Abstract: A suspension system for an automotive vehicle comprising a hydraulic actuator for mounting between a wheel assembly and a body of the automotive vehicle. The system also comprises a hydraulic system configured to provide a supply of fluid to the hydraulic actuator. The hydraulic system is configured during normal operation to provide fluid at a static pressure greater than 7 MPa (70 Bar) to the hydraulic actuator. In embodiments of the invention, the hydraulic system comprises a plurality of gas accumulators, wherein the system is configured to transmit changes in fluid pressure between the hydraulic actuator, common flow path and gas accumulators such that the hydraulic actuator has a first stiffness when the hydraulic system is in the first configuration and a second, different, stiffness when the hydraulic system in the second configuration.

Abstract: A radial piston pump comprising a rotor mounted for rotation on a pintle. The rotor comprises a plurality of piston chambers, a piston being mounted in each of said chambers for reciprocal movement. The pump comprises a supply flow path which connects the piston chambers to a supply of low-pressure fluid, an exit flow path via which high-pressure fluid from the piston chambers leaves the pump, and an auxiliary flow path which connects another component of the pump to the piston chambers. The pintle comprises a plurality of flow galleries comprising a supply flow gallery forming part of the supply flow path, an exit flow gallery forming part of the exit flow path, and an auxiliary flow gallery forming part of the auxiliary flow path. The radial piston pump uses the pintle as a fluid manifold providing fluid to or from the pistons.

Abstract: A rotary servo valve comprising a housing portion (105) defining a cylindrical cavity (107) and a first layer of ports. The rotary servo valve further comprises two opposing indented sides and two opposing sides having an increased radius relative to the indented sides, each side of increased radius extending between the two indented sides. The spool portion (103) is mounted for rotation relative to the cylindrical cavity (107), from a neutral position so as to prevent fluid flow through the valve, to an open position in which a fluid flow path is provided.

Abstract: A rotary servo valve comprising a housing portion (105) defining a cylindrical cavity (107) and a first layer of ports. The rotary servo valve further comprises two opposing indented sides and two opposing sides having an increased radius relative to the indented sides, each side of increased radius extending between the two indented sides. The spool portion (103) is mounted for rotation relative to the cylindrical cavity (107), from a neutral position so as to prevent fluid flow through the valve, to an open position in which a fluid flow path is provided.

Abstract: A servo actuator (1) comprises an actuator housing (4); an actuator member (2) located within the actuator housing (4) and at least one spool (8) located in a cavity (6) formed within the actuator housing (4). The housing (4) also comprises a first set of internal ports including an inlet port (P), an outlet port (T) and a pair of control ports (SI, S2), the inlet port (P) being arranged for connection to a first pressurised supply and a second set of internal ports comprising an inlet port (P?), an outlet port (T?) and a pair of control ports (SI?, S2?), the inlet port (P?) being arranged for connection to a second pressurised supply. In use, movement of the spool (8) alters the flow path of fluid through the first and second set of internal ports to control the movement of the actuator member (2).

Abstract: A servo actuator (1) comprises an actuator housing (4); an actuator member (2) located within the actuator housing (4) and at least one spool (8) located in a cavity (6) formed within the actuator housing (4). The housing (4) also comprises a first set of internal ports including an inlet port (P), an outlet port (T) and a pair of control ports (SI, S2), the inlet port (P) being arranged for connection to a first pressurised supply and a second set of internal ports comprising an inlet port (P?), an outlet port (T?) and a pair of control ports (SI?, S2?), the inlet port (P?) being arranged for connection to a second pressurised supply. In use, movement of the spool (8) alters the flow path of fluid through the first and second set of internal ports to control the movement of the actuator member (2).

Abstract: A radial piston pump 101 comprising a rotor 103 is disclosed. The rotor 103 includes a drive shaft 105 arranged to transmit rotary motion to or from the pump 101 and a piston housing 102 including at least one piston chamber 104, the at least one piston chamber 104 being arranged to receive a piston 108. The drive shaft 105 and the piston housing 102 are integrally formed.

Abstract: An active suspension system 1 for a vehicle. The suspension system 1 comprises a hydraulic actuator 4 for connection to the vehicle, an accumulator 30 arranged to provide fluid to the actuator 4 and a spool valve 16. The spool valve 16 comprises a spool 18 mounted for movement between a first position in which the flow of fluid from the accumulator 30 to the actuator 4 is prevented and a second position in which fluid can flow from the accumulator 30 to the actuator 4 via the spool 18 thereby causing movement of the actuator 4.