ED72/ED73 Valve Mounted on Hydraulic Pump

ED72/ED73 Valve Mounted on Hydraulic Pump Full Product Introduction

 

1. Basic Product Overview

 

The ED72/ED73 valve mounted on hydraulic pump is an integrated electro-hydraulic proportional control valve specially matched for variable displacement axial piston pumps. It serves as the core regulation unit of the whole hydraulic system, responsible for receiving electrical signals to automatically adjust pump displacement, output flow and system working pressure. It precisely coordinates with supporting pumps to supply matched hydraulic power to downstream Hydraulic piston motor and common hydraulic motor actuators, realizing stepless speed regulation and load adaptive operation of executing components. Widely fitted on Rexroth-style A7V, A4VG and other main piston pumps used in engineering machinery, road rollers and crawler equipment, ED72 and ED73 share identical overall installation dimensions with slight differences in current signal parameters and response speed for differentiated configuration demands.

 

Model Explanation

 

- ED: Code for electro-hydraulic proportional displacement control valve for hydraulic pumps

- ED72: Standard response type proportional control valve, general-purpose for medium and low frequency working conditions

- ED73: Fast-response upgraded version, optimized dynamic reaction for frequent load fluctuation scenarios

Both models are flange-mounted directly on the pump casing without extra pipeline layout, belonging to built-in pump control valve assembly.

 

2. Core Technical Parameters

 

Item Specification 

Product Type Pump Integrated Electro-hydraulic Proportional Control Valve 

Control Signal DC 0–10V or 4–20mA analog electric signal 

Working Voltage DC24V (mainstream vehicle power supply) 

Control Pressure Range 2–32MPa 

Pilot Supply Pressure 2.5–4MPa 

Response Time ED72: 80–120ms; ED73: 35–60ms (faster responsiveness) 

Mounting Form Direct flange installation on pump valve housing 

Valve Body Material Precision cast alloy steel, hardened valve spool and sleeve 

Sealing Kit NBR seals as standard; FKM high-temperature resistant seals optional 

Applicable Medium ISO VG46, VG68 anti-wear hydraulic oil 

Operating Temperature -20℃ ~ +85℃ 

Matching Pumps A4VG, A7VO, A11VO series variable piston pumps 

Warranty Period 1 year 

 

3. Structure & Working Principle

 

The assembly consists of proportional solenoid coil, pilot valve spool, feedback linkage mechanism, pressure sensing plunger and reset spring, integrally assembled on the hydraulic pump housing and interconnected with the pump swashplate adjustment mechanism. It collaborates closely with all actuators in the complete hydraulic system:

 

1. The controller outputs analog electric signals to the proportional coil, generating electromagnetic force to push the pilot spool to shift and distribute pilot control oil.

2. Pilot oil acts on the swashplate servo piston of the main hydraulic pump, changing the inclination angle of the swashplate to adjust pump displacement and real-time output flow.

3. Real-time system pressure is fed back to the valve body through a pressure sensing channel, forming closed-loop regulation to avoid overload of the hydraulic system.

4. By adjusting pump flow, the rotational speed of downstream Hydraulic piston motor and ordinary hydraulic motor is controlled, while pressure limiting protects the whole loop from overpressure damage.

5. ED73 optimizes the internal flow channel structure to shorten oil circuit transmission distance, achieving quicker swashplate adjustment compared with ED72 for high-frequency working cycles.

 

4. Core Product Advantages

 

1. Direct pump-mounted integrated structure eliminates external pilot pipelines, reducing leakage points and simplifying the overall layout of the hydraulic system.

2. Closed-loop electric proportional regulation enables stepless matching of pump output power with load requirements, lowering idle energy consumption and heat generation of the hydraulic unit.

3. ED72 economical type for conventional working conditions, ED73 high-speed response version for heavy-duty frequent operation, flexible model selection for different machine configurations.

4. High-precision hardened valve pair with strong anti-pollution capacity, stable operation under long-term continuous vibration of engineering machinery.

5. Perfect interchangeability with original ED72/ED73 parts, no modification required when replacing old units on existing pumps, compatible with mature hydraulic system matching logic.

6. Built-in overload pressure protection function, automatically limiting maximum system pressure to safeguard the main pump and rear-end Hydraulic piston motor against overload breakdown.

 

5. Typical Application Scenarios

 

1. Crawler loaders, excavators main piston pump configuration: ED72 for general working modes, ED73 for high-efficiency intensive operation, regulating walking hydraulic motor speed;

2. Road rollers, pavers hydraulic power assembly: control pump flow to adjust vibration roller and conveyor Hydraulic piston motor running state;

3. Drilling rigs, mining roadheaders main hydraulic station: realize load-sensitive power matching of the whole hydraulic system;

4. Modified hydraulic equipment upgrading: replace old mechanical control valves with ED72/ED73 to achieve electric remote intelligent regulation;

5. Large agricultural harvesters: adaptive flow regulation for reel and cutting mechanism hydraulic drive loops.