Piston engine assembly

A joint for positioning between first and second pistons of a double ended piston, the first and second pistons being arranged for linear motion along an axis of the double ended piston, the joint comprising:

• an outer member having first and second parallel flat sides, each flat side defining a plane perpendicular to the double ended piston axis, the outer member being configured for movement relative to the first and second pistons along first and second orthogonal axes, the first and second orthogonal axes being perpendicular to the double ended piston axis, the outer member defining an opening for receiving a drive arm, and
• an inner cylindrical member mounted within the outer member for rotation relative to the outer member about the first orthogonal axis, the inner member being coupled to the outer member for controlled motion along the first axis with the outer member, the inner member defining an opening for receiving the drive arm.

A method of reducing side load in a double ended member, the double ended member including first and second elements arranged for linear motion along an axis of the double ended member, the method comprising:

• providing a joint located between the first and second elements, the joint including an outer member configured for movement relative to the first and second elements along a first axis perpendicular to the double ended member axis, and an inner cylindrical member mounted within the outer member for rotation relative to the outer member about the first axis, the inner member being coupled to the outer member for controlled motion along the first axis with the outer member, and
• transferring load between the first and second elements and a drive arm mounted to the joint through two opposed surfaces of the outer member.

A method of reducing side load in a double ended piston assembly, the double ended piston assembly including first and second pistons arranged for linear motion along an axis of the double ended piston, the method comprising:

• providing a joint located between the first and second pistons, the joint including an outer member configured for movement relative to the first and second pistons along first and second orthogonal axes, the first and second orthogonal axes being perpendicular to the double ended piston axis, the outer member defining two opposed flat surfaces, and an inner cylindrical member mounted within the outer member for rotation relative to the outer member about the first axis, the inner member being coupled to the outer member for controlled motion along the first axis with the outer member, and
• transferring load between the first and second pistons and a drive arm mounted to the joint through the two opposed flat surfaces.

A joint for positioning between first and second elements, the first and second elements being arranged for linear motion along a common axis, comprising:

• an outer member configured for movement relative to the first and second elements along a first axis perpendicular to the common axis, the outer member defining an opening for receiving a drive arm,
• an inner member mounted within the outer member for rotation relative to the outer member about a second axis perpendicular to the first axis and the common axis, the inner member defining an opening for receiving the drive arm, and
• a thrust bearing for receiving an axial load transferred to the drive arm by the first and second elements.

A joint for positioning between first and second elements, the first and second elements being arranged for linear motion along a common axis, comprising:

• an outer member configured for movement relative to the first and second elements along a first axis perpendicular to the common axis, the outer member defining an opening for receiving a drive arm,
• an inner member mounted within the outer member for rotation relative to the outer member about a second axis perpendicular to the first axis and the common axis, the inner member defining an opening for receiving the drive arm, and
• a sleeve bearing for receiving a normal load transferred to the drive arm by the first and second elements.

A joint for positioning between first and second elements, the first and second elements being arranged for linear motion along a common axis, comprising:

• an outer member configured for movement relative to the first and second elements along a first axis perpendicular to the common axis, the outer member defining an opening for receiving a drive arm,
• an inner member mounted within the outer member for rotation relative to the outer member about a second axis perpendicular to the first axis and the common axis, the inner member defining an opening for receiving the drive arm, and
• a bearing located between the inner and outer members.