Chapter 3 Hydraulic Pumps 3.1.4 Classification Hydraulic pumps may be classified by the forms of main moving components and their moving manners:gear,vane,piston and screw pumps 1)Gear pumps may be further classified in two broad categories,external or internal mesh; 2)Vane pumps may be further divided into double-acting vane pumps,single- acting vane pumps and cam-rotor vane pumps; 3)Piston pumps consist of radial piston pumps and axial piston pumps; 4)Screw pumps include single-screw pumps,two-screw pumps and three-screw pumps. Hydraulic pumps may be further classified according to the types of delivery (1)Fixed delivery; (2)Variable delivery. variable delivery can be accomplished in single-acting vane pumps,radial or axial piston pumps 11 Homepage List Upwards Downwards Retumn Exit
Chapter 3 Hydraulic Pumps 11 3.1.4 Classification Hydraulic pumps may be classified by the forms of main moving components and their moving manners: gear, vane, piston and screw pumps. 1)Gear pumps may be further classified in two broad categories, external or internal mesh; 2)Vane pumps may be further divided into double-acting vane pumps, singleacting vane pumps and cam-rotor vane pumps; 3)Piston pumps consist of radial piston pumps and axial piston pumps; 4)Screw pumps include single-screw pumps, two-screw pumps and three-screw pumps. Hydraulic pumps may be further classified according to the types of delivery: (1) Fixed delivery; (2) Variable delivery. variable delivery can be accomplished in single-acting vane pumps, radial or axial piston pumps
Chapter 3 Hydraulic Pumps 3.1.5 Graphic symbols The graphic symbols of hydraulic pumps are shown in Fig 3-4 b) c) d) Fig.3-4 Graphic symbols a)Non-return fixed delivery hydraulic pumps b)Non-return variable delivery hydraulic pumps c)Reversible fixed delivery pump d)Reversible variable delivery pump 12 Homepage List Upwards Downwards Retumn Exit
Chapter 3 Hydraulic Pumps 12 3.1.5 Graphic symbols The graphic symbols of hydraulic pumps are shown in Fig.3-4. Fig. 3-4 Graphic symbols a) Non-return fixed delivery hydraulic pumps b) Non-return variable delivery hydraulic pumps c) Reversible fixed delivery pump d) Reversible variable delivery pump
Chapter 3 Hydraulic Pumps 3.2 Piston Pumps 3.2.1 Valve shaft radial piston pumps 3.2.2 Swash plate axial piston pumps 3.2.3 Bent axis axial piston pumps 13 Homepage List Upwards Downwards Retumn Exit
Chapter 3 Hydraulic Pumps 13 3.2 Piston Pumps 3.2.1 Valve shaft radial piston pumps 3.2.2 Swash plate axial piston pumps 3.2.3 Bent axis axial piston pumps
Chapter 3 Hydraulic Pumps 3.2 Piston Pumps The oil suction and delivery actions of a piston pump depend upon the size change of the chamber produced by the reciprocating movement of the pistons within their cylinder bores.The signal piston pump shown in Fig3-1 is a radical type. 3.2.1 Valve shaft radial piston pumps The pump's delivery 1.Operating principle expressed by: v-2 (3-1) 2 where d is the piston diameter,e is the offset between the stator and cylinder case (rotor),zis the number of the pistons. Fig.3-5 Valve shaft radial piston pump 1-Piston2-Rotor 3-Bush4-Stator5-Valve shaft Homepage List Upwards Dowrward达 Retumn Exit
Chapter 3 Hydraulic Pumps 14 3.2 Piston Pumps 3.2.1 Valve shaft radial piston pumps The oil suction and delivery actions of a piston pump depend upon the size change of the chamber produced by the reciprocating movement of the pistons within their cylinder bores. The signal piston pump shown in Fig.3-1 is a radical type. 1.Operating principle The pump ’ s delivery is expressed by: where d is the piston diameter, e is the offset between the stator and cylinder case (rotor), z is the number of the pistons. Fig. 3-5 Valve shaft radial piston pump 1- Piston 2-Rotor 3-Bush 4- Stator 5-Valve shaft 2 π (3-1) 2 d V ez =