In electric forklifts, stackers, and AGV transporters, the hydraulic system appears simple: a small pump, one cylinder, and a basic valve set.
However, in real warehouse environments, performance issues quickly become apparent.

Industry Background

Operators often encounter the following problems during daily operation:

Lifting and lowering are not smooth, with noticeable “nodding” under light load and jerking under heavy load

Noise levels are high due to the combined effect of motor vibration and pump whine, especially in indoor environments

Frequent start-stop cycles and variable loads accelerate wear and increase sensitivity to oil contamination

These issues affect both operator experience and long-term equipment reliability.

Technical Challenge

Although the system scale is small, the operating conditions are demanding:

Frequent start/stop operation

Wide load variation from empty forks to full load

Low-speed precision control during positioning

Continuous indoor operation with strict noise requirements

Traditional small external gear pumps often struggle to maintain stability under these conditions.

Solution Approach: FG Internal Gear Pumps for Compact Hydraulic Systems

To improve performance, more manufacturers are adopting FG series internal gear pumps in new designs and retrofit power units.

Typical Pump Selection

Engineers commonly select:

FG0 in the 4–24 mL/r range for compact systems

Small FG1 models around 25.3 mL/r for higher load requirements

This sizing matches 1–3 ton vehicles without oversizing the motor or increasing system complexity.

Key Technical Characteristics

Rated pressure up to 31.5 MPa (25 MPa for certain sizes)

Maximum pressure up to 35 MPa

Speed range from 200 to 3000 r/min

These parameters support both lifting force requirements and flexible speed control.

Structural Advantages

Internal gear design provides low flow and pressure pulsation, improving motion smoothness

Optimized internal structure and rigid housing reduce hydraulic noise

Better tolerance to oil contamination supports operation in dusty warehouse environments

System Integration

In typical applications, the FG pump is directly coupled with the motor to form a compact integrated power unit.

Compared with traditional external gear pump systems:

Lifting and lowering motions become smoother

Fine positioning control improves, especially during pallet alignment

Noise levels decrease, enhancing operator comfort in indoor environments

Performance Benefits in Variable-Speed Systems

Because FG pumps support a wide speed range, they integrate well with variable-frequency and servo drives:

Multiple lifting speeds can be achieved through speed control

Energy consumption can be optimized without complex valve arrangements

System response becomes more stable across different operating modes

Summary

In electric forklifts and AGVs, hydraulic performance is defined not by system complexity, but by stability under real operating conditions.

FG internal gear pumps provide:

Smooth and stable lifting motion

Reduced noise for indoor operation

Reliable performance under frequent start-stop cycles

Flexible integration with variable-speed drives

By replacing traditional small external gear pumps with FG pumps, manufacturers can significantly improve both operator experience and system reliability in compact mobile equipment.