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 system (15) regulates a temperature of fluid in a sector of a fluid distribution network, including a feed line (11) transporting fluid from a thermal energy source (3) to a thermal energy consumer (7) within the sector and a return line (13) transporting fluid back. A bypass line (17) connects the return line to the feed line, mixing fluid from the return line into the feed line. A pump is at the bypass line. A temperature sensor determines a temperature of fluid in the feed line downstream of the bypass line. A pressure sensor determines an uncontrolled pressure difference between the feed line and the return line, or an uncontrolled pressure difference correlated therewith. A control unit controls the speed of the pump with a closed-loop control for achieving a target feed line temperature based on the determined temperature, and a feed-forward control compensating fluctuations of the pressure difference.

A centrifugal pump assembly includes an electrical drive motor (4, 6), an impeller (14) which is driven by the electrical drive motor (4, 6) as well as with at least one valve element (18) which is directly or indirectly movable along a first movement path between at least two switching positions, by the electrical drive motor (4, 6). At least a part of the valve element (18) is additionally movable along a second movement path which is different to the first movement path, between a released position, in which the valve element is distanced to at least one contact surface and a bearing position, in which the valve element bears on the at least one contact surface.

An adhesive dispensing system for applying liquid adhesive to a substrate using different nozzles with the same manifold is disclosed. The adhesive dispensing system includes a manifold having a body, a first clamp configured to engage the body of the manifold, a second clamp configured to engage the body of the manifold, and a nozzle. The first and second clamps secure the nozzle to the body of the manifold. The body of the manifold has a first contact surface that engages the first clamp and a second contact surface that engages the second clamp and the nozzle, where the second contact surface is angularly offset from the first contact surface.

A blood pump is described that includes an impeller having proximal and distal bushings, at least one helical elongate element, a spring that is disposed inside of the helical elongate element and along an axis around which the helical elongate element winds, and a film of material supported between the helical elongate element and the spring. A frame is disposed around the impeller. A flexible elongate element extends radially from the spring to the helical elongate element, and maintains the helical elongate element within a given distance from the spring, to thereby maintain a gap between an outer edge of a blade of the impeller and an inner surface of the frame, during rotation of the impeller. Other applications are also described.

A device for tangential flow filtration includes a filter unit having first and second fluid openings, a filter element and a permeate opening, a first flow connection to connect the first fluid opening to a reservoir, a second flow connection to connect the second fluid opening to the reservoir, a first centrifugal pump in the first flow connection to convey the fluid from the reservoir to the filter unit, a first controller to actuate the first centrifugal pump, the filter unit designed such that the fluid for tangential flow filtration is capable of flowing substantially parallel to the filter element, a second centrifugal pump in the second flow connection, with which a counter-pressure is capable of being generated at the second fluid opening, and a second controller to actuate the second centrifugal pump.

A hydraulic motor-driven fuel boost pump includes redundant safeguards against overspeeding the impellers. A flow limiter limits the amount of hydraulic fluid that can be supplied to the hydraulic motor, thereby limiting the torque that can be applied to the impellers. A control valve also transitions between a non-restrictive operating state and a restrictive operating state. In the restrictive operating state the control valve regulates the displacement of the swash plate when in the non-restrictive operating state. The control valve does not counter the bias of the swash plate control spring when in the restrictive operating state.

A pump assembly includes at least one rotatingly driven impeller (14) and at least one valve element (18) which is rotatable about a rotation axis (X) between at least two switching positions. The valve element (18) includes a first face side (22) which extends transversely to the rotation axis of the valve element. A suction opening (24), which is engaged with a suction port (26) of the impeller (14), is formed in this first face side in a central region. The first face side (22) includes a pressure surface which surrounds the suction opening (24) and is adjacent to a delivery chamber (28) which surrounds the impeller (14).

Embodiments of the present disclosure relate to a refrigeration system that includes a compressor configured to circulate refrigerant along a refrigerant loop, a motor configured to drive the compressor, and a variable speed drive coupled to the motor and configured to supply power to the motor. The variable speed drive includes a primary winding of a step down transformer coupled to an alternating current (AC) power source, a first secondary winding of the step down transformer, where the first secondary winding is configured to supply power at a variable supplied voltage to the motor when the motor operates below a threshold voltage, and a second secondary winding of the step down transformer, where the second secondary winding is configured to supply power at a fixed supplied voltage when the motor operates at or above the threshold voltage.

A variable frequency drive system and a method of controlling a pump driven by a motor with the pump in fluid communication with a fluid system is provided. The method includes monitoring a pressure in the fluid system, monitoring and adjusting an operating frequency of the motor to maintain the pressure at a pressure set point, and, based on the monitored operating frequency, causing the pump to temporarily boost the pressure in the fluid system to a temporary boost set point for a first time period. The method also includes determining whether the temporarily boosted pressure in the fluid system stays above the pressure set point for a second time period and causing the pump to enter a sleep mode when the temporarily boosted pressure stays above the pressure set point through the second time period.