A motor-driven compressor includes a compression unit, an electric motor, a housing, a cover, wherein the cover includes a main body and a connector coupler, and the cover and the housing define an accommodating chamber, a motor driving circuit that is accommodated in the accommodating chamber and includes a circuit board, and a metal terminal held in the connector coupler, wherein the metal terminal includes first and second end portions. The cover has a shield including a first shield portion, which blocks electromagnetic noise and forms at least part of the connector coupler, and a second shield portion, which blocks electromagnetic noise and forms at least part of the main body. The first and second shield portions are coupled to each other. The second shield portion includes an insertion hole into which one of the first and second end portions of the metal terminal is insertable.

Motor-driven compressor

A motor control device includes an inverter circuit including a plurality of switching elements connected into a three-phase bridge configuration and converting a direct current into a three-phase alternate current, a current detecting element connected to a direct current side of the inverter circuit, thereby generating a signal corresponding to a current value, a PWM signal generating unit which determines a rotor position based on phase currents of the motor and generates a three-phase PWM signal pattern so that the signal pattern follows the rotor position, and a current detecting unit detecting phase currents based on the signal generated by the current detecting element and the PWM signal pattern. The PWM signal generating unit generates the three-phase PWM signal pattern so that the current detecting unit is capable of detecting two phase currents in synchronization with advent of two fixed time-points within a carrier period of the PWM signal respectively.

Motor control device

The invention concerns a scroll compressor which is low in noise caused by water hammering of a refrigerant gas just after a discharge valve is closed. The scroll compressor includes a discharge member (45) having a discharge port (8) opposed to a discharge port (5) of a fixed scroll (2) and a discharge valve (9) opposed to the discharge port (8) of the discharge member (45) and opened/closed depending on a difference between flow passage pressure of a refrigerant gas and pressure in a high pressure space (27) in a sealed vessel (1). At least either of the fixed scroll (2) and the discharge member (45) is formed with a muffler chamber communicated with the discharge port (5, 8) and having a diameter larger than a diameter of the discharge port (5) of the fixed scroll (2) for suppressing occurrence of an impulse wave caused by water hammering when the discharge valve (9) is closed. Noise caused by a pressure ripple of the discharge port lessens, quieting the operation of the scroll compressor.

Scroll compressor having a discharge muffler chamber

The scroll gas compressor of the invention is so constructed that an enclosed container is partitioned by a fixed scroll member into a high pressure chamber and a low pressure chamber for gas-liquid separating intake refrigerant and storing it, the low pressure chamber being disposed at the lower portion and the high pressure chamber at the upper portion of enclosed container, the high pressure chamber disposing therein a drive unit related to a scroll compression mechanism and a lubricating oil sump, and the fixed scroll member serving also as part of the bottom of the lubricating oil sump, thereby providing that is small-sized, wide in an operational speed range, and superior in durability, and that prevents absorption of heat and noise propagation from the low pressure chamber serving as both the gas-liquid separation chamber and the reservoir of fluid, thereby improving the compression efficiency and lowering noise.

Scroll compressor with heat insulating and soundproof cover in bottom disposed low pressure chamber

The present invention is a wobble plate pump typically used in a reverse osmosis water purification system. The pump has a piston that is coupled to a wobble plate by a rocker arm. The piston has a stem which snaps into a corresponding sleeve of a diaphragm. The diaphragm is attached to the rocker arm and extends across the inner diameter of the pump to provide an inner pump seal. The piston stem and diaphragm sleeve extend through an access opening in a diaphragm support plate. The access opening of the wobble plate has an inner lip defined by a first relatively small radius near the center of the pump and a second relatively larger radius at the outer portion of the pump. The dual radiuses allow the piston to symmetrically reciprocate about a surface of the diaphragm support plate without inducing excessive stresses in the diaphragm. The symmetrical reciprocating motion maximizes the compression ratio of the pump. The piston reciprocates within a pump chamber defined by a manifold plate. The manifold plate has outlet passages located in a top portion of the chamber, so that when the pump is mounted in a horizontal position any air collected in the top portion of the chamber will be pushed through the passages. The manifold plate also has an air bleed passage that allows entrapped air to escape the pump chamber when the pump is mounted in a vertical, motor up, position. The assembly has a mounting bracket which dampens the resonant audible frequency created by the pump motor and a desiccant that is located with a breather port of the motor.

Pump with base plate having spring supports

PURPOSE:To enable to miniaturize the compressor and at the same time reduce the vibration and noise thereof by a structure wherein leg parts fixed to the bottom part of the compression main body are supported by elastic vibration insulators and at the same time dynamic vibration absorbers comprising supporting a weight by means of an elastic support fixed onto the leg part are provided. CONSTITUTION:The compressor is rotated at a rotational frequency a little lower than the frequency of power source and large vibration is excited at said frequency. However, because the dynamic vibration absorbers 5, the primary natural resonance frequency of which is made coincide with the rotational frequency of the compressor or the frequency of power source, are installed at the leg parts 2, the dynamic vibration absorbers 5 vibrate with a phase opposite to the vibration of the compressor. Accordingly, the dynamic vibration absorbers 5 supply reaction torques to the compressor main body 1 at the installation positions of the leg parts 2 through the elastic supports 5b and the leg parts 2. As a result, the torque due to the vibration of the compressor and the torque supplied by the dynamic vibration absorber 5 deaden each other, resulting in effectively reducing the overall vibration of the compressor.

Antivibration device of electrically-operated enclosed compressor

PURPOSE:To prevent the associated vibration of the compressor by a method wherein the main body of the compressor is supported by slanted vibration-proof supporting members so as to coincide the elastic axis of the compressor with the inertia axis thereof CONSTITUTION:A supporting leg B, provided at the bottom of the compressor main body A, is bent and the compressor main body A is supported slant-wise through the vibration-proof supporting members D interposed between the leg B and a base C, inorder to coincide the elastic axis O with the inertia axis through the center of gravity G by selecting the elastic coefficient of the vibration-proof supporting member D and a slanted supporting angle properly According to this method, rotating vibration and parallel-going vibration are not associated, therefore, the level of vibration is averaged and, as a result, the vibration and the noise of the compressor may be reduced as a whole

Vibration insulating device for enclosed type motor compressor

Sound absorber for air conditioning equipment

PURPOSE:To reduce vibration and noise by oppositely installing compression boards and allowing each cylinder inner chamber in each discharge hole range in the compression part to communicate with each other through a communicaption passage control mechanism and revolving the electrically driving boards reversely to each other. CONSTITUTION:During the time when two boards of compression parts 10 and 11 revolve, the pressure of the coolant which flows into each cylinder inner chamber 17, 12 is increased by the compressive action of pistons 25 and 30. After the pressure reaches a certain value, discharge valves 31 and 14 are opened to discharge the coolant. When the top dead center reaches near the position of the partitioning vane, the pressure sharply reduces nearly to the suction pressure. During the course of pressure variation through a series of processes, the pressure of coolant acts correspondingly onto the eccentric pistons 25 and 30, and a kind of loading torque variation is generated, while on the hand, the variation of the torque of the motor parts 9 and 8 is generated. Said loading torque variation can be offset by setting the compression parts 10 and 11 in the state of reverse revolution.

Rotary type closed compressor

PURPOSE:To absorb vibration due to the fluctuation in the load torque which occurs in a compression mechanism by providing a dynamic damper consisting of a weight, a rubber member and metal fittings on the wall of a sealed container perpendicularly and by making the primary natural frequency of the dynamic damper to generally correspond with the rotation frequency of the electric compressor or the frequency of electric power supply. CONSTITUTION:A dynamic damper 4 consisting of a weight 4a, a rubber member 4b and metal fittings 4c is installed on the wall of a sealed container perpendicularly. The dynamic damper 4 is so arranged that the mass of the weight 4a and the diameter and thickness of the rubber member 4b are designed so its primary natural frequency may correspond with the rotation frequency of an electric compressor or the frequency of electric power supply. As the dynamic damper 4 vibrates in the phase which is the reversal of that of the vibration of the compressor, the dynamic damper 4 supplies a counter-torque to the sealed container 1 through the rubber member 4b to provide the node of vibration, resulting in reducing the vibration of the compressor in any direction of the dynamic damper.

Mitsui Kimiyoshi

Papers

Antivibration device of electrically-operated enclosed compressor

Vibration insulating device for enclosed type motor compressor

Sound absorber for air conditioning equipment

Rotary type closed compressor

Vibration damping device for rotary electric compressor