Thanks for identifying the reason for the continuous speed limitation - that it is bearing lubrication, rather than other aspects of the motor (such as winding temperature), and for sharing it. Sorry that the learning process was so painful.
Hyper 9 + TorqueBox = Bad News
I'm posting this to save others from my pain. I have a Ford Ranger that was converted back in 2007. It's 144 volt and had a series DC motor connected directly to the transmission. No clutch. Most of the time I drove in 2nd. I only need to shift to 3rd at speeds above 55mph. After 15 years of good use, I felt it was time for an upgrade and two things I wanted was regenerative braking (and one foot driving if possible) and to get rid of the tranny. I was dreaming of just a forward/reverse switch and some extra floor space. I didn't want to replace everything and the Hyper 9HV looked good for a 144 volt AC motor. I checked out a bunch of build pages and videos and it seems to be powerful enough for my needs. To get rid of the transmission, the Torque Trends TorqueBox seemed to fit the bill nicely. My DC motor has a redline of 6000 rpm. In 2nd gear (2:1) I get almost exactly 10mph per 1000rpm (hence the need to shift at 55mph). The Hyper9 theoretically maxes out at 8000 rpm and the TorqueBox is a 1.9:1 ratio so that should theoretically bring the truck to slightly over 80mph which I was fine with. I do almost no highway driving in it anyway.
All looked good until I did take it on the highway. Performance was quite good and it didn't seem to have any trouble getting to 70mph. When I got home there was the definitely smell of something very hot. Taking things apart showed that the motor had liquified all the grease in the rear bearing. It definitely overheated. Some of you know the answer already but it was a surprise to me. The Hyper9HV has a "max continuous" limitation of 3600rpm. I haven't found any mention of this on the NetGain site, although, now that I know to look, I have found it on some of the supplier's websites. Basically, the Hyper9 + TorqueBox is good for a vehicle that will only go 40mph or less.
Just a warning before you spend your hard-earned cash on this combo. I guess I'm going to have to put the #*([email protected]^ transmission back in. Even worse I guess I better think about using 3rd at speeds over 36mph. Ugh.
All looked good until I did take it on the highway. Performance was quite good and it didn't seem to have any trouble getting to 70mph. When I got home there was the definitely smell of something very hot. Taking things apart showed that the motor had liquified all the grease in the rear bearing. It definitely overheated. Some of you know the answer already but it was a surprise to me. The Hyper9HV has a "max continuous" limitation of 3600rpm. I haven't found any mention of this on the NetGain site, although, now that I know to look, I have found it on some of the supplier's websites. Basically, the Hyper9 + TorqueBox is good for a vehicle that will only go 40mph or less.
Just a warning before you spend your hard-earned cash on this combo. I guess I'm going to have to put the #*([email protected]^ transmission back in. Even worse I guess I better think about using 3rd at speeds over 36mph. Ugh.
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I don't know that the grease is the limitation or just a symptom. I haven't totally verified that the motor wasn't damaged.Thanks for identifying the reason for the continuous speed limitation - that it is bearing lubrication, rather than other aspects of the motor (such as winding temperature), and for sharing it. Sorry that the learning process was so painful.
Sounds like this would be a great application for a Gearvendors standalone under/overdrive unit. It's just too bad they are so expensive.
Do they make such a thing? I don't see it on their web site. The TorqueBox wasn't cheap either
Yeah, their website is terrible. Automatic 4-Speed 47 RH (618) Remote Mount - GearvendorsDo they make such a thing? I don't see it on their web site. The TorqueBox wasn't cheap either
Hi lordryck,All looked good until I did take it on the highway. Performance was quite good and it didn't seem to have any trouble getting to 70mph. When I got home there was the definitely smell of something very hot. Taking things apart showed that the motor had liquified all the grease in the rear bearing. It definitely overheated. Some of you know the answer already but it was a surprise to me. The Hyper9HV has a "max continuous" limitation of 3600rpm. I haven't found any mention of this on the NetGain site, although, now that I know to look, I have found it on some of the supplier's websites. Basically, the Hyper9 + TorqueBox is good for a vehicle that will only go 40mph or less.
Just a warning before you spend your hard-earned cash on this combo. I guess I'm going to have to put the #*([email protected]^ transmission back in. Even worse I guess I better think about using 3rd at speeds over 36mph. Ugh.
Does your TorqueBox have a temp indicator on it? Does your TorqueBox have fittings for a trans cooler?
The HyPer 9 motor has a nominal rated speed of 3,600RPM. This is the speed at which its max continuous power of 38kW is available. The motor can spin above this speed continuously, but the continuous power rating will be lower. Considering the torque and efficiency curve, <4,000RPM is best, but I always try to keep this motor's continuous speed <5,500RPM. The HyPer 9 runs at 5,500RPM in many different applications without this issue. 7,000RPM is an inefficient speed for the HyPer 9. It's possible the highway speeds caused excessive heat in the motor or gearbox.
More specifically, efficiency of the HyPer9 at full power doesn't vary much with speed above 1,000 RPM (as seen in performance charts published by NetGain), but running at combination of very high speed and low load will be less efficient (and therefore create more waste heat) than running at combination of moderate speed and moderate load.The HyPer 9 motor has a nominal rated speed of 3,600RPM. This is the speed at which its max continuous power of 38kW is available. The motor can spin above this speed continuously, but the continuous power rating will be lower. Considering the torque and efficiency curve, <4,000RPM is best, but I always try to keep this motor's continuous speed <5,500RPM. The HyPer 9 runs at 5,500RPM in many different applications without this issue. 7,000RPM is an inefficient speed for the HyPer 9. It's possible the highway speeds caused excessive heat in the motor or gearbox.
For some other motors efficiency maps are available, showing efficiency at all combinations of speed and load, but that is not available for the HyPer 9 motors. Left to guess, most efficient state is probably around the middle of the speed range and more than half of peak torque for that speed.
HHamstra, your speed approach seems very reasonable to me.
Excessive heat in the motor, definitely. You illustrate my original point--with my rear-end ratio and the TorqueBox's 1.9:1 ratio, motor RPM is just slightly less than 10mph per 1000rpm. So running at 3600 rpm is about 41mph. Taking the truck on the highway at 65mph is requiring the motor to spin continuously at 6000 rpm. It's very hard to find anything "official" saying "don't do that" and with an 8000rpm redline I figured it would be safe on the highway. I think the real problem is that it's air cooled. I think the folks at eveurope.eu have the right idea with a water cooled version of the motor.
Performance on the highway was just fine so if I can keep it cool it would work fine.
Performance on the highway was just fine so if I can keep it cool it would work fine.
That does NOT sound like a "motor" problem
Overheating a bearing sounds much more like an alignment or sideload problem
Overheating a bearing sounds much more like an alignment or sideload problem
Buried somewhere in the motor threads is a handbook for large diameter high revving series DC motor mods to get you to 8,000 longer than 14 seconds. If you have a high rated motor, the windings should be "H" insulated for 180C degrees. Your problem is that the rotating pieces generate most of the heat but don't cool well and the generated G Forces exceed the bond shear strengths. The front bearing is in cooling air, the rear bearing is stagnant and attached to all sorts of mass. Typical bearing Grease tend to pour-point flow slightly below the "H" rating.
My ranger uses a standard 5 bolt hub stud pattern. I would suggest F150 style rims and tires about 225x75x15 to get more vehicle speed at low cost and regrease that rear bearing with some silicone based high temp grease. 165's if you have a need for tire smoke. Finally, a way to monitor motor exhaust air temps because........ might want to learn speed shifting too.
My ranger uses a standard 5 bolt hub stud pattern. I would suggest F150 style rims and tires about 225x75x15 to get more vehicle speed at low cost and regrease that rear bearing with some silicone based high temp grease. 165's if you have a need for tire smoke. Finally, a way to monitor motor exhaust air temps because........ might want to learn speed shifting too.
I've been running Hyper 9 HV's with a Torque Box on my Corvette ( dual motors since) they were released. I never had an issue with heat from the motor or controller.
I have been running Tesla modules 7S2P (recently changed to 7S) and had a range of close to 180 miles per charge. I have driven freeway speeds 50 miles one way to car shows and back again with no issues . I did change the rear end from a 3.07 to a 2.59 to cruise at 60 at about 3500 rpm and get a little higher top end.
I'm on a second project with a single Hyper9HV with a Torque Box and I'm running a 9" Ford rear end with 3.00 I'm expecting to have similar performance since the car is only 2200 pounds.
Before swapping everything back out to a transmission, maybe consider changing out the rear end to a lower numeric number. With ~25" tires and the Torque Box I'm finding a 3.00 or close to that seems to work fine.
My setup runs very close to what HHamstra had suggested.
I hope you can get it sorted out.
Mo
I have been running Tesla modules 7S2P (recently changed to 7S) and had a range of close to 180 miles per charge. I have driven freeway speeds 50 miles one way to car shows and back again with no issues . I did change the rear end from a 3.07 to a 2.59 to cruise at 60 at about 3500 rpm and get a little higher top end.
I'm on a second project with a single Hyper9HV with a Torque Box and I'm running a 9" Ford rear end with 3.00 I'm expecting to have similar performance since the car is only 2200 pounds.
Before swapping everything back out to a transmission, maybe consider changing out the rear end to a lower numeric number. With ~25" tires and the Torque Box I'm finding a 3.00 or close to that seems to work fine.
My setup runs very close to what HHamstra had suggested.
I hope you can get it sorted out.
Mo
Don't know about Gen 3 or 4 rangers, but early ones you had two choices in the 8.8 series diff. 3:73 or 4:10 with the 4:10 belonging only to 4 bangers and some heavy duty options. Tire/rim swaps take about 15 minutes even with hand tools, swapping diffs takes all day. Motor rpm and back emf reduces efficiency, increases heat retention unless massively overcooled. Doubt you could overcool an electric motor Ranger
There's a lot of slop in the rear end. When I go into regen there's a big klunk. The truck has 150,000 miles on it so I was thinking of having it rebuilt anyway. Mine had a 4 cylinder. I don't have it here right now so I can't check which gears are in it. Yukon Gears makes a 3.07 gear set for the 8.8. That might be a worthwhile investment, although I want to be careful I don't take away all the low speed performance and load carrying capability
It does sound like an alignment issue. Or, maybe the motor shaft bearing is getting an excess thrust load as the motor and box are bolted together and/or as it operates. It doesn't take too much of an axial preload to do in a typical, regular non-angular contact ball bearing unit. If that's what's in the motor.
You could check the end clearance of the motor output shaft where it goes into the box input shaft. Also, allow some clearance for expansion.
Also, how tight is the clearance between the two shafts? You probably want a slightly loose fit to allow for expansion and contraction axially between the two. I'm not sure what kind of shafts you have. This is where splined shafts have a real benefit as far as torque capacity and less wear.
You could check the end clearance of the motor output shaft where it goes into the box input shaft. Also, allow some clearance for expansion.
Also, how tight is the clearance between the two shafts? You probably want a slightly loose fit to allow for expansion and contraction axially between the two. I'm not sure what kind of shafts you have. This is where splined shafts have a real benefit as far as torque capacity and less wear.
Gee 150 k miles. Kinda new then. Being a ranger, the source of engagement clunks are many and plentiful. Dual cardigan driveshaft, bad spicers, loose splines, lost preload in the diff, crap engine and trans mounts, steering box, drag bar, wheels.........
Then there's the body to frame attachments.
My ranger has a factory modified 8.8 so when you change gears you really need to pay attention to fit, the listings used to not actually provide a replacement set ratio other than factory but that was 10 years ago.
Then there's the body to frame attachments.
My ranger has a factory modified 8.8 so when you change gears you really need to pay attention to fit, the listings used to not actually provide a replacement set ratio other than factory but that was 10 years ago.
I also faced technical difficulties with car components in the past, I can relate to the frustration and disappointment that comes with investing time and money into a project only to have it fall short of expectations.
The money is largely recoverable.
A project usually only falls short if you let it because nothing but money and time stop you from iterating.
A project usually only falls short if you let it because nothing but money and time stop you from iterating.
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