Non-Syncromesh Gearboxes

Technical discussion on converting internal combustion to electric
Post Reply
Kasterborus
Groupie
Posts: 48
Joined: Mon, 07 Jan 2019, 17:14
Real Name: Chris

Non-Syncromesh Gearboxes

Post by Kasterborus » Mon, 03 Jun 2019, 09:07

Anyone know if there is a way to set up a controller to act like a syncromesh in a gearbox?

Maybe with an up/down switch on the side of the Gearshift, similar to where a gear split would be, so the controller knows if it's spinning up or down for the next gear.

Obviously you wouldn't be able to skip gears as you could use a gate sensor to say "This is third, switch is in up shift, so I'm matching 4th" to allow an easy slot for the next gear, then you can just float the gear in.

antiscab
Senior Member
Posts: 2329
Joined: Mon, 26 Nov 2007, 05:39
Real Name: Matthew Lacey
Location: Perth, WA

Re: Non-Syncromesh Gearboxes

Post by antiscab » Mon, 03 Jun 2019, 09:13

Tesla threw a few million at that problem 10 years ago and failed to get it to work reliably.

It would be worth having a look at their patents to see what was tried.
Matt
2017 Renault zoe - 25'000km
2007 vectrix - 156'000km
1998 prius - needs Batt
1999 Prius - needs batt
2000 prius - has 200 x headway 38120 cells

T1 Terry
Senior Member
Posts: 874
Joined: Thu, 30 Sep 2010, 20:11
Real Name: Terry Covill
Location: Mannum SA

Re: Non-Syncromesh Gearboxes

Post by T1 Terry » Mon, 03 Jun 2019, 16:38

An Alison auto direct drive (no torque converter) would be the easiest method. A 4sp would be enough because the electric motor has heaps of torque all the way through its rpm range, so no need to match a ratio to the torque sweet spot. Gear selection would be more a case of matching the required speed with the upper rpm range of the motor to minimise the current draw.
High rpm does not equate to high energy consumption like it would in an ICE motor application ....At least I think I've got that part right :?

T1 Terry
Green but want to learn

antiscab
Senior Member
Posts: 2329
Joined: Mon, 26 Nov 2007, 05:39
Real Name: Matthew Lacey
Location: Perth, WA

Re: Non-Syncromesh Gearboxes

Post by antiscab » Mon, 03 Jun 2019, 22:13

System efficiency you would have to measure for

My old mazda2 would draw fewer battery amps at low rpm, I suspect due to lower losses in the gearbox
Matt
2017 Renault zoe - 25'000km
2007 vectrix - 156'000km
1998 prius - needs Batt
1999 Prius - needs batt
2000 prius - has 200 x headway 38120 cells

T1 Terry
Senior Member
Posts: 874
Joined: Thu, 30 Sep 2010, 20:11
Real Name: Terry Covill
Location: Mannum SA

Re: Non-Syncromesh Gearboxes

Post by T1 Terry » Tue, 04 Jun 2019, 09:39

antiscab wrote:
Mon, 03 Jun 2019, 22:13
System efficiency you would have to measure for

My old mazda2 would draw fewer battery amps at low rpm, I suspect due to lower losses in the gearbox
Ah, a factor I hadn't thought about. More an issue in manual gearboxes than auto because there are multiple shafts turning and all the gears thrashing in the oil, plus the losses in any gear other than direct drive. With an auto, pumping losses are the same no matter what the speed, maybe some additional losses driving planetary gear sets compared to direct drive where all planetary gear sets are locked. The torque converter losses are negated by the direct drive so far less energy lost to heat as well.

T1 Terry
Green but want to learn

User avatar
Richo
Senior Member
Posts: 3564
Joined: Mon, 16 Jun 2008, 00:19
Real Name: Richard
Location: Perth, WA

Re: Non-Syncromesh Gearboxes

Post by Richo » Tue, 04 Jun 2019, 13:13

Kasterborus wrote:
Mon, 03 Jun 2019, 09:07
Anyone know if there is a way to set up a controller to act like a syncromesh in a gearbox?
antiscab wrote:
Mon, 03 Jun 2019, 09:13
Tesla threw a few million at that problem 10 years ago and failed to get it to work reliably.
WOW I'm screwed - I was going to do it in my spare time for under $10 :o

I decided to take the clutch out of the handi project.
The motor directly couples to the gearbox shaft.
The sensors are supposed to check when the gearbox goes into neutral and adjust the RPM to match the correct gear.
As Kaster mentioned you'd have to up/down through each gears - no skipping.

NOT something that is currently on offer for off the shelf controllers.
Help prevent road rage - get outta my way! Blasphemy is a swear word. Magnetic North is a south Pole.

antiscab
Senior Member
Posts: 2329
Joined: Mon, 26 Nov 2007, 05:39
Real Name: Matthew Lacey
Location: Perth, WA

Re: Non-Syncromesh Gearboxes

Post by antiscab » Tue, 04 Jun 2019, 20:42

to be fair Tesla were trying to shift in under a second, probably well under a second.

If trying to do it in 5 seconds or so, it probably wouldn't be as bad
Matt
2017 Renault zoe - 25'000km
2007 vectrix - 156'000km
1998 prius - needs Batt
1999 Prius - needs batt
2000 prius - has 200 x headway 38120 cells

User avatar
Richo
Senior Member
Posts: 3564
Joined: Mon, 16 Jun 2008, 00:19
Real Name: Richard
Location: Perth, WA

Re: Non-Syncromesh Gearboxes

Post by Richo » Wed, 05 Jun 2019, 09:45

Ah no - if I'm taking 5 secs to change gear I'll crash it into wall set fire to it and walk away...
Help prevent road rage - get outta my way! Blasphemy is a swear word. Magnetic North is a south Pole.

Kasterborus
Groupie
Posts: 48
Joined: Mon, 07 Jan 2019, 17:14
Real Name: Chris

Re: Non-Syncromesh Gearboxes

Post by Kasterborus » Wed, 05 Jun 2019, 11:31

antiscab wrote:
Tue, 04 Jun 2019, 20:42
to be fair Tesla were trying to shift in under a second, probably well under a second.

If trying to do it in 5 seconds or so, it probably wouldn't be as bad
Just timed myself on a drive, around 2.5-3 seconds without the Jake on, about 1.8-2.2 with the Jakes on

Post Reply