Principle
The horizontal arms connected to the road wheels are cranks that drive the vertical arm up and down. The vertical arm connects to the volute spring in the box-shaped area above.
The vertical volute spring suspension system is a type of vehicle suspension system which uses volute springs to compensate for surface irregularities. This type of the suspension system was mainly fitted on US and Italian tanks and armored fighting vehicles starting from throughout the 1930s up until after the end of the Second World War in 1945.
The horizontal arms connected to the road wheels are cranks that drive the vertical arm up and down. The vertical arm connects to the volute spring in the box-shaped area above.
During the 1930s, many innovations in the components of light tanks would make US tanks considerably more reliable.[ citation needed ] These included rubber-bushed tracks, rear mounted radial engines and the vertical volute spring suspension.
A volute spring is a compression spring in the form of a cone (a volute). Under compression the coils slide over each other, affording a long travel. The result is more stable and powerful than any leaf, coil, or torsion bar spring in the same volume.[ citation needed ] Mounted vertically in a road wheel bogie for a pair of road wheels on a tank made a very compact unit. [1]
The suspension was developed in 1933 by Harry Knox, better known for his Knox Automobile Company, and was first tested on T2E1 light tank prototype in 1934. [2] [3]
The Rock Island Arsenal produced a small tank for the cavalry which used vertical volute spring suspension instead of leaf spring suspension. Standardized as the M1 Combat Car, it entered service with the US Army in 1937. [4] The design was used in the M2 light tank and subsequent Stuart tank series. Design features of the Stuart were scaled up for use in the first M2 medium tanks which would evolve into the more successful M3 Lee and M4 Sherman, all using the VVSS.
Battle experience showed that the service life of the original vertical volute spring suspension (VVSS) of the late model M4 was shortening due to the tank's increasing combat weight with larger guns and heavier armor. Beginning in mid-1944, M4A3 models of the Sherman adopted a newly developed Horizontal Volute Spring Suspension (HVSS). [5]
This type of a suspension system involved springing the pair of dual-mounted road wheels on each bogie against each other with a volute spring. First tried by Harry Knox on the Light Tank T6 project in 1938, it was essentially a version of the British Horstmann suspension that replaced the Horstmann's coil spring with a pair of volute springs.
When the horizontally-affixed volute springs were placed in compression by either the front or the rear bogie wheel arm, the pressure from the load was transmitted onto the opposite arm, thus helping to maintain tension on the tracks. Compared to the VVSS system which it replaced on the M4, the HVSS system was heavier and stronger and allowed the changing of individual wheels aside from increasing wheel travel space.
A bogie is a chassis or framework that carries a wheelset, attached to a vehicle—a modular subassembly of wheels and axles. Bogies take various forms in various modes of transport. A bogie may remain normally attached or be quickly detachable. It may include a suspension component within it, or be solid and in turn be suspended ; it may be mounted on a swivel, as traditionally on a railway carriage or locomotive, additionally jointed and sprung, or held in place by other means.
The Christie suspension is a suspension system developed by American engineer J. Walter Christie for his tank designs. It allowed considerably longer movement than conventional leaf spring systems then in common use, which allowed his tanks to have considerably greater cross-country speed. The system was first introduced on his M1928 design, and used on all of his designs until his death in 1944.
A torsion bar suspension, also known as a torsion spring suspension, is any vehicle suspension that uses a torsion bar as its main weight-bearing spring. One end of a long metal bar is attached firmly to the vehicle chassis; the opposite end terminates in a lever, the torsion key, mounted perpendicular to the bar, that is attached to a suspension arm, a spindle, or the axle. Vertical motion of the wheel causes the bar to twist around its axis and is resisted by the bar's torsion resistance. The effective spring rate of the bar is determined by its length, cross section, shape, material, and manufacturing process.
A coil spring is a mechanical device which is typically used to store energy and subsequently release it, to absorb shock, or to maintain a force between contacting surfaces. They are made of an elastic material formed into the shape of a helix which returns to its natural length when unloaded.
Suspension is the system of tires, tire air, springs, shock absorbers and linkages that connects a vehicle to its wheels and allows relative motion between the two. Suspension systems must support both road holding/handling and ride quality, which are at odds with each other. The tuning of suspensions involves finding the right compromise. It is important for the suspension to keep the road wheel in contact with the road surface as much as possible, because all the road or ground forces acting on the vehicle do so through the contact patches of the tires. The suspension also protects the vehicle itself and any cargo or luggage from damage and wear. The design of front and rear suspension of a car may be different.
The M2 light tank, officially Light Tank, M2, was an American light tank of the interwar period which saw limited service during World War II. The most common model, the M2A4, was equipped with one 37 mm (1.5 in) M5 gun and five .30 cal M1919 Browning machine guns.
The Light Tank Mark I to Mark V were a series of related designs of light tank produced by Vickers for the British Army during the interwar period.
Horstmann suspension, also known as Horstman, Vickers-Horstman and rarely Slow Motion, is a type of tracked suspension devised by British tank designer John Carden and worked into a production design by engineer Sidney Horstmann.
The M4 Sherman tank was produced in several variants, a result of mass production spread across several manufacturers and several years. It was also the basis for a number of related vehicles and Shermans have been modified by several nations, ranging from upgrades to complete hull conversions for another task. Originally designed in 1941, M4 variants were still used by Israel during the 1967 and 1973 wars with its Arab neighbors.
This article deals with Sherman tanks extensive use around the world after World War II and catalogues foreign post–World War II use and conversions of Sherman tanks and variants based on the Sherman chassis.
The medium tank T20, medium tank T22 and medium tank T23 were prototype medium tanks, developed by the United States Army during World War II. They were designed as successors to the M4 Sherman. The standard main weapon for production versions of these designs was to be the 76 mm gun M1.
The Renault R40 or Char léger modèle 1935 R modifié 1939 was a French light infantry tank that was used early in World War II, an improvement of the Renault R35, of which it is often considered a variant.
A volute spring, also known as a conical spring, is a compression spring in the form of a cone. Under compression, the coils slide past each other, thus enabling the spring to be compressed to a very short length in comparison with what would be possible with a more conventional helical spring.
The M1 combat car, officially Light Tank, M1, was a light tank used by the United States Cavalry in the late 1930s and developed at the same time as the U.S. Army Infantry Branch's very similar Light Tank, M2.
The United States has produced tanks since their inception in World War I, up until the present day. While there were several American experiments in tank design, the first American tanks to see service were copies of French light tanks and a joint heavy tank design with the United Kingdom.
An equalising beam, equalising lever or equalising bar links the suspension of two or more adjacent axles of a vehicle, especially a railway locomotive.
The medium tank M7, initially light tank T7, was an American tank, originally conceived as an up-gunned replacement for the light tank M3/M5 ("Stuart"). The project developed to mount the same 75mm armament as the M4 Sherman while retaining the light weight and maneuverability of the M3 Stuart; however, during development the weight of the prototype surpassed the US Army's standard for light tanks and crossed into the medium tank category and was renamed. The M7 had significantly less armor than the M4 Sherman, no greater firepower, and held only a slight advantage in top speed. For these reasons, and because the M4 was already battle-tested and in full production, the M7 was cancelled in 1943.
The M32 tank recovery vehicle was an armored recovery vehicle (ARV) used during World War II and the Korean War by the United States, and was based on the chassis of the M4 Sherman medium tank. During World War II, the British also used several hundred M32s, which were obtained through lend-lease in 1944. The first four prototypes were produced in January 1943, labeled T5, T5E1, T5E2, T5E3, and T5E4. After a series of tests at the Aberdeen Proving Grounds, the prototypes were approved as M32, M32E1, M32E2, M32E3, and M32E4. However, the M32E4 never entered production. There were also variants that had horizontal volute spring suspension (HVSS), which were demarcated by the suffix "A1" after the model number.
The Vickers Light Dragon was a fully-tracked British field artillery tractor made by Vickers-Armstrongs Ltd from 1929 to 1935. Designed to tow small-calibre field guns, it complemented Vickers' Medium Dragon tractor, which pulled medium to heavy artillery.