Home>Products>Rexroth Vane pump>Rexroth PVQ4-1X/122RA-15DMC Vane pump
Rexroth PVQ4-1X/122RA-15DMC Vane pump
category
Rexroth Vane pump
Rexroth PVQ4-1X/122RA-15DMC SPECIFICATIONS
How RTA Pump Development Co., Ltd. do I place an EMERGENCY order for a Rexroth PVQ4-1X/122RA-15DMC Vane pump KOYO Brand that I want to pick up at UCFL216-50E Bearing number a our store?
- Rexroth
PVQ4-1X/122RA-15DMC
- 45.0 LB
- Flange Mount
- Left Hand (CCW)
- 2520VQ14A8-1CC20-LH
- 2 1/2
- Flange
- 3/16 in
- Standard Pilot
- RTA Pump Development Co., Ltd.2020-07-10 09:46:19
Welcome to my shop! Glad to serve you! Please send your question!
Rexroth PVQ4-1X/122RA-15DMC Vane pump Technical information
- 0.875 in
- Straight w/ Key
- 2520VQ
- 1.9375 in
- Buna-N
- 2700
- N/A
- SAE B, 2 Bolt
- Single Shaft Seal
- N/A
- 2700
- 2700
- N/A
- 8 gal/min @ 1200 rpm, 12 gal/min @ 1800 rpm
- N/A
- N/A
- N/A
- N/A
- N/A
- 14 gal/min @ 1200 rpm, 21 gal/min @ 1800 rpm
- 2520VQ14A8-1CC20-LH
- 3000
- 3000
- 12
- 21
- w/o Integral Valves
- Outlet 45° CW from Inlet
- Outlet Inline w/Inlet
- 3/4 in Flange
- 1 in Flange
- 1.67
- 2.77
Rexroth PVQ4-1X/122RA-15DMC Rexroth PVQ4-1X/122RA-15DMC Vane pump Cross reference
Frequently bought Rexroth PVQ4-1X/122RA-15DMC Vane pump together | |||||||||
---|---|---|---|---|---|---|---|---|---|
No. | Brand | m | D | B | C | d | L | H | Cu |
15BTM2122 | KOYO | - | 21 mm | - | 13 kN | 15 | - | - | - |
NAX 1223 | IKO | - | 21 mm | - | - | 12 | 23 mm | 9 mm | - |
NAX 1223Z | IKO | - | 21 mm | - | - | 12 | 23 mm | 9 mm | - |
NAXI 1223 | IKO | - | 24 mm | 16,5 mm | - | 12 mm | 23 mm | 9 mm | - |
NAXI 1223Z | IKO | - | 24 mm | 16,5 mm | - | 12 mm | 23 mm | 9 mm | - |
122FC87660 | KOYO | - | 870 mm | 660 mm | 15200 kN | 610 mm | - | - | 3360 |
122W | Timken | - | 175 mm | 30 mm | 116 kN | 110 mm | - | - | - |
122WD2N | Timken | - | 175 mm | 30 mm | 116 kN | 110 mm | - | - | - |
122WI | Timken | - | 175 mm | 30 mm | 116 kN | 110 mm | - | - | - |
TC1220 | INA | 0,006 kg / Weight | 31,75 | - | - | 19,05 | - | - | - |
XGB41225P | SNR | - | 83 mm | 44 mm | 44 mm | 45 mm | - | - | - |
Rexroth R901084887 PVV52-1X/193-045RA15DDMC Vane pump | Relief Valve Setting:45.0 LB; Pilot Type:Flange Mount; Shaft End Flow @ RPM:Left Hand (CCW); Manufacturer Part No.:2520VQ14A8-1CC20-LH; Port Size:2 1/2; Shaft Key:Flange; Model No.:3/16 in; Displacement Shaft End (cu in/revolution):Standard Pilot; Weight:0.875 in; Mounting Flange:Straight w/ Key; Pump Series:2520VQ; Shaft Length:1.9375 in; Seal Material:Buna-N; Max. RPM [Max:2700; Minor Diameter:N/A; Mounting Flange:SAE B, 2 Bolt; Shaft Seal Type:Single Shaft Seal; Spline Description:N/A; Cover End RPM [Max:2700; Shaft End RPM [Max:2700; Controlled Flow Rate:N/A; Cover End Flow @ RPM:8 gal/min @ 1200 rpm, 12 gal/min @ 1800 rpm; Major Diameter [Max:N/A; Major Diameter [Min:N/A; Minor Diameter [Max:N/A; Minor Diameter [Min:N/A; Relief Valve Setting:N/A; Shaft End Flow @ RPM:14 gal/min @ 1200 rpm, 21 gal/min @ 1800 rpm; Manufacturer Part No.:2520VQ14A8-1CC20-LH; Cover End Pressure [Max:3000; Shaft End Pressure [Max:3000; GPM @ 1,800 rpm, Cover End:12; GPM @ 1,800 rpm, Shaft End:21; Integral Valve Configuration:w/o Integral Valves; Port Orientation - Cover End:Outlet 45° CW from Inlet; Port Orientation - Shaft End:Outlet Inline w/Inlet; Pressure Port Size, Cover End:3/4 in Flange; Pressure Port Size, Shaft End:1 in Flange; Displacement Cover End (cu in/revolution):1.67; Displacement Shaft End (cu in/revolution):2.77; |
Rexroth R901085383 PVV41-1X/122-027RB15DDMC Vane pump | Displacement Shaft End (cu in/revolution):45.0 LB; Major Diameter [Min:Flange Mount; Spline Description:Left Hand (CCW); Minor Diameter [Min:2520VQ14A8-1CC20-LH; Max. RPM [Max:2 1/2; Mounting:Flange; Cover End RPM [Max:3/16 in; Shaft Dia.:Standard Pilot; Pilot Type:0.875 in; Minor Diameter:Straight w/ Key; Pump Series:2520VQ; Shaft Length:1.9375 in; Seal Material:Buna-N; Max. RPM [Max:2700; Minor Diameter:N/A; Mounting Flange:SAE B, 2 Bolt; Shaft Seal Type:Single Shaft Seal; Spline Description:N/A; Cover End RPM [Max:2700; Shaft End RPM [Max:2700; Controlled Flow Rate:N/A; Cover End Flow @ RPM:8 gal/min @ 1200 rpm, 12 gal/min @ 1800 rpm; Major Diameter [Max:N/A; Major Diameter [Min:N/A; Minor Diameter [Max:N/A; Minor Diameter [Min:N/A; Relief Valve Setting:N/A; Shaft End Flow @ RPM:14 gal/min @ 1200 rpm, 21 gal/min @ 1800 rpm; Manufacturer Part No.:2520VQ14A8-1CC20-LH; Cover End Pressure [Max:3000; Shaft End Pressure [Max:3000; GPM @ 1,800 rpm, Cover End:12; GPM @ 1,800 rpm, Shaft End:21; Integral Valve Configuration:w/o Integral Valves; Port Orientation - Cover End:Outlet 45° CW from Inlet; Port Orientation - Shaft End:Outlet Inline w/Inlet; Pressure Port Size, Cover End:3/4 in Flange; Pressure Port Size, Shaft End:1 in Flange; Displacement Cover End (cu in/revolution):1.67; Displacement Shaft End (cu in/revolution):2.77; |
Rexroth R901083429 PVV54-1X/139-113LB15DDMC Vane pump | GPM @ 1,800 rpm, Shaft End:45.0 LB; Cover End Flow @ RPM:Flange Mount; Shaft Seal Type:Left Hand (CCW); Shaft End RPM [Max:2520VQ14A8-1CC20-LH; Controlled Flow Rate:2 1/2; Relief Valve Setting:Flange; Max. RPM [Max:3/16 in; Seal Material:Standard Pilot; Port Type:0.875 in; Cover End RPM [Max:Straight w/ Key; Pump Series:2520VQ; Shaft Length:1.9375 in; Seal Material:Buna-N; Max. RPM [Max:2700; Minor Diameter:N/A; Mounting Flange:SAE B, 2 Bolt; Shaft Seal Type:Single Shaft Seal; Spline Description:N/A; Cover End RPM [Max:2700; Shaft End RPM [Max:2700; Controlled Flow Rate:N/A; Cover End Flow @ RPM:8 gal/min @ 1200 rpm, 12 gal/min @ 1800 rpm; Major Diameter [Max:N/A; Major Diameter [Min:N/A; Minor Diameter [Max:N/A; Minor Diameter [Min:N/A; Relief Valve Setting:N/A; Shaft End Flow @ RPM:14 gal/min @ 1200 rpm, 21 gal/min @ 1800 rpm; Manufacturer Part No.:2520VQ14A8-1CC20-LH; Cover End Pressure [Max:3000; Shaft End Pressure [Max:3000; GPM @ 1,800 rpm, Cover End:12; GPM @ 1,800 rpm, Shaft End:21; Integral Valve Configuration:w/o Integral Valves; Port Orientation - Cover End:Outlet 45° CW from Inlet; Port Orientation - Shaft End:Outlet Inline w/Inlet; Pressure Port Size, Cover End:3/4 in Flange; Pressure Port Size, Shaft End:1 in Flange; Displacement Cover End (cu in/revolution):1.67; Displacement Shaft End (cu in/revolution):2.77; |
Rexroth R901085379 PVV21-1X/055-027RB15DDMB Vane pump | Shaft Seal Type:45.0 LB; Major Diameter [Min:Flange Mount; Pilot Type:Left Hand (CCW); Minor Diameter [Min:2520VQ14A8-1CC20-LH; GPM @ 1,800 rpm, Cover End:2 1/2; Mounting:Flange; Weight:3/16 in; Pump Series:Standard Pilot; Shaft End Flow @ RPM:0.875 in; Shaft Dia.:Straight w/ Key; Pump Series:2520VQ; Shaft Length:1.9375 in; Seal Material:Buna-N; Max. RPM [Max:2700; Minor Diameter:N/A; Mounting Flange:SAE B, 2 Bolt; Shaft Seal Type:Single Shaft Seal; Spline Description:N/A; Cover End RPM [Max:2700; Shaft End RPM [Max:2700; Controlled Flow Rate:N/A; Cover End Flow @ RPM:8 gal/min @ 1200 rpm, 12 gal/min @ 1800 rpm; Major Diameter [Max:N/A; Major Diameter [Min:N/A; Minor Diameter [Max:N/A; Minor Diameter [Min:N/A; Relief Valve Setting:N/A; Shaft End Flow @ RPM:14 gal/min @ 1200 rpm, 21 gal/min @ 1800 rpm; Manufacturer Part No.:2520VQ14A8-1CC20-LH; Cover End Pressure [Max:3000; Shaft End Pressure [Max:3000; GPM @ 1,800 rpm, Cover End:12; GPM @ 1,800 rpm, Shaft End:21; Integral Valve Configuration:w/o Integral Valves; Port Orientation - Cover End:Outlet 45° CW from Inlet; Port Orientation - Shaft End:Outlet Inline w/Inlet; Pressure Port Size, Cover End:3/4 in Flange; Pressure Port Size, Shaft End:1 in Flange; Displacement Cover End (cu in/revolution):1.67; Displacement Shaft End (cu in/revolution):2.77; |
Rexroth R901085390 PVV42-1X/082-045RB15DDMC Vane pump | Major Diameter [Min:45.0 LB; Spline Description:Flange Mount; Shaft Length:Left Hand (CCW); Shaft Dia.:2520VQ14A8-1CC20-LH; Weight:2 1/2; Shaft End Flow @ RPM:Flange; GPM @ 1,800 rpm, Shaft End:3/16 in; Model No.:Standard Pilot; Port Size:0.875 in; Minor Diameter:Straight w/ Key; Pump Series:2520VQ; Shaft Length:1.9375 in; Seal Material:Buna-N; Max. RPM [Max:2700; Minor Diameter:N/A; Mounting Flange:SAE B, 2 Bolt; Shaft Seal Type:Single Shaft Seal; Spline Description:N/A; Cover End RPM [Max:2700; Shaft End RPM [Max:2700; Controlled Flow Rate:N/A; Cover End Flow @ RPM:8 gal/min @ 1200 rpm, 12 gal/min @ 1800 rpm; Major Diameter [Max:N/A; Major Diameter [Min:N/A; Minor Diameter [Max:N/A; Minor Diameter [Min:N/A; Relief Valve Setting:N/A; Shaft End Flow @ RPM:14 gal/min @ 1200 rpm, 21 gal/min @ 1800 rpm; Manufacturer Part No.:2520VQ14A8-1CC20-LH; Cover End Pressure [Max:3000; Shaft End Pressure [Max:3000; GPM @ 1,800 rpm, Cover End:12; GPM @ 1,800 rpm, Shaft End:21; Integral Valve Configuration:w/o Integral Valves; Port Orientation - Cover End:Outlet 45° CW from Inlet; Port Orientation - Shaft End:Outlet Inline w/Inlet; Pressure Port Size, Cover End:3/4 in Flange; Pressure Port Size, Shaft End:1 in Flange; Displacement Cover End (cu in/revolution):1.67; Displacement Shaft End (cu in/revolution):2.77; |
Rexroth R901085395 PVV51-1X/154-046RB15DDMC Vane pump | Pilot Type:45.0 LB; Mounting Flange:Flange Mount; Shaft End Flow @ RPM:Left Hand (CCW); Weight:2520VQ14A8-1CC20-LH; Port Orientation - Shaft End:2 1/2; Relief Valve Setting:Flange; Cover End RPM [Max:3/16 in; Displacement Shaft End (cu in/revolution):Standard Pilot; Port Type:0.875 in; Cover End Flow @ RPM:Straight w/ Key; Pump Series:2520VQ; Shaft Length:1.9375 in; Seal Material:Buna-N; Max. RPM [Max:2700; Minor Diameter:N/A; Mounting Flange:SAE B, 2 Bolt; Shaft Seal Type:Single Shaft Seal; Spline Description:N/A; Cover End RPM [Max:2700; Shaft End RPM [Max:2700; Controlled Flow Rate:N/A; Cover End Flow @ RPM:8 gal/min @ 1200 rpm, 12 gal/min @ 1800 rpm; Major Diameter [Max:N/A; Major Diameter [Min:N/A; Minor Diameter [Max:N/A; Minor Diameter [Min:N/A; Relief Valve Setting:N/A; Shaft End Flow @ RPM:14 gal/min @ 1200 rpm, 21 gal/min @ 1800 rpm; Manufacturer Part No.:2520VQ14A8-1CC20-LH; Cover End Pressure [Max:3000; Shaft End Pressure [Max:3000; GPM @ 1,800 rpm, Cover End:12; GPM @ 1,800 rpm, Shaft End:21; Integral Valve Configuration:w/o Integral Valves; Port Orientation - Cover End:Outlet 45° CW from Inlet; Port Orientation - Shaft End:Outlet Inline w/Inlet; Pressure Port Size, Cover End:3/4 in Flange; Pressure Port Size, Shaft End:1 in Flange; Displacement Cover End (cu in/revolution):1.67; Displacement Shaft End (cu in/revolution):2.77; |
Rexroth R901085385 PVV41-1X/113-018RB15DDMC Vane pump | Pressure Port Size, Cover End:45.0 LB; Major Diameter [Min:Flange Mount; Mounting:Left Hand (CCW); Shaft Length:2520VQ14A8-1CC20-LH; GPM @ 1,800 rpm, Cover End:2 1/2; Spline Description:Flange; Cover End Pressure [Max:3/16 in; Weight:Standard Pilot; Mounting Flange:0.875 in; Displacement Shaft End (cu in/revolution):Straight w/ Key; Pump Series:2520VQ; Shaft Length:1.9375 in; Seal Material:Buna-N; Max. RPM [Max:2700; Minor Diameter:N/A; Mounting Flange:SAE B, 2 Bolt; Shaft Seal Type:Single Shaft Seal; Spline Description:N/A; Cover End RPM [Max:2700; Shaft End RPM [Max:2700; Controlled Flow Rate:N/A; Cover End Flow @ RPM:8 gal/min @ 1200 rpm, 12 gal/min @ 1800 rpm; Major Diameter [Max:N/A; Major Diameter [Min:N/A; Minor Diameter [Max:N/A; Minor Diameter [Min:N/A; Relief Valve Setting:N/A; Shaft End Flow @ RPM:14 gal/min @ 1200 rpm, 21 gal/min @ 1800 rpm; Manufacturer Part No.:2520VQ14A8-1CC20-LH; Cover End Pressure [Max:3000; Shaft End Pressure [Max:3000; GPM @ 1,800 rpm, Cover End:12; GPM @ 1,800 rpm, Shaft End:21; Integral Valve Configuration:w/o Integral Valves; Port Orientation - Cover End:Outlet 45° CW from Inlet; Port Orientation - Shaft End:Outlet Inline w/Inlet; Pressure Port Size, Cover End:3/4 in Flange; Pressure Port Size, Shaft End:1 in Flange; Displacement Cover End (cu in/revolution):1.67; Displacement Shaft End (cu in/revolution):2.77; |
Rexroth R901085381 PVV21-1X/068-018RB15DDMB Vane pump | Port Orientation - Cover End:45.0 LB; Shaft Seal Type:Flange Mount; Pressure Port Size, Cover End:Left Hand (CCW); Minor Diameter [Max:2520VQ14A8-1CC20-LH; Manufacturer Part No.:2 1/2; GPM @ 1,800 rpm, Shaft End:Flange; Pressure Port Size, Shaft End:3/16 in; Shaft End Pressure [Max:Standard Pilot; Weight:0.875 in; Spline Description:Straight w/ Key; Pump Series:2520VQ; Shaft Length:1.9375 in; Seal Material:Buna-N; Max. RPM [Max:2700; Minor Diameter:N/A; Mounting Flange:SAE B, 2 Bolt; Shaft Seal Type:Single Shaft Seal; Spline Description:N/A; Cover End RPM [Max:2700; Shaft End RPM [Max:2700; Controlled Flow Rate:N/A; Cover End Flow @ RPM:8 gal/min @ 1200 rpm, 12 gal/min @ 1800 rpm; Major Diameter [Max:N/A; Major Diameter [Min:N/A; Minor Diameter [Max:N/A; Minor Diameter [Min:N/A; Relief Valve Setting:N/A; Shaft End Flow @ RPM:14 gal/min @ 1200 rpm, 21 gal/min @ 1800 rpm; Manufacturer Part No.:2520VQ14A8-1CC20-LH; Cover End Pressure [Max:3000; Shaft End Pressure [Max:3000; GPM @ 1,800 rpm, Cover End:12; GPM @ 1,800 rpm, Shaft End:21; Integral Valve Configuration:w/o Integral Valves; Port Orientation - Cover End:Outlet 45° CW from Inlet; Port Orientation - Shaft End:Outlet Inline w/Inlet; Pressure Port Size, Cover End:3/4 in Flange; Pressure Port Size, Shaft End:1 in Flange; Displacement Cover End (cu in/revolution):1.67; Displacement Shaft End (cu in/revolution):2.77; |
Rexroth R901085392 PVV51-1X/139-027RB15DDMC Vane pump | Port Type:45.0 LB; Port Orientation - Shaft End:Flange Mount; Relief Valve Setting:Left Hand (CCW); Port Orientation - Cover End:2520VQ14A8-1CC20-LH; Minor Diameter:2 1/2; Shaft Key:Flange; Pressure Port Size, Shaft End:3/16 in; Pump Series:Standard Pilot; Displacement Shaft End (cu in/revolution):0.875 in; Weight:Straight w/ Key; Pump Series:2520VQ; Shaft Length:1.9375 in; Seal Material:Buna-N; Max. RPM [Max:2700; Minor Diameter:N/A; Mounting Flange:SAE B, 2 Bolt; Shaft Seal Type:Single Shaft Seal; Spline Description:N/A; Cover End RPM [Max:2700; Shaft End RPM [Max:2700; Controlled Flow Rate:N/A; Cover End Flow @ RPM:8 gal/min @ 1200 rpm, 12 gal/min @ 1800 rpm; Major Diameter [Max:N/A; Major Diameter [Min:N/A; Minor Diameter [Max:N/A; Minor Diameter [Min:N/A; Relief Valve Setting:N/A; Shaft End Flow @ RPM:14 gal/min @ 1200 rpm, 21 gal/min @ 1800 rpm; Manufacturer Part No.:2520VQ14A8-1CC20-LH; Cover End Pressure [Max:3000; Shaft End Pressure [Max:3000; GPM @ 1,800 rpm, Cover End:12; GPM @ 1,800 rpm, Shaft End:21; Integral Valve Configuration:w/o Integral Valves; Port Orientation - Cover End:Outlet 45° CW from Inlet; Port Orientation - Shaft End:Outlet Inline w/Inlet; Pressure Port Size, Cover End:3/4 in Flange; Pressure Port Size, Shaft End:1 in Flange; Displacement Cover End (cu in/revolution):1.67; Displacement Shaft End (cu in/revolution):2.77; |
Rexroth R901085387 PVV42-1X/098-040RB15DDMC Vane pump | Port Size:45.0 LB; Weight:Flange Mount; Spline Description:Left Hand (CCW); Shaft Key:2520VQ14A8-1CC20-LH; Port Orientation - Shaft End:2 1/2; Max. RPM [Max:Flange; Minor Diameter:3/16 in; Cover End Flow @ RPM:Standard Pilot; Manufacturer Part No.:0.875 in; Major Diameter [Max:Straight w/ Key; Pump Series:2520VQ; Shaft Length:1.9375 in; Seal Material:Buna-N; Max. RPM [Max:2700; Minor Diameter:N/A; Mounting Flange:SAE B, 2 Bolt; Shaft Seal Type:Single Shaft Seal; Spline Description:N/A; Cover End RPM [Max:2700; Shaft End RPM [Max:2700; Controlled Flow Rate:N/A; Cover End Flow @ RPM:8 gal/min @ 1200 rpm, 12 gal/min @ 1800 rpm; Major Diameter [Max:N/A; Major Diameter [Min:N/A; Minor Diameter [Max:N/A; Minor Diameter [Min:N/A; Relief Valve Setting:N/A; Shaft End Flow @ RPM:14 gal/min @ 1200 rpm, 21 gal/min @ 1800 rpm; Manufacturer Part No.:2520VQ14A8-1CC20-LH; Cover End Pressure [Max:3000; Shaft End Pressure [Max:3000; GPM @ 1,800 rpm, Cover End:12; GPM @ 1,800 rpm, Shaft End:21; Integral Valve Configuration:w/o Integral Valves; Port Orientation - Cover End:Outlet 45° CW from Inlet; Port Orientation - Shaft End:Outlet Inline w/Inlet; Pressure Port Size, Cover End:3/4 in Flange; Pressure Port Size, Shaft End:1 in Flange; Displacement Cover End (cu in/revolution):1.67; Displacement Shaft End (cu in/revolution):2.77; |
Vane pumps | Bosch Rexroth AG
Vane pumps are available in a wider range of sizes. They are used in applications requiring medium operating pressures and low noise emissions
Variable vane pumps, direct controlled | Bosch Rexroth AG
Hydraulic pumps of type PV7...A are direct operated vane pumps with adjustable displacement. For limitation of the maximum flow, the pump is equipped with a
Vane pumps | Bosch Rexroth USA
Vane pumps are available in a wider range of sizes. They are used in applications requiring medium operating pressures and low noise emissions
Vane Pumps | Bosch Rexroth USA
Bosch vane pumps are designed to meet the requirements of the machine tool, general machinery, and other markets where low noise, high performance, and
Fixed displacement vane pumps | Bosch Rexroth AG
Hydraulic pumps of type PVQ are vane pumps with constant displacement in mobile version
Rexroth PVQ4-1X/122RA-15DMC Vane pump Video
Contact Us
- RTA Pump Development Co., Ltd.
- Address810, 8th Floor, International Trade Tower, Nehru Place, New Delhi - 1100019, India
Rexroth PVQ4-1X/122RA-15DMC Technical Articles
How do I choose a hydraulic pump? |
What's the difference between a hydraulic pump and a hydraulic motor? |
Why is loss of pressure usually not a symptom of pump malfunction? |
Rexroth Vane pump CATEGORIES
- Rexroth Vane pump
- Danfoss Shut-off valves
- Rexroth THROTTLE VALVE
- Yuken single Vane pump
- Rexroth Piston Pump
- DENISON vane pump
- Yuken pressure valve
- Rexroth check valve
- Rexroth Solenoid directional valve
- Rexroth PRESSURE RELIEF VALVE
- Yuken Double Vane pump
- PAKER Piston Pump
- Yuken Piston pump
- BOSCH injector
- CUMMINS injector
- DEUTZ injector
- COMMON RAIL injector
- Denison Vane Pumps
- High Pressure Vane Pump
- Hydraulic Gear Pump
- Hydraulic Piston Pump
- Hydraulic Vane Motor
- Hydraulic Vane Pump
- Industrial Vane Pump
- Tokimec Vane Pump
- Vickers Vane Pump
- Yuken Vane Pump