Another gearbox discussion

[just-an-allusion]

I'll throw in that they had a quantity issue as well.
The numbers they needed to make were well under the minimums the majors were even willing to look at especially for a unknown company.

Whomever ended up making the gearbox it was going to be far more expensive than any other because of 1. difficult large shifting ratios and, 2. no high volume price breaks.

That's one of the problems that often hamstring new technologies/inventions, i.e., research and development-you've got to find out what works before you can mass reproduce it.

[power]

Good point. probably possible. with electric motors and those kind of small resonance characteristics due to the motors natural frequencies could be an issue with gears with some backlash. so, a flywheel could be usefull there. I dont think it would solve any issues with the changing of gears. actually, the less inertia in that regard, the better. less force on the teeth if the rpms were mismatched as they are with sequential gear boxes.

mk

With regards to the flywheel (or lack thereof), I don't think people are getting my point (or maybe I am wrong about it), but I think one thing a flywheel does is smooth out torque delivery. Lets say the PEM has some high frequency noise and the torque delivery fluctuates very rapidly with rapid, subtle variations in torque. A flywheel slows down the rotational changes so the gears don't experience those "fluttering fluctuations". With no flywheel the eMotor may be able to "micro-jackhammer" at the gear teeth during shifts. This is just my own (perhaps half baked) pet theory.

JB alluded to the fact that there were multiple "modes of failure" for the DT1.0 transmission, so we are probably only "scratching the surface" here.

[TEG]

Yeah a flywheel would definitely work against their goal of trying to get the eMotor to change RPMs as quickly as possible. It sounds like the existing mass of the rotor was too much as it is.

If they ever need variable ratios it would be good if they found a CVT that could work.

[just-an-allusion]

Despite the mindset expressed here (just as it is in a greater extent with Tesla and just about any other other EV manufacturers), though in keeping with this particular train of thought for the purposes of relaying an ideology in a manner in which it would be understood under the present frame of mind, I'd like to point out that the inherent proprietary operational disposition of any (electric) motor is in a single "gear" orientation. Any attempt to implement additional "gearing" would only serve to overly complicate a predominantly simple (singular) functional aspect of the technology, i.e., "over thinking" the basics, as previous history with the development of this technology demonstrates.

To this end, IMHO, my thoughts on this issue are that Tesla (or any EV manufacturer) should abandon any efforts to devise an "economical" method (note that I haven't mentioned that it could not be done, only that it would not be financially feasible from any reasonable perspective at this point in time given the exorbitant material cost of implementing a multi-geared transmission) as an ill-conceived pipe dream and stick with the time proven, standard method of operation commonly associated with motors, i.e., one speed/"gear".

With that said, it is my view that if it is the intent of any EV manufacturer to actually produce a multiple speed motor, they should do so by working to elaborate on/to evolve the parent technology while strictly adhering to the confines of that particular technology and not attempting to implement the technology of a completely differing discipline (electrical as opposed to mechanical), in the process avoiding pollution of an intrinsically pure technology (electric) with another (mechanic) that is atypically dirty like some form of bastardized cross-pollination.

Following this train of thought, instead of beating the metaphorical now long dead horse, if an EV manufacturer wishes to add differing speeds/"gears" to their motors, why not merely stick to the tech and simply add additional "poles" with associated "synchros" to "govern"/"modulate" their activation/operational "frequencies", hmm"?"

Why not merely go to "source" instead of outsourcing"?!?" Pass it along please.

[doug]

^^^^

I really don't see what you're going on about here. Cars are inherently mechanical objects and you still seem to be missing the point of gearing.

Or is this "reduction gearbox" more so a practical application as a means of "de-tuning" the motor so that no one kills themselves/Tesla drivers cannot outrun the police? Just curious.

Simply put, reduction gearing allows for more torque at the wheels by providing "mechanical advantage". This is a concept worth reviewing.

[just-an-allusion]

^^^^

I really don't see what you're going on about here. Cars are inherently mechanical objects and you still seem to be missing the point of gearing.

Simply put, reduction gearing allows for more lateral force at the wheels by providing "mechanical advantage". This is a concept worth reviewing.

Are you referring to LF as it equates to a tire's properties of deflection and recovery during operation as it relates to peak-to-peak, first harmonic, second harmonic, and higher-order harmonics?



Or another form of LF?

[just-an-allusion]

Granted...

Cars are inherently mechanical objects...

...In the totality of their design, yet the sole feature that I'm alluding to is that which concerns it's power plant/motor which, from the overview, is wherein the troubles lies, is it not?

Sometimes progress comes in the form of baby steps instead of leaps and bounds, as we would all wish.

[doug]

Are you referring to LF as it equates to a tire's properties of deflection and recovery during operation as it relates to peak-to-peak, first harmonic, second harmonic, and higher-order harmonics?

No, I suppose should have said linear force as in horizontal, non-rotational (lateral was perhaps a confusing word to use in this context). Actually, I should have taken it back one step and said torque but that tends to be a harder concept. Torque is converted to linear force through the "simple machine" of the wheel. Mechanical advantage, sometimes known as force multiplication, allows you to get more force (or torque) at the output than you supply at the input at the cost of distance (or rotation). Energy is conserved.

[just-an-allusion]

No, I suppose should have said linear force as in horizontal (lateral was perhaps a confusing word to use in this context). Actually, I should have taken it back one step and said torque but that tends to be a harder concept. Torque is converted to linear force through the simple machine of the wheel. Mechanical advantage, sometimes known as force multiplication, allows you to get more force (or torque) at the output then you supply at the input at the cost of distance (or rotation). Energy is conserved.

In other words, you're concerns are centered on transferring the rotational force of the motor, the "torque", to the wheels/drive train, correct?

If so, please note that nothing mentioned in the technique that I alluded to above refers to transferring the workload from the motor to the pavement, only in modulating/regulating the rate of the rotation of the motor, it's "speed", at any given time since that was the topic being discussed.

As for actually transferring the workload to the pavement...really, how hard could it be to facilitate?

Think "propeller".

[doug]

In other words, you're concerns are centered on transferring the rotational force of the motor, the "torque", to the wheels/drive train, correct?

Well that is, by definition, what a transmission (or a gearbox) does, which is the topic of this thread. My concern (i.e. my reason for replying) is that your posts suggest gaps in understanding. I've suggested some topics you could look into to fill those gaps.

... the sole feature that I'm alluding to is that which concerns it's power plant/motor which, from the overview, is wherein the troubles lies, is it not?

If with all that you're trying to say Tesla should make a better motor, I'm sure they're working on it. What they have now with DT1.5 is working pretty well, though.