A method can include: providing a connecting rod device disposed inside of a cylinder of an engine, the connecting rod device coupled to a piston head and extending therefrom, the connecting rod device including a variable-length connecting rod and a connecting rod magnet movably coupled to the variable-length connecting rod; and adjusting a length of the connecting rod by supplying a current to pass through a solenoid wrapped around the cylinder, the current passing through the solenoid generating a magnetic field which activates the connecting rod magnet. The activation of the connecting rod magnet can cause an increase or a decrease of the length of the connecting rod.

The invention provides a design method for a connecting rod. The connecting rod includes a first end, a shank and a second end; and the shank is connected between the first end and the second end. The design method includes: determining a weight m.sub.1 of a standard steel connecting rod; determining a weight m.sub.2 of a nodular cast iron connecting rod having the same size with the standard steel connecting rod; and simulating to reinforce the shank with a reinforcement material having a preset weight m, and calculating a size of the reinforced shank; where m.sub.1>m.sub.2, and m<m.sub.1m.sub.2. The present invention overcomes the technical problem that existing steel connecting rods have larger weights.

A connecting rod is provided, which includes a rod shaft and a rod cap. The rod shaft and the rod cap can be releasably fastened through connecting means to form a connected state, and when the rod shaft and the rod cap are in the connected state, they form a rod eye configured to enclose a bore for mounting the connecting rod on a crank shaft. The rod shaft and the rod cap have contact surfaces at which they touch each other in the connected state. The contact surfaces have an interlocking section-wise serration, and the contact surfaces have an un-serrated section.

A combustion engine is disclosed having a cylinder with a piston travelling through same, coupled by means of a piston rod to a crankshaft, wherein the piston rod has: a first hub in its head for coupling with the crankshaft; a second hub in its foot substantially aligned with or parallel to the first hub in the longitudinal direction of the cylinder when the crankshaft is in the upper or lower position; and a third hub in its foot, which is offset laterally towards the front with respect to the second hub in the direction of rotation of the crankshaft; the piston being coupled with the third hub, having a guide for the travel of the piston rod coupled with the second hub, and the piston being coupled with the third hub via a link rod.

transmission device, particularly for an engine with variable compression rate and/or variable displacement, includes, in a cylinder housing: a combustion piston capable of moving in a combustion cylinder of the engine and secured to a transmission member; a gear engaging with a first rack of the transmission member and providing transmission of the movement between the combustion piston and a crankshaft of the engine; a connecting rod engaging, at a first end, with the gear and, at a second end, with the crankshaft; and a control member engaging with the gear and secured to a control piston. The combustion piston and the transmission member are slidably linked with the cylinder housing in a main direction.

A crank cap assembly provided with a crank cap rotatably supporting a crankshaft includes a mass portion, two cap bolts fixing the crank cap to an engine body, and an elastic supporter disposed between the two cap bolts. The elastic supporter elastically supports the mass portion with respect to the crank cap in an axial direction of the crankshaft.

A method includes powder forging and machining a workpiece that is fractured to divide the workpiece into separate components. In a green form in which the workpiece is formed of compacted powdered metal and has a body that is generally shaped as a parallelepiped with a pair of end faces. The body defines a bore, a pair of V-notches and a pair of channels. The V-notches are formed into the bore parallel to the central axis of the bore and cooperate to define a separation plane. Each of the channels is formed in an associated one of the end faces at a location where the separation plane intersects the end face. During forging, the channels are closed but create a stress riser that aids in directing the fracture when the components are separated from one another.

The subject matter of this specification can be embodied in, among other things, a linear-to-rotary apparatus that includes a linear actuator having an actuator housing including a piston chamber, a piston shaft disposed in the piston chamber, and a rotor apparatus. The rotor apparatus includes a rotary joint defining a rotational axis, a rotor arm extending radially from the rotary joint and configured to at least partially pivot about the rotary joint, and a torque linkage pivotably connected to the rotor arm. The torque linkage is also attached to an end of the piston shaft of the piston at a pivot connection joint, where the pivot connection joint defines a pivot axis that is substantially perpendicular to the translation axis of the piston shaft.

A forged component having a chemical composition including, by mass %, C: 0.30 to 0.45%, Si: 0.05 to 0.35%, Mn: 0.50 to 0.90%, P: 0.030 to 0.070%, S: 0.040 to 0.070%, Cr: 0.01 to 0.50%, Al: 0.001 to 0.050%, V: 0.25 to 0.35%, Ca: 0 to 0.0100%, N: 0.0150% or less, and the balance being Fe and unavoidable impurities, and satisfying formula 1. Metal structure is a ferrite pearlite structure, and a ferrite area ratio is 30% or more. Vickers hardness is in the range of 320 to 380 HV. 0.2% yield strength is 800 MPa or more. A Charpy V-notch impact value is in the range of 7 to 15 J/cm.sup.2.

A transmission device, particularly for an engine with variable compression rate and/or variable displacement, includes, in a cylinder housing: a combustion piston capable of moving in a combustion cylinder of the engine and secured to a transmission member; a gear engaging with a first rack of the transmission member and providing transmission of the movement between the combustion piston and a crankshaft of the engine; a connecting rod engaging, at a first end, with the gear and, at a second end, with the crankshaft; and a control member engaging with the gear and secured to a control piston. The combustion piston and the transmission member are slidably linked with the cylinder housing in a main direction.