I need to design a rack and pinion elevator for a project in school. Where can I find sketches of designs of these types of elevators in order to have an idea of how to design it. Thanks a lot.
Start by looking at a screw drive garage door opener. Rotate upright instead of parallel to floor, now think through your specific load and height requirements etc -- always try not to reinvent the wheel!
i think you mention coblet(ball)screw mechanism that is used in garage , shops to move shutter up and down were screw rotations cause to coblet to move along its grooves , rack and pinion are different as though were geared wheel moves along toothed rail as grip, both techniques are usedfor displacement apart from other modes , accurate positioning in control mechanism ,your geared wheel can be powered by motor with reduction gearing mechanism for torque , these lifts are used in construction , hazardeous areas due to there safety , as cable operated lifts are dangerous even though they can be operated with safety features
Let me just ask some questions. Hopefully, as you answer them you will come up with your design.
1. Torque is defined as ______. Your elevator is being held in place by a pinion gear on the rack (actually more than one, but I'll keep it simple for now). The weight (mass) of the elevator is the force part of your formula for torque--(can you state why?) The radius from the center of the pinion to the contact point of its teeth on the rack (you can find this out from gear manufacturers' catalogs) is the length of the lever arm. Therefore how much torque do you need to hold the elevator in place?
2. What is the relationship between torque and power? It has something to do with time. If you know how fast you want to move the elevator, will this tell you how much power you need to have? I think so, but will let you work it out (both the relationship or formula, and the answer for your particular design). If you can't, come back on this thread with what you have figured out and I or others will help you try to see past that problem.
3. For stability and ease of motion, it seems to me that your elevator will need two racks and pinions (one set near or at the middle of two opposite sides) or four racks (one set each near each corner). Can you draw this? If you have only two sets, how will you keep the elevator level, so it doesn't tip if the load is not centered?
4. You need to turn these pinion gears at the same speeds simultaneously. What type of mechanism can you think of which will do this? Think of how power is transmitted to the wheels in a car or in a bicycle or motor cycle.
5. You will need a source of power to move this elevator, with the necessary parts to match its output torque and speed to the design you had from questions 1 & 2 above. Gear ratios are like lever arms, in how they affect speed and torque. You should now be able to match a motor's power to your system.
6. How about safety? How will you hold your elevator in position so it doesn't fall when the power is off. Can you come up with at least two different ways to do this, then add them to your design?
Very nicely put jmueller , you have given answers with requestions , that was one of our favourite school teachers way of teaching when he used to requestion the students when they approached for clearance .
this is a school project , you can get it from do it your self kits available in the market , you don`t have to go that deep , you can get assistance from your guide teacher ,it is only demonstration you will be put, but these are important points for perfection put by jmueller
Rack and pinion elevators
Re: Rack and pinion elevators
