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Do electric drive trains have gearing? Can't the applied torque be regulated electrically?

• SigmundA 4y ago
  Yes there is usually a single speed gear case with gear reduction to increase wheel torque. Sometimes you will see multi-speed transmission on EV's but it is not as necessary since electric motors put out maximum torque at 0 rpm and spin up to 20,000 rpm. The Tesla semi for instance has 4 model 3 motors putting out 307 ft lbs each with a single speed gearbox of 23:1 on the front drive and 15:1 on the rear drive allowing a kind of electronically controlled two speed system. So the front drive can put down 307 * 2 * 23 = 14122 ft lbs while the rear can put down 307 * 2 * 15 = 9210 ft lbs for a total of 23332 at the wheels. The main point to remember is torque can be increased by gearing while power cannot, and measuring torque at the wheels seems impressive but doesn't tell you much, you can get a lawnmower engine to put huge torque numbers at the wheels with the right gearing and most EV have gear reduction except maybe hub motors even then they might use planetary reduction.