This paper presents the numerical simulation and experimental investigation on impact factors on premature failure of the self-lubricated piston rings in oil-free compressor. In this paper, the finite element method (FEM) was applied to study the non-uniform pressure distributions between the piston rings and the friction process between the self-lubricating piston rings and the cylinder wall, ...

This paper considers the theoretical and experimental approaches to performance improvement of pneumatic linear actuators. Two On/Off, 3/2 pneumatic valves were used to control the position of a pneumatic piston rod through the closed-loop application of a PWM (Pulse Width Modulation)-sliding mode algorithm. System parameters have been experimentally selected in order to reduce the tracking err...

there are many studies about epidural fibrosis after surgical manipulation of the spine. we have studied formation of the post laminectomy epidural fibrosis after application of two materials (silicone and teflon) in this report. this expriment is on two groups of rats. two separated laminectomies were done in each rat, one serving as control while in the other laminectomy spaces silicone was u...

Electro hydraulic actuator (EHA) system has inner and outer loops like a cascade system. The inner loop consists of an electric motor, a gear pump, and an angular velocity controller, and the outer loop consists of a hydro-actuator and a position controller. Especially, dead-band nonlinearity that exists between the electric motor and the gear pump and friction that occurs between the cylinder ...

Free-piston diesel engines are characterized by freely moving pistons without any crankshaft or camshaft connected to the pistons. This allows a compact and efficient engine design, but requires automatic control of the piston motion. This paper present a dynamic mathematical model of a free-piston diesel engine, and a control oriented dynamic analysis leading to a piston motion control structu...

Free-piston engines are under investigation by a number of research groups worldwide, as an alternative to conventional technology in applications such as electric and hydraulic power generation. The piston dynamics of the freepiston engine differ significantly from those of conventional engines, and this may influence in-cylinder gas motion, combustion and emissions formation. Due to the compl...

write: A pump has been constructed as a possible solution to a problem posed by one of us (D.W.)-namely, to produce a device which would wash out the bladder after prostatectomy vwithout breaking the closed drainage system (which could result ia an infection) and which could be used by relatively unskilled staff. The pump with its associated valves is composed of only two parts-a piston and a c...