A vehicle lubrication structure includes a rotating electrical machine, a driving force transmission apparatus, a first reservoir, a second reservoir, a first oil path, a second oil path, and an electric oil pump. The second reservoir has a capacity smaller than that of the first reservoir. The first oil path connects the first reservoir to the second reservoir. The second oil path connects the second reservoir to the driving force transmission apparatus and the rotating electrical machine. The electric oil pump is configured to supply oil stored in the first reservoir to the driving force transmission apparatus and the rotating electrical machine. The electric oil pump is provided in the first oil path or the second oil path.

A vehicle lubrication structure includes a rotating electrical machine, a driving force transmission apparatus, a first reservoir, a second reservoir, a first oil path, a second oil path, and an electric oil pump. The second reservoir has a capacity smaller than that of the first reservoir. The first oil path connects the first reservoir to the second reservoir. The second oil path connects the second reservoir to the driving force transmission apparatus and the rotating electrical machine. The electric oil pump is configured to supply oil stored in the first reservoir to the driving force transmission apparatus and the rotating electrical machine. The electric oil pump is provided in the first oil path or the second oil path.

This invention relates to the field of opposed-piston engines having two pistons in one cylinder configured to have facing heads. Specifically, this is an engine with two crankshafts, two piston heads facing each other in a single cylinder, with the following features: compact size relative to a comparable design, improved or equivalent performance to a comparable design as a result of any of the following: locating crankshafts in a different plane from the cylinder axes; the use of shared duct structures; and the use of an embedded compressor chamber for efficient operation to cover all volumetric requirements, fulfilling the entire thermodynamic cycle, and performing in addition the sweeping and overloading of air or an air/fuel mixture in the cylinder combustion chamber in each revolution of two or more crankshafts, either with or without advancement between the crankshafts.

This invention relates to the field of opposed-piston engines having two pistons in one cylinder configured to have facing heads. Specifically, this is an engine with two crankshafts, two piston heads facing each other in a single cylinder, with the following features: compact size relative to a comparable design, improved or equivalent performance to a comparable design as a result of any of the following: locating crankshafts in a different plane from the cylinder axes; the use of shared duct structures; and the use of an embedded compressor chamber for efficient operation to cover all volumetric requirements, fulfilling the entire thermodynamic cycle, and performing in addition the sweeping and overloading of air or an air/fuel mixture in the cylinder combustion chamber in each revolution of two or more crankshafts, either with or without advancement between the crankshafts.

Methods and systems are provided for supplying cooling oil to a piston of an engine cylinder. In one example, a method may include repeatedly activating an oil supply only during a part of a cylinder cycle synchronous with a reciprocating motion of the piston. In particular, supply of cooling oil may be initiated by displacing a poppet valve arranged within a piston cooling assembly via a reciprocating motion of the piston.

Methods and systems are provided for supplying cooling oil to a piston of an engine cylinder. In one example, a method may include repeatedly activating an oil supply only during a part of a cylinder cycle synchronous with a reciprocating motion of the piston. In particular, supply of cooling oil may be initiated by displacing a poppet valve arranged within a piston cooling assembly via a reciprocating motion of the piston.

A spool is configured to reciprocate at an inside space of a sleeve and includes: a spool tube; a spool cover, which closes an end portion of the spool tube located on a camshaft side; a pressure accumulation space, which is formed at an inside of the spool tube; a supply passage, which is configured to connect between the pressure accumulation space and a supply port; a control passage, which is configured to connect between the pressure accumulation space and a primary control port; and a control passage, which is configured to connect between the pressure accumulation space and a secondary control port. A variable volume space is formed between the spool cover and a sleeve bottom. The sleeve includes a breathing hole at an outside of the inside space while the breathing hole is a hole that communicates between the variable volume space and the atmosphere.

A spool is configured to reciprocate at an inside space of a sleeve and includes: a spool tube; a spool cover, which closes an end portion of the spool tube located on a camshaft side; a pressure accumulation space, which is formed at an inside of the spool tube; a supply passage, which is configured to connect between the pressure accumulation space and a supply port; a control passage, which is configured to connect between the pressure accumulation space and a primary control port; and a control passage, which is configured to connect between the pressure accumulation space and a secondary control port. A variable volume space is formed between the spool cover and a sleeve bottom. The sleeve includes a breathing hole at an outside of the inside space while the breathing hole is a hole that communicates between the variable volume space and the atmosphere.

A retard supply passage connects between a hydraulic oil supply source and a retard chamber through a hydraulic oil controller. An advance supply passage connects between the hydraulic oil supply source and an advance chamber through the hydraulic oil controller. A drain passage and a drain passage connect the retard chamber and the advance chamber to an oil discharge portion, respectively. A recycle passage connects the drain passage and the drain passage to the retard supply passage and the advance supply passage, respectively. A recycle check valve enables only a flow of hydraulic oil from the drain passages toward the retard supply passage and the advance supply passage in the recycle passage. The recycle passage is connected to the drain passages at an inside of the hydraulic oil controller.

A retard supply passage connects between a hydraulic oil supply source and a retard chamber through a hydraulic oil controller. An advance supply passage connects between the hydraulic oil supply source and an advance chamber through the hydraulic oil controller. A drain passage and a drain passage connect the retard chamber and the advance chamber to an oil discharge portion, respectively. A recycle passage connects the drain passage and the drain passage to the retard supply passage and the advance supply passage, respectively. A recycle check valve enables only a flow of hydraulic oil from the drain passages toward the retard supply passage and the advance supply passage in the recycle passage. The recycle passage is connected to the drain passages at an inside of the hydraulic oil controller.