Operating Principle for Synchronous Belts
It consists of a circular belt with equidistant teeth on its inner circumference and corresponding teeth on the pulleys. During operation, the belt teeth mesh with the pulley grooves to transmit movement and power. It is a new type of belt transmission that combines the advantages of belt, chain and gear transmissions.
Today we will only discuss the design and assembly methods of synchronous pulleys.
We will summarize and share several common installation methods, which are generally used for installing the output shaft (power shaft) of the motor and synchronous belt pulley.
They are provided as a reference for everyone. If anyone has a better structure, you can leave a message.
There are several ways to install the synchronous belt pulley on the motor shaft (output shaft) or driven shaft. Let's discuss some of the conventional methods.
The first method
This is the most common method, which I believe everyone has seen and used before.
It involves using a radial set screw on the synchronous belt pulley to secure the flat end of the motor shaft.
(1) Remove burrs at the interface between the motor shaft and the synchronous belt pulley.
(2) Install the synchronous belt pulley onto the motor shaft (for pulleys with shaft bosses, install them to the end of the shaft), adjust the distance and tighten the fixing screw.
Note: For this type of installation method, the mating surface of the shaft needs to be machined to have a flat cutting surface.
Characteristics:
This method uses a set screw to position and transmit drive torque and is suitable for light loads.
Explanation:
- If the set screw provided is too short to securely attach the synchronous belt pulley to the flat end of the motor shaft, a longer set screw must be used.
- When the pulley wall thickness is more than 10mm, two fixing screws can be used in a single hole.
- The mounting bolts must not protrude beyond the end face of the bolt mounting hole in the synchronous belt pulley.
- For synchronous belt pulleys fixed with fixing screws larger than M3, thread locking adhesive can be used to fix them.
- The fixing screw must be placed in the flat end of the D-shaped groove on the motor shaft (as shown in the figure).
The second method:
This method involves fixing the synchronous belt pulley with a tensioning sleeve and fixing it parallel to the axial direction of the motor shaft using screws.
This method is suitable for compact spaces where installation can only be done axially and at a higher cost.
I like this method because it reduces the design workload.
This installation method is also simple and easy, but the only disadvantage is that it is a little more expensive and cannot be used in situations where high torque transmission is required.
Installation Precautions:
(1) When installing, clean the surface of the motor shaft and apply a thin layer of lubricating oil or grease.
(2) Before installation, clean the contact surface between the synchronous belt pulley and the bushing and apply lubricating oil and grease. (The threaded surface and the bearing surface of the fastening screws must also be coated.)
(3) Temporarily assemble the synchronous belt pulley and bushing, and then insert them into the motor shaft. (It is not allowed to directly fix the bushing with screws without inserting it into the shaft.)
(4) After positioning is completed, gradually tighten the bushing screws in a diagonal order, then lock them and mark different lines.
Characteristics:
The absence of a keyway does not reduce the strength of the shaft and is easy to position.
Concentricity can be easily guaranteed, but the price is relatively higher.
The third method:
This method involves connecting the synchronous belt pulley to the shaft using a flat key and a set screw. This method is suitable for high torque applications.
(1) Remove burrs from the flat key and shaft to ensure cleanliness of the part.
(2) Install the synchronous belt pulley on the shaft, adjust the distance or tighten the shaft shoulder according to the design dimension, and then tighten the fixing screw.
Characteristics:
This method uses a keyway to transmit greater torque and is suitable for medium to heavy loads.
(This is the ideal and most commonly used method.)
The fourth method:
This method involves directly holding the synchronous belt pulley with a stepped design on the shaft and screwing it to the motor shaft in the radial direction. This is the most commonly used method and is suitable for low torque applications. Not commonly used when transmitting higher torques.
These are the four common methods for designing and installing synchronous belt pulleys. You can choose between them based on specific application scenarios, cost considerations, and maintenance needs.
