Abstract: A scroll compressor comprises an operating state detection part (27) detecting an operating state, a variable-speed motor (28), a control part (26) and an unloading mechanism (12) serving as capacity control means. The control part (26) controls operation of the unloading mechanism (12) and the rotational frequency of the motor (28) in response to the operating state detected by the operating state detection part (27). An air conditioner comprises the aforementioned scroll compressor, a condenser (23), an expansion valve (24) and an evaporator (25).

Abstract: A first bypass valve (27) that sets discharge capacity to 60% is provided in a first scroll 21 of an asymmetrical spiral-type scroll compressor. Also, a second bypass valve (40) that makes suction side and discharge side communicated with each other so that set load of the compressor becomes 50% is provided outside a scroll of the first scroll (21). In this way, by closing the first and second bypass valves (27, 40), effective load of the compressor is set to 100%. Also, by opening the first bypass valve (27) and concurrently closing the second bypass valve (40), the effective load of the compressor is set to 60%. Further, by opening both the first and second bypass valves (27, 40), the effective load of the compressor is set to 30%.

Abstract: A machining apparatus simultaneously machining at least two portions of one workpiece is disclosed. The machining apparatus includes a worktable unit for rotatably driving workpiece, at least two tool heads each of which supports a tool and moves forward to or away from the workpiece, at least two gauging units measuring a diameter of each portion, and control unit controlling motion of each wheel head individually. The control unit controls motions of the wheel heads in according to signals provided from the gauging units, wherein controls all of tool heads to execute a finish grinding process, controls one tool head corresponding to one portion whose diameter became a required value to back off, and controls all of tool heads to execute a spark-out process after diameters of all of the portions became each required value. Therefore, it can prevent that accuracy of one portion machined by one tool head is deteriorated by effect of machining by another wheel head.

Abstract: A porous bronze 1b and a resin 1c impregnated in pores of the porous bronze 1b formed on a backing metal 1a constitute a bearing 1. At a surface to be brought into contact with a crank shaft 5, porous bronze 1b and resin 1c are sparsely exposed. Ratio of area of exposure of porous bronze 1b at the contact surface 1d is at least 5% and at most 60%. Thus a bearing for a refrigerating compressor having high seizure resistance at the time of boundary lubrication and having small amount of wear caused by sliding as well as a refrigerating compressor employing the same can be obtained.

Abstract: A first bypass valve (27) that sets discharge capacity to 60% is provided in a first scroll 21 of an asymmetrical spiral-type scroll compressor. Also, a second bypass valve (40) that makes suction side and discharge side communicated with each other so that set load of the compressor becomes 50% is provided outside a scroll of the first scroll (21). In this way, by closing the first and second bypass valves (27, 40), effective load of the compressor is set to 100%. Also, by opening the first bypass valve (27) and concurrently closing the second bypass valve (40), the effective load of the compressor is set to 60%. Further, by opening both the first and second bypass valves (27, 40), the effective load of the compressor is set to 30%. That is, 50% or lower partial load operation with high reliability is performed by setting volume ratio Vr during minimum capacity operation to a value of “1” or more. As a result of this, 50% or lower partial load operation can be changed over in multiple stages.