Hollow shaft drive
A hollow shaft drive is a component of electrically powered traction vehicles , especially railways and other railways , as well as other electrical machines, e.g. B. CNC machines . It is characterized by the fact that the torque is transmitted to the shaft that is ultimately to be driven , such as the axle of a vehicle, by a resiliently or articulated hollow shaft that gives it its name , such as the motor shaft. The play between the shaft to be driven and the hollow shaft ensures the mechanical decoupling of the motor from vibrations.
The power is transmitted from the drive motor via a pinion to a hollow shaft that surrounds the wheelset shaft . This hollow shaft can be mounted in the frame or bogie frame. This is the case, for example, with the AEG Kleinow spring pot drive and the cardan drives. In this case, the spring play must be completely compensated by the drive. In the case of rubber and conical ring spring drives, on the other hand, the hollow shaft is only supported by the rubber springs on the axle shaft. At one end of the hollow shaft there is a large gear wheel , to which spring elements are attached all around, which in turn are connected to the wheel body on the opposite side . The opposite wheel is also driven by the wheelset shaft located in the hollow shaft. This reduces torque peaks in the entire drive train from the traction motor to the drive wheels as well as shocks from the track to the traction motor and reduces the negative effects of high, unsprung masses on the superstructure .
Comparison with the peg bearing drive
The hollow shaft drive is mostly used for high-speed locomotives and railcars because of the higher manufacturing costs (speeds above about 140 km / h). A simpler type of drive is the paw-bearing drive .
The Deutsche Bundesbahn has been using hollow shaft drives since the standard electric locomotive for all of the electric locomotives it built, as the pawl bearing drive wears down the route excessively due to the high unsprung masses. With the separation into DB Netz AG and various independent operating companies, there is no longer this joint responsibility, so that Deutsche Bahn AG is once again procuring locomotives with peg bearing drives.
For this reason, the Swiss Federal Railways ( SBB) have been charging train-path fees based on wear and tear since 2017, classifying traction vehicles with peg bearing drives at the highest level.
Westinghouse spring drive
The Westinghouse spring drive is the oldest type of hollow shaft drive with a spring clutch.
It was used, for example, in the USA on the locomotives of the Boston and Maine Railroad from 1910, which were originally numbered 2501 to 2505 , and on the well-known GG1 class of the Pennsylvania Railroad from 1935 to 1943. The Geneva-based Sécheron manufactured the Westinghouse drive under license and developed it further into the Sécheron spring drive .
Sécheron spring drive
The Swiss Société Anonyme des Ateliers de Sécheron in Geneva, colloquially known as Sécheron , or SAAS for short, further developed the Westinghouse drive into the Sécheron spring drive . Sécheron replaced the six individual clock springs, the evolute springs, per wheel of the Westinghouse drive with three double spring elements. The clutch springs were thus less stressed and the space for the springs was better used. As a result, smaller wheel diameters than with the Westinghouse drive were possible and the way was cleared for use in the bogies of railcars .
The Sécheron spring drive is characterized by low maintenance costs, especially since it has been possible to weld broken drive springs together.
The first Sécheron spring drives were used for the first time in the frame locomotive Be 4/7 of the Swiss Federal Railways in 1921 . They were originally intended for express train service on the Gotthard mountain route . The frame locomotives Ae 3/5 and Ae 3/6 III of the Swiss Federal Railways also have this drive. A highlight of its use is the frame locomotive Be 6/8 built from 1926 , the later Ae 6/8 of the BLS .
The possibility of using the Sécheron spring drive for smaller wheel diameters also gave bogie locomotives without running axles a corresponding drive. In Austria, for example, with the later series 1045 , 1145 and 1245 as well as 1040 of the Austrian Federal Railways . In Switzerland, for example, the Be 4/4, which was first delivered to the Bodensee-Toggenburg Railway in 1931, or the mixed passenger baggage car with the original designation CFe 4/4, which was first delivered to the Emmental Railway .
With the Westinghouse and Sécheron spring drives, the firmly clamped springs are subjected to considerable bending stress at higher speeds. This disadvantage is avoided, for example, by the AEG Kleinow spring pot drive described below .
Spring cup drive
An early further development of the Westinghouse drive was the spring cup drive (e.g. the "AEG Kleinow spring cup drive") with which the Deutsche Reichsbahn built the series E 04 (from 1933), E 17 (from 1928) after a few prototypes. , E 18 (from 1935) and E 19 (from 1938).
For this drive, six protruding spokes are usually attached to the hollow shaft, the ends of which lead outwards like cantilevers between the wheel spokes. On the outside of the wheel spokes there are coil springs mounted in cup-shaped sockets , each of which is articulated to the hollow-shaft spoke ends. The spoke star and wheel spokes are offset by 30 ° to each other. With this arrangement, the motor rotation is transmitted to the wheels, with both the jerky motor torque when switching on for starting or a gear change while driving is damped relative to the wheel body. In addition, these springs compensate for the relative movements between the wheel set and the hollow shaft mounted in the frame during compression and due to the lateral displacement in the arc.
The steel springs showed themselves to be very susceptible to spring breakage after a long period of operation. The German Federal Railroad replaced them with more modern rubber parabolic springs. With this measure, the top speed of the German E 18 and E 19 series electric locomotives, which was limited to 120 km / h in the post-war period, could be increased back to 140 km / h.
Rubber ring spring drive
The rubber ring spring drive is a further development of the spring cup drive. The drive motor is sprung and supported by the bogie frame and the hollow shaft of the drive wheel set. This type of drive also makes it easier to start off under heavy loads. However, the spring action is only reliable up to a speed of around 160 km / h, and there is a risk of spring breakage. The rubber ring spring drive was first used in Germany on the Deutsche Bundesbahn from 1956 in the group of standard electric locomotives with the series E10 , E40 , E41 and E50 (second batch). This drive is still used in the 111 and 151 series .
The power transmission from the drive motor to the wheel takes place first via a gear on a hollow shaft that surrounds the axle shaft of the wheelset . Several hard rubber elements, so-called rubber ring spring segments (also called rubber segment springs) are attached to both ends of the hollow shaft . These are attached to the wheel disc in a circle on the inside of the wheel set. In some cases these rubber elements also reach through wheel spokes and are attached to them. Thus, an elastic inner and by the friction of rubber elements torsional damping torque transmission in which also the driving motor against shock when riding over results track rugged landscape is better protected.
Joint mechanism with "dancing ring"
At the end of the 1920s, Alstom developed a drive with a spring-loaded gear wheel, hollow shaft, Anneau dansant (French for "dancing ring") and articulated lever. The power is transmitted from the hollow shaft to the wheel set outside the wheel set via a flange-shaped ring that is connected to the hollow shaft by pins that are guided through holes in the wheel disc. The ring is elastically connected on the outside of the wheel with levers that engage pins in the wheel disc. This shape allows for height compensation and smooth start-up without overstressing the electric motors.
The design of the levers is slightly different depending on the design. In the Alstom drive, the ring is connected to the wheel disc with four straight levers, while the version used in Italy only has two lever systems arranged at right angles.
An early version of this drive was used in a bogie of the PLM 242 AE 1 , but can also be found on the SNCF CC 7100 . The drive variant was first used in Italy with the E 434.068 and then installed in the FS E.646 and FS E.444 series .
Cardan rubber ring spring drive
With the cardan rubber ring spring drive, the drive motors are built directly into the bogie to keep the unsprung masses small. This dampens the strong bumps in the road at high speeds and compensates for the movements between the wheelset and the drive motor. A well-known representative of this drive is the 103 series .
BBC shaft drive
The BBC cardan drive is the further development of the cardan rubber ring spring drive. For the development of the DB series 120 , thanks to the uniform torque of the three-phase asynchronous travel motors, the rubber ring springs mounted on the outside of the wheel discs were no longer necessary. All that remained was a drive via the hollow shaft and the rubber-mounted handlebars mounted on the inside of the wheel. The wheels were also equipped as monobloc wheels . Tests were carried out beforehand on the test field and with the Henschel BBC DE 2500 . With the DB class 120, it was possible for the first time to achieve an output per wheelset of 1.4 MW. The basis for this was the higher speed of the three-phase asynchronous machine compared to the single-phase series motor with commutator . Then it was possible to build a four-axle locomotive with a total mass of 84 tons with 6 MW power.
Conical ring spring drive
For the German Reichsbahn developed in the GDR , the locomotive electrotechnical works (LEW) their own version of the hollow shaft drive. An electric drive motor, which is completely cushioned, acts on each axle. Gears arranged on both sides in connection with rubber conical ring springs enable elastic torque transmission. The drives are used in the 112, 114, 143 , 155 and 156 series.
Sécheron cardan lamella drive
The lamellar spring drive is a special form, also a development by the Sécheron company. It consists of a hollow armature shaft, which is connected to a torsion axis on both sides via drivers. This torsion axle drives an axle reduction gear, so the drive is a hybrid of a hollow shaft drive and a journal drive. The drivers, two of which are offset crosswise, are connected to the eponymous lamellae, bundles of thin sheet metal strips, and thus take over the cushioning and torque transmission of the motor, similar to a wedge pack coupling. This drive was used, for example, in Düwag cars of the Vestische tram and in railcars of the ÖBB series 4030 and 1046 .
- price wear in the track price 2017. Accessed on July 3, 2018 .
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