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Compressor Types
Published in Tony Giampaolo, Compressor Handbook, 2020
The distance piece is used to provide sufficient space to facilitate separation of toxic vapors from the oil system and the atmosphere. The “distance piece” mounts to the compressor frame. Besides housing the crosshead guide the distance piece also houses the oil wiper packing (Figure 3-19). The piston rod traverses through the packing as it moves from the head-end to the crank-end thereby acting to seal the process gas in the cylinder from the lubricating environment. Due to the wear created on the piston rod resulting from contact with the packing the piston is often hardened in this contact area. The rod packing is originally assembled when the piston and rod assembly is installed. However, after assembly the sealing rings can be removed and replaced as needed.
Pumps and Turbines
Published in Henry Liu, Pipeline Engineering, 2017
Figure 9.7a shows the main features of a piston pump: Cylinder (chamber) — The cylinder is the casing of the pump that contains a piston and the fluid in the pump. It is open to the discharge pipe downstream, and to the suction pipe upstream.Piston — The piston moves back and forth in the cylinder, driven by a motor or an engine either directly or indirectly. The reciprocating motion of the piston causes the fluid in the cylinder to be pushed out during the forward stroke of the piston.Rod — The piston rod connects the piston to the reciprocating part of the machine that drives the piston.Check Valves — Two spring-loaded check valves, one connected to the discharge pipe and the other connected to the suction pipe, control the direction of flow. When the piston is moving forward, the discharge check valve opens and the suction check valve closes. This forces the fluid in the pump to enter the discharge pipe. In contrast, when the piston is moving backward, the discharge check valve closes and the suction check valve opens. This causes the fluid in the suction pipe to be drawn into the pump. Packing for Piston and Rod — The piston packing material seals the gap between the piston and its surrounding wall, preventing leakage and increasing the efficiency of the pump. Likewise, the piston-rod packing seals the gap between the piston rod and its surroundings, preventing leakage and increasing pump efficiency.
Actuators
Published in Ian C. Turner, Engineering Applications of Pneumatics and Hydraulics, 2020
The piston rod is preferably made from heat-treated steel. A certain percentage of chrome in the steel protects against rusting. Generally the threads are rolled to reduce the danger of fracture.
Regenerative hydraulic shock absorber for vehicle applications: prototype design
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
Vjekoslav Tvrdić, Srdjan Podrug, Damir Jelaska, Milan Perkušić
In Figure 3 there are 25 positions (arrow markings and numbers) that indicate individual parts of the regenerative hydraulic shock absorber prototype. Positions and parts of the proposed prototype are listed on the right side of the assembly technical drawing. Axially installed retaining rings (position 1 in Figure 3) prevent axial displacement of the bolt (2). The bolt is connected to the welded grips (3) with a transitional seat. This bolt is used to connect the regenerative hydraulic shock absorber to the shaft with wheels, as can be seen in Figure 1. The two grips are welded (fillet type of weld) to the lower cover (4) of the regenerative hydraulic shock absorber. The lower cover is welded (single V groove weld) to the hydraulic cylinder tube (7) to obtain closed hydraulic chambers (“A” and “B” cylinder chambers in Figure 1). The lower cover also serves for centering the torsion spring (5) in order to restore the hydraulic piston (9) to the neutral position after the energy transmission through the hydraulic fluid. The torsion spring (5) is mechanically connected (can be replaced and dismantled) with the lower cover and hydraulic cylinder piston. The connections (6 and 15) are welded with the fillet type welds to the wall of the hydraulic pipe (7). There are 4 connections on the structure, which serve for the later installation of 4 check valves that allow the regenerative operation of the hydraulic shock absorber. Within each of these connectors, a metric thread was made together with the hole to enable hydraulic elements to connect and to pass hydraulic fluid to the high pressure hydraulic accumulator. On the edges of the hydraulic piston, there are three urethane seals (10, 11 and 13) which prevent fluid flow from one hydraulic cylinder chamber to the other. The hydraulic piston and piston rod (12) are connected with the nut (8) on the underside of the piston, and on the upper side there is a ridge on the piston rod which allows tightening between the piston and the piston rod. All these parts can easily be disassembled and re-assembled, which is very important because of the regenerative device maintenance problem. Another torsion spring (14)