An actuation mechanism for an electromagnetic switch for a hydraulic cylinder includes a housing adapted to be inserted into a cylinder head. A rod is slidably engaged in the housing and is adapted to move between a first position and a second position. A biasing element, which may be located inside or outside of the housing biases the rod into the first position.

An actuation mechanism for an electromagnetic switch for a hydraulic cylinder includes a housing adapted to be inserted into a cylinder head. A rod is slidably engaged in the housing and is adapted to move between a first position and a second position. A biasing element, which may be located inside or outside of the housing biases the rod into the first position.

In some two-stroke engines, a stationary ring is disposed in a groove in the cylinder liner. However, it is a challenge to install such a stationary ring while maintaining a narrow gap to minimize gas flow through the gap. A ring system for an internal combustion engine is disclosed that includes an L-shaped, split ring with a reentrant angle and a nested, split ring with a convex quadrilateral cross section nested with the L-shaped ring proximate the reentrant angle. The two rings are affixed so that the two gaps of the split rings cannot align. Or, in other embodiments, the two are allowed to rotate relative to each other over a predetermined angle.

A shoe for use with a hydraulic piston motor or pump is disclosed herein. The shoe includes an upper portion configured to receive the hydraulic piston, a lower portion configured to contact a swashplate, a counterbore formed in the lower portion, a vertical channel extending through the upper portion and the lower portion into the counterbore, and a seal disposed within the counterbore and extending around a circumference of the counterbore.