A linear reciprocating engine may include an engine block, a cylinder having combustion chambers at opposing ends, cylinder heads located at an end of the respective combustion chambers, respectively, and a double-faced piston. The engine may further include piston rod portions extending from both faces of the piston through the combustion chambers. The engine may further include an exhaust outlet in a peripheral cylinder wall and elongated channels in the piston rod portions being configured to serve as an intake inlet for gas from a location external to the cylinder. When the piston is in a combustion stage in a first combustion chamber, the piston blocks the exhaust outlet from communicating with the first chamber with the first channel access opening outside the first chamber, while simultaneously the exhaust outlet is in communication with a second combustion chamber with the second channel access opening within the second chamber.

An internal combustion engine may include an engine block, a cylinder within the engine block, and a piston within the cylinder. The piston may have an outer peripheral wall, and a groove in the outer peripheral wall of the piston may have a first edge and a second edge spaced from the first edge. The piston may have a piston ring in the groove, and the piston ring may have a shape that meanders within the groove, such that the shape of the piston ring differs from a shape of the groove and such that the piston ring does not substantially fill the groove. The piston ring may be constructed of a material that when subjected to heat causes a shape of the meanderings to change, thereby enabling the piston ring to expand in an axial direction of the piston, between the edges of the groove.

A linear reciprocating engine may include a cylinder having a first combustion chamber at one end and a second combustion chamber at an opposing end, first and second cylinder heads located at an end of the first and second combustion chambers, respectively, and a double-faced piston slidably mounted within the cylinder. The engine may further include a first piston rod portion extending from a first face of the double-faced piston through the first combustion chamber, and a second piston rod portion extending from a second face of the piston through the second combustion chamber. Passageways in the piston rod portions may be configured to communicate gases between the combustion chamber and a location outside the cylinder and configured to prevent gases from being exchanged between the cylinder and a location outside the cylinder via a path that crosses both face of the piston.

A motor vehicle structure includes two left and right bell-shaped suspension element supports arranged inside a front compartment close to a bulkhead of the vehicle. The suspension element supports are respectively adjacent to side walls of the front compartment. Each of the suspension element supports includes an internal face opposite the side wall. The structure also includes left and right spacers that extend respectively between the left and right suspension element supports and the rigid cross member, in a substantially longitudinal direction. The spacers are respectively anchored to the internal faces of the two suspension element supports. The spacers each have a skirt-shaped edge that can be applied to the suspension element supports, and a folded edge extending between a free end and an opposing attachment end to be joined to the cross member. The spacers include a central portion joining the folded edge and the skirt-shaped edge together.

An engine system is provided. The engine system includes a first piston movable within a cylinder, a second piston movable within a hollow body of the first piston, the movement defining a boundary of a reservoir within the hollow body, a spring device coupled to the first piston and the second piston, and a vent passage fluidically connecting the reservoir to the cylinder.

A linear reciprocating engine may include a cylinder having first and second combustion chambers at opposing ends, first and second cylinder heads at an end of the first and second combustion chambers, respectively, and a double-faced piston slidably mounted within the cylinder. The engine may further include an exhaust port located in a peripheral cylinder wall and at least one combustion gas inlet in a location other than the peripheral cylinder wall. The combustion gas inlet and the exhaust port may be configured to cooperate such that combustion gases introduced through the inlet are evacuated from the cylinder through the exhaust port. The double-faced piston may have an axial length from one face to an opposite face of the piston less than or equal to of a distance from at least one of the first cylinder head and the second cylinder head to the exhaust port.

A variable displacement hydraulic device comprising: a housing having an inlet for receiving hydraulic fluid and an outlet for outputting the hydraulic fluid, the housing having a reciprocation axis; a first cylinder positioned in the housing along the reciprocation axis, the first cylinder having a first input for receiving the hydraulic fluid on a first intake stroke and a first output for ejecting the hydraulic fluid on a first exhaust stroke; a first piston positioned for a first reciprocal motion within the first cylinder, the first piston having a first main end exposed to the hydraulic fluid and a second main end coupled to an actuator, the actuator for driving the second main end when coupled to the actuator for causing the first reciprocal motion to induce a first portion of said outputting of the hydraulic fluid; a second cylinder positioned in the first piston along the reciprocation axis, the second cylinder having a second input for receiving the hydraulic fluid on a second intake stroke and a second output for ejecting the hydraulic fluid on a second exhaust stroke; a second piston positioned for a second reciprocal motion within the second cylinder, the second piston having a first secondary end exposed to the hydraulic fluid and a second secondary end coupled to the actuator, the actuator for driving the second secondary end when coupled to the actuator for causing the second reciprocal motion to induce a second portion of said outputting of the hydraulic fluid; and a locking mechanism for inhibiting the first reciprocal motion of the first piston; wherein when engaged the locking mechanism inhibits the first portion of said outputting of the hydraulic fluid by decoupling the first piston from the actuator while continued operation of the actuator provides the second portion of said outputting of the hydraulic fluid by the second piston.

A variable displacement hydraulic device comprising: a housing having an inlet for receiving hydraulic fluid and an outlet for outputting the hydraulic fluid, the housing having a reciprocation axis; a first cylinder positioned in the housing along the reciprocation axis, the first cylinder having a first input for receiving the hydraulic fluid on a first intake stroke and a first output for ejecting the hydraulic fluid on a first exhaust stroke; a first piston positioned for a first reciprocal motion within the first cylinder, the first piston having a first main end exposed to the hydraulic fluid and a second main end coupled to an actuator, the actuator for driving the second main end when coupled to the actuator for causing the first reciprocal motion to induce a first portion of said outputting of the hydraulic fluid; a second cylinder positioned in the first piston along the reciprocation axis, the second cylinder having a second input for receiving the hydraulic fluid on a second intake stroke and a second output for ejecting the hydraulic fluid on a second exhaust stroke; a second piston positioned for a second reciprocal motion within the second cylinder, the second piston having a first secondary end exposed to the hydraulic fluid and a second secondary end coupled to the actuator, the actuator for driving the second secondary end when coupled to the actuator for causing the second reciprocal motion to induce a second portion of said outputting of the hydraulic fluid; and a locking mechanism for inhibiting the first reciprocal motion of the first piston; wherein when engaged the locking mechanism inhibits the first portion of said outputting of the hydraulic fluid by decoupling the first piston from the actuator while continued operation of the actuator provides the second portion of said outputting of the hydraulic fluid by the second piston.

A linear reciprocating engine may include a cylinder having a first combustion chamber at one end and a second combustion chamber at an opposing end, first and second cylinder heads located at an end of the first and second combustion chambers, respectively, and a double-faced piston slidably mounted within the cylinder. The engine may further include a first piston rod portion extending from a first face of the double-faced piston through the first combustion chamber, and a second piston rod portion extending from a second face of the piston through the second combustion chamber. Passageways in the piston rod portions may be configured to communicate gases between the combustion chamber and a location outside the cylinder and configured to prevent gases from being exchanged between the cylinder and a location outside the cylinder via a path that crosses both face of the piston.

A motor vehicle structure includes two left and right bell-shaped suspension element supports arranged inside a front compartment close to a bulkhead of the vehicle. The suspension element supports are respectively adjacent to side walls of the front compartment. Each of the suspension element supports includes an internal face opposite the side wall. The structure also includes left and right spacers that extend respectively between the left and right suspension element supports and the rigid cross member, in a substantially longitudinal direction. The spacers are respectively anchored to the internal faces of the two suspension element supports. The spacers each have a skirt-shaped edge that can be applied to the suspension element supports, and a folded edge extending between a free end and an opposing attachment end to be joined to the cross member. The spacers include a central portion joining the folded edge and the skirt-shaped edge together.