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Hydraulic Components Usage Precautions & Maintenance Guide | Hydraulic Pump Troubleshooting Manual
Standard operation specifications & fault troubleshooting solutions for hydraulic components, covering 4 core scenarios: assembly, hydraulic oil, oil suction & pressure protection.
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Complete Guide to Hydraulic Gear Pump Operation
Selection & Operation Requirements
When selecting our hydraulic pumps, please strictly refer to our product catalogs and consider: nominal displacement, rated pressure, rated speed, working oil temperature, working fluid, installation connection dimensions, rotation direction, and other factors.
Special Note: Our hydraulic pumps allow working oil temperatures of -30°C to 80°C (excluding custom-designed non-standard products per customer requirements); optimal working fluid viscosity is 20mm²/s to 46mm²/s (hydraulic oil); oil contamination should not exceed 19/16 per GB/T14039-2002.
Within one year from the date of shipment, if the product fails to operate normally due to design or manufacturing defects while used according to the instruction manual, and with complete usage records, we will replace, repair, or accept return at no charge.
Preventive Measures for Common Faults
Operating Instructions & Precautions
1
The drive shaft of the pump must not bear radial or axial forces (e.g., during installation, the spline sleeve length must not exceed the effective spline length of the pump drive shaft; the power shaft end and coupling must not have any axial contact with the spline end or shaft steps).
2
The coaxiality between the pump drive shaft and the prime mover output shaft must not exceed 0.08mm, and the perpendicularity of the pump bracket mounting surface to the pilot must not exceed 0.05mm.
3
The pump suction height must not exceed 0.5m. The inlet and outlet pipes and flanges must be leak-free.
4
Working fluid must be kept clean. Install a filter with 80-100μm filtration accuracy on the suction line, and a filter with no less than 10-20μm accuracy on the return line. The effective flow capacity of the inlet filter should be at least twice the pump maximum suction flow, kept clear and free of blockages. Clean or replace regularly based on contamination levels.
5
Before initial commissioning, the pump must be filled with oil and bled of air to ensure timely oil uptake during startup. It is recommended to loosen a pipe joint in the pressure line, jog the power unit until oil flows out free of air bubbles, then tighten the joint (failure to perform this step is the most common cause of early damage). After installation, run the pump under no-load for at least 10 minutes followed by brief loaded operation.
6
Under continuous operation, the maximum oil temperature must not exceed 80°C, and the instantaneous oil temperature must not exceed 110°C to prevent premature seal aging.
7
Inlet/outlet flow velocity: V (m/s) = q (ml/r) × n (r/min) / 6000S (S: flow area in cm²). That is: pipe bore d ≥ 3.25√Q (mm), where Q is pump inlet/outlet flow Q (liters) = q·n. Recommended: inlet velocity ≤ 3m/s, outlet velocity ≤ 6m/s.
8
Under rated conditions, the service life of a gear pump is generally 3,000 hours.
Troubleshooting Methods for Common Faults
Frequently Asked Questions
What operating oil temperature range do SDH-HP hydraulic pumps allow?
Our hydraulic pumps allow working oil temperatures of -30°C to 80°C. Custom-designed non-standard products built to specific customer requirements may differ.
What hydraulic oil viscosity and cleanliness level are recommended?
The optimal working fluid viscosity is 20 mm²/s to 46 mm²/s hydraulic oil, and oil contamination should not exceed 19/16 per GB/T14039-2002.
What warranty do SDH-HP hydraulic pumps carry?
Within one year from the date of shipment, if the product fails to operate normally due to design or manufacturing defects while used according to the instruction manual and with complete usage records, we will replace, repair or accept the return at no charge.
What installation tolerances must be observed when mounting a gear pump?
The coaxiality between the pump drive shaft and the prime mover output shaft must not exceed 0.08 mm, and the perpendicularity of the pump bracket mounting surface to the pilot must not exceed 0.05 mm. Pump suction height must not exceed 0.5 m.
What filtration should be installed on the suction and return lines?
Install a filter with 80-100 μm filtration accuracy on the suction line, and a filter of no less than 10-20 μm accuracy on the return line. The effective flow capacity of the inlet filter should be at least twice the pump maximum suction flow.
What is the expected service life of a gear pump?
Under rated conditions the service life of a gear pump is generally 3,000 hours. Keep the maximum continuous oil temperature at or below 80°C (110°C instantaneous) to prevent premature seal ageing.