Aspects of the present invention relate to a carriage assembly (3-n) for a swash plate engine (1) having a swash plate (7). The carriage assembly (3-n) has a carriage body (19) for reciprocating along a longitudinal axis (X-n). The carriage body (19) is configured to be connected to at least one piston (5-n). At least one bearing assembly (20-n) is disposed on the carriage body (19). The or each bearing assembly (20-n) includes a rolling bearing (21-n) configured to engage a rolling face of the swashplate (7); and a yoke (23-n) for supporting the rolling bearing (21-n). The yoke (23-n) is movable relative to the carriage body along the longitudinal axis. Aspects of the present invention also relate to a swash plate drive assembly (15); and a swash plate engine (1).

An apparatus includes a connecting rod having a surface that defines an opening to receive a pin for coupling the connecting rod to a piston at a first end of the connecting rod. The surface includes a groove arrangement to collect, retain and distribute lubrication fluid in the space between the pin and the inner surface. The surface can be formed by the connecting rod or a bushing in an opening of the connecting rod.

Aspects of the present invention relate to a carriage assembly (3-n) for a swash plate engine (1) having a swash plate (7). The carriage assembly (3-n) has a carriage body (19) for reciprocating along a longitudinal axis (X-n). The carriage body (19) is configured to be connected to at least one piston (5-n). At least one bearing assembly (20-n) is disposed on the carriage body (19). The or each bearing assembly (20-n) includes a rolling bearing (21-n) configured to engage a rolling face of the swashplate (7); and a yoke (23-n) for supporting the rolling bearing (21-n). The yoke (23-n) is movable relative to the carriage body along the longitudinal axis. Aspects of the present invention also relate to a swash plate drive assembly (15); and a swash plate engine (1).

An opening on one end side of a pin-boss oil passage opens to the inner circumferential surface of a pin boss part of an upper link, while an opening on the other end side thereof opens to the outer circumferential surface of the pin boss part of the upper link. A lower-link oil passage has a one-end-side opening structured to open to a pin-boss-facing surface of the lower link facing the outer circumferential surface of the pin boss part of the upper link and its other-end-side opening structured to open to a crankpin bearing surface. The lower-link oil passage is configured to point, at a prescribed crankangle, to a specified end edge of end edges of the other-end-side opening of the pin-boss oil passage, the specified end edge facing one end side of the upper link.

An engine case includes bearings, an oil pump, lubricating oil passages, and a relief device. The bearings rotatably support a crankshaft and a camshaft. The oil pump and the lubricating oil passages are configured to pressure-feed lubricating oil to the bearings. The relief device is configured to adjust a pressure of the lubricating oil. The lubricating oil passages include main lubricating oil passages. The main lubricating oil passages include communication portions linearly formed with extending portions. The communication portions communicate between the respective bearings of the crankshaft and the camshaft from outside the engine case. The extending portions extend from outside the engine case to the bearing of the camshaft. The relief device is disposed having a relief valve and a relief hole at the extending portions.