A compressor assembly for use with a Pulse Tube cryocooler is disclosed. The compressor assembly includes a central hub having a plurality of faces, and at least four compressor modules mounted on the central hub. Each of the compressor modules is mounted on a face of the plurality of faces. Each compressor module comprises a piston mounted in the central hub and configured to reciprocate along an axis of travel within the central hub. The pistons are mounted head-to-head with each other and collective reciprocation of the pistons along the respective axes minimizes vibration forces of the compressor assembly in X, Y, and Z translational axes of motion.

A hydraulic system employing an electronically commutated fluid working machine having working chambers, each having one or more electronically controllable valves actively controlled by a controller to regulate the net displacement of working fluid into or out of low- and high-pressure manifolds on a cycle by cycle basis to meet an indicated demand. The high-pressure manifold has an additional outlet, regulated by a controllable outlet valve. If the demand indicated by a demand signal is expected to cause pulsatile flow or vibrations which may excite resonant modes, the controller causes the displacement of working fluid by the working chambers to exceed the demand indicated by the demand signal, and the controller simultaneously opens an electronically controllable outlet valve to allow some of the excess flow to leave, such that the net displacement of fluid meets the demanded displacement of fluid, while mitigating the pulsatile flow or undesirable vibrations.

A hydraulic system employing an electronically commutated fluid working machine having working chambers, each having one or more electronically controllable valves actively controlled by a controller to regulate the net displacement of working fluid into or out of low- and high-pressure manifolds on a cycle by cycle basis to meet an indicated demand. The high-pressure manifold has an additional outlet, regulated by a controllable outlet valve. If the demand indicated by a demand signal is expected to cause pulsatile flow or vibrations which may excite resonant modes, the controller causes the displacement of working fluid by the working chambers to exceed the demand indicated by the demand signal, and the controller simultaneously opens an electronically controllable outlet valve to allow some of the excess flow to leave, such that the net displacement of fluid meets the demanded displacement of fluid, while mitigating the pulsatile flow or undesirable vibrations.

Hydraulic actuating system 21 for actuating a movable part, like a roof part or a wheel suspension. The actuating system comprises a pump unit 26. The pump unit comprises a piston pump 4 which has a pump rotor 46 and an electric motor 3 which has a motor rotor 31. The pump rotor 46 and motor rotor 31 are incorporated into a single common rotor 6. The rotor 6 is a one-piece item. The rotor 6 is positioned inside a pump chamber 264 around a pump stator 42 of the piston pump. The pump stator provides a full support to the common rotor 6. Advantageously, without a separate motor stator, the pump unit has a more compact configuration. Additionally, the pump unit has an improved dynamic performance which contributes to a silent and reliable operation at a high rotational speed.

The invention provides a fluid working machine comprising: a crankshaft (2) which is rotatable about an axis of rotation (3); adjacent first and second groups (5, 6, 8, 10) of valve cylinder devices (13) spaced from each other about the axis of rotation (3), one or each of the first and second groups (5, 6, 8, 10) of valve cylinder devices having first, second and third valve cylinder devices (13) arranged about and extending outwards with respect to the crankshaft (2), the first and third valve cylinder devices being axially offset from each other, the second valve cylinder device being axially offset from the first and third valve cylinder devices and the second valve cylinder device being offset from the first and third valve cylinder devices about the axis of rotation, wherein the second valve cylinder device has an axial extent which overlaps with the axial extent of one, or the axial extents of both, of the first and third valve cylinder devices.

The invention provides a fluid working machine comprising: a crankshaft (2) which is rotatable about an axis of rotation (3); adjacent first and second groups (5, 6, 8, 10) of valve cylinder devices (13) spaced from each other about the axis of rotation (3), one or each of the first and second groups (5, 6, 8, 10) of valve cylinder devices having first, second and third valve cylinder devices (13) arranged about and extending outwards with respect to the crankshaft (2), the first and third valve cylinder devices being axially offset from each other, the second valve cylinder device being axially offset from the first and third valve cylinder devices and the second valve cylinder device being offset from the first and third valve cylinder devices about the axis of rotation, wherein the second valve cylinder device has an axial extent which overlaps with the axial extent of one, or the axial extents of both, of the first and third valve cylinder devices.

Wind turbine generator with hydraulic pump Wind turbine, comprising a tower (2) and a head (6) mounted at an upper end of said tower (2), rotational around a head axis, wherein a propeller (9) is mounted to said head (6), rotatable around a propeller axis, wherein a hydraulic pump (10) is provided, driven by said propeller (9), wherein the hydraulic pump (10) is provided substantially in the propeller (9).

A multiple cavity reciprocating positive displacement pump comprising plural pump cavities each including at least one pair of one-way valves the at least one pair including an inlet valve and an outlet valve, the pump being characterised in that respective inlet valves are in fluid communication with a common inlet and respective outlet valves are in fluid communication with a common outlet. The multiple cavities may include diaphragm arranged in a radial configuration for more uniform pressure output.

A multiple cavity reciprocating positive displacement pump comprising plural pump cavities each including at least one pair of one-way valves the at least one pair including an inlet valve and an outlet valve, the pump being characterised in that respective inlet valves are in fluid communication with a common inlet and respective outlet valves are in fluid communication with a common outlet. The multiple cavities may include diaphragm arranged in a radial configuration for more uniform pressure output.

The invention relates to an assembly including a hydraulic apparatus having a rotor and a stator. The rotor is mounted so as to turn about a second rotation axis with respect to the stator and is secured to a device suitable for mounting a vehicle wheel. A pivot-pin element is intended to be mounted on an axle and is mounted so as to rotate about a first rotation axis with respect to the hydraulic apparatus. The stator is mounted so as to turn about the first rotation axis with respect to the axle. An air chamber is formed between the pivot-pin element and the hydraulic apparatus, the air chamber is connected to a distribution passage formed in the hydraulic apparatus. An axle passage is formed in the pivot-pin element so as to form a pneumatic passage between the pivot-pin element and the hydraulic apparatus.