The linear actuator comprises a double-chamber solenoid pump comprising at least one pump coil, a multi-way valve and at least one pump armature that can be moved by energizing the at least one pump coil and is provided with a switching armature by means of which the multi-way valve can be switched and which can be moved by energizing the at least one pump coil. In the method, both the switching armature and the pump armature are moved by energizing the pump coil.

A fluid machine for a pneumatic or hydraulic drive system, said fluid machine being able to work as a fluid motor or as a fluid pump, comprising: at least two piston assemblies each comprising a piston means (110a-c), the at least two piston assemblies being operable to cause sequential reciprocating movement of the pistons means (110a-c); a drive member (120) rotatable about an axis and providing an annular, wave-like surface (122) extending at least partially radially to the axis, towards which the piston means (110a-c) project, wherein, in case of working as a fluid motor, the pistons means (110a-c) are arranged to drive rotation of the drive member (120) about the axis at least by a pushing action on said wave-like surface (122) or, in the case of working as a fluid pump, the piston means (110a-c) are arranged to cooperate with said wave-like surface (122) so that rotation of the drive member (120) drives sequential reciprocating motion of the piston means (110a-c).

A two cycle-opposed piston, two cycle, homogenous charge compression ignition engine with cylinder sets, each cylinder set having a first cylinder with an intake port; a second cylinder coaxially aligned with the first cylinder and having an exhaust port; a first piston engaged within the first cylinder; a second piston engaged within the second cylinder; a combustion chamber formed between the first piston and the second piston; a first cam mechanically engaged with the first piston; a mechanical device to convert reciprocating motion to rotational motion connected to the second piston; and a charge pump connected to the intake port by an intake passage.

An opposed piston engine has a driveshaft with at least one combustion cylinder positioned between opposing, curvilinear shaped cams mounted on the driveshaft, where the center axis of the combustion cylinder is parallel with but spaced apart from the driveshaft axis. A piston assembly is disposed in each end of the cylinder, with one piston assembly engaging one cam and the other piston assembly engaging the other cam. Each piston assembly includes a cam follower that can move along a curvilinear shaped cam to reciprocate the piston assembly within the cylinder. The combustion cylinder includes an intake port in fluid communication with an annular intake channel formed in the engine block in which the cylinder is mounted, and an exhaust port in fluid communication with an annular exhaust channel formed in the engine block.

An opposed piston engine has a driveshaft with at least one combustion cylinder positioned between opposing, curvilinear shaped cams mounted on the driveshaft, where the center axis of the combustion cylinder is parallel with but spaced apart from the driveshaft axis. A piston assembly is disposed in each end of the cylinder, with one piston assembly engaging one cam and the other piston assembly engaging the other cam. Each piston assembly includes a cam follower that can move along a curvilinear shaped cam to reciprocate the piston assembly within the cylinder. The combustion cylinder includes an intake port in fluid communication with an annular intake channel formed in the engine block in which the cylinder is mounted, and an exhaust port in fluid communication with an annular exhaust channel formed in the engine block.

A two cycle-opposed piston, two cycle, homogenous charge compression ignition engine with cylinder sets, each cylinder set having a first cylinder with an intake port; a second cylinder coaxially aligned with the first cylinder and having an exhaust port; a first piston engaged within the first cylinder; a second piston engaged within the second cylinder; a combustion chamber formed between the first piston and the second piston; a first cam mechanically engaged with the first piston; a mechanical device to convert reciprocating motion to rotational motion connected to the second piston; and a charge pump connected to the intake port by an intake passage.

A balanced rotary engine for applying torque to a drive shaft. The engine has an outer casing with a main drive case. A cylinder is rotably mounted in the casing and a piston is mounted to move longitudinally within the cylinder. Two connecting arms, each with a connecting end, one of the ends is connected to the piston, and two crankshafts, each one being rotably connected to the other connecting end of the connecting arms. Two drive wheels are contra-rotably connected to the respective first and second crankshafts. A fixed drive ring has a circumferentially disposed drive member surface. The fixed drive ring is mounted in the case so that the drive member surface faces the piston. The two drive wheels mesh with the drive ring.

An opposed piston engine has a driveshaft with at least one combustion cylinder positioned between opposing, curvilinear shaped cams mounted on the driveshaft, where the center axis of the combustion cylinder is parallel with but spaced apart from the driveshaft axis. A piston assembly is disposed in each end of the cylinder, with one piston assembly engaging one cam and the other piston assembly engaging the other cam. Each piston assembly includes a cam follower that can move along a curvilinear shaped cam to reciprocate the piston assembly within the cylinder. The combustion cylinder includes an intake port in fluid communication with an annular intake channel formed in the engine block in which the cylinder is mounted, and an exhaust port in fluid communication with an annular exhaust channel formed in the engine block.

A two cycle-opposed piston, two cycle, homogenous charge compression ignition engine with cylinder sets, each cylinder set having a first cylinder with an intake port; a second cylinder coaxially aligned with the first cylinder and having an exhaust port; a first piston engaged within the first cylinder; a second piston engaged within the second cylinder; a combustion chamber formed between the first piston and the second piston; a first cam mechanically engaged with the first piston; a mechanical device to convert reciprocating motion to rotational motion connected to the second piston; and a charge pump connected to the intake port by an intake passage.

The linear actuator comprises a double-chamber solenoid pump comprising at least one pump coil, a multi-way valve and at least one pump armature that can be moved by energizing the at least one pump coil and is provided with a switching armature by means of which the multi-way valve can be switched and which can be moved by energizing the at least one pump coil. In the method, both the switching armature and the pump armature are moved by energizing the pump coil.