Torque tube
Encyclopedia
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. Driveshafts are sometimes also used for other vehicles and machinery.
to the transmission
and therefore propels the car forward by pushing on the engine/transmission and then through the engine mounts to the car frame .
In contrast, the Hotchkiss drive has the traction forces transmitted to the car frame by using other suspension components such as leaf springs or trailing arm
s. A ball and socket type of joint called a "torque ball" is used at one end of the torque tube to allow relative motion between the axle and transmission due to suspension travel. Since the torque tube does not constrain the axle in the lateral (side-to-side) direction a panhard rod
is often used for this purpose. The combination of the panhard rod and the torque tube allows the easy implementation of soft coil springs in the rear to give good ride quality .
In addition to transmitting the traction forces, the torque tube is hollow and contains the rotating driveshaft
. Inside the hollow torque ball is the universal joint
of the driveshaft that allows relative motion between the two ends of the driveshaft. In most applications the drive shaft uses a single universal joint which has the disadvantage that it causes speed fluctuations in the driveshaft when the shaft is not straight. The Hotchkiss drive uses two universal joints which has the effect of canceling the speed fluctuations and gives a constant speed even when the shaft is no longer straight .
Buick started using coil springs in the 1930s, as did Nash's
post-war Airflyte model; these also necessitated using a torque tube. American Motors
(AMC) also continued to use a coil spring rear suspension design with a torque tube on their large-sized cars (Rambler Classic
and Ambassador
) through the 1966 model year. The 1961-1963 Pontiac Tempest
incorporated an unusual curved “torque-tube” with a 4-inch drop (about 10 centimeters) that housed a 3/4 inch (2 cm) solid steel driveshaft (nicknamed the "rope shaft") without universal joints on each end. The main purpose was to make the floor lower, thus increasing the car's interior room. The Peugeot 504
and the Volvo 300 Series
also used a torque tube.
The torque tube driveline is also used in Sprintcars
and Midget cars
. The C5 and C6 Chevrolet Corvette
, Lexus LF-A, Porsche 924
, Porsche 928
, Porsche 944
, Aston Martin DBR9
, Aston Martin DBS
, Aston Martin DB7
, and the Mercedes-Benz SLS AMG also use variations on this design, mostly with rear-mounted transaxle
s.
The Czech made Tatra truck is the only full size truck using a torque tube and independent suspension on all wheels.
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...
technology, often used in automobiles with a front engine and rear drive. It is not as widespread as the Hotchkiss drive
Hotchkiss drive
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...
, but is still occasionally used to this day. Driveshafts are sometimes also used for other vehicles and machinery.
Construction
The "torque" that is referred to in the name is not that of the driveshaft, along the axis of the car, but that applied by the wheels. The design problem that the torque tube solves is how to get the traction forces generated by the wheels to the car frame. The "torque tube" transmits this force by directly coupling the axle differentialDifferential (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...
to 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...
and therefore propels the car forward by pushing on the engine/transmission and then through the engine mounts to the car frame .
In contrast, the Hotchkiss drive has the traction forces transmitted to the car frame by using other suspension components such as leaf springs or trailing arm
Trailing arm
thumb|220px|Trailing arm rear suspension of [[Front-engine, front-wheel drive layout|FF]] carsA trailing-arm suspension is an automobile suspension design in which one or more arms are connected between the axle and the chassis. It is usually used on rear axles...
s. A ball and socket type of joint called a "torque ball" is used at one end of the torque tube to allow relative motion between the axle and transmission due to suspension travel. Since the torque tube does not constrain the axle in the lateral (side-to-side) direction a panhard rod
Panhard rod
A Panhard rod is a component of a car suspension system that provides lateral location of the axle...
is often used for this purpose. The combination of the panhard rod and the torque tube allows the easy implementation of soft coil springs in the rear to give good ride quality .
In addition to transmitting the traction forces, the torque tube is hollow and contains the rotating 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...
. Inside the hollow torque ball is the 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...
of the driveshaft that allows relative motion between the two ends of the driveshaft. In most applications the drive shaft uses a single universal joint which has the disadvantage that it causes speed fluctuations in the driveshaft when the shaft is not straight. The Hotchkiss drive uses two universal joints which has the effect of canceling the speed fluctuations and gives a constant speed even when the shaft is no longer straight .
Application
Examples of the torque tube were the American cars of the Ford brand up through 1948, which used the less expensive transverse springs that could not take the thrust.Buick started using coil springs in the 1930s, as did Nash's
Nash Motors
Also see: Kelvinator and American Motors CorporationNash Motors was an automobile manufacturer based in Kenosha, Wisconsin, in the United States from 1916 to 1938. From 1938 to 1954, Nash was the automotive division of the Nash-Kelvinator Corporation...
post-war Airflyte model; these also necessitated using a torque tube. American Motors
American Motors
American Motors Corporation was an American automobile company formed by the 1954 merger of Nash-Kelvinator Corporation and Hudson Motor Car Company. At the time, it was the largest corporate merger in U.S. history.George W...
(AMC) also continued to use a coil spring rear suspension design with a torque tube on their large-sized cars (Rambler Classic
Rambler Classic
The Rambler Classic was an intermediate sized automobile that was built and sold by American Motors Corporation from model year 1961 to 1966...
and Ambassador
AMC Ambassador
- 1958 :American Motors planned to produce a stretched a wheelbase version of the Rambler platform for Nash dealers to be the new Nash Ambassador, and another for Hudson dealers...
) through the 1966 model year. The 1961-1963 Pontiac Tempest
Pontiac Tempest
The Pontiac Tempest was an entry-level compact produced by the Pontiac Motor Division of General Motors, introduced in September 1960 for the 1961 model year....
incorporated an unusual curved “torque-tube” with a 4-inch drop (about 10 centimeters) that housed a 3/4 inch (2 cm) solid steel driveshaft (nicknamed the "rope shaft") without universal joints on each end. The main purpose was to make the floor lower, thus increasing the car's interior room. The Peugeot 504
Peugeot 504
The Peugeot 504 is a large family car manufactured by French automaker Peugeot between 1968 and 1983, with licensed production continuing until 2006.-1968 — introduction:...
and the Volvo 300 Series
Volvo 300 series
The Volvo 300 series is a rear wheel drive automobile sold as both a hatchback and a conventional saloon from 1976-1991. It was launched in the Netherlands shortly after Volvo acquired a major stake in the passenger car division of DAF in 1973...
also used a torque tube.
The torque tube driveline is also used in Sprintcars
Sprint car racing
Sprint cars are high-powered race cars designed primarily for the purpose of running on short oval or circular dirt or paved tracks. Sprint car racing is popular in the United States, Canada, Australia, New Zealand and South Africa....
and Midget cars
Midget car racing
Midget cars, also Speedcars in Australia, are very small race cars with a very high power-to-weight ratio and typically use four-cylinder engines.-Cars:Typically, these cars have 300 to 400 horsepower and weigh...
. The C5 and C6 Chevrolet Corvette
Chevrolet Corvette
The Chevrolet Corvette is a sports car by the Chevrolet division of General Motors that has been produced in six generations. The first model, a convertible, was designed by Harley Earl and introduced at the GM Motorama in 1953 as a concept show car. Myron Scott is credited for naming the car after...
, Lexus LF-A, Porsche 924
Porsche 924
The Porsche 924 is an automobile produced by Porsche AG of Germany from 1976 to 1988. A two-door, 2+2 coupé, the 924 replaced the 914 as the company's entry-level model, and was the model that finally retired the 912. In production terms, the 924 was the first Porsche model powered by a...
, Porsche 928
Porsche 928
The Porsche 928 was a sports-GT car sold by Porsche AG of Germany from 1978 to 1995. Originally intended to replace the company's iconic 911, the 928 attempted to combine the power, poise, and handling of a sports car with the refinement, comfort, and equipment of a luxury sedan to create what some...
, Porsche 944
Porsche 944
The Porsche 944 is a sports car built by Porsche from 1982 to 1991. It was built on the same platform as the 924, although 924 production continued through 1988. The 944 was intended to last into the 1990s, but major revisions planned for a 944 S3 model were eventually rolled into the 968 instead,...
, Aston Martin DBR9
Aston Martin DBR9
The Aston Martin DBR9 is a racing car built by Aston Martin Racing, debuting in 2005. The name DBR9 is derived from the original 24 Hours of Le Mans-winning DBR1 car, named for then-owner David Brown, which not only won the 24 Hour race in 1959 but also the World Sportscar title.-Development:Based...
, Aston Martin DBS
Aston Martin DBS
The Aston Martin DBS is a GT car produced by the British manufacturer Aston Martin Lagonda Limited. Originally produced from 1967–72, it featured in the 1969 James Bond film On Her Majesty's Secret Service...
, Aston Martin DB7
Aston Martin DB7
The Aston Martin DB7 is a grand tourer which was produced by Aston Martin from September 1994 to December 2004. The grand tourer was available either as a coupé or a convertible. The prototype was complete by November 1992, and debuted at the Geneva Motor Show in March, 1993, the car was styled by...
, and the Mercedes-Benz SLS AMG also use variations on this design, mostly with rear-mounted transaxle
Transaxle
In the automotive field, a transaxle is a major mechanical component that combines the functionality of the transmission, the differential, and associated components of the driven axle into one integrated assembly....
s.
The Czech made Tatra truck is the only full size truck using a torque tube and independent suspension on all wheels.