For a lot of pressure changes, way too much, but the last to be considered together with the flow changes. For example, the multi-stage pressure switch, electro-hydraulic proportional valve manually variable pump, proportional pressure pumps, plus turbocharger, plus electric high-pressure pump as a booster (these two are local booster), and so on. 5) with constant pressure does not change, but the change of flow conditions; constant power with all changes in pressure and flow, but the same power condition .6) governor, there are two options: First, the pump motor control system ; a valve-controlled motor system. The former program are: a quantitative variable motor pump + 2 variable displacement pump (inverter motor + dosing pumps) + quantitative motor manually variable axial piston pump, which is characterized by the body and body composition variables; the body from the pump casing (12) drive shaft (1), the cylinder (15), a plurality of pistons (11), the shoe (10), return plate (9), the return spring (13), the sleeve (20), one-way thrust ball bearings (18), a small spring (14), ball joints (8), thimble (22), hole retainer (19), with oil pan (16) and pump (17) composition; the drive shaft (1) and the cylinder intermediate (15) splined, multiple plungers (11) were installed in the cylinder (15) on the plunger bore piston pump v38, the plunger (11) of the ball and the shoe (10 ) lead shoe (10) in the card return plate (9 holes) on the return plate (9) of the central hole and the ball joints (8) cooperates, the thimble (22) mounted in the cylinder (15) thimble hole, the return spring (13) and bushing sleeve small spring (14) after the (20) mounted on the drive shaft (1) and the cylinder (15) between the pump body (17) and the casing ( 12) between the screw associated with the oil pan (16) is mounted between the cylinder (15) and pump body (17); hole retainer (19) mounted in the cylinder (15) close to the oil pan ( 16) end; variable by variable housing body (2), the variable head (3), a small dial block (4), dial column (5), variable valve (6) and a large dial blocks (7), with variable valve (6) with screws at the top of the shell variables (2), the variable head (3) with variable housing (2) through the bush between (23) linked to a small dial blocks (4) mounted on the dial column (5) mounted on the rear in the variable valve (6) Domestic variable pump, the lower dial column (5) is inserted in the large dial block (7) on the hole, large dial block (4) with screws in the variable head (3) between the main body and the variables associated with screws, one end of the shaft (1) through a bearing mounted on the pump (17) on the other end by a bearing mounted in the variable housing (2), the one-way thrust ball bearings (18 ) disposed between the pump (bearings and sleeve 17) (20). Maintenance record variable hydraulic pump _ Crystal (certified) _ variable pump from Jinan Jing Chong hydraulic machinery Limited. Jinan Jing Chong Hydraulic Machinery Co., Ltd. (www.jnjcyy.com) (www.jnjcyy.com) Shandong Jinan, mining machinery leaders, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, the maximum meet customer needs. In the crystal to create a hydraulic leadership with the staff warmly welcome all inquiries negotiations to create the crystal to create a better future for the hydraulic.