A piston ring installation jig is to be used when installing a piston ring having a ring gap in a ring groove formed in an outer peripheral surface of a piston. The piston ring installation jig includes a main body including a groove. The main body has in a semi-cylindrical shape surrounding the outer peripheral surface of the piston. The groove has a substantially semicircular arc shape, and is formed in an inner peripheral surface of the main body in a region corresponding to the ring groove of the piston. A portion of the piston ring in a circumferential direction is inserted into the groove. The groove has a shape of an arc of a circle which has a circle center biased more to an outer peripheral side of the main body than a circle center of an inner peripheral surface of the main body.

A piston ring installation jig is to be used when installing a piston ring having a ring gap in a ring groove formed in an outer peripheral surface of a piston. The piston ring installation jig includes a main body including a groove. The main body has in a semi-cylindrical shape surrounding the outer peripheral surface of the piston. The groove has a substantially semicircular arc shape, and is formed in an inner peripheral surface of the main body in a region corresponding to the ring groove of the piston. A portion of the piston ring in a circumferential direction is inserted into the groove. The groove has a shape of an arc of a circle which has a circle center biased more to an outer peripheral side of the main body than a circle center of an inner peripheral surface of the main body.

Piston assembly installation tools are disclosed, each installation tool configured for installation of the piston assembly into an opposed-piston engine from a crankcase area of the engine. The installation tools comprise cutouts to account for cylinder block main journal saddles located on either side of a cylinder bore where the piston assembly may be installed.

Piston assembly installation tools are disclosed, each installation tool configured for installation of the piston assembly into an opposed-piston engine from a crankcase area of the engine. The installation tools comprise cutouts to account for cylinder block main journal saddles located on either side of a cylinder bore where the piston assembly may be installed.

A wheel assembly to be coupled to a hub of a vehicle may include an inner rim to be coupled to the hub of the vehicle, an outer rim surrounding the inner rim, and gas springs operatively coupled between the inner rim and the outer rim to provide a gas suspension permitting relative movement between the inner rim and the outer rim. Each of the gas springs may include a gas cylinder having an inner surface, and a piston movable within the gas cylinder. The piston may include a shaft, a piston head coupled to the shaft and having at least one recess therein, and at least one biasing member within the at least one recess. Each gas spring may also include at least one damping member adjacent the at least one biasing member and within the at least one recess to frictionally engage the inner surface of the gas cylinder.

A wheel assembly to be coupled to a hub of a vehicle may include an inner rim to be coupled to the hub of the vehicle, an outer rim surrounding the inner rim, and gas springs operatively coupled between the inner rim and the outer rim to provide a gas suspension permitting relative movement between the inner rim and the outer rim. Each of the gas springs may include a gas cylinder having an inner surface, and a piston movable within the gas cylinder. The piston may include a shaft, a piston head coupled to the shaft and having at least one recess therein, and at least one biasing member within the at least one recess. Each gas spring may also include at least one damping member adjacent the at least one biasing member and within the at least one recess to frictionally engage the inner surface of the gas cylinder.

A piston alignment tool and an engine kit having the piston alignment tool help facilitate improved positioning of a piston with respect to a cylinder liner. The piston alignment tool includes a body and an inner guide surface extending along an inner diameter of the body. The inner guide surface is configured to guide the piston with respect to an inner diameter of the cylinder liner. An axially extending overhang engagement tab extends from the body, with the axially extending overhang engagement tab being configured to interface with an outer circumference of the cylinder liner.

A piston alignment tool and an engine kit having the piston alignment tool help facilitate improved positioning of a piston with respect to a cylinder liner. The piston alignment tool includes a body and an inner guide surface extending along an inner diameter of the body. The inner guide surface is configured to guide the piston with respect to an inner diameter of the cylinder liner. An axially extending overhang engagement tab extends from the body, with the axially extending overhang engagement tab being configured to interface with an outer circumference of the cylinder liner.

A retaining unit that retains a stack body in which piston rings are stacked in an axial direction, a cutting-out unit that delivers a piston ring at the tip end of the stack body from the stack body, and a detecting unit that detects a boundary between the piston rings that are adjacent to each other in the stack body are included, and the cutting-out unit includes a moving unit that moves a pushing-out unit and a restricting unit, and after inserting the pushing-out unit and the restricting unit into a dividing portion that is a boundary between the piston ring at the tip end and a piston ring that is adjacent to the piston ring at the tip end in the stack body, in a state in which movement of the piston ring that is adjacent to the piston ring at the tip end in a delivering direction in which the piston ring at the tip end is delivered is restricted by the restricting unit, the moving unit moves the pushing-out unit in the delivering direction, so that the piston ring at the tip end is separated from the stack body, and the piston ring at the tip end is delivered along the retaining unit.

A retaining unit that retains a stack body in which piston rings are stacked in an axial direction, a cutting-out unit that delivers a piston ring at the tip end of the stack body from the stack body, and a detecting unit that detects a boundary between the piston rings that are adjacent to each other in the stack body are included, and the cutting-out unit includes a moving unit that moves a pushing-out unit and a restricting unit, and after inserting the pushing-out unit and the restricting unit into a dividing portion that is a boundary between the piston ring at the tip end and a piston ring that is adjacent to the piston ring at the tip end in the stack body, in a state in which movement of the piston ring that is adjacent to the piston ring at the tip end in a delivering direction in which the piston ring at the tip end is delivered is restricted by the restricting unit, the moving unit moves the pushing-out unit in the delivering direction, so that the piston ring at the tip end is separated from the stack body, and the piston ring at the tip end is delivered along the retaining unit.