Disclosed is a dual-stage fluidics system that has reduced pulsation. This system uses inexpensive peristaltic pumps and two reservoirs that dampen pulsations in pressure. Peristaltic pumps are used as air pressure pumps and sheath fluid pumps that are placed between the two pressurized reservoirs and isolate the two reservoirs. Since the two reservoirs are maintained at a substantially even pressure, pulsations are reduced so that the peristaltic pumps essentially provide air flow and sheath fluid flow as needed.

Disclosed is a dual-stage fluidics system that has reduced pulsation. This system uses inexpensive peristaltic pumps and two reservoirs that dampen pulsations in pressure. Peristaltic pumps are used as air pressure pumps and sheath fluid pumps that are placed between the two pressurized reservoirs and isolate the two reservoirs. Since the two reservoirs are maintained at a substantially even pressure, pulsations are reduced so that the peristaltic pumps essentially provide air flow and sheath fluid flow as needed.

The damper mechanism used for a high-pressure fuel supply pump is configured so that an outer circumferential surface of a cover in regard to the thickness direction of the base material of the cover engages with the inner circumference of an open end part of a bottomed tubular concave part formed in a damper housing or in a pump housing of the high-pressure fuel supply pump. The total height of the damper as a low-pressure pulsation reducing mechanism can be reduced, and the dimensions of the damper in the radial directions can also be reduced. In cases where the damper mechanism is formed integrally with the high-pressure fuel supply pump, the total height of the high-pressure fuel supply pump can be reduced and the dimensions of the damper part in the radial directions can also be reduced.

The damper mechanism used for a high-pressure fuel supply pump is configured so that an outer circumferential surface of a cover in regard to the thickness direction of the base material of the cover engages with the inner circumference of an open end part of a bottomed tubular concave part formed in a damper housing or in a pump housing of the high-pressure fuel supply pump. The total height of the damper as a low-pressure pulsation reducing mechanism can be reduced, and the dimensions of the damper in the radial directions can also be reduced. In cases where the damper mechanism is formed integrally with the high-pressure fuel supply pump, the total height of the high-pressure fuel supply pump can be reduced and the dimensions of the damper part in the radial directions can also be reduced.

A motor vehicle pump arrangement has a first pump and a second pump, and an electric motor for driving the two pumps. The electric motor is drive-connected fixedly to the first pump and connected via a clutch arrangement to the second pump, in such a way that the first pump can be driven on its own and the first and second pump can be driven together. The first pump is configured as a reversible pump which can be operated in two rotational directions. A valve arrangement generates a uniformly directed fluid volumetric flow which is independent of the rotational direction being provided for the first pump in a fluid circuit. The clutch arrangement is configured as a freewheeling clutch, via which the electric motor is drive-connected to the second pump.

It is disclosed a method for reducing the pulsation level in a multi-compressor plant where each compressor of a plurality of compressors is driven by a respective motor. The method manages to reduce the pulsation level by starting a first motor of a first compressor and then starting in succession each one of the other motors in a way to synchronize all motors between each other with a specified phase shift.

It is disclosed a method for reducing the pulsation level in a multi-compressor plant where each compressor of a plurality of compressors is driven by a respective motor. The method manages to reduce the pulsation level by starting a first motor of a first compressor and then starting in succession each one of the other motors in a way to synchronize all motors between each other with a specified phase shift.

A hydraulic assembly, particularly for supplying a brake circuit of a vehicle brake system with fluid at brake pressure, includes a throttle element, which in the unpressurized state rests with an upper side on a first support and with an underside on a second support, the supports being formed on opposite sides of the gap. The throttle device advantageously dispenses with a spring element for axial pre-tensioning, is accordingly of compact and cost-effective construction and is moreover easy to assemble.

A valve includes a valve body having a valve plunger barrel formed therein and configured to be mounted to a pump head of a fuel pump, a valve plunger arranged to perform reciprocal motion with respect to the valve plunger barrel, a drive assembly configured to cause the valve plunger to perform reciprocal motion, and a spacer configured to couple to the valve plunger to perform reciprocal motion together with the valve plunger and configured to interface with the pump head. The spacer has a spacer body with first and second opposing spacer surfaces and with a central aperture extending from the first to the second spacer surface and configured to receive the valve plunger therethrough. At least one of the first and second spacer surfaces includes one or more grooves recessed into the spacer body to reduce or inhibit cavitation of the interface of the spacer and pump head.

A valve includes a valve body having a valve plunger barrel formed therein and configured to be mounted to a pump head of a fuel pump, a valve plunger arranged to perform reciprocal motion with respect to the valve plunger barrel, a drive assembly configured to cause the valve plunger to perform reciprocal motion, and a spacer configured to couple to the valve plunger to perform reciprocal motion together with the valve plunger and configured to interface with the pump head. The spacer has a spacer body with first and second opposing spacer surfaces and with a central aperture extending from the first to the second spacer surface and configured to receive the valve plunger therethrough. At least one of the first and second spacer surfaces includes one or more grooves recessed into the spacer body to reduce or inhibit cavitation of the interface of the spacer and pump head.