CAT EMS 921

The SEM921 motor grader from Shandong SEM Machinery Co., Ltd. (a wholly-owned subsidiary of Caterpillar) is a construction machinery product.

Basic Parameters

The total weight of the machine is 15930kg, and the overall dimensions (length × width × height) are 8854mm × 2630mm × 3360mm. The rated power is 162kW, and the emission standard meets China’s National III. The blade length ranges from 4.279m to 4.3m, the maximum traction force is ≥85kN, the maximum steering angle of the front axle is 47.5°, and the minimum turning radius is ≤7.8m.

Power System

It is equipped with Shangchai SC9D220G2 or SC9DK220G3 engines, with a rated power of 162kW/2200rpm, featuring large torque reserve and strong power. It is equipped with the internationally advanced 6WG180 fixed-shaft power shift transmission, with electro-hydraulic control for power shifting, 6 forward and 3 reverse gears, ensuring smooth operation and convenient shifting.

Hydraulic System

It comes standard with an imported Rexroth variable displacement piston pump, which distributes flow on demand to save energy consumption. It adopts Caterpillar’s unique Proportional Priority and Pressure Compensating (PPPC) control valve, making the implement control more sensitive, enabling multiple compound actions and improving work efficiency.

Blade and Working Devices

The blade length × height is 4279mm × 610mm, with a lifting height of 475mm and a digging depth of 715mm. Various blade specifications are available, ensuring good material passing performance. It uses an electro-hydraulically controlled seven-hole linkage mechanism, allowing the driver to switch hole positions in the cab to conveniently adjust the angle between the blade and the ground. The front axle has an arched structure, with tire specifications of 17.5-25. The tire tilt angle and steering angle are industry-leading, ensuring strong operability.

Cab and Control System

The cab is tall and spacious, with an overall volume 30% larger than previous models, and a net height of 1.9m, providing a clear view. A roll-over protective structure (ROPS) is available as an option. The front console can move forward and backward, and the joysticks are arranged according to industry standards, with small spacing and short stroke, allowing the driver to operate multiple joysticks with one hand. The instrument panel is rich in information, facilitating understanding of the overall operation status.

Other Features

The newly designed cooling system can work in an ambient temperature range of -40°C to 50°C. The service brake adopts air-over-hydraulic drum brakes, and the parking brake uses air-controlled spring-assisted drum brakes, with a dual-circuit design, ensuring safety and reliability. It is standard-equipped with a blade floating function, reducing work difficulty and improving work efficiency. The A-type traction frame and box-type front frame offer good durability and a long service life.