1. Quick Steel Coil Mover in the Large Steel Plate Production Line
Sha Linnan Lu Peng Advisor: Prof. Jeremy Li
University of Bridgeport, Bridgeport, CT
Abstract
This poster introduces the quick material mover applied in the large steel plate production line. Nowadays, with the development of technique, the raw material or products transmission on the large steel production line has become a necessary step into which we should take consideration to improve the efficiency of production. The traditional way is using the crane in the workshop to load and unload the raw material and products, which actually wastes a lot of time because of waiting for the crane. Furthermore, the safe problem is the main concern. In pursue of more economical way and more guarantee on the safe problem, there is an idea by designing a quick material mover to fit this large steel plate production line. This quick material mover is cheaper, safer and more reliable in large steel plate production line and it also satisfies the demand of high-speed, high-effective and more economical in real production.
Design layout
Introduction
The material mover, which comprises walking-mechanism, jacking system, hydraulic system, vehicle body and brackets, is designed to carry and load the steel coil to the uncoiler or unload the steel coil from the coiler and carry away by using hydraulic and electrical system on the production line. The walking-mechanism includes a frequency-speed motor and transmission mechanism. When the motor drives a couple of sprocket wheels, the sprocket wheels pass the impetus to wheels. The material mover can work quickly by positive and reserve rotation of the frequency-speed motor. Jacking system of material mover will gain the impetus from the hydraulic system connected with production liner, which makes the mover accomplish the raising and descending motion. Different style of brackets with the diversity of work pieces, which are mounted on the material mover, will be driven by the guider pillar of jacking system to achieve the material transmitting procession.
The material mover is made up of walking-mechanism, jacking system, hydraulic system which is in the production line and rail. The max working weight of the mover we designed is 30 tones which include the weight of the mover (2 tones). The speed of the mover is 130mm/s
V sharp bracket is a good choice for steel coil. Delivery table is for steel plates and cylindrical container whose underpan could open is for steel pipes.
Walking-mechanism is made up of bodywork, a frequency-speed motor, chain transmission, bearings, axles and wheels. It will make the whole system move on the rail.
Jacking system which is shown in figure 6 will gain the impetus from the hydraulic system connected with production liner, which makes it accomplish the raising and descending motion.
The cylinder will be connected to the hydraulic system which is mounted on the large steel plate production line for controlling going up or down of steel coil movers. It is the main mechanism to raise and descend the raw material in the jacking system.
The guide pillars and bushes are assistant system in the jacking system. It will guide the cylinder to move and keep the bracket stable. The guide pillars and bushes are designed separately for reducing the weight of the mover to save the energy and raw material.
A frequency-speed motor is chosen for the mover because it can change the speed optionally. Then the mover can speed up, slow down and brake as our requirement. The transmission is made up of two sprocket wheels and a hinge. One of them connects on the motor with shaft pin and the other one connects the axle to drive the mover.
Deep groove ball bearing SKF6318 is chosen. This type of bearing basically affords the radial load with small rotation resistance and high maximum rotation speed, and suffers certain axial loading simultaneously. What’s more, it could reach high rotation accuracy and low level of vibration.
Checking Calculation for Steel Coil Mover
Conclusion
The steel coil mover belongs to material mover which acts more and more important part in the large modern industry instead of cranes. When we designed this steel coil mover, there are several rules we need to abbey. For example, we need do our best to reduce the weight of the mover to save the energy and raw material. That is why the guide pillars and bushes are designed separately. I choose the sprocket wheels as the transmission mechanism instead of bevel gears because they are cheaper and they can satisfy the requirement of transmission system. The hydraulic system is in the production line not on the material mover because it can serve other equipments. That can save a lot of energy. The mover can carry the steel coil because of the V sharp bracket and we can carry other products by changing different brackets. For example, using delivery table could carry steel plates in the cutting line. Or using cylindrical containers whose underpan could open can carry steel pipes. It will open the underpan to unload steel pipes when it moves to the destination.
In a word, Material mover has comprehensive application in modern industry by designed different brackets and it is safer, more reliable, satisfying the demand of high-speed, high-effective and more economical in real production.
Design Requirement
Load Bearing: 28T, Travel Speed: 130mm/s
Distance of cylinder for going up/down: 800mm
Calculation of Travel Speed
Tooth number of small sprocket wheel = 20, and the big one= 40.
Sprocket Wheel Drive Ratio: Is =40/20=2
Reducer Drive Ratio: IR=71 (X L D C )
where, X- Planetary Reducer, L- Stehende Installation, D- Motor Direct Connection, C- Inner Motor, 2.2- Power of Motor, 5- No.5 Engine Seat, 71- Drive Ratio
Total Drive Ratio: I=Is X IR= 2 X 71 =142
Rotation Speed of Motor: Input n=1500r/m Output n=21r/m
Rotation Speed of Big Chain Wheel: = n2 = = =10.5r/min
Rotation Speed of Mover Wheel n3=n2=10.5r/min
Diameter of Mover Wheel: D=250mm
Girth of Mover Wheel =
Travel Speed per Minute =8246.7mm/min
Travel Speed per Second = /60 = 137.4mm/s ＞130mm/s
Satisfying the demand of Mover Travel Speed
Checking Calculation of Bearing
The formula for estimating the main load axletrees suffers is P = Fr =, T= Load Bearing (28T= 28000kg), and P is each axletrees load. Here the pressure on the axletrees added by the chain is very small because the mesh transmission results in the small tension on the chain.
P = Fr = = 7000kg, and rotation speed: n3=10.5r/min
1000 hours is as the reference of axletrees life for calculating.
Cr = ,
where Cr- theoretic load of bearing, fh- life factor of ball bearing on 1000hr = 2.78
fd- factor of impact load = 1, ft- factor of temperature = 1
fn- factor of speed = (All these value come from the handbook of bearing)
Cr = = 126KN ＞ 7000 X 9.8 = 70KN
Thus, this type of axletrees satisfies the demand.