1. Structural Integration: Ultimate Space Utilization and High Power Density
The core design highlight of the built-in planetary gearbox lies in "integrated integration", which completely abandons the splicing mode of independent components such as motors, gearboxes, couplings, and brackets in traditional split-type transmission. It embeds the planetary reduction mechanism directly into the motor housing or realizes coaxial integration with the motor output shaft. This design brings two core values:
First, significant optimization of volume and weight. The built-in structure does not require additional connection space and fixed components. Its overall length is only 60%-80% of that of the traditional split-type combination, and its weight is reduced by 20%-40%. Taking the collaborative robot joint as an example, after adopting the built-in planetary gearbox, the joint diameter can be reduced by more than 30%, providing key support for the lightweight and miniaturized design of the robot. In mobile equipment such as AGVs (Automated Guided Vehicles) and UAVs (Unmanned Aerial Vehicles), the lightweight advantage can further reduce energy consumption and extend battery life.
Second, breakthrough in high power density. Within a limited volume, the built-in planetary gearbox realizes the dual functions of "reduction + transmission", and the output torque per unit space is more than 30% higher than that of the split-type. Its multi-tooth meshing structure of the planetary gear train (usually 3-4 planetary gears driving around the sun gear) can evenly distribute the load and improve the torque-bearing capacity. The single-stage reduction ratio can cover 3-10, and the maximum reduction ratio can reach more than 1000 after multi-stage combination. The output torque ranges from several N·m to hundreds of N·m, which can easily meet the needs of low-speed and high-torque scenarios without sacrificing the installation space of the equipment.
2. High Transmission Precision: Minimal Backlash and Excellent Operational Stability
For equipment requiring precision positioning and high-frequency start-stop (such as CNC machine tools, electronic component assembly equipment, and robotic arms), transmission precision directly determines product quality and production efficiency. The built-in planetary gearbox has inherent advantages in precision control:
First, elimination of connection gap errors. In traditional split-type transmission, the motor and gearbox are connected through a coupling, which inevitably has installation gaps and coaxiality deviations (usually ≥0.05mm). These deviations will lead to positioning errors and operational vibrations. Through integrated processing technology (such as integral forming of the housing and motor end cover, and precise matching of the output shaft and planet carrier), the built-in design controls the coaxiality within 0.01mm, completely eliminating the gap in the connection link and improving transmission precision from the source.
Second, backlash reaching the industry's top level. The meshing precision of the planetary gear train itself is higher than that of ordinary gear transmission. Combined with the rigid constraint of the built-in structure, the backlash of the built-in planetary gearbox can be as low as 1-3 arcminutes, and some high-precision models can even reach below 0.5 arcminutes, which is far better than the 5-10 arcminutes of the traditional split-type. This means that the equipment has almost no idle stroke during reverse movement, and the positioning precision can be improved by an order of magnitude. It is especially suitable for scenarios requiring high-frequency commutation and precise alignment (such as chip packaging equipment and laser cutting machine tools).
In addition, excellent operational stability and low-noise advantage are prominent. The integrated structure reduces vibration sources (such as coupling eccentric vibration and bracket resonance), and the multi-tooth meshing of the planetary gear train also reduces meshing impact. The operating noise is usually ≤60dB, which is much lower than the 75dB or more of traditional gearboxes. It is suitable for environments sensitive to noise, such as medical equipment and laboratory instruments.
3. Easy Installation and Maintenance: Practical Value of Cost Reduction and Efficiency Improvement
The integrated design of the built-in planetary gearbox not only optimizes performance but also reduces assembly and maintenance costs in practical applications, improving the operation and maintenance efficiency of the equipment:
In the assembly process, the built-in gearbox serves as an "integrated power unit". There is no need to adjust the coaxiality between the motor and the gearbox, install fixed brackets, or assemble couplings separately. It can be directly connected to the equipment through a standard flange interface, shortening the assembly time by more than 50%. Taking an automated production line as an example, a production line usually requires dozens of transmission units. The use of built-in planetary gearboxes can save a lot of manual assembly time and avoid equipment failures caused by assembly errors.
In the maintenance process, the integrated design reduces the number of sealing surfaces and connecting components, greatly reducing the risk of oil leakage. Most high-end models use long-life maintenance-free grease to achieve "lifetime oil-free maintenance", eliminating the need for regular shutdown maintenance. It is especially suitable for scenarios that are difficult to maintain, such as high-altitude operation equipment and continuously operating assembly lines. In addition, the standardized interface design of the built-in planetary gearbox (such as a universal flange compatible with servo/stepper/DC motors) can directly replace the traditional split-type combination without modifying the equipment installation structure, resulting in strong compatibility.
4. High Transmission Efficiency: Energy Conservation and Enhanced Structural Rigidity
The high-efficiency transmission characteristics of the built-in planetary gearbox not only conform to the industrial trend of energy conservation and environmental protection but also improve the load capacity of the equipment:
From the efficiency perspective, the meshing efficiency of the planetary gear train itself is as high as 97%-99%. The built-in structure reduces the friction loss of intermediate components such as couplings and brackets, and the overall transmission efficiency is 3%-5% higher than that of the split-type. For equipment operating continuously for 24 hours (such as conveyor lines and automated sorting equipment), the energy-saving effect brought by this efficiency improvement is significant. Taking a 10kW motor-matched gearbox as an example, it can save about 2,000-3,000 yuan in electricity costs per year, showing prominent economic benefits in long-term operation.
From the structural rigidity perspective, the integrated design of the housing and the motor enhances the rigidity of the overall structure and reduces elastic deformation during transmission. When bearing impact loads or high torque, the deformation of the built-in planetary gearbox is only 1/3 of that of the split-type, with better stability. For example, in scenarios such as machine tool spindles and heavy-duty robotic arms, high rigidity can avoid processing errors or operational jams caused by deformation, improving the reliability and service life of the equipment.
