Abstract: A motor stator is fixed to a body shell by shrinkage fit with a large fitting margin, and a compression mechanism is then shrinkage fit with a small fitting margin, and welded thereafter. Afterwards, an auxiliary bearing assembly is fixed in position with reference to the compression mechanism by shrinkage fit with a small fitting margin, followed further by welding.

Abstract: A motor stator is fixed to a body shell by shrinkage fit with a large fitting margin, and a compression mechanism is then shrinkage fit with a small fitting margin, and welded thereafter. Afterwards, an auxiliary bearing assembly is fixed in position with reference to the compression mechanism by shrinkage fit with a small fitting margin, followed further by welding.

Abstract: When sliding elements, slide bushings, vanes and Oldham rings employed in various types of refrigeration compressors and other applications meet the following conditions, they resist sticking to aluminum-base components, resist depletion of the oil film on slide faces, and exhibit excellent wear resistance. Firstly, the elements must comprise an iron-base sinter having closed cells on at least the slide face. Secondly, in order for the oil film to be maintained on the slide face by the closed cells and to enhance lubricating properties, the proportion of closed cells having circular-equivalent diameter of 10 &mgr;m or less, i.e. the number of ≦10 &mgr;m cells/total number of cells, must equal 85% or more, and the opening area of the closed cells on the slide face must equal 5% or less. Finally, the sliding element density must be 7.3 g/cm3 or higher.

Abstract: A gear pump is used in an electrically-operated sealed compressor. The compressor includes a compression mechanism, an electric motor for driving the compression mechanism, and a crankshaft for transmitting the rotational force of the electric motor to the compression mechanism. The gear pump includes a pair of gears being in mesh with each other, one of which is connected to one end of the crankshaft, and a pump casing accommodating only the pair of gears. The pump casing together with the gear pair is disposed on one side of a cover plate, while other elements constituting the gear pump are disposed on the other side of the cover plate. By this construction, the distance between the gear pair and an auxiliary bearing to which the gear pump is secured can be reduced and, hence, an undesirable whirling of one end portion of the crankshaft can also be reduced.

Abstract: In an electric motor, a stator is formed with multiple slots axially on the inner circumference thereof. Provided inside of each slot are an outer slot insulation film and an inner insulation film each made of a material having a different dielectric constant from the other. The slot insulation films assure such an earth capacitance as not to adversely affect a refrigerant compressor while allowing the increase in efficiency of the electric motor.

Abstract: A gear pump is used in an electrically-operated sealed compressor. The compressor includes a compression mechanism, an electric motor for driving the compression mechanism, and a crankshaft for transmitting the rotational force of the electric motor to the compression mechanism. The gear pump includes a pair of gears being in mesh with each other, one of which is connected to one end of the crankshaft, and a pump casing accommodating only the pair of gears. The pump casing together with the gear pair is disposed on one side of a cover plate, while other elements constituting the gear pump are disposed on the other side of the cover plate. By this construction, the distance between the gear pair and an auxiliary bearing to which the gear pump is secured can be reduced and, hence, an undesirable whirling of one end portion of the crankshaft can also be reduced.

Abstract: An orbiting scroll is engaged to and moved orbitally in relation to a fixed scroll at variable speeds. An offset surface is provided in at least one of the wraps of the fixed scroll and/or the orbiting scroll, by which a space S is created in one of the compression chambers formed between the fixed scroll and the orbiting scroll, which is thereby unsealed and opened to the inlet port side. The offset surface has a length from a position in the spiral length which satisfies the required compression ratio of one of the compression chambers in a low speed operation to the end of the spiral. An injection port is positioned such as to open to an unsealed area of this compression chamber, and gas injection shutoff and resumption is controlled through this injection port as appropriate to the situation.

Abstract: A gear pump is used in an electrically-operated sealed compressor. The compressor includes a compression mechanism, an electric motor for driving the compression mechanism, and a crankshaft for transmitting the rotational force of the electric motor to the compression mechanism. The gear pump includes a pair of gears being in mesh with each other, one of which is connected to one end of the crankshaft, and a pump casing accommodating only the pair of gears. The pump casing together with the gear pair is disposed on one side of a cover plate, while other elements constituting the gear pump are disposed on the other side of the cover plate. By this construction, the distance between the gear pair and an auxiliary bearing to which the gear pump is secured can be reduced and, hence, an undesirable whirling of one end portion of the crankshaft can also be reduced.

Abstract: A voltage value of an impulse voltage repetitively applied on a test-piece coil is increased in accordance with time elapse. A terminal voltage applied on both ends of the test-piece coil is monitored to detect an electric breakdown of the test-piece coil. Upon detecting such a breakdown, application of the impulse voltage is immediately stopped to prevent the test-piece coil from being unnecessarily damaged. Meanwhile, a voltage value of the impulse voltage is measured quantitatively at the time the electric breakdown is detected and the measured data is stored in a memory, so that the memorized data can be used later as a breakdown voltage value.

Abstract: A method of nondestructive insulation testing is disclosed which comprises the steps of: (a) placing an electric device, having a core and at least one winding provided on the core, in a reduced atmospheric pressure; (b) insulating the laminated core from the ground; (c) supplying a voltage signal having a first surge waveform to the winding; and detecting a glow discharge which may result from step (c) to detect an insulation condition of the winding, wherein the reduced atmospheric pressure ranges from 65 to 75 Torr and the voltage signal is applied in the first direction of the winding and then, is applied in the second, opposite, direction of the winding.

Abstract: A scroll compressor is designed to exert a stable pressure on the rear surface of the rotary scroll without causing excessive pressure rise or pressure gradient by the lubricating oil which flows out from a back pressure partitioning member in a very little gap of an axial supporting portion. A bearing member 18 has an inner portion extending radially inwardly from annular groove 22 and an outer portion extending radially outwardly from the annular groove 22 to an inner edge of an axial supporting portion 24. The inner and outer portions of the bearing member 18 are formed in a bottom portion of the bearing member 18 and have a difference in level d relative to a bottom surface of the axial supporting portion 24.

Abstract: In a sealed-type scroll compressor having a stationary scroll member and an orbiting scroll member, the stationary scroll member is fixed after rotating it in an orbiting direction of the orbiting scroll member by a predetermined angle from a phase angle position where a possible orbiting radius between both scroll members is made maximum at the temperature before driving the scroll compressor.

Abstract: A compressor for a refrigeration machine is provided without any problems of reduction in the life of a thrust bearing structure even when a substitutive coolant not containing any chlorine is used. In the compressor for a refrigeration machine having a thrust bearing made of steel for supporting a thrust load applied to a drive shaft, a thrust bearing surface made of a material different from that of the drive shaft is formed in the thrust bearing by means of a surface treatment. Alternatively a washer defining the thrust bearing surface may be surface treated to provide a material different from that of the drive shaft. The washer may also be made of a material different from that of the drive shaft. According to the the present invention, even when a boundary lubricating state is produced between the drive shaft and the thrust bearing surface sticking is prevented.

Abstract: In a sealed-type scroll compressor having a stationary scroll member and an orbiting scroll member, the stationary scroll member is fixed after rotating it in an orbiting direction of the orbiting scroll member by a predetermined angle from a phase angle position where a possible orbiting radius between both scroll members is made maximum at the temperature before driving the scroll compressor.

Abstract: To carry out a non-destructive test for testing insulation of a small-size electric machine having a coil, a surge voltage is applied to the coil of the electric machine mounted in a decompression tank whose inner pressure is kept from 15 to 25 [Torr] so as to generate glow discharge in case there exists a flaw in the coil.

Abstract: In a sealed electric scroll compressor, lubricating oil is collected in an oil collection pan mounted under a compression mechanism after the compression mechanism is lubricated thereby, the lubricating oil collected in the oil collection pan is discharged from a small hole at the side of the oil collection pan which is located remote from a delivery pipe for delivering a high-pressure refrigerant gas outward from a sealed container of the sealed electric compressor. The high-pressure refrigerant gas flows between the inner wall of the sealed container and a vertical cut part formed on the circumference of a stator of an electric motor.