I actually just wanted to do the drawing, but once the drawing was done I figured since I had come that far, I might as well explain the darn thing too. =)
Outstanding drafting skills! And a good explanation too. As a side note you could definitely do a series of these in real time with the sound on and call them ASMR.
I am not generally highly impressionable. But in your case, I am making a large exception. This presentation removed the confusion that I have had with worm gears. I am coming back for more of your information and enlightenment. Thank you. You should market the “cad system” that drew your opening graphics. Again, thank you.
Another excellent explanation. Little side note: A worm gear assembly is basically self-locking. The worm wheel cannot (back-)drive the worm. Only the worm can drive the wheel due to inherent friction and direction of forces. Can be desired or not. But if you want to use it, you should be aware of this.
I was going to make this important point as well - but checked and see you have it covered. This locking feature is what makes it a perfect design for a tuning gear on a guitar for example- not only the gear reduction.
man this is probably one of the more difficult things to model in CAD, is there some video in detail about dimensioning the gears and teeth, of both parts? meshing and stuff
I would like to ask you about, what are the differences between putting the warm speed reducer on the input (filling material) and on the output (where the material is being discharged “
Hai, wonderful vedio. I have 2 questions for you. Does the worm and roller require grease or steering oil of ranges 140 or 300 or 450 or 600. By second question is does the worm and roller make driving more effortless than circulating ball bearing also called as ball and nut or is the recirculating ball mechanism more effortless than the worn and roller. As I had a fiat 118 NE which was the 124 fitted with the Nissan A12 engine which had the recirculating ball mechanism which was smooth like butter , I still regret for having sold it. It was so smooth even though it didn't have power assistance
I didn’t realize how much torque was multiplied through the worm gear assembly! You didnt mention that a worm gear may turn a worm wheel, but a worm wheel may not turn a worm gear.
There is definitely energy loss, whether or not you need to worry about it depends on the application. One thing to keep in mind though, is that energy loss will NOT affect the gear ratio, only the actual mechanical advantage.
Very good explanation. And yea draft skills are like other said outstanding. Could You please only check direction of moving wheel (3:08) I believe it is oposite direction. It would be very good if You can clear it out please. Thank You in advance.
Im not sure of the application, but all other conditions being the same, changing gear ratio like that is likely to overload the motor. Additionally a 10t worm wheel is going to be VERY difficult to design to run smoothly.
If you could design your own tools (especially disregarding costs) would you prefer power tools to have worm gears, wholistically than a hyper specific tool? Say if you wanted to design a circular saw and choose if its direct drive or not (for I assume worm gears would overall provide, on average, less RPM while giving you higher torque and maybe more suited through going into hardwoods) (also direct drive might be more cost effective and probably ideal for small drill bits that you need wicked fast RPMs to have the correct cutting speeds but this being a niche case?). Thanks!
I like the idea but at first glance there may be a problem. The issue being that the worm wheel can not (typically) drive the worm. So if you are using something like a circular saw, the moment you let up off the trigger, the motor stops, but the blade would not... and the inertia of the blade would tear the gears apart.
Great video, can you help me with some worm ratios. I’m making an ebike and using a worm gear with motor to power it, I have a motor that spins at 3500 rpm and would like an output of 350 rpm. I’m looking at a NMRV030 gearbox. What ratio would I need for an input of 3500rpm to get an out put rpm of 350? 10:1? Many thanks
I suggest you determine the desired gear ratio. Then, provided you know the desired output torque, find the gear tooth size that will support the needed torque (theoretically this is based on the shear strength of the material as well as tooth profile, gear lash, tolerances and width). In reality, find an existing worm gear design that is rated to a certain load for a given material, use that design.
Could varying the thread distance (pitch) allow you to change the gear ratio along one shaft? For instance, if it was used in a vehicle moving the gear further forward would change the gear ratio and increase speed.
@@INTEGRALPHYSICS I don't quite know how to describe this, but if a normal rotation of the worm would move one tooth of the wheel, couldn't it be adjusted so half a rotation would move one tooth?
hi all. i have a question. is it possible for a worm wheel to rotate a worm gear . im trying to design a pedal sysyem for my boat . im after max revolutions on the prop shaft to one turn of the pedal. cheers. plus a worm gear would eliminate the need for a 90 degree gear box
Yes but... When you factor friction into things, I suggest you consider a bevel gear. You can produce the low gear ratio you desire and easily build in the perpendicular relationship between the crank spindle and the prop shaft. Hope my suggestion helps, let me know how it goes and good luck!
I have a silly question actually!! If we directly rotate wormwheel and not using the worm what will be the difference!? Should we have to gather more torque or power to work!?
The point of the worm gear is to provide an increase in torque. Using a worm gear, a low torque motor can be used to produce high torque on an output shaft.
Recommend that you take a look at a modern spinning reel schematic.. this is the exact case use in real life.. the worm wheel (handle) is used to turn a pinion gear (which is what drives the rotor) which lays the line The point of using this great mechanical advantage is that it can still drive the rotor even under heavy load (the fish pulling) which is torque I believe Google spinning reel schematic (stella, saltiga, exist, Certate) all model names 👍🏻
Is there a way to switch the input and output shafts on a worm gear? As in could I hookup a gear reducer to the worm wheel to produce an output force to cause translational movement on the worm shaft?
Under normal circumstances if you drive the wheel it will not turn the worm. However if you allow the worm to move translationally, what you essentially have is a rack and pinon.
I am surprised that leads on the worm wasn't mention, that is extremely important on knowing the ratio, the example assumes the worm gear will always be a single lead, but there are worms with more then one lead, that is how a worm gearbox achieves various ratios, such as four leads on a worm would have changed this example to a 6:1 ratio, when you have a gearbox with a missing nameplate where the reducer is so worn out you cannot turn it by hand to get the ratio you must know this because the speed reducer once broken down almost always has enough tooth left on the wheel gear to count as well as counting the leads on the worm to know the ratio.
Short answer: its 40x the input torque. Longer answer: you are going to need to know the frictional losses along with the worm pitch and tooth profile to factor in losses and inefficiencies.
@@INTEGRALPHYSICS Worm gears aren't anything close to 100% efficiency. Spur gears in the limit of perfection can be 100% efficient, and in practice tend to be 98% efficient. Worm gears are inherently inefficient and are limited by the kinetic friction coefficients of the materials we can use. For a worm gear, 50% efficiency is optimistic, and is typical of what you can expect from the best worm gears available. A worm gear not built specifically for efficiency, will likely have an efficiency around 25%.
i want to make my electric train (DC) free rolling. I.e., u can push it back n forth w ur hand when the elec. pwr is not applied. I call it a free rotating gear box. All the electric model locomotives i have can't be pushed to rotate the driver wheels freely. The drivers r stationary. The only way to rotate the drive whls is to rotate the worm shaft either by the motor or by my fingers... Do u get the picture? How do u design that? I've heard u need a helix worm w a matching wheel gear. But i think it's much more complicated than just the two gears (a worm and a wheel gear plus perhaps a spur gear?). Yes, to produce torque to pull more cars, the gear box also need the gear ratio reduction as u've explained in ur video. I've searched here in the utube and guogle et al, for: 'Free turning worm gear' or 'Free turning gear box' but no luck. Pls advice, u or any audience?
@@INTEGRALPHYSICS Thx 4 ur immediate reply. There was a man from Japan who was able to do that on his 0-scale - 2 rail locos. But lost touch w him. I don't think he used a clutch (to disengage the spur gear from the worm). But perhaps, i may need to look into this clutch deal.
Most worm gear systems are specifically designed so you can't drive it in reverse. An application of the worm gear, is the tuning knobs on a musical instrument, which allow you to tighten the string, but don't allow the string to unwind the tuning knob. It is possible with an extremely steep helix of the worm threads, to make a worm gear that can be driven by the worm wheel, but it is rare that we desire such an application. It is much more likely that we would use other gear arrangements if we wanted bidirectional power transmission.
Short Answer: Gear lash = wiggle room between gears Longer Answer: In reality the line of action between gears is not tangent to the base circle of a gear. As a result the gears are not moving PRECISELY at angular velocities given by GR=Win/Wout. To put it another way... If the input shaft turns at constant velocity, the output shaft is going to speed up and slow down just a little bit with every tooth. Gear lash can affect how rapidly that speeding up and slowing down occurs.
Where is the actual math? I need to figure out the dimensions and angles etc. to make a worm gear for an extruder... I don't know a whole lot about this but i need to make the worm gear to at least... work
you want to machine one? as far as I know it's one of the hardest to machine gears so good luck :D what you should do is just check classified ads, or scrap yards in your area, some snowblowers use worm gears in the differential. some cars do too. save yourself the headaches.
I try to keep these sorts of videos very general because, as you are seeing, things become very specific very quick. My suggestion is start at your desired gear ratio and work backwards from there. The distance between the shafts is the effective sum of the worm and worm wheel radii (to the line of action). Tooth profile and pitch are dictated by load, shaft speed, shaft stiffness, motor torque, gear hardness, surface finish, service life etc. I assume you are trying to 3d print these parts. Worm gears are based on slippage, they are effectively inclined planes, so think about your print orientation. I suggest you print the worm gear on its end so that the layers are mostly in the direction of slip. The wheel can be printed laying on its face. Its not perfect but at least that way the edges of the layers will be perpendicular to each other along the line of action which should smooth the action of the gear set. If 3d printing, I suggest you coat the parts or sand them smooth between the teeth. If you are going to turn or cnc these parts I suggest you pull gears from something like Autodesk Inventor which already has gears designed in the catalog.
@@INTEGRALPHYSICS Thankyou, we have a 4th axis in class in one of our Haas machines, and im thinking about making the gear in there, I'm trying to use everything from a Bondtech Bmg extruder, except I designed a new case, heatsink and now working on the worm gear problem. It's going to be really small so printing won't work great
