Mitsubishi Electric Corporation

Shimizu Construction Co., Ltd.

Other

Yuji Hirosawa

Masahiro Nigo

Seiji Takishima

Hiromitsu Takada

Fumito Takagi

Yoshio Takahashi

Emi Tsukamoto

Ryukichi Kijima

Eiji Goto

Tadashi Takakura

Einosuke Mifune

A rotor core has a magnet insertion hole, an opening formed adjacent to the magnet insertion hole in the circumferential direction, and a thin wall portion formed between the opening and an outer circumference of the rotor core. A stator core has a length in the axial direction shorter than that of the rotor core. The rotor core has a facing region where the rotor core faces the stator core in the radial direction and an overhang region where the rotor core protrudes from the stator core in the axial direction. A distance from the center axis to a portion of the outer circumference located on a radially outer side of the magnet insertion hole is longer in at least part of the overhang region than in the facing region. The minimum width of the thin wall portion in the radial direction is the same in both regions.

Motor, compressor, and air conditioner

A driving device includes an inverter to output a voltage to coils, a connection switching unit to switch a connection state of the coils between a Y connection and a delta connection, and a controller. The controller causes the inverter to stop outputting, when the connection state of the coils is the Y connection and a current value of the inverter reaches a first threshold A, or when the connection state of the coils is the delta connection and the current value of the inverter reaches a second threshold B. The first threshold A and the second threshold B satisfy B&#x3c;&#x221a;3&#xd7;A.

Driving device, compressor, air conditioner, and driving method

A stator includes a yoke portion, and a tooth portion located inside the yoke portion in a radial direction. A fracture surface ratio of an inner surface of the tooth portion in the radial direction is lower than a fracture surface ratio of a side surface of the yoke portion.

Stator, electric motor, compressor, refrigerating and air conditioning apparatus, and method for manufacturing stator

An air conditioner includes a compressor having a compressor motor including coils, an indoor fan having a fan motor, a connection switching unit that switches a connection state of the coils between a first connection state and a second connection state in which a line voltage is lower than a line voltage in the first connection state, and a controller that controls the compressor motor, the fan motor, and the connection switching unit. The controller provides a stop period during which rotation of the compressor motor stops before the connection switching unit switches the connection state of the coils, and rotates the fan motor for at least a time period within the stop period.

Air conditioner and method for controlling operation of air conditioner

A motor includes a stator and a rotor provided inside the stator. The rotor includes a rotor core having a magnet insertion hole and two permanent magnets disposed in the magnet insertion hole. The rotor core has a first magnet holding portion disposed between the two permanent magnets and holding the two permanent magnets, an opening disposed on an inner side of the first magnet holding portion in a radial direction of the rotor core, and a center hole disposed at a center of the rotor core in the radial direction. A distance from the opening to the magnet insertion hole is shorter than a distance from the opening to the center hole.

Motor, rotor, compressor, and refrigeration and air conditioning apparatus

A driving device includes a connection switching unit to switch a connection state of coils between a first connection state and a second connection state in which a line voltage is lower than in the first connection state, a controller to control a motor and the connection switching unit, and a rotation speed detector to detect a rotation speed of the motor. When the connection state of the coils is the first connection state and the rotation speed detected by the rotation speed detector becomes higher than or equal to a first rotation speed, the controller causes the motor to rotate at a second rotation speed higher than the first rotation speed, and then causes the connection switching unit to switch the connection state of the coils from the first connection state to the second connection state.

Driving device, air conditioner, and driving method

A driving device includes a connection switching unit that switches connection condition of a coil between Y connection and delta connection, an inverter, and a control device that controls a carrier frequency of the inverter. The carrier frequency is set at a first carrier frequency when the connection condition of the coil is the Y connection. The carrier frequency is set at a second carrier frequency when the connection condition of the coil is the delta connection.

Driving device, compressor, air conditioner and method of driving interior permanent magnet motor

A stator includes: a stator core including a first core part formed by at least one first sheet and a second core part provided on a side face of the first core part and formed by at least one second sheet; and a winding wound around an outer periphery of the first core part and the second core part.

Stator, motor, driving device, compressor, refrigeration air conditioner, and method of producing stator

A stator core includes a first core portion including a plurality of first plates stacked in a first direction; a second core portion including a plurality of second plates stacked in the first direction; and a third core portion including a plurality of third plates stacked in at least one direction orthogonal to the first direction, the third core portion being sandwiched between the first core portion and the second core portion. The third core portion has a yoke portion formed of a subset of the plurality of third plates stacked in a second direction orthogonal to the first direction.

Stator core, stator, electric motor, drive device, compressor, air conditioner, and a method of manufacturing a stator core

In a plant cultivation method, in cultivation of a plurality of plants within a cultivation bed which includes nutritive elements required for growth of the plants, a location adjacent a growing point of the plants is selected to supply gas to the growing point. In a plant cultivation apparatus, a cultivation bed is provided on which a plurality of plants are cultivated. The cultivation bed includes nutritive elements required for growth of the plants. An apparatus body for accommodating the cultivation bed has a gas-supply unit for supplying gas toward a location in the vicinity of a growing point of the plants. A gas-conditioning unit is arranged on the apparatus body for conditioning gas therewithin. An illumination unit for emitting a light to the plants.

Plant cultivation method and apparatus therefor

In a plant culture apparatus, plants being cultured are accommodated in a body. A culture bed is arranged within the body for culturing the plants. An illuminating device is arranged within the body for emitting a light to the plants on the culture bed. A gas-conditioning device is mounted to the body for recirculating gas therethrough. The illuminating device includes a lighting unit for emitting ultraviolet rays to the plants, and a transducing unit arranged below the lighting device for transducing the ultraviolet rays emitted from the lighting unit, to visible radiation. The transducing unit has long-wave absorbability and is formed by a plate element having its entire surface which is coated with phosphor.

Growing community of inventors

Tokyo, Japan

Yuji Hirosawa