SAI GM Series Radial Piston Hydraulic Motor

The SAI GM Series is a comprehensive range of crankshaft-design radial piston hydraulic motors (Low Speed High Torque – LSHT). Ranging from the compact GM1 to the massive GM9, this series offers high mechanical efficiency and exceptional starting torque. Unlike conventional radial motors, the SAI GM series features swiveling cylinders and a double piston support system, ensuring durability and high speed capabilities alongside heavy-load performance.

Key Features:

Series: GM1, GM2, GM3, GM4, GM5, GM6, GM7, GM9
Displacement: 60 to 4300 cm³/rev
Torque: Up to 20,000+ Nm
Design: Radial Piston, Crankshaft Type.

Product Overview The SAI GM Series utilizes a unique patented design where the cylinders swivel on the crankshaft, combined with a linear piston movement. This minimizes friction and side loads, resulting in extremely high volumetric and mechanical efficiency (often exceeding 98%). The GM series is capable of running at very low speeds (down to 1 rpm) smoothly without “cogging,” while also handling higher speeds better than cam-lobe type motors.

Why Choose SAI GM Series?

High Starting Torque: Delivers nearly constant torque from startup (0 rpm) to maximum speed, ideal for lifting and winching under load.
Cavitation Resistance: The design is inherently robust against cavitation, even in high-speed free-wheeling conditions.
Thermal Shock Resistance: Capable of handling rapid temperature changes in the hydraulic circuit.
Wide Range: From the GM1 for small winches to the GM9 for heavy mining equipment, the modular design fits almost any torque requirement.

Common Applications:

Marine: Winches, Capstans, Anchor handling.
Construction: Drilling rigs, Rotary heads, Trenchers.
Industrial: Plastic Injection Molding (Screw drive), Shredders.
Mining: Conveyors, Excavator swing drives.

Specification	Value / Description
Product Type	Radial Piston Hydraulic Motor (Crankshaft Design)
Brand	SAI Hydraulics (Italy)
Series Range	GM05, GM1, GM2, GM3, GM4, GM5, GM6, GM7, GM9
Nominal Pressure	250 bar (3600 psi)
Peak Pressure	300 – 350 bar (depending on model)
Speed Range ( $n$ )	1 – 1000 rpm (Small sizes run faster, large sizes slower)
Displacement Overview ( $V_g$ )	GM1: 60 – 100 cc/rev GM2: 200 – 630 cc/rev GM3: 350 – 1000 cc/rev GM4: 800 – 1300 cc/rev GM5: 1200 – 2000 cc/rev GM6: 1600 – 3000 cc/rev GM7: 2500 – 4300 cc/rev GM9: High displacement custom configs
Shaft Types	Cylindrical Keyed, Splined (DIN 5480), Tapered
Distributors	D31, D40, D47 (Standard back covers)
Common Part Numbers	Model Code Structure: [Series]-[Disp]-[Shaft]-[Distributor] GM1-100-9M-D31 (100cc, Splined) GM2-630-9M-D40 (630cc, Splined) GM3-800-40H-D40 (800cc, Cylindrical) GM4-1300… GM5-2000… GM6-3000… (Note: SAI codes are highly customizable. Please provide full plate data.)