Hotchkiss drive
Encyclopedia
The Hotchkiss drive is a system of power transmission
. It was the dominant form of power transmission for front-engine, rear-wheel drive layout
cars
in the 20th century. The name comes from the inventor Albert Hotchkiss born in the United Kingdom later migrating to Australia (noted for over 5,000 inventions including the modern front loading washing machine), although it is clear that other makers (such as Peerless
) used similar systems before Hotchkiss.
During the early part of the 20th century the two major competing systems of power transmission were the shaft-drive and chain-drive
configurations. The Hotchkiss drive is a shaft-drive system (another type of direct-drive transmission system is the torque tube
, which was also popular until the 1950s).
All shaft-drive systems consist of a driveshaft
(also called a "propeller shaft" or Cardan
shaft) extending from the transmission
in front to the differential
in the rear. The differentiating characteristic of the Hotchkiss drive is the fact that it uses universal joint
s at both ends of the driveshaft, which is not enclosed. The use of two universal joints, properly phased and with parallel alignment of the drive and driven shafts, allows the use of simple cross-type universals. (In a torque tube arrangement only a single universal is used at the end of the transmission tailshaft, and this universal should be a constant velocity joint.) In the Hotchkiss drive, splines
eliminate thrust transmitted back up the driveshaft from the wheels, allowing simple rear-axle positioning using parallel leaf spring
s. (In the torque tube type this thrust is taken by the torque tube to the transmission and thence to the transmission and motor mounts to the frame. While the torque tube type requires additional locating elements, such as a Panhard rod
, this allows the use of coil springs.)
Some Hotchkiss driveshafts are made in two pieces with another universal joint in the center for greater flexibility, typically in truck
s and specialty vehicles built on truck frames. Some installations use rubber
mounts to isolate noise and vibration. The 1984-1987 RWD Toyota Corolla (i.e., Corolla SR5 and GT-S) coupe is another example of a car that uses a 2-part Hotchkiss driveshaft with a rubber-mounted center bearing.
This design was the main form of power transmission for most cars from the 1920s through the 1970s. Presently (circa 2008), it remains common in pick-up truck
s and sport utility vehicle
s (while front-wheel drive with a transverse mounted engine and transaxle, connected to the front wheels through axles with CV joints to allow steering, is most common for sedans and minivans.)
Power transmission
Power transmission is the movement of energy from its place of generation to a location where it is applied to performing useful work.Power is defined formally as units of energy per unit time...
. It was the dominant form of power transmission for front-engine, rear-wheel drive layout
Front-engine, rear-wheel drive layout
In automotive design, an FR, or Front-engine, Rear-wheel drive layout is one where the engine is located at the front of the vehicle and driven wheels are located at the rear. This was the traditional automobile layout for most of the 20th century....
cars
Automobile
An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...
in the 20th century. The name comes from the inventor Albert Hotchkiss born in the United Kingdom later migrating to Australia (noted for over 5,000 inventions including the modern front loading washing machine), although it is clear that other makers (such as Peerless
Peerless
Peerless was a United States automobile produced by the Peerless Motor Company of Cleveland, Ohio from 1900 to 1931. The company was known for building high-quality, precision luxury automobiles. Peerless' factory was located at 9400 Quincy Avenue in Cleveland...
) used similar systems before Hotchkiss.
During the early part of the 20th century the two major competing systems of power transmission were the shaft-drive and chain-drive
Chain drive
Chain drive is a way of transmitting mechanical power from one place to another. It is often used to convey power to the wheels of a vehicle, particularly bicycles and motorcycles...
configurations. The Hotchkiss drive is a shaft-drive system (another type of direct-drive transmission system is the torque tube
Torque tube
A torque tube system is a driveshaft technology, often used in automobiles with a front engine and rear drive. It is not as widespread as the Hotchkiss drive, but is still occasionally used to this day...
, which was also popular until the 1950s).
All shaft-drive systems consist of a driveshaft
Driveshaft
A drive shaft, driveshaft, driving shaft, propeller shaft, or Cardan shaft 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...
(also called a "propeller shaft" or Cardan
Cardan
Cardan may refer to:* Gerolamo Cardano or Jerome Cardan , a Renaissance mathematician, physician, astrologer, and gambler* A universal joint, U joint or Cardan joint, a joint in a rigid rod that allows the rod to 'bend' in any direction...
shaft) extending from the transmission
Transmission (mechanics)
A machine consists of a power source and a power transmission system, which provides controlled application of the power. Merriam-Webster defines transmission as: an assembly of parts including the speed-changing gears and the propeller shaft by which the power is transmitted from an engine to a...
in front to the differential
Differential (mechanics)
A differential is a device, usually, but not necessarily, employing gears, capable of transmitting torque and rotation through three shafts, almost always used in one of two ways: in one way, it receives one input and provides two outputs—this is found in most automobiles—and in the other way, it...
in the rear. The differentiating characteristic of the Hotchkiss drive is the fact that it uses universal joint
Universal joint
A universal joint, universal coupling, U joint, Cardan joint, Hardy-Spicer joint, or Hooke's joint is a joint or coupling in a rigid rod that allows the rod to 'bend' in any direction, and is commonly used in shafts that transmit rotary motion...
s at both ends of the driveshaft, which is not enclosed. The use of two universal joints, properly phased and with parallel alignment of the drive and driven shafts, allows the use of simple cross-type universals. (In a torque tube arrangement only a single universal is used at the end of the transmission tailshaft, and this universal should be a constant velocity joint.) In the Hotchkiss drive, splines
Rotating spline
Splines are ridges or teethon a drive shaft that mesh with grooves in a mating piece and transfer torque to it, maintaining the angular correspondence between them....
eliminate thrust transmitted back up the driveshaft from the wheels, allowing simple rear-axle positioning using parallel leaf spring
Leaf spring
Originally called laminated or carriage spring, a leaf spring is a simple form of spring, commonly used for the suspension in wheeled vehicles...
s. (In the torque tube type this thrust is taken by the torque tube to the transmission and thence to the transmission and motor mounts to the frame. While the torque tube type requires additional locating elements, such as a Panhard rod
Panhard rod
A Panhard rod is a component of a car suspension system that provides lateral location of the axle...
, this allows the use of coil springs.)
Some Hotchkiss driveshafts are made in two pieces with another universal joint in the center for greater flexibility, typically in truck
Truck
A truck or lorry is a motor vehicle designed to transport cargo. Trucks vary greatly in size, power, and configuration, with the smallest being mechanically similar to an automobile...
s and specialty vehicles built on truck frames. Some installations use rubber
Rubber
Natural rubber, also called India rubber or caoutchouc, is an elastomer that was originally derived from latex, a milky colloid produced by some plants. The plants would be ‘tapped’, that is, an incision made into the bark of the tree and the sticky, milk colored latex sap collected and refined...
mounts to isolate noise and vibration. The 1984-1987 RWD Toyota Corolla (i.e., Corolla SR5 and GT-S) coupe is another example of a car that uses a 2-part Hotchkiss driveshaft with a rubber-mounted center bearing.
This design was the main form of power transmission for most cars from the 1920s through the 1970s. Presently (circa 2008), it remains common in pick-up truck
Pick-Up Truck
"Pick-Up Truck" is a song written and recorded by Belgian acid house musician Praga Khan. It is the third single from Praga's eighth studio album, Soundscraper....
s and sport utility vehicle
Sport utility vehicle
A sport utility vehicle is a generic marketing term for a vehicle similar to a station wagon, but built on a light-truck chassis. It is usually equipped with four-wheel drive for on- or off-road ability, and with some pretension or ability to be used as an off-road vehicle. Not all four-wheel...
s (while front-wheel drive with a transverse mounted engine and transaxle, connected to the front wheels through axles with CV joints to allow steering, is most common for sedans and minivans.)