Abstract: A driving device includes an electric motor, a drive gear, a deceleration mechanism, a driven gear, and a housing. At least either one of the drive gear and the driven gear is provided as a helical gear. The deceleration mechanism includes a plurality of reduction gear shafts, a plurality of bearings, and a biasing member provided for at least any one of the bearings. The biasing member axially biases an outer ring of the at least any one of the bearings that supports at least either one of end parts of the shaft portion of a corresponding one of the reduction gear shafts, the end parts including an end part on the large-diameter gear wheel side and an end part on the small-diameter gear wheel side.

Abstract: An outdoor unit control unit has a defrosting operation condition table that defines an activation rotational speed based on the total sum of the rated capacity of indoor units and a refrigerant pipe length that is the length of a liquid pipe or of a gas pipe. The outdoor unit control unit uses the total sum of the rated capacity of the indoor units and refers to the defrosting operation condition table, so as to determine the activation rotational speed, and then the outdoor unit control unit activates a compressor at the determined activation rotational speed when starting a defrosting operation, maintains this activation rotational speed for a predetermined time (one minute) from the start of the defrosting operation, and drives the compressor.

Abstract: A CPU 210 receives suction pressure PL and a suction temperature Te, calculates a saturation temperature corresponding to the evaporation pressure Ts1 by using the suction pressure PL, and calculates a suction superheating degree SHs of a compressor 21 by using the suction temperature Te and the saturation temperature corresponding to the evaporation pressure Ts1. The CPU 210 reads a current opening degree De of an outdoor expansion valve 24. Next, the CPU 210 uses the received suction pressure PL and opening degree De of the outdoor expansion valve 24 and the calculated suction superheating degree SHs, refers to an outdoor fan control table 300, and determines a control aspect of an outdoor fan 27. The CPU 210 executes control of the outdoor fan 27 in accordance with the control aspect that is determined by referring to an outdoor fan control table 300.

Abstract: An outdoor unit control unit 200 has a defrosting operation condition table 300a that defines a defrosting operation interval time Tm in accordance with a total sum of rated capacity of indoor units 5a to 5c and a refrigerant pipe length as lengths of a liquid pipe 8 and a gas pipe 9. The outdoor unit control unit 200 uses the total sum of the rated capacity of indoor units 5a to 5c input by using an installation information input unit 250 and refers to the defrosting operation condition table 300a, so as to determine the defrosting operation interval time Tm. Then, the outdoor unit control unit 200 forcibly performs a defrosting operation when the defrosting operation interval time Tm elapses without establishment of a defrosting operation start condition since the last defrosting operation is terminated.

Abstract: A rotational speed Cr of a compressor 21 during a defrosting operation is controlled within a control range that corresponds to a capacity ratio P, a total sum Pi of rated capacity of an indoor unit, or a refrigerant pipe length Lr. Accordingly, even in the case where a refrigerant circulation amount during the defrosting operation is reduced due to an installation state of an air conditioner 1, it is possible to prevent suction pressure from being significantly reduced and falling below a performance lower limit value of the compressor 21. Thus, damage to the compressor 21 can be prevented. In addition, it is possible to prevent a case where the suction pressure falls below the performance lower limit value of the compressor 21 and thus low-pressure protection control is executed. Therefore, a case where the restoration of the heating operation is delayed does not occur.

Abstract: An outdoor unit control unit 200 has a defrosting operation condition table 300a that defines an activation rotational speed Cr in accordance with a total sum of flow rate coefficients Cva that is a total sum of flow rate coefficients Cv representing capacities of indoor expansion valves 52a to 52c. The outdoor unit control unit 200 calculates the total sum of the flow rate coefficients Cva by adding the flow rate coefficient Cv of each of the indoor expansion valves 52a to 52c, and refers to the defrosting operation condition table 300a, so as to determine the activation rotational speed Cr. Then, the outdoor unit control unit 200 activates a compressor 21 at the determined activation rotational speed Cr when starting a defrosting operation, maintains this activation rotational speed Cr for a predetermined time from the start of the defrosting operation, and drives the compressor 21.

Abstract: An outdoor unit of an air conditioner includes: an outdoor fan; an outdoor air temperature detector; and a controller, wherein the controller performs: a fan defrost operation to circulate the refrigerant in the same order as in the case of a cooling operation and rotate the outdoor fan when the outdoor air temperature is within a predetermined temperature range, a fan defrost operation over a period of a first fan defrost operation time when the outdoor air temperature is lower than a first predetermined temperature, and a fan defrost operation over a period of a second fan defrost operation time that is longer than the first fan defrost operation time when the outdoor air temperature is equal to or higher than a second predetermined temperature that is higher than the first predetermined temperature.

Abstract: A CPU 210 receives suction pressure PL and a suction temperature Te, calculates a saturation temperature corresponding to the evaporation pressure Ts1 by using the suction pressure PL, and calculates a suction superheating degree SHs of a compressor 21 by using the suction temperature Te and the saturation temperature corresponding to the evaporation pressure Ts1. The CPU 210 reads a current opening degree De of an outdoor expansion valve 24. Next, the CPU 210 uses the received suction pressure PL and opening degree De of the outdoor expansion valve 24 and the calculated suction superheating degree SHs, refers to an outdoor fan control table 300, and determines a control aspect of an outdoor fan 27. The CPU 210 executes control of the outdoor fan 27 in accordance with the control aspect that is determined by referring to an outdoor fan control table 300.

Abstract: An outdoor unit control unit 200 has a defrosting operation condition table 300a that defines an activation rotational speed Cr in accordance with a total sum of flow rate coefficients Cva that is a total sum of flow rate coefficients Cv representing capacities of indoor expansion valves 52a to 52c. The outdoor unit control unit 200 calculates the total sum of the flow rate coefficients Cva by adding the flow rate coefficient Cv of each of the indoor expansion valves 52a to 52c, and refers to the defrosting operation condition table 300a, so as to determine the activation rotational speed Cr. Then, the outdoor unit control unit 200 activates a compressor 21 at the determined activation rotational speed Cr when starting a defrosting operation, maintains this activation rotational speed Cr for a predetermined time from the start of the defrosting operation, and drives the compressor 21.

Abstract: A rotational speed Cr of a compressor 21 during a defrosting operation is controlled within a control range that corresponds to a capacity ratio P, a total sum Pi of rated capacity of an indoor unit, or a refrigerant pipe length Lr. Accordingly, even in the case where a refrigerant circulation amount during the defrosting operation is reduced due to an installation state of an air conditioner 1, it is possible to prevent suction pressure from being significantly reduced and falling below a performance lower limit value of the compressor 21. Thus, damage to the compressor 21 can be prevented. In addition, it is possible to prevent a case where the suction pressure falls below the performance lower limit value of the compressor 21 and thus low-pressure protection control is executed. Therefore, a case where the restoration of the heating operation is delayed does not occur.

Abstract: An outdoor unit control unit 200 has a defrosting operation condition table 300a that defines a defrosting operation interval time Tm in accordance with a total sum of rated capacity of indoor units 5a to 5c and a refrigerant pipe length as lengths of a liquid pipe 8 and a gas pipe 9. The outdoor unit control unit 200 uses the total sum of the rated capacity of indoor units 5a to 5c input by using an installation information input unit 250 and refers to the defrosting operation condition table 300a, so as to determine the defrosting operation interval time Tm. Then, the outdoor unit control unit 200 forcibly performs a defrosting operation when the defrosting operation interval time Tm elapses without establishment of a defrosting operation start condition since the last defrosting operation is terminated.

Abstract: An outdoor unit control unit 200 has a defrosting operation condition table 300a that defines an activation rotational speed Cr in accordance with a total sum of rated capacity of indoor units 5a to 5c and a refrigerant pipe length that is lengths of a liquid pipe 8 or a gas pipe 9. The outdoor unit control unit 200 uses the total sum of the rated capacity of the indoor units 5a to 5c and refers to the defrosting operation condition table 300a, so as to determine the activation rotational speed Cr. Then, the outdoor unit control unit 200 activates a compressor 21 at the determined activation rotational speed Cr when starting a defrosting operation, maintains this activation rotational speed Cr for a predetermined time (one minute) from the start of the defrosting operation, and drives the compressor 21.

Abstract: An outdoor unit of an air conditioner includes: an outdoor fan; an outdoor air temperature detector; and a controller, wherein the controller performs: a fan defrost operation to circulate the refrigerant in the same order as in the case of a cooling operation and rotate the outdoor fan when the outdoor air temperature is within a predetermined temperature range, a fan defrost operation over a period of a first fan defrost operation time when the outdoor air temperature is lower than a first predetermined temperature, and a fan defrost operation over a period of a second fan defrost operation time that is longer than the first fan defrost operation time when the outdoor air temperature is equal to or higher than a second predetermined temperature that is higher than the first predetermined temperature.

Abstract: An air conditioner outdoor unit includes: a compressor; a heat source-side heat exchanger connected to the compressor; an oil separator disposed between a refrigerant discharge opening of the compressor and the heat source-side heat exchanger configured to separate a refrigerant oil from a refrigerant discharged from the compressor; and a first three-way valve fitted to a refrigerant pipe between the oil separator and the heat source-side heat exchange.