Drum gear coupling is a rigid-flexible coupling device that belongs to the advanced form of gear coupling. It consists of an inner ring gear with the same number of teeth and a flange half coupling with external teeth. The external teeth are divided into straight teeth and drum teeth, with the drum teeth being made into a spherical shape with the center of the sphere on the gear axis. This unique design allows the coupling to compensate for radial, axial, and angular shaft deviations while transmitting torque efficiently.
Working Principle
The working principle of the drum gear coupling is based on the precise meshing of the inner and outer teeth to transmit torque. When the driving shaft rotates, power is transmitted to the driven shaft through the meshing of the outer gear sleeve and the inner gear ring. Due to the special design of the drum-shaped teeth, the tooth surface can maintain good contact when there is relative displacement between the two axes, including radial, axial, and angular deviations.
The drum-shaped tooth profile allows the teeth to pivot slightly during operation, enabling the coupling to handle significant loads under low-speed, heavy-duty conditions. The meshing action distributes torque evenly across the teeth, reducing wear and vibration, while the compact structure supports high transmission efficiency up to 99.7%.
Key Features and Advantages
1. Strong Load-Bearing Capacity
Under the same outer diameter of the inner gear sleeve and the maximum outer diameter of the coupling, the load-bearing capacity of the drum gear coupling is 15-20% higher than that of the straight gear coupling on average. This is due to the improved contact conditions between the inner and outer teeth.
2. Large Angular Displacement Compensation
The drum gear coupling allows for larger angular displacements compared to spur gear couplings. When the radial displacement is zero, the allowable angular displacement of the straight gear coupling is 1°, while the drum gear coupling allows 1°30', an increase of 50%. Under the same modulus, number of teeth, and tooth width, the drum teeth allow a larger angular displacement than straight teeth.
3. Improved Contact Conditions
The drum-shaped tooth surface improves the contact conditions of the inner and outer teeth, avoiding the drawbacks of edge extrusion and stress concentration that occur with straight teeth under angular displacement. This improves the friction and wear conditions of the tooth surface, reduces noise, and extends the maintenance cycle.
4. Easy Assembly and Disassembly
The outer gear sleeve has a trumpet-shaped tooth end, making it very convenient to assemble and disassemble the inner and outer teeth, improving work efficiency.
5. Compact Structure and High Efficiency
The coupling has a compact structure with a small turning radius, making it suitable for space-limited applications. The transmission efficiency reaches up to 99.7%, ensuring stable and efficient mechanical transmission.
