Abstract: An electric expansion valve includes a drive unit, an output shaft, a main body, a valve body, and a joint portion. The drive unit receives supply of electric power and generates drive force to rotate and translate the output shaft. The main body includes a first inflow/outflow port, a second inflow/outflow port, a valve chamber, and a valve seat. The valve chamber is disposed in a refrigerant passage connecting the first inflow/outflow port and the second inflow/outflow port. The valve seat is disposed inside the valve chamber. The valve body is disposed within the valve chamber to open and close an opening of the valve seat. The joint portion connects an end of the output shaft and the valve body to be integrally displaceable.

Abstract: A motor-operated valve includes a motor, valve seat, valve body, magnetic gear, and controller. The motor generates rotational force when powered, allowing the valve body to open and close the valve port, which permits fluid passage. The magnetic gear transmits this force from the motor to the valve body. The controller regulates the electric current supplied to the motor. During fully-closed operation, the controller limits the current to less than a fully-closed current limit value, ensuring the valve port is completely closed. This limit value is higher than the adjusting current value, which is the current supplied during valve opening adjustments.

Abstract: A power transmission device includes a magnetic gear with an input shaft magnet that receives rotational driving force, a magnetic modulator to modulate magnetic flux, a multi-pole magnet with more poles than the input shaft magnet, and an output shaft rotating with either the magnetic modulator or the multi-pole magnet. The device also features a magnetic circuit where the magnetic flux flows in parallel from the input shaft magnet. Between the input shaft magnet and the magnetic modulator is a flux-forming member with higher magnetic permeability than a vacuum, forming a short-circuiting flux path. The magnetic circuit creates two paths: a torque generation path, where magnetic flux flows through the magnetic modulator and multi-pole magnet, and a short-circuit flux path, where it bypasses the magnetic modulator. The flux-forming member's magnetic permeability is within ±20% of the value that maximizes torque.

Abstract: A power transmission device includes: a pole piece configured to rotate by modulating a magnetic flux between a drive-side magnet and a stationary magnet; and a sealing member that partitions an inside of a housing into a driving side space where the drive-side magnet is disposed and a driven side space where the stationary magnet and the pole piece are disposed, so as to seal fluid between the driving side space and the driven side space. The pole piece and the stationary magnet have a cylindrical shape and are disposed coaxially with and radially outer side of the drive-side magnet. The sealing member includes: a sealing cylinder portion positioned radially outer side of the drive-side magnet; and a sealing bottom surface portion covering the sealing cylinder portion from the driving side space.