Cannon bearing

Last updated

A cannon bearing or cannon box bearing is an arrangement of bearings on a shaft, usually an axle, where two bearings are mounted in an enclosed tube.

Contents

The function of the cannon box is to preserve the alignment of the two bearings, even if the overall tube is allowed to move. The two bearings will retain their same relative position. The bearing tube can be attached to the vehicle frame through either a pivot or springs.

The name 'cannon box' derives from the appearance of the hollow tube. Also from the boring machines used to machine the accurately aligned bearing seats, the same machines developed for the boring of cannon and also used for machining the cylinders of steam engines.

Cannon box bearings are still found today, although much of the need for them was removed by the development of self-aligning ball bearings. These allow the inner race of a bearing to move independently of its outer, so that each bearing can align to both shaft and housing simultaneously, even if the housing moves around.

Railway use

'Java bogie' of a Swiss-built JGR class 7000 [de] electric locomotive Java-Drehgestell.JPG
'Java bogie' of a Swiss-built JGR class 7000  [ de ] electric locomotive

The 'cannon box' bearing was introduced by George Stephenson on his locomotive Locomotion of 1825 for the Stockton and Darlington Railway. [1] One of the axles was carried in a 'cannon box' bearing that was pivoted centrally and could tilt from side to side. [1] Unlike Stephenson's earlier locomotives and their steam springs, this new suspension had no springing but was a compensated suspension: as one side was raised, the bearing tube pivoted and the other side was pushed downwards. Although not giving a stable ride for the locomotive, it did allow the wheels to follow uneven track. Rails of this period were short pieces of cast iron rather than lengths of rolled steel and had frequent, often misaligned, joints.

A side-effect of the cannon box is that the centre of the shaft is now enclosed and inaccessible. Previously Stephenson had coupled the driving axles of his locomotives with a central chain. The need for an alternate system spurred the development of the coupling rods, [1] where the drive was connected on the outside face of the wheels.

The enclosure of the shaft and bearing also had advantages for enclosing the bearings to exclude dirt and to contain lubricating oil. [2]

Francis Webb's form of radial axle design for the LNWR used a cannon box. A radial axle is a form of single axle pony truck, where instead of a pivoted frame, the two axle bearings can slide sideways in a circular track. Webb's design placed them into a curved cannon box. David Joy, designer of the eponymous valvegear, described encountering these axleboxes on Webb's Precedent class. [3] The earlier Adams design for a similar axle had relied on the axle and thrust-faces within the axle bearings to keep the hornblocks in position.

In the 1920s, some electric locomotives used rigid frames with a leading and trailing truck, where a cannon bearing was a convenient inside-framed bearing for the truck. The Swiss 'Java bogie' design, developed by Jakob Buchli, even used this for a driving axle, with the drive provided by a one-sided Buchli drive outside the wheels.

Roller bearings, and their enclosing cannon boxes, were used for the British Railways Standard classes, on bogie axles and also on the driving axles of some of the larger classes. [4] This use was simplified, as the Standard classes (with the unique exception of the single Class 8) had just two outside cylinders. Railway use of such bearings continues today. The Peppercorn Class A1 Tornado replica uses roller bearings rather than the original plain bearings and these use cannon tube bearings for both the driving and bogie axles, although not for the central cylinder's crank axle. [5]

The rigidity of the cannon box also allows the faces of the axleboxes which move up and down in the hornguides to only need a single horn flange. Conventional axleboxes have a pair of flanges with the guide between them, so that they can move up and down for suspension without any axial movement. If they are both held at the correct spacing by the cannon tube, only one flange is needed. [2] The thinner axlebox, without the external flange, can allow the hornguides and frames to be placed closer to the inner face of the wheel, giving better support for a heavily-loaded axle.

Traction engines

Traction engines began as agricultural vehicles and ignored springing or suspension on their main wheels. As light steam tractors developed from 1896 for road haulage though, [6] locomotives with solid rubber tyres and suspension became favoured. The driving wheels of a traction engine are carried on a single axle, running closely behind the rear plate of the boiler firebox and carried in bearings fitted to the hornplates on either side of the boiler. Where springs were used, the cannon box bearing was favoured for maintaining the bearing alignment, with a further advantage of enclosing the axle away from the coal and ash from the firebox. Designs such as the Tasker Little Giant [7] [8] used another compensated suspension, where the tube was suspended from a single transverse leaf spring.

Related Research Articles

Bogie Chassis for wheels and suspension under railroad cars or large trucks

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 contain a suspension 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.

Axle 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 axle is referred to as a spindle.

DB Class 101

The DB Class 101 is a class of three-phase electric locomotives built by Adtranz and operated by DB Fernverkehr in Germany. 145 locomotives were built between 1996 and 1999 to replace the 30-year-old and aging Class 103 as the flagship of the Deutsche Bahn, primarily hauling Intercity services. This class encompasses the latest generation of locomotives of the Deutsche Bahn.

BR Caprotti Black Fives

British Railways built twenty locomotives of the LMS Stanier Black Five type, fitted with Caprotti valve gear, in 1948; the BR Caprotti Black Fives. These were numbered 44738-57, 44686 and 44687. The Black Fives had been fitted with Walschaerts valve gear as standard. In 1947, as part of an experimental programme by George Ivatt to try to improve the already good design, (4)4767 was built with Stephenson link motion. The Caprotti-fitted Black Fives were part of the same programme.

B-B and Bo-Bo are the Association of American Railroads (AAR) and British classifications of wheel arrangement for railway locomotives with four axles in two individual bogies. They are equivalent to the B′B′ and Bo′Bo′ classifications in the UIC system. The arrangement of two, two-axled, bogies is a common wheel arrangement for modern electric and diesel locomotives.

Jackshaft (locomotive)

A jackshaft is an intermediate shaft used to transfer power from a powered shaft such as the output shaft of an engine or motor to driven shafts such as the drive axles of a locomotive. As applied to railroad locomotives in the 19th and 20th centuries, jackshafts were typically in line with the drive axles of locomotives and connected to them by side rods. In general, each drive axle on a locomotive is free to move about one inch (2.5 cm) vertically relative to the frame, with the locomotive weight carried on springs. This means that if the engine, motor or transmission is rigidly attached to the locomotive frame, it cannot be rigidly connected to the axle. This problem can be solved by mounting the jackshaft on unsprung bearings and using side-rods or chain drives.

Rhodesia Railways class DE2 are a type of diesel locomotive built for operations on Rhodesia Railways in the 1950s. The first DE2, number 1200, entered service on 22 June 1955.

A lateral motion device is a mechanism used in some railroad locomotives which permits the axles to move sideways relative to the frame. The device facilitates cornering.

Buchli drive

The Buchli drive is a transmission system used in electric locomotives. It was named after its inventor, Swiss engineer Jakob Buchli. The drive is a fully spring-loaded drive, in which each floating axle has an individual motor, that is placed in the spring mounted locomotive frame. The weight of the driving motors is completely disconnected from the driving wheels, which are exposed to movement of the rails.

A radial axle is an axle on a railway locomotive or carriage which has been designed to move laterally, along the arc of a circle, when entering a curve in order to reduce the flange and rail wear.

ICF coaches

Integral Coach Factory (ICF) coaches are conventional passenger coaches used on the majority of main-line trains in India. The design of the coach was developed by Integral Coach Factory, Perambur, Chennai, India in collaboration with the Swiss Car & Elevator Manufacturing Co, Schlieren, Switzerland in the 1950s. The design is also called the Schlieren design based on the location of the Swiss company. The 1st ICF coach had been flagged by then Prime Minister Jawaharlal Nehru on 2 October 1955. The last ICF coach was flagged off by senior technician Shri Bhaskar P. in the presence of Railway Board Chairman Ashwani Lohani on 19 January 2018. The Indian Railways intends to phase out ICF coaches and replace all of them with the newer LHB coaches and Train 18 or Train 20 coaches over a period of time, once the codal life of the existing ICF coaches end.

South African Class 5E1, Series 2

The South African Railways Class 5E1, Series 2 of 1963 was an electric locomotive.

South African Class 5E1, Series 3

The South African Railways Class 5E1, Series 3 of 1964 was an electric locomotive.

Steam spring

Steam springs or steam suspension are a form of suspension used for some early steam locomotives designed and built by George Stephenson. They were only briefly used and may have been used for fewer than ten locomotives.

SBB-CFF-FFS Ae 4/6

The Swiss locomotive class Ae 4/6 was a class of electric locomotives. They were intended as a powerful locomotive for the steep gradients of the Gotthard Railway, but smaller than the huge 'double locomotives' which had previously been tested there. They were built from 1941, during WWII, and although Switzerland remained neutral through this, material shortages led to some quality problems with these locomotives.

Rigid-framed electric locomotive

Rigid-framed electric locomotives were some of the first generations of electric locomotive design. When these began the traction motors of these early locomotives, particularly with AC motors, were too large and heavy to be mounted directly to the axles and so were carried on the frame. One of the initial simplest wheel arrangements for a mainline electric locomotive, from around 1900, was the 1′C1′ arrangement, in UIC classification.

The 1001 class were a class of ten diesel-electric locomotive built by English Electric and Vulcan Foundry in 1955 for Nigerian Railways along with fourteen for the Gold Coast Railways as their 1000 class. Construction and layout was a very similar to the earlier NZR De class.

Bangladesh Railway Class 3100

Bangladesh Railway Class 3100 is a class of 26 meter-gauge diesel-electric locomotives of Bangladesh, operated by Bangladesh Railway, numbered 3101 to 3126. They entered service from the middle of 1971 and were classified as MEE-5, where M = Meter-gauge, E = Diesel-electric, E = English-electric and 5 = 5×100 hp = 500 hp.

Indian locomotive class WCP-2

The Indian locomotive class WCP-2 is a class of 1.5 kV DC electric locomotives that was developed in late 1920s by Swiss Locomotive and Machine Works (SLM) for Indian Railways. The model name stands for broad gauge (W), Direct Current (C), Passenger traffic (P) engine, 2nd generation (2). They entered service in 1938. A single WCP-1 was built at England in 1938.

References

  1. 1 2 3 Bailey, Michael R. (2014). "The George Stephenson Types, 1820s". Loco Motion. The History Press. pp. 35–36. ISBN   978-0-7524-9101-1.
  2. 1 2 Ransome-Wallis, P., ed. (2001) [1959]. Encyclopedia of World Railway Locomotives. Dover Transportation. Courier Corporation. pp. 243, 245. ISBN   0486412474.
  3. ↑ Joy, David (September 1884). Diaries.
  4. ↑ Allen, G. Freeman (1959). British Railways today and tomorrow. Ian Allan. p. 37.
  5. ↑ "Significant Progress". Tornado Trust . 29 April 2009.
  6. ↑ Whitehead, Robert A. (1970). "1: Origins and Makers". The Age of the Traction Engine. Ian Allan. p. 25. ISBN   0-7110-0129-4.
  7. ↑ Whitehead (1970), p. 27.
  8. ↑ "'Little Giant' Tractor". Army Service Corps Training, Mechanical Transport. 1911. pp. 194–195.
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.