Crane Gearbox: Smooth Transmission, High Load Capacity, Multi-Mechanism Compatible

In lifting machinery, a crane gearbox is a device that converts high-speed, low-torque input power into low-speed, high-torque output through internal transmission mechanisms such as gears, worm gears or planetary gear trains. Motors typically provide high-speed rotational power, but directly driving lifting mechanisms (such as hoists, slewing mechanisms, etc.) will result in excessively fast and uncontrollable motion. Therefore, gearboxes have become the critical component connecting motors and lifting mechanisms. Through the speed reduction effect of gearboxes, the high-speed rotation of motors is converted into the low-speed, high-torque motion required by lifting mechanisms, enabling smooth and precise lifting operations.

CẨU CẨU KUANGSHAN provides not only standalone gearbox products, but also custom three-in-one geared motors matched to your complete crane systems. Featuring an integrated design of gearbox, motor and brake, they offer easier installation, more stable operation and a one-stop complete

Gear Reducer Product Categories

Soft Tooth Tooth Gearbox

Medium-hardened Tooth Gearbox

Hardened Tooth Gearbox

Functions of the Gearbox

• Reduce motor speed: Converts high-speed motor rotation into the low-speed motion required by lifting mechanisms, ensuring the safety and precision of lifting operations.
• Increase output torque: Achieves a multiplied increase in output torque through the mechanical gear ratio amplification effect of gear meshing.
• Transmit power: Delivers the required power and operating speed from the equipment to the working mechanisms.
• Cushion transmission shocks: Absorbs instantaneous impact loads during crane lifting and operation, optimizes force distribution, and improves the stability and reliability of the transmission system.

How to Select Crane Gearbox

Calculate reduction ratio

Figure out required reduction ratio i via either formula: Motor Speed ÷ Working Speed or Actual Load ÷ Motor Output Force.

Check output torque

Calculate required operating torque = Max Motor Torque × Reduction Ratio × Transmission Efficiency × Overload Factor. The calculated value shall be less than gearbox rated max output torque; pick up a larger model if not satisfied.

Check rated speed

Calculate average working-end speed, which must be lower than gearbox rated output speed; modify model when failing to meet the requirement.

Check shaft end load

Compute actual axial & radial loads based on working conditions and compare with gearbox allowable load; upgrade model for insufficient load capacity.

Confirm structure & matching

Determine mounting type, backlash precision and moment of inertia according to space layout, check motor matching to confirm final model. Horizontal-mounted gearboxes apply to hoist trolley of conventional & European overhead/gantry cranes and long-travel mechanism of traditional overhead cranes; Vertical-mounted gearboxes mostly fit cross-travel of conventional overhead cranes and long-travel of traditional gantry cranes; Torque-arm mounted gearboxes are widely used for long & cross travel of European overhead/gantry cranes.

Câu hỏi thường gặp

Q: What are the mounting types of gearboxes?

A: Gearboxes are categorized into horizontal, vertical and torque-arm mounting types by installation mode.

Q: How to select tooth hardness for crane working class A1-A8? What standards do different tooth hardness grades meet?

• A1-A3 (intermittent duty): Soft-tooth gearbox ≤350HBW (≤HRC38), manufactured via quenching plus high-temperature tempering for uniform bulk hardness.
• A4-A6 (normal regular duty): Medium-hardened gearbox 350–450HBW (HRC38–45), treated by tempering + surface quenching for improved tooth hardness vs soft-tooth products.
• A7-A8 (continuous heavy-duty): Hardened gearbox ≥450HBW (≥HRC45), carburized & quenched for high surface hardness with tough core; final gear grinding ensures precision.

Q: Pros & Cons of soft-tooth and hardened-tooth gearboxes?

• Soft-tooth: Low cost, easy processing, fits basic application for budget-limited or temporary projects.
• Medium/Hardened-tooth: Higher load capacity, longer service life and fewer breakdowns, ideal for high-reliability required projects with sufficient budget.

Q: Can gearboxes for hoisting and travelling mechanisms be interchanged?

A: No. Hoisting gearboxes adopt higher safety standards. They differ entirely in selection criteria, safety fittings and load requirements. Cross-use is forbidden to avoid tooth breakage or cargo falling accidents.