A valve system that includes a housing defining an intake port, a cylinder port and a valve bore; wherein the intake port defining a valve seat portion at an interface between the intake port and the cylinder port. The valve system also includes a valve to control fluid communication between the intake port and the cylinder port. The valve includes a valve stem disposed within the valve bore and extending into the cylinder port and extending out of the housing, the valve stem having an open face exposed to atmospheric pressure and a valve head coupled to the valve stem comprising a first face and an opposing second face. A diameter of the valve stem is selected to control a closing force on the first face of the valve head.

A valve system that includes a housing defining an intake port, a cylinder port and a valve bore; wherein the intake port defining a valve seat portion at an interface between the intake port and the cylinder port. The valve system also includes a valve to control fluid communication between the intake port and the cylinder port. The valve includes a valve stem disposed within the valve bore and extending into the cylinder port and extending out of the housing, the valve stem having an open face exposed to atmospheric pressure and a valve head coupled to the valve stem comprising a first face and an opposing second face. A diameter of the valve stem is selected to control a closing force on the first face of the valve head.

A valve timing adjusting device adjusts an opening/closing timing of a first valve driven by a rotation of a first camshaft and an opening/closing timing of a second valve driven by a rotation of a second camshaft. The valve timing adjusting device includes a first driving circuit controlling a first motor configured to generate a torque to shift a rotation phase of the first camshaft and a second driving circuit controlling a second motor configured to generate a torque to shift a rotation phase of the second camshaft. A first switching element of the first driving circuit operates at a switching frequency that is different from that of a second switching element of the second driving circuit.

A valve train system that eliminates the inefficiencies of current spring biased systems. The system uses teeter beams that are manipulated by cams that are driven by cam shafts to control and operate the valve system more efficiently and dependably.

An electromagnetic valve actuator (100) and method of control thereof. The electromagnetic valve actuator is for at least one valve (300) of an internal combustion engine (40), the electromagnetic valve actuator comprising: a rotor (102); a stator (101) for rotating the rotor; output means (104, 106) for actuating the valve in dependence on rotation of the rotor; mechanical energy storage means (108, 110, 116, 118) arranged to store energy in dependence on rotation of the rotor and release the energy to assist rotation of the rotor; and phase varying means (400) for varying a phase between the mechanical energy storage means and the output means.

A rotary electromagnetic actuator is provided which is suitable for opening and closing a valve for example. The actuator comprises a rotor, a stator, and a biasing arrangement for applying a torque to the rotor during at least part of its rotation. A plurality of stable rest positions for the rotor are defined by forces acting on the rotor and the actuator is controllable to move the rotor from one stable rest position to another. The torque applied by the biasing arrangement varies with the rotational position of the rotor such that at a primary rest position and at least a second rest position, it is sufficiently low to enable selection of those positions, and then it increases beyond the second rest position.

A rotary electromagnetic actuator is provided which is suitable for opening and closing a valve for example. The actuator comprises a rotor, a stator, and a biasing arrangement for applying a torque to the rotor during at least part of its rotation. A plurality of stable rest positions for the rotor are defined by forces acting on the rotor and the actuator is controllable to move the rotor from one stable rest position to another. The torque applied by the biasing arrangement varies with the rotational position of the rotor such that at a primary rest position and at least a second rest position, it is sufficiently low to enable selection of those positions, and then it increases beyond the second rest position.

Embodiments relate generally to energy storage systems, and in particular to energy storage systems using compressed gas as an energy storage medium. In various embodiments, a compressed gas storage system may include a plurality of stages to convert energy into compressed gas for storage, and then to recover that stored energy by gas expansion. In certain embodiments, a stage may comprise a reversible compressor/expander having a reciprocating piston. Pump designs for introducing liquid for heat exchange with the gas, are described. Gas flow valves featuring shroud and/or curtain portions, are also described.

An electromagnetic valve actuator and method of control thereof. The electromagnetic valve actuator is for at least one valve of an internal combustion engine, the electromagnetic valve actuator comprising: a rotor; a stator for rotating the rotor; output means for actuating the valve in dependence on rotation of the rotor; mechanical energy storage means arranged to store energy in dependence on rotation of the rotor and release the energy to assist rotation of the rotor and phase varying means for varying a phase between the mechanical energy storage means and the output means.

An electromagnetic valve actuator and method of control thereof. The electromagnetic valve actuator is for at least one valve of an internal combustion engine, the electromagnetic valve actuator comprising: a rotor; a stator for rotating the rotor; output means for actuating the valve in dependence on rotation of the rotor; mechanical energy storage means arranged to store energy in dependence on rotation of the rotor and release the energy to assist rotation of the rotor and phase varying means for varying a phase between the mechanical energy storage means and the output means.