A laundry treating machine includes a case, a tub, a drum, a drain pump housing, and a drain pump motor, wherein a plurality of fastening protrusions that are formed at one of the drain pump housing and the drain pump motor are inserted into a plurality of fastening grooves that are formed at the other of the drain pump housing and the drain pump motor, and wherein a length of one fastening protrusion is formed to be different from lengths of the other fastening protrusion such that the drain pump housing and the drain pump motor is prevented from being assembled wrongly.

A device for protecting an electric pump against overpressures, which comprises a main body which forms a cavity with an axis of extension which is substantially parallel to an axis of extension of the main body and a flow control element which can slide in the cavity along the axis of extension of the cavity between a closed position, in which the flow control element affects an inlet of the cavity which can be connected fluidically to a delivery port of an electric pump, and an open position, in which the flow control element clears at least partially the inlet so as to place it in fluidic connection with an outlet of said cavity, elastic means designed to push the flow control element in response to the pressure that is present in the delivery port.

A device for protecting an electric pump against overpressures, which comprises a main body which forms a cavity with an axis of extension which is substantially parallel to an axis of extension of the main body and a flow control element which can slide in the cavity along the axis of extension of the cavity between a closed position, in which the flow control element affects an inlet of the cavity which can be connected fluidically to a delivery port of an electric pump, and an open position, in which the flow control element clears at least partially the inlet so as to place it in fluidic connection with an outlet of said cavity, elastic means designed to push the flow control element in response to the pressure that is present in the delivery port.

A method for controlling a machine with at least one inverter-operated electric drive unit includes determining the instantaneous mains frequency of the mains supply to the machine and a deviation of the determined mains frequency over a standard frequency of the mains supply, determining a frequency correction value for adjusting the target drive frequency at which the electric motor of the machine is operated by weighting the deviation with a factor k, the factor k being specified dynamically as a function of at least one process variable of the drive load and/or of the operated drive process, and operating the machine at the adjusted target frequency.

A method for controlling a machine with at least one inverter-operated electric drive unit includes determining the instantaneous mains frequency of the mains supply to the machine and a deviation of the determined mains frequency over a standard frequency of the mains supply, determining a frequency correction value for adjusting the target drive frequency at which the electric motor of the machine is operated by weighting the deviation with a factor k, the factor k being specified dynamically as a function of at least one process variable of the drive load and/or of the operated drive process, and operating the machine at the adjusted target frequency.

A motor driving device for driving a motor is provided. The motor driving device includes: a driver outputting a drive signal for driving the motor to the motor; and a controller controlling a duty ratio of the drive signal based on three control parameters which are an initial duty ratio, a duty ratio increasing speed, and a target duty ratio. The controller has a normal control mode in which each of the three control parameters is a predetermined value, and a cryogenic control mode in which at least one of the three control parameters is a smaller value than in the normal control mode.

A motor driving device for driving a motor is provided. The motor driving device includes: a driver outputting a drive signal for driving the motor to the motor; and a controller controlling a duty ratio of the drive signal based on three control parameters which are an initial duty ratio, a duty ratio increasing speed, and a target duty ratio. The controller has a normal control mode in which each of the three control parameters is a predetermined value, and a cryogenic control mode in which at least one of the three control parameters is a smaller value than in the normal control mode.

An electric motor system includes a drive shaft, first and second magnetic bearing portions facing each other and supporting the drive shaft, an electric motor to rotate the drive shaft, and a gap detection unit to detect a position of the drive shaft During rotation of the drive shaft, greater external force acts, on average, on the drive shaft in a first direction than in a second direction. The first and second direction extend from the second and first magnetic bearing portions to the first and second magnetic bearing portion. The first and second magnetic bearing portions produce first and second magnetic forces on the drive shaft in the first and second directions. A magnitude of the second magnetic force is greater than a magnitude of the first magnetic force. The gap detection unit is arranged closer to the second magnetic bearing portion than to the first magnetic bearing portion.

A temperature destratification assembly can include an outer housing. An impeller can be positioned within the outer housing between the inlet and outlet of the outer housing. The impeller can have an impeller hub and a plurality of impeller blades extending radially outward from the impeller hub. The assembly can include an impeller motor configured to rotate the impeller blades about an axis of rotation. A stator can be positioned within the outer housing between the impeller and the outlet of the outer housing. The stator can include a plurality of vanes. The stator vanes can include an upstream edge at the upstream end of the stator, a first surface extending from the upstream edge to the downstream edge of the vane, and a second surface opposite the first surface and extending from the upstream edge to the downstream edge of vane. A plurality of the vanes can have a downstream edge at the outlet of the outer housing.

The present disclosure relates to the technical field of low-temperature pumps, in particular to a permanent magnet leakage-free low-temperature pump. The permanent magnet leakage-free low-temperature pump comprises a pump body, wherein a pump impeller is arranged in the pump body, the pump impeller and a permanent magnet motor are of a coaxial structure, no coupler device is arranged between the pump impeller and the permanent magnet motor, a motor barrel is arranged in the pump body and connected with an external power source through a wiring device to work, a first flange plate is arranged at the position, located at the front end, of the outer wall of the pump body, and a second flange plate is arranged at the position, located at the rear end, of the outer wall of the pump body.