What Is a Cycloidal Reducer?
A cycloidal reducer refers to a type of gear mechanism with a trochoidal curve (a smooth curve) that can efficiently reduce speed with minimal slippage. Compared to gears with rectangular teeth, cycloidal reducers are known for their characteristics of reducing wear, vibration, and extended service life. These reducers are commonly employed in devices that rely on rotational motion, such as motors and pistons.
Their structure typically consists of a large-diameter gear enclosing a smaller-diameter gear, enabling them to achieve high reduction ratios.
Applications of Cycloidal Reducers
Cycloidal reducers find applications in various industries, including industrial robotics, pumps, automotive drives, ship propulsion systems, aircraft propellers, and wind turbine propellers. They play a crucial role in converting rotational motion and torque produced by sources like engine pistons and electric drive motors into torque and speed levels suitable for other equipment. When selecting cycloidal reducers, factors such as reduction ratio, frictional losses, size, and ease of maintenance should be considered.
Principles of Cycloidal Reducers
Cycloidal reducers consist of two mounting shafts, two reduction gears, and bearings supporting the shafts and gears. The gears are designed in the shape of a trochoidal curve, which represents the locus of the outer point of a circle moving smoothly along the curve without slipping. This gear system operates with one gear rotating within another gear.
During operation, rotational motion is transmitted from the shaft with higher speed to the high-speed gear, often an internal gear, which, together with an eccentric bearing, moves along the inner circumference of the external low-speed gear. This motion results in a reduction in speed, with the output shaft delivering lower-speed, higher-torque rotation compared to the input torque.
Some cycloidal reducers incorporate holes in the gears, using external pins or similar mechanisms to reduce the load on the eccentric bearings.
Advantages of Cycloidal Reducers
Cycloidal reducers offer several advantages:
- High Reduction Ratio: They can achieve high reduction ratios, often up to 1/150, due to minimal differences in the number of teeth between gears.
- Compact Design: A single gear can provide a high reduction ratio, eliminating the need for multiple gears and enabling a slim design.
- Efficiency: Cycloidal reducers operate with rolling gears rather than sliding gears, resulting in minimal friction loss and high transmission efficiency.
Due to these features, they are commonly used as reduction gears in various applications.
Oil Change for Cycloidal Reducers
Cycloidal reducers use lubricating oil, and it is essential to maintain the proper oil level. Monitoring the oil level with an oil gauge is necessary because the oil volume can fluctuate during operation.
Using too much or too little oil can have adverse effects. Excessive oil may lead to motor-side oil infiltration, leaks, or abnormal temperature increases. Insufficient oil can result in inadequate lubrication of gears and bearings, leading to abnormal wear or temperature rises due to inadequate cooling.
Guidelines for oil replacement can be found in the technical documentation provided by each manufacturer. However, it is essential to periodically check and replenish the oil to maintain the correct level. Typically, the first oil change should be performed early in the equipment’s lifecycle, followed by regular replacements.
If the oil contains iron particles or other contaminants, it may indicate wear in the gears and bearings, necessitating inspection and maintenance. Changes in oil viscosity and other factors can also lead to malfunctions.
During routine inspections, early-stage abnormalities can be detected by comparing factors such as oil quantity, oil condition (presence of dirt, etc.), oil leaks in the surrounding area, temperature changes during rotation, and abnormal noises during operation with normal operation data. Therefore, keeping records of data (temperature, vibration, sound, etc.) during regular operation can be valuable for maintenance purposes.