Abstract: There are provided an operation number control device and a method for controlling the same that can level the operation times of the fluid machines, which are connected to the operation number control device. A fluid machine system comprises a plurality of fluid machines, and an operation number control device capable of individually controlling start and stop of the fluid machines. The operation number control device sets a continuous operation time for each of the fluid machines based on total operation times of the fluid machine and other fluid machines. When among fluid machines in operation, there is a fluid machine for which the continuous operation time set for the fluid machine has elapsed and there is a fluid machine at stop, the operation number control device causes the fluid machine at stop to start and causes the fluid machine to stop.

Abstract: A gas compression system that can continue control of the number of operated pieces of a compressor even when an abnormality has occurred and a control method thereof are provided. The gas compression system includes compressors, a number-of-pieces controller that executes master control to control the number of operated pieces of the compressor, and a communication network that connects the compressors and the number-of-pieces controller with each other in a mutually communicable manner. Each compressor includes a compressor main unit that compresses a gas and a controller that executes slave control to control the compressor main unit in response to a command from the number-of-pieces controller.

Abstract: A gas compressor includes inverters, a plurality of compressor units and a control device for controlling each of the inverters. The control device increases the number of compressor bodies to be operated after confirming that the rotational speed of the operational motors will reach a steady value immediately after causing the number of the compressor bodies to be operated to increase.

Abstract: The purpose of the present invention is to provide a gas compressor capable of reducing variation in discharge pressure through control of the number of compressor bodies and a control method for the gas compressor. In order to solve the problem, this gas compressor includes a plurality of compressor units each having a compressor body, a motor for driving the compressor body, and an inverter for controlling a rotational speed of the motor, and a control device for controlling the inverters. Discharge pipes of the compressor bodies converge on one main discharge pipe. A drive frequency of the motor of each compressor body is controlled by the corresponding inverter, whereby a pressure of each discharge pipe is controlled and a discharge pressure of the main discharge pipe is controlled.

Abstract: There are provided an operation number control device and a method for controlling the same that can level the operation times of the fluid machines, which are connected to the operation number control device. A fluid machine system comprises a plurality of fluid machines, and an operation number control device capable of individually controlling start and stop of the fluid machines. The operation number control device sets a continuous operation time for each of the fluid machines based on total operation times of the fluid machine and other fluid machines. When among fluid machines in operation, there is a fluid machine for which the continuous operation time set for the fluid machine has elapsed and there is a fluid machine at stop, the operation number control device causes the fluid machine at stop to start and causes the fluid machine to stop.

Abstract: The purpose of the present invention is to provide a gas compressor that can achieve reduced fluctuation of discharge pressure during compressor body number control, and a method for controlling the gas compressor. This gas compressor includes a plurality of compressor units each having a compressor body, a motor for driving the compressor body, and an inverter for controlling a rotational speed of the motor, and a control device for controlling each of the inverters, in which discharge pipes of the compressor bodies are merged with one main discharge pipe and discharge pressure of the main discharge pipe is controlled through control of pressure of the respective discharge pipes by controlling, by means of the respective inverters, driving frequencies of the compressor bodies.

Abstract: The purpose of the present invention is to provide a gas compressor capable of reducing variation in discharge pressure through control of the number of compressor bodies and a control method for the gas compressor. In order to solve the problem, this gas compressor includes a plurality of compressor units each having a compressor body, a motor for driving the compressor body, and an inverter for controlling a rotational speed of the motor, and a control device for controlling the inverters. Discharge pipes of the compressor bodies converge on one main discharge pipe. A drive frequency of the motor of each compressor body is controlled by the corresponding inverter, whereby a pressure of each discharge pipe is controlled and a discharge pressure of the main discharge pipe is controlled.

Abstract: A miniature motor including a case made of a metallic material and formed into a bottomed hollow cylindrical shape and having a permanent magnet fixedly fitted to the inner circumferential surface thereof, a rotor comprising an armature and a commutator, a case cap fitted to an open end of the case and having brushes making sliding contact with the commutator, and terminals electrically connected to the brushes; the rotor being rotatably supported by bearings provided on the bottom of the case and the case cap; in which the input terminals are mounted on the case cap made of a resin material and fixedly fitted to the case cap by means of lanced and raised retainer pieces formed on the input terminals near the outer end face of the case cap is disclosed. Also disclosed is a method of making miniature motors comprising a process of press-fitting input terminals into a case cap, and a process of forming lanced and raised retainer pieces in the vicinity of the outer end face of the case cap.