drive train how cars work

Continuously variable transmission CVT

provide automatic, seamless shifting that cannot be felt even mechanically simpler than regular transmission

Transaxle

serves in place of a transmission and differential in front-wheel vehicles the "differential" of a front wheel drive vehicle

three jobs of a drive train

1. transferring spin force from an engine to the wheels 2. changing the rate of spin delivered to the the wheels by shifting gears 3. Connecting and disconnecting an engine from the wheels in order to start or idle

flywheel

A heavy wheel fastened to one end of the crankshaft to improve the running quality of the engine. The inertia of the flywheel keeps the crankshaft spinning and smoothes engine operation. a heavy wheel that takes a lot of force to spin around bolted to a crankshaft at the rear of the engine. large size and weight of a flywheel helps absorb rattling and vibrations as a clutch disc makes contact. A flywheel also quiets vibrations

release bearing (throw-out bearing)

A release bearing, sometimes called a throw-out bearing, reduces wear on a pressure plate when a clutch pedal is pushed down.

transverse engine

Mounts sideways in the engine compartment.

drive shaft

The connecting component (a steel tube) that carries torque and transmits rotation in rwd, extends from transmission to a differential with U-Joints attached at each end. A long shaft is Susceptible to issues because it is a delicate balance, soo... 2 short drive shafts are sometimes used instead, requiring an additional U-joint in the middle. In fwd, half shafts are used in place of along drive shaft. Short steel rod that connects a wheel assembly to transaxle using CV-joints to make the connections. Also susceptible to damage, these CV joints are protected by rubber boots

Bell Housing (Clutch Housing)

The metal covering around the flywheel and clutch or torque converter assembly. A bell housing encloses all these parts to protect them from moisture and dirt.

countershaft

The shaft in a manual gearbox that carries power by means of gears from the input shaft to the main

Rear-wheel drive

Transfer of power from a vehicles engine to its rear wheels transmission connects to the rear of the engine and a drive shaft connects to the rear of the transmission to extend the spin motion to the differential. A differential transfers the spin motion to the axle shaft which connects to the rear wheels.

only one

________ wheel receives spin power at a time in most cars

Torque

a force that causes rotation

overdrive

a high gear used at high speeds to maintain the driving speed with less output power

standard transmission

a transmission that requires manually switching from gear to gear using a clutch Spin force from engine transferred to mainshaft and drive gear, which can be slid along the countershaft cluster gear to change gear combinations. Synchronizer helps slide one gear to another Usually have 3 to 6 forward gears for cars. Sometimes an overdrive or high gear

transmission

a way to change car speed besides the gas pedal or brakes. uses different sized gears to change speed of rotation given to wheels

torque converter

automatically shifts the amount of torque used according to what is needed the "clutch" for an automatic transmission no mechanical connection between the engine and the drive train, no solid clutch disc. Uses as liquid connection to transfer spin force. Viscosity and kinetic energy used to transfer spinning power to the drive train. This liquid is transmission fluid. Also lubricates entire transmission. Works like 2 fans facing each other. One on makes the other still spin. Same idea but instead of force in air, it's in liquid which is more reliable and stronger.

four wheel drive (4WD)

drive train variation combining rear and front wheel drive systems. All four wheels receive spin power for slippery conditions.

Splined shaft

extends through the center of the pressure plate and release bearing, sliding perfectly into matching notches in the center of the clutch disc. The splined end of a mainshaft secures and centers a clutch disc, which has not other attachment. Splines are ridges or teeth[1][2][3] on a drive shaft that mesh with grooves in a mating piece and transfer torque to it, maintaining the angular correspondence between them. For instance, a gear mounted on a shaft might use a male spline on the shaft that matches the female spline on the gear. The splines on the pictured drive shaft match with the female splines in the center of the clutch plate, while the smooth tip of the axle is supported in the pilot bearing in the flywheel. An alternative to splines is a keyway and key, though splines provide a longer fatigue life.[2]

transfer case

located between the transmission and the drive axles on a four wheel drive vehicle. The transfer case splits the engines power between the front and rear drive axle. shifts from 2wd to 4wd. serves as second differential for the front two wheels in the 4 wheel drive

pressure plate

the driving member of the clutch assembly. Between the clutch plate and the spring, all of which are under the cover

Front-wheel drive

the entire drivetrain is located at the front of the vehicle and drives the front wheels. complicates matters because the front wheels must receive the powerful spin force from the engine plus do the turning engine often is placed sideways to save space and eliminate need of drive shaft and separate differential crankshaft aimed specifically at wheel assembly Has transaxle

drive wheel

the only wheel that actually receives power. adequate for most road surfaces excluding mud, sand, snow where the wheels can slip or get stuck

clutch disc

the part of a clutch that receives the driving motion from the flywheel and pressure plate assembly and transmits that motion to the transmission input shaft

Universal Joint (U-Joint)

transfer spinning power through the changing angles from road bumps and the away caused by steering around corners. Transfer must be smooth continuous despite constant changing attached to each end of a drive shaft these are also used in some steering systems and in other automotive applications

drive train

transmits power from the engine to the vehicles drive wheels includes many parts from an engine to the wheels. Begins at rear of an engine, connecting to a crankshaft where it extends through a block. Must engage and disengage quickly and smoothly and with enough force to move a car fast.

Limited slip differential or positraction

transmits power to the driving wheel that has traction eliminates problem of getting stuck or sliding by automatically transferring power from a slipping drive wheel to the opposite wheel, doubling chances of good traction

constant velocity joints (CV joints)

use ball bearing mechanisms to reduce friction and provide extra strength required to handle complex forces and movements used in front wheel drive designs attaches wheel assembly to the transaxle on fwd vehicles

clutch

used with a manual transmission pushing this in separates the spinning part of an engine from the rest of a drive train allowing the driver to shift gear. separation releases pressure on gears, allowing them to slide easily from one gear combo to another. Separation of engine from rest of drive train also provides a "neutral" position for starting and idling As the clutch is eased out, a clutch disc is slowly forced into contact with the spinning surface of a flywheel. Slipping and small vibrations occur at first and heat is generated. With clutch all the way out, a clutch disc is pressed to a flywheel by the strong springs of a pressure plate and no slipping or clutch wear occurs; transfer of spin power is complete

differential

watermelon-sized part located between the two rear wheels. Only used in rear wheel vehicles and contains gears necessary to transfer spin force around a corner as well as mechanisms for several other important tasks. hollow arms that extend to each rear wheel assembly. These arms enclose the axles which connect the wheels with the main rotating gears in ______ Also allows the two rear wheels to rotate at different speeds (outside tire travels greater distance on corners). Can't be a solid connection between both wheels with both rotating at different speeds or it'd break. ____ solves this problem 4WD has two _____. on in front and one in back A transfer case is the front one. The ____ is the back one