Torque tube

Last updated

Scan from 1937 Manual of Driving and Maintenance for Mechanical Vehicles (Wheeled), via HMSO, part of OPSI. The diagonal radius arms are discretionary. Rear axle with torque tube (Manual of Driving and Maintenance).jpg
Scan from 1937 Manual of Driving and Maintenance for Mechanical Vehicles (Wheeled), via HMSO, part of OPSI.
The diagonal radius arms are discretionary.

A torque tube system is a power transmission and braking technology that involves a stationary housing around the drive shaft, often used in automobiles with a front engine and rear drive. The torque tube consists of a large diameter stationary housing between the transmission and rear end that fully encloses a rotating tubular steel or small-diameter solid drive shaft (known colloquially in the U.S. as a "rope drive" [1] ) that transmits the power of the engine to a regular or limited-slip differential. [2] The purpose of a torque tube is to hold the rear end in place during acceleration and braking. Otherwise, the axle housing would suffer axle wrap, such that the front of the differential would lift up excessively during acceleration and sink down during braking. Its use is not as widespread in modern automobiles [3] as is the Hotchkiss drive, which holds the rear end in place and prevents it from flipping up or down, during acceleration and braking, by anchoring the axle housings to the leaf springs using spring perches. [4]

Contents

Construction

Rudimentary torque tube
Rover 8 chassis elevation.jpg
The 1904 Rover 8 chassis in side and plan.
Rover 8 chassis plan.jpg
The Rover 8 had a torque-tube like backbone, lacking a pivoting joint between the transmission and the proper torque-tube to the rear differential casing, to allow suspension travel.

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 engineering problem that the torque tube solves is how to get the traction forces generated by the wheels to the car frame. The torque moving the wheels and axles in a forward direction is met with an "equal and opposite" reaction of the axle housing and differential, making the differential want to spin in a reverse direction, in the same way that a cyclist "pops a wheelie", lifting the bicycle in the air in the opposite direction from the turn of the wheel. The essential problem is how to keep the differential from rotating during acceleration and braking. The torque tube solves that problem by coupling the differential housing to the transmission housing and therefore propels the car forward by pushing up on the engine/transmission and then through the engine mounts to the car frame, with the reverse happening during braking. In contrast, the Hotchkiss drive transmits the traction forces to the car frame by using suspension components such as leaf springs or trailing arms. [4]

A type of ball and socket 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. Later American Motors Rambler models (1962 through 1966) used a flange and cushion mount in place of the ball and socket. [5] Since the torque tube does not constrain the car's body to 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, as in Buicks after 1937. Before 1937, Buicks used leaf springs, so the panhard rod was not used, though the torque tube allowed a cantilever spring suspension, which gives a softer ride than a center-mount axle on the leaf spring, as required by the Hotchkiss setup.

In addition to transmitting 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 [ citation needed ]. V8-powered models of the 1963-1966 AMC Rambler used a double-Cardan constant velocity joint to eliminate driveshaft fluctuations, though six-cylinder and earlier V8 models used only one standard universal joint. [6]

The torque tube design is typically heavier and securely ties the rear end together, thus providing for a rigid rear end and assuring good alignment under all conditions. However, because of the greater unsprung weight of the torque tube and radius rods, there may be a "little hopping around of the rear end when cornering fast or on washboard roads". [7]

Application

Examples of the torque tube were the American cars of the Ford brand up through 1948, including over 19,000,000 Model Ts. [7] Ford used the less expensive transverse springs that could not take forward thrust. For many of those years, Chevrolet used the torque tube, while Buick used it starting in 1906 (in the model D). [8] [9] The torque tube also allowed Buick, beginning in 1938, [10] to use coil springs for a softer ride than traditional leaf springs, which can use a Hotchkiss drive, but coil springs cannot. Buick's use of a torque tube and coil springs [11] became a Buick "engineering trademark", until it was dropped with the 1961 model year full-sized models. [12] The Nash 600 model adopted torque-tube drive in 1941 without an enclosed joint, but utilized a "horizontal yoke at the front end of the torque tube is supported by rubber biscuits at each side." [13]

After the merger of Nash and Hudson in 1954, American Motors Corporation (AMC) continued to use the coil spring and torque tube rear suspension design on their large-sized cars (Rambler Classic and Ambassador) from the 1956 through the 1966 model year. [14] The enclosed driveshaft made for more complicated gear swaps and hampered hot rodders. [15] The discontinued torque-tube drive was replaced by a completely new open driveshaft and four-link axle-location system. [16]

The 1961 Pontiac Tempest was introduced as a new model, featuring an inline 4 coupled to a transaxle via a torque tube, giving it a perfect 50-50 front-rear weight balance.

The Peugeot 403 and 404 models used a torque tube. [17] The Peugeot 504, and Peugeot 505 estate/station wagons, as well as most export-market sedans also had torque tubes, while domestic and European-market sedan models had a transaxle and individual rear suspension.

The Chevrolet Chevette (1976-1988) and the similar Pontiac T-1000 used a torque tube and center bearing. [18] This design was unlike any other Chevrolet model "to isolate impacts to the rear wheels, cut down on road noise, and reduce engine vibration ... also allows a reduction in the height of the drive shaft and tunnel." [19]

The continuing limited production of the Avanti switched to a new chassis in 1986 that utilized a torque tube along with an independent rear suspension. [20]

The Mercedes SLS has a torque tube, but only to align the transaxle with the engine. [21]

The Chevrolet Corvette has used a torque tube since the 1996 introduction of the C5 version in the 1997 model year. [22]

Related Research Articles

<span class="mw-page-title-main">Axle</span> Central shaft for a rotating wheel or gear

An axle or axletree is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In the former case, bearings or bushings are provided at the mounting points where the axle is supported. In the latter case, a bearing or bushing sits inside a central hole in the wheel to allow the wheel or gear to rotate around the axle. Sometimes, especially on bicycles, the latter type of axle is referred to as a spindle.

<span class="mw-page-title-main">Unsprung mass</span> Portion of a vehicle not supported by its suspension system

The unsprung mass of a vehicle is the mass of the suspension, wheels or tracks, and other components directly connected to them. This contrasts with the sprung mass supported by the suspension, which includes the body and other components within or attached to it. Components of the unsprung mass include the wheel axles, wheel bearings, wheel hubs, tires, and a portion of the weight of driveshafts, springs, shock absorbers, and suspension links. Brakes that are mounted inboard are part of a vehicle's sprung mass.

<span class="mw-page-title-main">Four-wheel drive</span> Type of drivetrain with four driven wheels

A four-wheel drive, also called 4×4 or 4WD, is a two-axled vehicle drivetrain capable of providing torque to all of its wheels simultaneously. It may be full-time or on-demand, and is typically linked via a transfer case providing an additional output drive shaft and, in many instances, additional gear ranges.

<span class="mw-page-title-main">Pontiac Tempest</span> Automobile manufactured by Pontiac

The Tempest is an automobile that was produced by Pontiac from 1960 to 1970, and again from 1987 to 1991. The name "tempest" is from Old French tempeste, from Latin tempestas ("storm"), from tempus.

<span class="mw-page-title-main">Quattro (four-wheel-drive system)</span> Sub-brand by Audi that designed for its all-wheel-drive cars

Quattro is the trademark used by the automotive brand Audi to indicate that all-wheel drive (AWD) technologies or systems are used on specific models of its automobiles.

<span class="mw-page-title-main">Front-engine, front-wheel-drive layout</span> Term used in automotive technology

In automotive design, a front-engine, front-wheel-drive (FWD) layout, or FF layout, places both the internal combustion engine and driven roadwheels at the front of the vehicle.

<span class="mw-page-title-main">General Motors Y platform</span>

The Y platform, or Y body, designation has been used twice by the General Motors Corporation to describe a series of vehicles all built on the same basic body and sharing many parts and characteristics. The first was for a group of entry-level compacts including the conventional front-engine compacts built by GM divisions Buick, Oldsmobile and Pontiac from 1961 to 1963. The second, and current, incarnation is used for a high-end rear-wheel drive sports-car platform from the 1970s through the 2000s.

<span class="mw-page-title-main">Transaxle</span> Combined transmission, axle and differential in one assembly.

A transaxle is a single mechanical device which combines the functions of an automobile's transmission, axle, and differential into one integrated assembly. It can be produced in both manual and automatic versions.

<span class="mw-page-title-main">Drive shaft</span> Mechanical component for transmitting torque and rotation

A drive shaft, driveshaft, driving shaft, tailshaft, propeller shaft, or Cardan shaft is a component for transmitting mechanical power, torque, and rotation, usually used to connect other components of a drivetrain that cannot be connected directly because of distance or the need to allow for relative movement between them.

A swing axle is a simple type of independent suspension, almost always for the rear axles, designed and patented by Edmund Rumpler in 1903. This was a revolutionary invention in automotive suspension, allowing driven (powered) wheels to follow uneven road surfaces independently, thus enabling the vehicle's wheels to maintain better road contact and holding; plus each wheel's reduced unsprung weight means their movements have less impact on the vehicle as a whole. The first automotive application was the Rumpler Tropfenwagen, later followed by the Mercedes 130H/150H/170H, the Standard Superior, the Volkswagen Beetle and its derivatives, the Chevrolet Corvair, and the roll-over prone M151 jeep amongst others.

<span class="mw-page-title-main">De Dion suspension</span>

A de Dion tube is a form of non-independent automobile suspension. It is a considerable improvement over the swing axle, Hotchkiss drive, or live axle. Because it plays no part in transmitting power to the drive wheels, it is sometimes called a "dead axle".

<span class="mw-page-title-main">Hotchkiss drive</span> Shaft drive form of power transmission

The Hotchkiss drive is a shaft drive form of power transmission. It was the dominant means for front-engine, rear-wheel drive layout cars in the 20th century. The name comes from the French automobile manufacturer Hotchkiss, although other makers, such as Peerless, used similar systems before Hotchkiss.

Torque steer is the unintended influence of engine torque on the steering, especially in front-wheel-drive vehicles. For example, during heavy acceleration, the steering may pull to one side, which may be disturbing to the driver. The effect is manifested either as a tugging sensation in the steering wheel, or a veering of the vehicle from the intended path. Torque steer is directly related to differences in the forces in the contact patches of the left and right drive wheels. The effect becomes more evident when high torques are applied to the drive wheels because of a high overall reduction ratio between the engine and wheels, high engine torque, or some combination of the two. Torque steer is distinct from steering kickback.

<span class="mw-page-title-main">Beam axle</span> Automobile mechanism

A beam axle, rigid axle or solid axle is a dependent suspension design in which a set of wheels is connected laterally by a single beam or shaft. Beam axles were once commonly used at the rear wheels of a vehicle, but historically they have also been used as front axles in four-wheel-drive vehicles. In most automobiles, beam axles have been replaced with front (IFS) and rear independent suspensions (IRS).

ATTESA is a four-wheel drive system used in some automobiles produced by the Japanese automaker Nissan, including some models under its luxury marque Infiniti.

The Chevrolet Engineering Research Vehicle (CERV) is a series of Chevrolet experimental cars. Chevrolet Staff engineer, designer, and race car driver Zora Arkus-Duntov started development of the CERV I in 1959, and began work on the CERV II in 1963. Chevrolet chief engineer Don Runkle and Lotus' Tony Rudd discussed creating a new show car to demonstrate their engineering expertise in 1985; It would become the CERV III. Corvette chief engineer Dave Hill unveiled the CERV IV in 1993, a test vehicle for the 1997 C5 Corvette.

<span class="mw-page-title-main">Drivetrain</span> Group of components that deliver power to the driving wheels

A drivetrain or transmission system, is the group of components that deliver mechanical power from the prime mover to the driven components. In automotive engineering, the drivetrain is the components of a motor vehicle that deliver power to the drive wheels. This excludes the engine or motor that generates the power. In marine applications, the drive shaft will drive a propeller, thruster, or waterjet rather than a drive axle, while the actual engine might be similar to an automotive engine. Other machinery, equipment and vehicles may also use a drivetrain to deliver power from the engine(s) to the driven components.

<span class="mw-page-title-main">H-drive</span> Drivetrain for off-road vehicles

An H-drive drivetrain is a system used for heavy off-road vehicles with 6×6 or 8×8 drive to supply power to each wheel station.

The Audi R8 LMS Cup was a one-make sports car racing series by Audi based in Asia. Audi R8 LMS Cup cars were based on the Audi R8 LMS (GT3).

<span class="mw-page-title-main">Platform chassis</span>

A platform chassis is a form of vehicle frame / automobile chassis, constructed as a flat plate or platform, sometimes integrating a backbone or frame-structure with a vehicle's floor-pan.

References

  1. ↑ "Cut-Down Engine of the Week: Pontiac Trophy 4", Autoweek, Murilee Martin, Sept. 20, 2017
  2. ↑ Mitchell Automechanics. Prentice Hall. 1991. p. 456. ISBN   9780135837825.
  3. ↑ "Open Shaft Advantages". The Glasgow Herald. 23 July 1929.
  4. 1 2 Severson, Aaron (22 March 2009). "Hotchkiss Drive". Ate Up With Motor.
  5. ↑ 1962-1966 AMC Technical Service Manuals
  6. ↑ 1963-1966 AMC Technical Service Manuals.
  7. 1 2 Clymer, Floyd (October 1955). "Clymer Tests the Hudson Hornet V8". Popular Mechanics. 104 (4): 131.
  8. ↑ "Buick, The Golden Era" by Prof. Francis Therou
  9. ↑ "Seventy Years of Buick" by George H. Damman, page 18 "Buick pioneered the torque tube this year" referring to the model D built in 1906.
  10. ↑ "When was the first torque tube Buick?". Antique Automobile Club of America. Retrieved 27 April 2019.
  11. ↑ Kuns, Ray Forest; Hall, Morris Albert (1948). Fundamentals of Automobile Chassis and Power Transmission. American Technical Society. p. 335.
  12. ↑ "Big Buick models have new bodies, frame, suspension for '61". Popular Mechanics. 114 (4): 103. October 1960.
  13. ↑ "Drivetrains". The SAE Journal. 57. Society of Automotive Engineers: 30. 1949.
  14. ↑ Magnant, Steve (2013). Steve Magnante's 1001 Muscle Car Facts. Caltech. p. 372. ISBN   9781613250570.
  15. ↑ Magnante, Steve (2013). Steve Magnante's 1001 Muscle Car Facts. CarTech. p. 372. ISBN   9781613250570.
  16. ↑ "Steering and Suspension Stress Safety". Popular Science. 189 (4): 96 and 98. October 1966.
  17. ↑ Chilton's Foreign Car Repair Manual. Vol. 2. Chilton Book Company. 1971. p. 989. ISBN   9780801956324. 403, 404, and 504 models use a torque tube driveshaft. This type of driveshaft consists of an outer tube which takes the thrust of the rear wheels which are in turn driven by an inner shaft
  18. ↑ Kovacik, Robert T.; Creager, Clifford (1983). Manual Transmissions and Drivetrains. Thomson South-Western. p. 66. ISBN   9780538330503.
  19. ↑ "Chevette: U.S. Economy Champ?". Popular Science. 207 (4): 116. October 1975.
  20. ↑ Ross, Daniel Charles (October 1984). "Detroit Listening Post - Avanti garde". Popular Mechanics. 161 (10): 42.
  21. ↑ "Mercedes SLS Torque Tube animation". Archived from the original on 13 December 2021 – via YouTube.
  22. ↑ Thurn, Walt (2007). High-Performance C5 Corvette Builder's Guide. CarTech. p. 67. ISBN   9781932494334.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.