R910991846 AA10VS018DFR1/31R-VPA12N00 Rexroth hydraulic pump made in Germany

Frequently Asked Questions (FAQ)

Q1: What is the function of the "DFR1" control?

A:​ DFR1​ stands for "Pressure Flow Controller". It combines two functions:

1. Pressure Control (Limiting): Acts as a pressure compensator, destrokeing the pump when system pressure reaches the set value (like a DR control).

2. Flow Control (Load Sensing): Automatically adjusts displacement to maintain a constant pressure differential (Δp) across a downstream orifice, providing load-independent flow control. This makes it highly energy-efficient for systems with varying loads.

Q2: What does the "VPA12N00" suffix indicate?

A:​ This code defines the mechanical configuration:

• V: FKM (Viton)​ seals, offering superior chemical and temperature resistance.

• P: Standard parallel key shaft​ (DIN 6885).

• A12: Port size code 12​ (metric threads).

• N00: No through-drive​ (solid shaft end, cannot mount additional pumps on the shaft).

Q3: What is the key difference between DFR and DFR1?

A:​ The primary difference is the integration of the pressure limiter and flow controller. The DFR1 is a more compact and optimized version of the DFR control, offering similar functionality with potentially faster response times and simplified external piping.

Q4: What are the X and L ports used for?

A:​

• X Port (Control): Used for load-sensing feedback. It connects to the downstream system to sense the load pressure, allowing the pump to adjust its displacement to maintain the set Δp.

• L Port (Case Drain): Must be connected directly to the tank. It relieves internal leakage pressure to protect the shaft seal (max backpressure typically 2 bar).

Q5: Can this pump be used in a closed-loop system?

A:​ No.​ The A10VSO DFR1 is designed exclusively for open-circuit applications​ (pump → valve → actuator → tank). For closed-loop hydrostatic transmissions, you would need an A4VG or A2FM series unit.