变速箱和超大轮胎：齿轮比如何有助于防止动力传动系统损坏

inst在卡车上的较大轮胎是美国作为棒球，乡村音乐和苹果派。不幸的是，大轮胎也携手共进，令人愉快的东西：传输失败。您可以通过了解超大轮胎对变性的意想不到的后果来防范问题，更好地排除长期失败，尤其是在传动系统中行驶时的角色齿轮比在管理扭矩中的作用。

虽然大轮胎是一个受欢迎的车间，发现在整个美国，但有些人会争辩说，这一趋势实际上受到了20世纪初的法国工程师的工作。Adolphe Kegresse安装了一个越野轨道系统，进入各种劳斯莱斯汽车和Packard Trucks，后来开发了它在第二次世界大战中使用的车辆抵达远程位置。战争后，私人承包商和公司开始利用增加更多地面清关的概念，以便使用其车辆进入该国的远程部分。它们的方法的差异是它们改变悬架以抬起车辆并置于较大的直径轮胎上。这主要是在这个时候对大型商业工作卡车进行了。

快进到1970年代，你会发现这是当举起的大轮胎热潮起飞时。“Bigfoot，”可以说是第一个怪物卡车，在这个时间段内由Bob Chandler创建。一旦怪物卡车活动被电视剧，趋势所捕获的趋势，普通人想复制这种酷炫的外观和探索他们无法访问的地区。为了适应更大的轮胎，公司开始提升套装，汽车制造商开始提供特殊的越野版本的流行拾音器。然而，艰难的旋转轮胎的艰难外观和别人不能带来一些垮台的能力。现在我们知道趋势如何开始，让我们看看超大轮胎的一些消极方面。

升级到较大的外径轮胎自然地增加了轮胎外部周围的距离。圆周用于计算速度，因此从工厂轮胎尺寸的任何偏差都会影响这一点。在使用电子速度传感器的较新的车辆中，此问题最小，并且可以用可编程调谐器校正。然而，在依赖电缆和齿轮驱动的车速表的旧车辆中，允许适配器，校准盒或车速表齿轮变化是必要的。

安装更高轮胎的最大问题是导流带有的增加。为了更好地看看这种后果，我们可以回到物理课程 - 我甚至会给你一些功课。对于这个例子，我们将使用此扭矩公式：

增加杠杆臂的长度（L）增加施加的扭矩（t）。这一理论每次到达那个顽固的生锈螺栓的更长的断路器栏时都会进行测试。

This theory works against you, however, when you increase the radius of a tire, because it now requires more torque from your driveline to turn that larger tire. This generally does not have much of a negative effect on the engine components themselves, although it will now require the engine to work harder to maintain the same speed as before. The transmission components, on the other hand, especially the clutches and bands, take the brunt of the abuse. Clutches and bands will begin to create excessive heat as they struggle to operate under higher constant stress. Excessive heat cycles will cause the friction surfaces to start slipping, and at that point the transmission will need to be overhauled. If the core problem of the failure is not addressed — increased tire size — problems will occur again and again.

So how do you safely run those big, 35” tires on a vehicle that didn’t come stock with them?

重新装修。

All rear wheel drive (RWD) vehicles have a set of gears inside the rear axle housing called the ring and pinion gear that determine the final gear ratio. Four wheel drive (4WD) vehicles have a set in the front and rear axle housings.

The pinion gear has significantly less teeth and will rotate more than the ring gear. Gear ratios will be labeled as 3.42:1, or 3.42 revolutions of the pinion and driveshaft for one revolution of the axle shaft. If you were to order a new truck, you could request from a small selection of available gear ratios. These gear ratios are calculated by engineers to maximize torque, acceleration, engine RPM at highway speeds and ultimately gas mileage, all while taking into account the known tire diameter. These gear sets can be changed out by professionals for either different aftermarket or original equipment gear sets. Modifying the final gear ratio will correct the drivetrain deficiencies caused by larger tires. Obviously it is more expensive and difficult to modify a 4WD drive gear ratio than RWD because there are two sets to change.
要找到新的最佳齿轮比，可以使用此公式：

Let’s see how this formula applies to a 2017 GMC Sierra Z71, which came stock with 265/65-18 (31.6” dia.) tires. Assuming a 3.42:1 gear ratio, we can calculate the new gear ratio like this:

现在我们已经恢复了车辆的驾驶特性和力量，是时候出去了，安全和负责任地享受户外活动。一个非常受欢迎的爱好，叫做普米兰德是越来越受欢迎的，人们装备他们的卡车和SUV的帐篷，床铺，烹饪有关和其他设施，以及在国内未经改善的道路上驾驶。当然，还将总是有4WD卡车安装35“轮胎，从来没有看到泥土道路。这些车辆特别需要重新驾驶，因为它们在公路速度时经常被驱动。

Jason Larochelle is a Sonnax product support representative. He is a member of theSonnax TASC Force（技术汽车专业委员会），一批认可的行业技术专家，传输重建者和Sonnax技术人员。