The difference between spur gear slewing bearing and helical gear slewing bearing

Slewing bearing also called slewing ring, is a supporting rotating part widely used in various mechanical equipment. Due to transmission requirements, slewing bearings usually have gears. The most common ones are spur gear and helical gear. The most intuitive difference between spur gear and helical gear is that the gear shape is different. In addition, there are differences in load capacity and noise. Let’s take a look together.

1. Appearance

The gears of the spur gears are arranged in a straight line on gear ring, while the helical gears are evenly distributed on gear ring at an oblique angle.

2. Precision

The helical gear slewing drive is easier to obtain high precision than the spur gear slewing drive and the helical gear accuracy can be maintained for a longer time.

3. Noise

The noise generated by the spur gear slewing drive itself is larger than that of the helical gear slewing drive due to the design, manufacturing, structure and other reasons. Because the spur gear is in direct contact, the gear will vibrate when the gear is engaged. The helical gear bite is gradually contacted and separated gradually, so the transmission of the helical gears will be relatively stable and the vibration will be relatively small.

4. Efficiency

In terms of transmission efficiency, the transmission efficiency of spur gear is higher than helical gear, because helical gear will produce axial force during transmission and will lose part of the input torque. It is necessary to consider the influence of axial force on the slewing drive when designing. While spur gear does not have this problem and the transmission efficiency is as high as 95%.

5. Line of action

In the case of the same module and same gear height, the meshing line of the helical gear is longer than spur gear when the gear is engaged, because the meshing line of the helical gear is longer, the force that each gear can bear will be greater and the torque that the corresponding gear can bear will also be greater. However, the meshing line of spur gears is relatively short when occluding, the collision force of the gears is more direct, the force range is shorter than helical gear and the torque it bears is also smaller.

When selecting the gear and gear profile of the slewing ring, it is necessary to consider the installation form of the slewing ring, layout of the equipment, rated output torque, load condition, speed, noise, vibration requirements and other factors. It is necessary to select a suitable slewing ring according to the specific situation. Only a suitable slewing bearing can ensure the normal and smooth equipment operation. If it’s possible, please kindly inform the engineers of Unique Transmission as much as possible about the working conditions when selecting models, our engineers will provide you with cost-effective solutions.