Abstract: The present invention provides a linear motor, which can improve motor efficiency and which can be manufactured by a simplified procedure. The linear motor of the present invention includes a movable unit of cylindrical shape and having the central axis at the intersection of the X-axis and the Y-axis. An inner yoke is arranged on an inner side of the movable unit with a given spacing in the radial direction of the movable unit and is formed by laminating a multiple of thin plates each in approximately rectangular in shape and having strong magnetic permeability arranged in the direction of the X-axis. An outer yoke is arranged on the outer side of the movable unit with a given spacing in a radial direction of the movable unit and is formed by laminating a multiple of thin plates, each approximately rectangularly shaped and arranged in the same direction as the thin plates of the inner yoke. A pair of permanent magnets are magnetized in a direction from the inner yoke to the outer yoke.

Abstract: A linear motor comprising prismatic inner yokes each constructed in a manner that a large number of sheets each having a generally rectangular configuration and having a high magnetic permeability are piled up each other and outer yokes each constructed in a manner that a number of sheets each having a generally rectangular configuration and having a high magnetic permeability are piled up each other. Each of coils is wound around a central portion of three magnetic pole portions of the outer yoke to alternately establish different magnetic poles along a direction of an axis of the linear motor. A surface of the outer yoke, holding the magnetic pole portions, is disposed in an opposed relation to the inner yoke to define a predetermined gap therebetween so that the inner yoke and the outer yoke form each of a plurality of yoke blocks. The yoke blocks are placed around the axis so that the sheet piling-up direction is perpendicular to a diametrical direction of a shaft.

Abstract: When a lock detector detects a locked state of a DC motor in a starting stage, a torque increasing circuit immediately selects a starting sequence pattern of an output torque that is greater in magnitude by one preselected step, and outputs the selected output torque to a starting sequence controller, so that a compressor can be restarted speedily without repeating starting failures. A compressor, driven by a DC motor, has a shell of an internal pressure approximately equal to the pressure of an inhalation gas. An inverter is provided to make the speed of the DC motor variable. A rotational frequency setting circuit sets the rotational frequency of the DC motor to a frequency that is not greater than the frequency of a commercial power source when the internal temperature of a refrigerator is stabilized. By this construction, the power consumption can be remarkably reduced.

Abstract: When a lock detector detects a locked state of a DC motor in a starting stage, a torque increasing circuit immediately selects a starting sequence pattern of an output torque that is greater in magnitude by one preselected step, and outputs the selected output torque to a starting sequence controller, so that a compressor can be restarted speedily without repeating starting failures. A compressor, driven by a DC motor, has a shell of an internal pressure approximately equal to the pressure of an inhalation gas. An inverter is provided to make the speed of the DC motor variable. A rotational frequency setting circuit sets the rotational frequency of the DC motor to a frequency that is not greater than the frequency of a commercial power source when the internal temperature of a refrigerator is stabilized. By this construction, the power consumption can be remarkably reduced.

Abstract: A vibrating compressor of the present invention, which comprises a piston driving section for driving a piston by supplying a piston driving force, a displacement detecting section connected in an axial direction of the piston, an upper dead point position detecting section for detecting an upper dead point position based on a piston position signal from the displacement detecting section, and a driving force control section for changing the driving force supplied to the piston by the piston driving section according to a difference between the upper dead point position and a preset upper dead point position reference value immediately after the upper dead point position detecting section detects the upper dead point position, prevents its compression efficiency from decreasing due to stabilization and prevents a device from being damaged. In the vibrating compressor, it is also possible to calculate a stroke based on a detected piston position or to control the driving force based on a detected frequency.

Abstract: When a lock detector detects a locked state of a DC motor in a starting stage, a torque increasing circuit immediately selects a starting sequence pattern of an output torque that is greater in magnitude by one preselected step, and outputs the selected output torque to a starting sequence controller, so that a compressor can be restarted speedily without repeating starting failures. A compressor, driven by a DC motor, has a shell of an internal pressure approximately equal to the pressure of an inhalation gas. An inverter is provided to make the speed of the DC motor variable. A rotational frequency setting circuit sets the rotational frequency of the DC motor to a frequency that is not greater than the frequency of a commercial power source when the internal temperature of a refrigerator is stabilized. By this construction, the power consumption can be remarkably reduced.