n*********3
发帖数: 534 | 1 Tesla type S.
transmission: 1-speed direct drive
How could that be?? How does it accelerate? Does not seem to make sense.
What kind of new technology is that?
Anyone who is knowledgeable about this?? |
i****x
发帖数: 17565 | 2 电动车马力曲线基本是平的，不需要换挡。如果还不理解说明你不理解为什么车要换挡
，可以看看这个
https://www.reddit.com/r/NoStupidQuestions/comments/2v3bhg/why_do_cars_need_
to_shift_gears_what_does_it_do/ |
c*****0
发帖数: 224 | |
j******0
发帖数: 1043 | 4 大概意思：内燃机负载太大就熄火。所以有变速箱。电动马达负载大就是不动而已。加
大电流动能超过负载就动起来了。一动起来有了惯性总负载就小很多，加速就快了。大
概意思
【在 n*********3 的大作中提到】
: Tesla type S.
: transmission: 1-speed direct drive
: How could that be?? How does it accelerate? Does not seem to make sense.
: What kind of new technology is that?
: Anyone who is knowledgeable about this??
|
f****o
发帖数: 4067 | |
n*********3
发帖数: 534 | 6 thanks,
my understanding of changing gear is the same as that for a bike.
So, electric car can generate enough power immediately to move a car from
zero speed to a high speed using a small gear. That implies a lot more power
is needed for accelerating at zero and low speed. Isn't that less efficient?
and when the car is going really fast, the gear must over-spin, so it
implies that the gear must be for high speed already.
need_
【在 i****x 的大作中提到】
: 电动车马力曲线基本是平的，不需要换挡。如果还不理解说明你不理解为什么车要换挡
: ，可以看看这个
: https://www.reddit.com/r/NoStupidQuestions/comments/2v3bhg/why_do_cars_need_
: to_shift_gears_what_does_it_do/
|
i****x
发帖数: 17565 | 7 还是不对。关键在于马力曲线。用功率的物理概念解释最清楚。变速箱可以让车速相同
时马达工作在不同转速上。内燃机不同转速输出功率不同，所以通过变速实现最优转速
。电动机马力曲线比较平稳，所以无论怎么变速输出功率都差不多，所以就不用变速了。
这只是个道理，实际上model s的马力曲线也不完全是平的，但是比较平或者说足够平
，所以换挡的好处就不抵复杂度和成本的代价了。
作为对比，贴个bmw 328的动力曲线。这种车如果要维持高输出，就得无论什么车速都
维持高转速，就需要变速箱来帮忙了。
.resource.1373896122694.jpg
power
efficient?
【在 n*********3 的大作中提到】
: thanks,
: my understanding of changing gear is the same as that for a bike.
: So, electric car can generate enough power immediately to move a car from
: zero speed to a high speed using a small gear. That implies a lot more power
: is needed for accelerating at zero and low speed. Isn't that less efficient?
: and when the car is going really fast, the gear must over-spin, so it
: implies that the gear must be for high speed already.
:
: need_
|
n*********3
发帖数: 534 | 8 Thanks,
Will study.
了。
【在 i****x 的大作中提到】
: 还是不对。关键在于马力曲线。用功率的物理概念解释最清楚。变速箱可以让车速相同
: 时马达工作在不同转速上。内燃机不同转速输出功率不同，所以通过变速实现最优转速
: 。电动机马力曲线比较平稳，所以无论怎么变速输出功率都差不多，所以就不用变速了。
: 这只是个道理，实际上model s的马力曲线也不完全是平的，但是比较平或者说足够平
: ，所以换挡的好处就不抵复杂度和成本的代价了。
: 作为对比，贴个bmw 328的动力曲线。这种车如果要维持高输出，就得无论什么车速都
: 维持高转速，就需要变速箱来帮忙了。
: .resource.1373896122694.jpg
:
: power
|
c*****0
发帖数: 224 | 9 楼上都费劲了，山地车骑过吧？变速箱一个原理。电车，高压高速，低压低速。that&#
39;s all！ |
