The invention relates to a longitudinally adjustable connecting rod (7) for a reciprocating piston engine, in particular a reciprocating piston internal combustion engine, a reciprocating piston engine, and a vehicle comprising a reciprocating piston engine. The longitudinally adjustable connecting rod (7) comprises a longitudinal adjusting mechanism (8) for adjusting an effective length (L) of the connecting rod, a hydraulically actuated control device (12), switchable at least between two control modes, for controlling the longitudinal adjustment, and an electromagnetically actuated hydraulic switching valve (9) for hydraulically actuating the control device (12).

Provided is an engine, including: a cylinder including a cylinder liner; a piston provided inside the cylinder liner; a piston ring provided on the piston; a contact detector configured to detect a contact between a step formed in an inner peripheral surface of the cylinder liner and the piston ring; and a compression ratio controller configured to control a top dead center position of the piston so that the piston ring at the top dead center position is located on a combustion chamber side with respect to the step when the contact is detected.

The present invention relates to a control device and to a control method for a vehicle drive mechanism including a moving body having a movability range regulated by two stoppers, and a sensor which senses a position of the moving body. The control device of the present invention learns an output of the sensor corresponding to a contact state of a high-rigidity stopper, and limits, to a lower level, an operation variable of the actuator for moving the moving body toward a low-rigidity stopper along with an increase in an amount of change in the output of the sensor from the contact state of the high-rigidity stopper. Then, the control device learns the output of the sensor corresponding to the contact state of the low-rigidity stopper, and controls the actuator based on the output of the sensor learned at both the stopper positions.

Methods and systems are provided for a piston. In one example, system may comprise a piston comprising a chamber in which a piston bowl may actuated independent of an oscillation of the piston. The chamber may receive a hydraulic fluid in order to adjust a position of the piston bowl within the chamber, thereby adjusting a compression ratio of a combustion chamber in which the piston may oscillate.

A device for an internal combustion engine, in particular a spark ignition engine, with a length-adjustable connecting rod and a sensor unit for detecting the adjustment in length of the connecting rod is provided. The length-adjustable connecting rod comprises a first connecting rod member for receiving a piston pin and a second connecting rod member for receiving a crankshaft journal, where the distance in length between the piston pin and the crankshaft journal is adjustable by way of the connecting rod. The sensor unit comprises a sensor and an index region provided on the length-adjustable connecting rod, where a property of the index region that is dependent upon the adjustment in length of the connecting rod can be detected by way of the sensor. An internal combustion engine with such a device, comprises a length-adjustable connecting rod and a sensor unit as well as the use of such a sensor unit and a length-adjustable connecting rod.

An eccentric sleeve for a crankshaft of a compressor, a crankshaft, a crankshaft assembly, and a compressor are provided. The crankshaft has a main shaft, a counterbalance and an eccentric shaft. The main shaft and the eccentric shaft are provided at two sides of the counterbalance and arranged eccentrically. The main shaft is internally provided with a main lubrication oil passage. An outer circumferential wall of the eccentric shaft is provided with an oil leakage hole in fluid communication with the main lubrication oil passage. The eccentric sleeve is fitted over the eccentric shaft. An outer circumferential wall of the eccentric sleeve is provided with a shaft flow hole extending through the outer circumferential wall in a thickness direction of the eccentric sleeve.

A piston with external pins boss connected with at least two coupled crankshafts, transforming reciprocating linear movement of the piston into rotary motion of the crankshafts. A cylinder jacket with the piston head forms the combustion chamber. Piston inner space with static counterpart forms an additional intake-breathing chamber. On static counterpart, an income and outgo valves can be located. From reciprocating movement of the piston, the intake-breathing chamber will provide intake gases to the combustion chamber employing a transfer port. Previous to the transfer port, a control valve may be disposed to regulate the volume of intake gases entering the combustion chamber. The intake-breathing gases not used for combustion may be mixed with combustion exhaust gases. Length of connecting links, on inverse configuration, provides extra time at maximum compression rate; improving evaporation and combustion stage timing.

A longitudinally adjustable connecting rod for a piston engine having a hydraulic control device for adjusting the effective length of the longitudinally adjustable connecting rod is provided. The hydraulic control device comprises a hydraulic control valve which has a control cylinder, a spool valve and at least one drain valve that can be actuated by the spool valve, wherein the spool valve comprises a control piston, which is displaceably guided in the control cylinder and to which hydraulic control pressure can be applied, and a slide plunger. The spool valve comprises two spool valve parts which can be separately manufactured and rigidly joined together for the intended use of the spool valve. Moreover, the invention relates to a spool valve for the hydraulic control valve of a longitudinally adjustable connecting rod and to a piston engine having at least one such longitudinally adjustable connecting rod.

A method for starting an internal combustion engine of a snowmobile is disclosed. The method comprises actuating a start switch of the snowmobile; in response to the start switch being actuated, sensing a temperature; in response to the sensed temperature being above a predetermined temperature, starting the engine using a motor-generator; and in response to the sensed temperature being below the predetermined temperature, starting the engine using a recoil starter.

A method for starting an internal combustion engine of a snowmobile is disclosed. The method comprises actuating a start switch of the snowmobile; in response to the start switch being actuated, sensing a temperature; in response to the sensed temperature being above a predetermined temperature, starting the engine using a motor-generator; and in response to the sensed temperature being below the predetermined temperature, starting the engine using a recoil starter.