Torque tube
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]
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 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
A type of
In addition to transmitting traction forces, the torque tube is hollow and contains the rotating
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,
The 1961
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
References
- ^ [1] "Cut-Down Engine of the Week: Pontiac Trophy 4", Autoweek, Murilee Martin, Sept. 20, 2017
- ISBN 9780135837825.
- ^ "Open Shaft Advantages". The Glasgow Herald. 23 July 1929.
- ^ a b Severson, Aaron (22 March 2009). "Hotchkiss Drive". Ate Up With Motor.
- ^ 1962-1966 AMC Technical Service Manuals
- ^ 1963-1966 AMC Technical Service Manuals.
- ^ a b Clymer, Floyd (October 1955). "Clymer Tests the Hudson Hornet V8". Popular Mechanics. 104 (4): 131.
- ^ "Buick, The Golden Era" by Prof. Francis Therou
- ^ "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.
- ^ "When was the first torque tube Buick?". Antique Automobile Club of America. Retrieved 27 April 2019.
- ^ Kuns, Ray Forest; Hall, Morris Albert (1948). Fundamentals of Automobile Chassis and Power Transmission. American Technical Society. p. 335.
- ^ "Big Buick models have new bodies, frame, suspension for '61". Popular Mechanics. 114 (4): 103. October 1960.
- ^ "Drivetrains". The SAE Journal. 57. Society of Automotive Engineers: 30. 1949.
- ISBN 9781613250570.
- ISBN 9781613250570.
- ^ "Steering and Suspension Stress Safety". Popular Science. 189 (4): 96 and 98. October 1966.
- 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
- ISBN 9780538330503.
- ^ "Chevette: U.S. Economy Champ?". Popular Science. 207 (4): 116. October 1975.
- ^ Ross, Daniel Charles (October 1984). "Detroit Listening Post - Avanti garde". Popular Mechanics. 161 (10): 42.
- ^ "Mercedes SLS Torque Tube animation". Archived from the original on 13 December 2021 – via YouTube.
- ISBN 9781932494334.