GFT Travel Drives are unsurpassed by any crawler or milling machines. Thanks to compact, rugged design, high torque and load capabilities, and optional mechanical lifetime seals, these solutions are the best possible option for the machine. All units are available with a fail-safe parking brake and most have the option of cartridge type fixed or variable systems.
1. Product Overview
TheGFT24 Travel Reduction Gearboxis a high-performance planetary gear reducer manufactured byBosch Rexrothand other leading suppliers, designed specifically for the travel drive systems oftracked/wheeled construction machinery(e.g., excavators, bulldozers, drilling rigs). Its core function is to convert the high-speed, low-torque output of hydraulic motors or electric motors into low-speed, high-torque output to drive equipment movement.
Model Breakdown:
• GFT: Series designation (may stand for "Gearbox Final Drive").
• 24: Typically indicates the gearbox specification or torque rating (e.g., rated output torque ~24 kNm; refer to manufacturer data for exact values).
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2. Core Structure & Components
(1) Main Parts
1. Planetary Gear Set:
• Composed of a sun gear, planetary gears, and a ring gear for efficient torque transmission.
• Multi-stage planetary reduction design provides high reduction ratios (e.g., i=50–100).
2. Input Shaft:
• Connects to hydraulic motors or electric motors viasplined shafts, flanges, or couplings.
3. Output Shaft:
• Connects to track sprockets or wheels viasplined shafts or bolt-on flanges.
4. Brake System:
• Integratedwet multi-disc brake(normally closed) for automatic braking during power failure.
5. Lubrication System:
• Forced or splash lubrication ensures stable operation under high-temperature, heavy-load conditions.
(2) Typical Specifications (Bosch Rexroth GFT24 Example)
【表格】
Parameter Value Range Description
Rated Input Speed 2000–3000 rpm Matches hydraulic motor max. speed
Rated Output Torque 20–28 kNm (model-dependent) Adapts to equipment weight
Reduction Ratio 50:1 – 100:1 Adjustable for travel speed needs
Brake Torque 1.5–2× rated output torque Ensures emergency braking reliability
Weight 80–120 kg Lightweight design for easy installation
Protection Grade IP67 Dustproof/waterproof for harsh environments
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3. Key Features
1. High Torque Density:
• Compact planetary design maximizes torque output per unit volume.
2. High Efficiency:
•
95% transmission efficiency reduces energy loss.
3. Shock-Resistant Design:
• Gears and bearings use high-strength materials (e.g., 20CrMnTi carburized steel) to withstand track impact loads.
4. Modular Design:
• Standardized input/output interfaces for easy replacement or upgrades.
5. Cold-Start Capability:
• Low-temperature grease and heating options support operation at -40°C.
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4. Applications
(1) Typical Equipment
• Tracked Excavators(20–50-ton class): Drives tracks for steering and climbing.
• Rotary Drilling Rigs: Provides mobility and positioning torque.
• Pavers: Drives tracks for precise road surfacing.
• Mining Dump Trucks: Wheel-type variants for heavy-duty transport.
(2) Operational Requirements
• Heavy-Duty Starting: Overcomes equipment weight and ground resistance.
• Continuous Operation: Withstands prolonged high-load use with excellent heat dissipation.
• Multi-Directional Travel: Supports straight, steering, and crab-walking movements.
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5. Common Failures & Maintenance
(1) Typical Faults
【表格】
Symptom Possible Causes Solutions
Weak Travel Worn gears, brake not fully released Replace gears, check hydraulic brake circuit
Abnormal Noise Bearing damage, poor gear mesh Replace bearings, adjust gear backlash
Oil Leakage Aged seals, cracked housing Replace seals, weld-repair housing
Brake Failure Worn brake discs, low hydraulic pressure Replace discs, check hydraulic pump
(2) Maintenance Recommendations
1. Oil Replacement:
• Change gear oil every 500 hours (Bosch Rexroth HDX synthetic oil recommended).
2. Oil Analysis:
• Monitor metal particle content (NAS 1638 ≤ Class 9).
3. Brake Inspection:
• Check brake disc thickness every 1000 hours (min. residual thickness ≥3 mm).
4. Seal Replacement:
• Replace all dynamic seals (e.g., O-rings, shaft seals) every 2000 hours.
5. Storage:
• Fill with gear oil and rotate periodically to prevent rust during long-term storage.
