| 摘要 |
An electrically driven vehicle, such as a local transportation vehicle, suburban runabout, light service vehicle or golf car, has a non-articulated frame with drive wheels associated with one end and a steerable wheel or wheels with the other end. Each of the drive wheels has its own permanent magnet direct current motor drive. The motors pass through a series-connected stage with unlimited differential action to a parallel-connected stage with limited differential action as the vehicle is brought up to speed from a stationary position. No mechanical differential is necessary and the vehicle may have a very low center of gravity and excellent center ground clearance. The drive system provides dynamic braking and energy restoration, with attendant control and energy saving advantages. This contributes to good traction and steerability under the varying operating conditions encountered. The weight of the batteries for the vehicle is sprung by the rear axle, so that the frame is relieved of carrying bending loads associated with the considerable proportion of total weight represented by the batteries. A vehicle embodying the invention can comfortably carry two 180-pound riders and two 20 or 30-pound golf bags more than 40 holes on a moderately hilly golf course using four standard 621/2 pound 6-volt rechargeable batteries, and this use can be repeated indefinitely, using two or more interchangeable battery packs. The vehicle can perform as well with four batteries as other currently manufactured vehicles do with six.
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