) selectively, so as to generate a rotation at the motor-compressor assembly (20, 21), the compressor (21) having a minimum rotation (RPMmin) of the compressor (21) so that the oil film will not be broken.

Abstract: A mounting arrangement for the piston of a reciprocating hermetic compressor, comprising: a cylinder (1), inside which is defined a compression chamber (C); and a piston (10) provided with a pair of radial holes (11), each lodging and retaining one end of a pin (20), to which is coupled a driving mechanism of the compressor to reciprocate the piston (10) inside the cylinder (1), said radial holes (11) being completely sealed in relation to the radial gaps (15) of the bearing surfaces (10a, 10b) of the piston (10), so that both radial gaps (15) operate as means for restraining the leakage of refrigerant gas outwardly and inwardly in relation to the compression chamber (C).