This simplified automated system for positioning and transferring incoming workpieces on a conveyor can be used as an auxiliary system for a series of operations including, for example, feeding, positioning/inspection, and pre-ejection pauses. The components of this system are as follows:
- Flat belt driven mechanism and belt tension adjustment mechanism
- Motor torque transmission chain mechanism
- Work positioning mechanism
- Work detecting and drive controlling sensor system
Some creativity has gone into the following points to develop a low-cost, assembly, adjustment, and maintenance-friendly automation system:
|Design Highlights||Design Goals|
|Belt tension adjustment mechanism||Easy assembly, adjustment, maintenance, and cost reductions|
|Bracket support for lower part of conveyor||Cost reduction (welded structure)|
|Chain tension adjustment mechanism||Easy assembly, adjustment, and maintenance|
|Selection of conveyed work detection sensor||Selection of low-cost, reliable sensor|
|Positioning pusher material||Maintenance-free design (material selection), scratch prevention|
Since rotation torque is transmitted using friction in a mechanism with a flat belt, the conveyor belt tension, the contact angle between the pulley and the belt, and the friction coefficient are important design parameters. Specifically, the belt tension is a factor directly affecting the force of friction, and an inappropriately adjusted belt frequently causes problems, such as meandering. Therefore, it is important to design a proper conveyor belt tension adjustment mechanism.
The tension of the flat belt is generated by the tensile force from the two barrel-like flat belt pulleys held by bearing holder sets pulled toward both ends (see Photo 1). The design of the mechanism in which tension is placed on the flat belt (conveyor) when the two flat belt pulleys are in parallel is a feature of the conveyor belt tension adjustment mechanism.
Construction of Conveyor Belt Tension Adjustment Mechanism
Below is an enlarged view of the conveyor belt tension adjustment mechanism. The unit consists of the flat belt pulleys holding the flat belt and the bearing holder sets mounted on an adjusting plate (roller plate), and the adjustment mechanism positions the belts parallel to the roller plate.
This mechanism is composed of
Easy adjustment and maintenance of the assembly are thanks to this construction along with
Chain-Driven Power Transmission
A transfer conveyor belt is usually driven at a low constant speed. Accordingly, a gear head induction motor with a reduction ratio of 60:1 is selected here as a driving power source. To transmit this driving power efficiently to the flat belt pulley for driving the conveyor belt, a chain-driven power transmission system is applied here:
The table below shows the comparison of typical power transmission systems. A chain-driven power transmission system is selected here for high transmission efficiency and ease of design (with high flexibility for the design of two shafts space distance):
|Performance Parameter||Chain||Timing Belt||Gear|
(98% or higher)
|Noise and vibration||High||Low||High|