A compressor includes a compression mechanism, a motor, a drive shaft, and a motor cooler. The compressor is configured to compress a working fluid. The motor dives the compression mechanism and is housed within a motor housing. The drive shaft is engaged with the motor and the compression mechanism and is configured to drive operation of the compression mechanism. The motor cooler is disposed adjacent the motor and is configured to pump a cooling working fluid around the motor. The motor cooler includes a pump that pumps the cooling working fluid into the motor housing based on a rotational speed of the drive shaft.

A refrigeration cycle apparatus (1) is capable of performing a refrigeration cycle using a small-GWP refrigerant. The refrigeration cycle apparatus (1) includes a refrigerant circuit (10) and a refrigerant enclosed in the refrigerant circuit (10). The refrigerant circuit includes a compressor (21), a condenser (23), a decompressing section (24), and an evaporator (31). The refrigerant contains at least 1,2-difluoroethylene.

A drive device for an AC motor includes: an adaptive observation unit that adaptively estimates an angular velocity of a rotor of an AC motor; a speed control unit that determines a first torque command with which an angular velocity command matches an average value of an estimated angular velocity; a phase lead amount calculation unit that calculates, based on a disturbance frequency, a phase lead amount of a transfer function from a true angular velocity to a model deviation; a vibration suppression control unit that determines, based on a frequency of load torque pulsations, the model deviation, and the phase lead amount, a second torque command with which speed pulsations in the AC motor are suppressed; and a torque control unit that controls a torque of the AC motor based on the first torque command and the second torque command.

An electric compressor, an inverter assembly jig and an inverter manufacturing method, an inverter of the compressor includes a frame coupled to a circuit board, the frame includes a base plate opposite the circuit board, fixing means protruding from the base plate and supporting an outer periphery of the circuit board, and a through-hole formed at a position corresponding to the fixing means, the inverter assembly jig includes an expansion pin inserted into the through-hole, and an expansion pin actuation mechanism moving the expansion pin closer to and away from the fixing means, the inverter method includes inserting the expansion pin into the through-hole, manipulating the expansion pin actuation mechanism to deform the fixing means, seating the circuit board on the base plate, and manipulating the expansion pin actuation mechanism so that the fixing means is restored and coupled to the circuit board.

A centrifugal compressor, including: a housing; a motor assembly disposed in the housing and a motor cavity and a motor shaft located in the motor cavity, the motor shaft having a first end and a second end extending from the motor cavity; a first impeller assembly located at the first end of the motor shaft and provided with a first labyrinth sealing mechanism; a second impeller assembly located at the second end of the motor shaft and provided with a second labyrinth sealing mechanism; a first gas bearing assembly provided between the motor cavity and the first impeller assembly; and a second gas bearing assembly provided between the motor cavity and the second impeller assembly; wherein the first labyrinth sealing mechanism is kept in gas communication with the first gas bearing assembly, and the second labyrinth sealing mechanism is kept in gas communication with the second gas bearing assembly.

In an air conditioner that uses a refrigerant mixture containing at least 1,2-difluoroethylene, high efficiency is achieved. The motor rotation rate of a compressor (100) can be changed in accordance with an air conditioning load, and thus a high annual performance factor (APF) can be achieved. In addition, an electrolytic capacitor is not required on an output side of a rectifier circuit (21), and thus an increase in the size and cost of the circuit is suppressed.

A rotor is a rotor for a pump. The rotor includes a rotor core having a magnet insertion hole and having an annular shape about an axis, a permanent magnet inserted in the magnet insertion hole, and a rotor cover surrounding the rotor core from outside in a radial direction about the axis. The rotor core has a first core portion disposed on an inner side of the magnet insertion hole in the radial direction, a second core portion disposed on an outer side of the magnet insertion hole in the radial direction, and a hole separating the first core portion and the second core portion from each other. The rotor cover has a positioning portion that positions the first core portion and the second core portion in a circumferential direction about the axis.

A direct-current power supply includes: a rectifier circuit in which switching elements are bridge-connected; a reactor; a gate circuitry that drives the switching elements; and a gate circuitry that drives the switching elements. A connection point between the switching element and the switching element is connected to an alternating-current power supply via the reactor, and a connection point between the switching element and the switching element is connected to the alternating-current power supply without via the reactor. A time during which the gate circuitry turns on the switching elements is longer than a time during which the gate circuitry turns on the switching elements.

A rotary compressor according to an embodiment includes a plurality of eccentric parts, a first balancer, and a second balancer. The plurality of eccentric parts include a first eccentric part, a second eccentric part, and a third eccentric part disposed to be aligned from one side to the other side. The second balancer is disposed on the other side of the first balancer. Angles between a direction of eccentricity of the first balancer and directions of eccentricity of the plurality of eccentric parts are configured to increase in an order of the third eccentric part, the second eccentric part, and the first eccentric part. Angles between a direction of eccentricity of the second balancer and directions of eccentricity of the plurality of eccentric parts are configured to increase in an order of the first eccentric part, the second eccentric part, and the third eccentric part.

This disclosure relates to an axial magnetic bearing for a centrifugal refrigerant compressor, and a corresponding system and method. A centrifugal refrigerant compressor system according to an exemplary aspect of the present disclosure includes, among other things, an impeller connected to a shaft, and a magnetic bearing system supporting the shaft. The magnetic bearing system includes an axial magnetic bearing, which itself includes a first permanent magnet configured to generate a first bias flux, a second permanent magnet axially spaced-apart from the first permanent magnet and configured to generate a second bias flux, and an electromagnet. The electromagnet includes a coil arranged radially outward of the first and second permanent magnets, and the electromagnet is configured to selectively generate either a first control flux or a second control flux to apply a force to the shaft in a first axial direction or second axial direction opposite the first axial direction, respectively.