A cylinder unit includes a piston disposed in the cylinder bore that is connected to a piston connecting frame member. The piston connecting frame member replaces a conventional connecting rod, and reciprocates exclusively along the bore axis. A crank connecting member has a linear rail at its top that is captured in a transverse gap along the bottom of the piston connecting frame member, and converts the circular movement of a crank throw to linear motion of the piston connecting frame member.

A guide ring for a pump element of a hydraulic unit of a vehicle brake system is configured to guide a pump piston in a pump housing when the pump piston is displaced along the axis thereof in the pump housing. On the inner side of the guide ring facing the pump piston, the guide ring includes a first step that has a first inner diameter and a second inner diameter.

A locking apparatus for a hydromechanical spring energy store drive for actuating a medium-voltage or high-voltage circuit breaker is disclosed, the spring energy store drive includes a working piston, which is guided in an axial cutout in a pressure housing or working cylinder, and a spring energy store arrangement. The locking apparatus includes a first pressure region and a second pressure region, which are under elevated pressure when the circuit breaker is closed, and a third pressure region, which is unpressurized. The latching bolt can be arranged perpendicular to the working piston, via a latching apparatus, which can be arranged on a side of the latching bolt, which is to point towards the working piston and via the spring energy store arrangement, which is to be pushed away from the working piston.

A locking apparatus for a hydromechanical spring energy store drive for actuating a medium-voltage or high-voltage circuit breaker is disclosed, the spring energy store drive includes a working piston, which is guided in an axial cutout in a pressure housing or working cylinder, and a spring energy store arrangement. The locking apparatus includes a first pressure region and a second pressure region, which are under elevated pressure when the circuit breaker is closed, and a third pressure region, which is unpressurized. The latching bolt can be arranged perpendicular to the working piston, via a latching apparatus, which can be arranged on a side of the latching bolt, which is to point towards the working piston and via the spring energy store arrangement, which is to be pushed away from the working piston.

A closed compressor includes: a compressor body; and a closed vessel in which the compressor body is accommodated and oil is stored. The compressor body has an electric element and a compression element that is driven by the electric element. The compression element has a cylinder block that forms a cylinder, a piston that performs a reciprocating motion in the cylinder, and a crankshaft that actuates the piston. The cylinder block configures a bearing that pivotally supports the crankshaft. The cylinder forms a compression chamber. The compressor body has a support that forms a curved surface. A contact portion, at which the curved surface comes into contact with a receiving surface in the closed vessel, is formed.

A hybrid opposed piston engine is described that can include a cylindrical chamber and first and second pistons slidably disposed in the cylindrical chamber, surfaces of the first and second pistons and walls of the cylindrical chamber defining an internal combustion volume. The hybrid opposed piston engine can also include at least one port in the cylindrical chamber to allow air and fuel into and exhaust gas out of the internal combustion volume. In some embodiments, the hybrid opposed piston engine includes a drive shaft including a first mechanical linkage between the first piston and a crankshaft that is configured to move the first piston within the cylindrical chamber. In some embodiments, the hybrid opposed piston engine includes an electrical component adjacent to the second piston, the electrical component configured to move the second piston within the cylindrical chamber.

A hybrid opposed piston engine is described that can include a cylindrical chamber and first and second pistons slidably disposed in the cylindrical chamber, surfaces of the first and second pistons and walls of the cylindrical chamber defining an internal combustion volume. The hybrid opposed piston engine can also include at least one port in the cylindrical chamber to allow air and fuel into and exhaust gas out of the internal combustion volume. In some embodiments, the hybrid opposed piston engine includes a drive shaft including a first mechanical linkage between the first piston and a crankshaft that is configured to move the first piston within the cylindrical chamber. In some embodiments, the hybrid opposed piston engine includes an electrical component adjacent to the second piston, the electrical component configured to move the second piston within the cylindrical chamber.

A closed compressor includes: a compressor body; and a closed vessel in which the compressor body is accommodated and oil is stored. The compressor body has an electric element and a compression element that is driven by the electric element. The compression element has a cylinder block that forms a cylinder, a piston that performs a reciprocating motion in the cylinder, and a crankshaft that actuates the piston. The cylinder block configures a bearing that pivotally supports the crankshaft. The cylinder forms a compression chamber. The compressor body has a support that forms a curved surface. A contact portion, at which the curved surface comes into contact with a receiving surface in the closed vessel, is formed.

A closed compressor includes: a compressor body; and a closed vessel in which the compressor body is accommodated and oil is stored. The compressor body has an electric element and a compression element that is driven by the electric element. The compression element has a cylinder block that forms a cylinder, a piston that performs a reciprocating motion in the cylinder, and a crankshaft that actuates the piston. The cylinder block configures a bearing that pivotally supports the crankshaft. The cylinder forms a compression chamber. The compressor body has a support that forms a curved surface. A contact portion, at which the curved surface comes into contact with a receiving surface in the closed vessel, is formed.

A piston may include a first center bore and a second center bore configured to receive a piston pin. The first center bore and the second center bore may have different diameters. An axis of the first center bore may extend parallel to an axis of the second center bore.