An annular cylinder liner includes an annular body defining a longitudinal axis, a radial direction perpendicular to the longitudinal axis, a circumferential direction, a first longitudinal end, a second longitudinal end, and a liner length measured from the first longitudinal end to the second longitudinal end along the longitudinal axis. The annular body also includes a shoulder that is disposed at the first longitudinal end, defining a shoulder axial thickness measured along the longitudinal axis. A ratio of the liner length to the shoulder axial thickness ranges from 24.0 to 46.0.

A vehicle-mounted electric oil-free air compressor, including a motor, a box body, a piston, and a flywheel shaft. The motor is fixed on the box body, a cylinder cover is at the top of the box body, a main shaft of the motor includes a coupling driving end, the flywheel shaft is driven by an elastic body to rotate. The piston includes a primary intake valve piece and a primary exhaust valve piece, the box body is provided with a secondary cavity, a secondary exhaust valve piece is provided at a vent hole on one side of the cavity, and the primary exhaust valve piece is also a secondary intake valve piece of the compressor, increasing the exhaust pressure. When the piston reciprocates, the stress is balanced and the vibration is small, and with the assistance of a high-efficiency flywheel, the operation of the air compressor is stable.

An engine balancing system includes an engine body. At least two slider-crank mechanisms are provided inside the engine body. One of the slider-crank mechanisms is arranged opposite to the other slider-crank mechanism. A slider in one of the slider-crank mechanisms is moved at a speed and acceleration similar to a speed and acceleration of a slider in the other slider-crank mechanism. The slider-crank mechanism includes a connecting rod and a crankshaft with a crank. One end of one of the slider-crank mechanisms and one end of the other slider-crank mechanism are connected to the same crankshaft through the crank. The balancing system can effectively eliminate first-order, second-order and higher-order vibrations generated during engine operation, thus reducing the probability of equipment damage.

An internal combustion engine includes a crankshaft having a first end and a second end opposite the first end. The crankshaft defines a crank axis and is rotatable about the crank axis. The internal combustion engine also includes a camshaft that defines a camshaft axis and is rotatable about the camshaft axis. The internal combustion engine further includes a cam drive assembly that is operable to transfer rotation from the crankshaft to the camshaft, a balance mass rotatable about the crankshaft, and a balancer drive assembly operable to drive the balance mass through the cam drive assembly.

A crank and connecting rod mechanism which can realize a Miller cycle and its control method, wherein an interior of a crankshaft is provided with a drive oil channel and a lock-up oil channel. A connecting rod neck of the crankshaft is arranged with an eccentric connecting rod bearing. In a crankshaft balance weight, a drive gear meshing with an outer meshing gear ring of the eccentric connecting rod bearing through an idle gear is installed. A planetary gear is installed in a drive gear hollow shaft. A lockpin is designed for the drive gear hollow shaft so as to lock with the crankshaft balance weight or with a planetary gear shaft.

A modular active valve system having a reduced footprint for use in a smaller shock platform is disclosed. The modular active valve system includes a multi-stage valve having a first stage and at least a second stage, wherein at least the first stage includes a semi-active valve for electronic damping control.

Systems and methods for reducing inertial forces of a reciprocating piston internal combustion engine are described. The systems and methods may provide for counterweights in a form of pistons in cylinders that are moved via electromagnets. The counterweights may be moved at a frequency that corresponds to engine speed via an alternating current.

A balance shaft structure includes a balance shaft including a balance weight, a driven gear to rotate the balance shaft by being engaged with a drive gear, a scissors mechanism, whose position in an axial direction is regulated, including a scissors gear to reduce backlash between the drive gear and the driven gear and an axially urging member to urge the scissors gear toward the driven gear in the axial direction, a first regulating portion to regulate an axially inner position of the scissors mechanism, and a second regulating portion fixed to the balance shaft on a side close to the shaft end part of the balance shaft beyond the first regulating portion and configured to regulate an axially outer position of the scissors mechanism.

A crank and connecting rod mechanism which can realize Miller cycle and its control method, wherein an interior of a crankshaft is provided with a drive oil channel and a lock-up oil channel. A connecting rod neck of the crankshaft is arranged with an eccentric connecting rod bearing. In a crankshaft balance weight, a drive gear meshing with an outer meshing gear ring of the eccentric connecting rod bearing through an idle gear is installed. A planetary gear is installed in a drive gear hollow shaft. A lockpin is designed for the drive gear hollow shaft so as to lock with the crankshaft balance weight or with a planetary gear shaft.

Variable counterweight apparatuses, systems and methods. The variable counterweight system includes at least one rotatable actuator, a first variable counterweight assembly, and a second variable counterweight assembly. The first variable counterweight assembly is rotatably coupled to the rotatable actuator to rotate about a first axis. The first variable counterweight assembly is configured to geometrically reconfigure so as to change a first variable counterweight assembly center of gravity position with respect to the first variable counterweight assembly. The second variable counterweight assembly is rotatably coupled to the rotatable actuator to rotate about a second axis. The second variable counterweight assembly is configured to geometrically reconfigure so as to change a second variable counterweight assembly center of gravity position with respect to the second variable counterweight assembly.