The necessity of gearbox

Why is a gearbox necessary?
Yeah. Gearbox very important!

Control over power output, by means of the throttle pedal, simply regulates the rate at which the engine is doing work: at very high speeds.
the torque output can at the same time be significantly less than at considerably lower speeds. In other words, maximum torque may be available over only a very limited speed range. Consequently, one needs to be able to regulate both the power output and the speed range of the engine relative to the range of speeds over which the vehicle is at any given time likely to be required to operate. Only in this way can the torque at the wheels be balanced against demands for either a steady speed uphill or downhill, or on the level, or for acceleration or deceleration. A gearbox is necessary, therefore, so that the driver can regulate torque by selecting the appropriate speed range or, in other words, the vehicle speed at which maximum torque is obtainable.

When a vehicle is moving at a uniform speed, the driving force, or tractive effort, at the wheels must be such as to exactly balance the sum of three categories of variable forces tending to oppose the motion. If it is greater, the car will accelerate, and if it is smaller, it will decelerate until a balance is obtained. Such a balance will be established eventually, because two of the forces vary with speed. The three forces are: (1) aerodynamic, or air, resistance; (2) gradient resistance, which can be either positive or negative; and (3) rolling
resistance.

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General Clutch

Clutch is a mechanical device that provides for the transmission of power (and therefore usually motion) from one component (the driving member) to another (the driven member).
Clutch arranged between the engine and gearbox

A clutch is a releasable coupling connecting the adjacent ends of two coaxial

shafts. It is said to be engaged or, in, when the shafts are coupled, and

disengaged, or out, when they are released. Mechanical clutches fall into two

main categories: positive engagement and progressive engagement.

The former is either positively disengaged, so that no torque can be

transmitted from the driving to the driven shaft, or positively engaged, in

which case the shafts rotate together, connected by some mechanical devices

such as splines, keys or dogs. In contrast, the progressive type is gradually

engaged, so that the speed of the driving shaft falls while, simultaneously,

that of the driven shaft rises from its initial stationary state until both are

rotating at equal speeds.

Positive engagement clutches are unsuitable for connecting the engine to

the gearbox, though they are used inside gearboxes. In this chapter, however,

we are dealing with the interconnection between the engine and gearbox, so

descriptions of this type will be left until later.

For road vehicles, a progressive engagement clutch of the friction type is

interposed between the engine and the gearbox. As mentioned in Chapter 23,

it can be either in an entirely separate housing, with a short shaft in front

connecting it to the engine, and another behind to connect it to the gearbox.

Alternatively, it can be integral with either unit, or indeed with both. In the

latter case it is in either a single or a multi-piece housing, the pieces being

bolted together to form a single engine-and-transmission unit. The housing

for the clutch can be one of the pieces or, alternatively, it can be integral with

either the engine crankcase or the gearbox housing.

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Cardan Shaft

Cardan Shaft

It has many different names:  drive shaft, driveshaft, driving shaft, propeller shaft, or Cardan shaft

Cardan Shafts is a mechanical component for transmitting torque and rotation, usually used to connect other components of a drive train that cannot be connected directly because of distance or the need to allow for relative movement between them.

Cardan shafts are carriers of torque: they are subject to torsion and shear stress, equivalent to the difference between the input torque and the load. They must therefore be strong enough to bear the stress, whilst avoiding too much additional weight as that would in turn increase their inertia.

Cardan shafts frequently incorporate one or more universal joints or jaw couplings, and sometimes a splined joint or prismatic joint to allow for variations in the alignment and distance between the driving and driven components.
Please visit Rcmast.com to view and learn mor knowledge Cardan shafts!

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