KIT-SHIM 1368627 - Caterpillar

General View
Structural Diagram
Function
Basic functionsThe hydraulic cylinder is a kind of hydraulic actuator. It converts the hydraulic energy supplied from the hydraulic pump into a linear motion force through a piston. This force is used to change the direction of movements, extension or retraction, by operating the control valve lever. That is, the basic function of the hydraulic cylinder is to produce a strong force of linear motion and thereby change the direction of movements. All cylinders are based on the same principle. This chapter, therefore, describes the boom cylinder as a typical example. Functions of major parts1. Dust seal (8) Dust seal (8) is positioned at the lip of cylinde tube (1) through which piston rod (3) moves. It prevents entry of dust and water into rod packing (10) and the rod seals of buffer ring (11), etc. It also scrapes the mud off piston rod (3) as piston rod (3) moves.2. Rod packing (10) Rod packing (10) is located between dust seal (8) and buffer ring (11). It hermetically seals the circular clearance formed between piston rod (3) and packing case (5) against the pressure oil between rod packing (10) and buffer ring (11). It also allows an appropriate rustproofing oil film on piston rod (3).3. Buffer ring (11) Buffer ring (11) is positioned between rod packing (10) and rod bushing (12). It is an auxiliary seal which is in direct contact with high pressure oil in the cylinder. It buffers the high pressure to reduce the load on rod packing (10), thereby prolonging the lifetime of rod packing (10).4. Rod bushing (12) and snapring (36) Rod bushing (12) and snapring (36) are installed on the inner surface of packing case (5) and are in contact with piston rod (3). Along with the linear sliding guide for piston rod (3) and wear ring (19) on the outer surface of piston (17), rod bushing (12) bears the lateral load on the cylinder to reduce the eccentricity that adversely affects the seals. Snapring (36) prevents rod bushing (12) from dislocating.5. Cushion ring (15) Cushion ring (15) is positioned between packing case (5) and the faucet end of cylinder tube (1). When the cylinder extends almost fully, cushion (15) and cushion piston (16) form a circular clearance to throttle the oil, thereby reducing the piston speed. This lessens the impact on the cylinder that is given when the cylinder extends fully.6. Packing case (5) Packing case is located at the opening of cylinder tube (1). It holds dust seal (8), backup ring (9), rod packing (10), buffer ring (11), and rod bushing (12). Packing case (5) and cylinder tube (1) constitute a pressure vessel. 7. Piston packing (18) Piston packing (18) is positioned on the outer surface of piston (17). It consists of the slipper ring, back ring, and backup ring. Piston packing (18) hermetically seals the circular clearance between piston (17) and cylinder tube (1) to divide cylinder tube (1) into high and low pressure sections with piston (17)