FI66318C - FOERFARINGSSAETT OCH ANLAEGGNING FOER KRAFTOEVERFOERING I TUNGDRIFT - Google Patents

Description

1 66318

Procedure and equipment for heavy-duty transmission

The invention particularly relates to high-power transmissions in which the torque changes according to the speed of the machine used. Such transmissions are needed, for example, in locomotives.

5 For example, in a diesel locomotive, the engine uses a generator, which in turn provides direct current to, for example, 4 or 6 track motors, up to eight track motors, each of which drives its wheel set by means of a mechanical gear.

The DC motor is perfectly suited for this transmission due to its electrical properties. As it moves, the f torque is large and as the speed increases, the torque decreases. For example, the traction curve according to Figure 1 is obtained.

However, the DC generator and motor are expensive to manufacture and sensitive to moisture. In addition, the commutator and 15 carbons are consumable and coal dust causes excesses in the bridges. For this reason, efforts have been made to use 3-phase alternating current in electric transmissions. The short-circuit motor and the alternator are durable.

In particular, the rotor of the short-circuit motor is durable and is not at all sensitive to moisture.

But the disadvantage of the short-circuit motor in this case is the constant speed determined by the frequency of the alternating current.

If you want to adjust the speed, you need to adjust the net cycle number -2- 6631 8. Between 1970 and 1982, a number of intermittent AC transmissions were built in different countries, but the frequency converter required to develop an adjustable frequency 3-phase current has so far been so complex, expensive and susceptible to interference that, for example, a 1500 kW diesel locomotive is almost twice as expensive as locomotive with DC transmission or 16 2/3 Hz AC transmission.

Thus, although the track motors are simple, whether the use of safe and cheap short-circuit motors is a rectifier and especially the frequency converter has brought expensive and interference-prone equipment to the locomotive.

Figure 2 shows the torque omission of the short-circuit track motor.

Figure 2 shows that the short-circuit motor is in principle not suitable for speed-controlled transmission, as the starting torque is only less than 2 times, the normal torque and the maximum torque approx. 3 times. These values can be changed with special constructions, but not enough for 20 speed adjustments.

It can be seen from Figure 3 that the starting current when starting at full load would become so high that it is not possible to achieve it, for example in a diesel locomotive. According to the present invention, the start-up of the short-circuit motor can be performed without a high starting current and without a continuous period-read control of the network. For example, a 1: 4 control is also achieved without large current peaks and without an expensive, interfering electronically controlled period converter.

The method according to the invention is characterized by the features set forth in the characterizing part of claim 1 and the apparatus for applying the method is set out in the characterizing part of claim 6.

In order to describe the invention, an electric power transmission of a diesel locomotive according to the invention is shown below, in which the track motors are short-circuit motors.

The diesel engine uses a 3-phase generator that supplies alternating current to the locomotive’s electric transmission network. When moving to 15, the frequency of the alternating current is, for example, 25 Hz.

When the locomotive starts, the frequency is increased, e.g. 50, then 100 and at maximum speed e.g. 150. The "synchronous" speeds of the track motors are 750 rpm, 1500 rpm, 3000 rpm and 4500 rpm respectively.

20 These speeds correspond to a heavy changeover locomotive, e.g.

speeding locomotive speeds eg 3.5, 7.5, 15 and 34 km / h.

When the diesel engine and generator are made in such a way that they give full power, for example at half the speed, they become larger and more expensive than conventional ones. But the weight of -4- 6631 8 is not a disadvantage in a change locomotive, for example, and there is space in the engine room of the locomotive. On the other hand, the AC short-circuit motors are light and when no rectifier or cycle converter with accessories is required, the total weight of the 5 locomotives does not increase too much.

It can be seen from Figure 3 that the short-circuit motor draws so much current, 1 = 7 · In, under heavy load, for about 10 seconds that the diesel engine would stop before the train was in motion.

10 This disadvantage is avoided by connecting the root motors of the track motors to the wheel folds via hydraulic clutches. Figure 4 shows the start of a locomotive, as a function of the start time. The starting current of the short-circuit motor is I, the rotor speed n ^ and the locomotive wheel speed 15 n2 *

In the case shown in Fig. 4, when the locomotive is started, the diesel engine speed is increased from idle speed 600 rpm, e.g. to 1000 rpm, and the generator generates 25 Hz alternating current, the rotors of track-20 motors start to rotate rapidly, reaching the maximum short-circuit motors after approx. torque with 15 to 10% of the hydraulic couplings left. The locomotive and train start moving and the short-circuit motors reach an almost synchronous speed (synchronous speed -25 left), in practice approx. 740 rpm only approx. 30 sec. costs- -5- 6631 8 tua, in which case the speed of the locomotive is e.g. 3.5 km / h.

Thereafter, when the diesel engine speed is increased to its full value of 1800 rpm, the synchronous engine speed and locomotive speed of the track engines increase to x 3.5 5 6 km / h. The gap left by the hydraulic clutches is reduced so much that it is possible to drive at full speed continuously at full power. The speed of the locomotive is adjusted by adjusting the engine speed.

"Switching" to a higher speed reduces the excitation of the generator 10 and lowers the diesel engine speed to approx. 1000 rpm, switches the generator to give the next higher frequency, eg 50 Hz, and fully magnetizes the generator and raises the diesel engine and generator speed to 15 synchronous "speed of 1500 rpm for diesel engine and generator speed of 1000 rpm.

The speed of the locomotive is 6 km / h. When the engine speed is increased to 1800 rpm, a synchronous speed of ~ x 6 * 11 km / h is obtained for the locomotive.

1000 20 The following driving range is obtained at 100 Hz at a generator speed of 1000 rpm, the locomotive speed is 11 km / h and the maximum speed in this driving range at 180 Hz is 20 km / h at a track engine speed of 3000 rpm.

6631 8 * -6-

The next 4th driving range is at a cycle speed of 150 Hz and a generator speed of 1000 rpm. 18.5 km / h and generator speed 1800 rpm. 34 km / h at an engine speed of 4500 rpm.

The transmission of the locomotive according to the present invention is thus based on dimensioning the diesel engine and generator at low speeds so as to give the required power at partial speed and to select suitable constant frequencies so that the locomotive can be started by a hydraulic clutch and the diesel engine move from a smaller episode reading range to a larger one. These "synchronous" frequency values of the AC mains and the short-circuit motors are obtained by changing the frequency given by the generator or by changing the pole number of the short-circuit motors or both so as to obtain the required driving ranges.

For example, downhill work has a normal working speed of 3-5-10 km / h, so the transmission according to the invention is suitable for such work. The hydraulic clutch 20 may be built into the track motor, i.e. the short-circuit motor, or if the locomotive has 2 or 3 wheels connected together, in which case they have a common drive motor in the engine room of the locomotive with more space than the bogie and wheel set, the track motor and hydraulic clutch 25 can be built and installed separately on a bogie inside the engine room.

-7- 6631 8

The design of the hydraulic clutch can also be such that its omission is adjusted so that the omission of the speed remains even in increments of 5 to 7%.

The construction of the hydraulic clutch is normal in that it operates in both directions of rotation while leaving, i.e. the direction of travel of the locomotive is changed by exchanging 2 power lines with each other.

In this example, a high-speed diesel engine has been selected for the locomotive to facilitate the presentation of the invention. Also in practice, the transmission according to the invention becomes more advantageous when using a high-speed diesel engine as a power source.

Claims (7)

8 6631 8 1. Procedure for using alternating current, eg 3-phase alternating current for variable transmission, eg diesel locomotive transmission from diesel engine to wheelset, characterized in at start-up and after switching on a higher frequency. Method according to Claim 1, characterized in that the pole number of the track motors is also changed in such a way that the greatest possible control of the running speed of the locomotive is achieved with the change in the cycle number of the generator. A method according to claim 1, characterized in that the generator is dimensioned to give full power at a speed lower than the maximum speed. Method according to one of the preceding claims, characterized in that when the speed of the locomotive is increased, the engine and generator speeds are first increased, the AC mains frequency rises and then the diesel engine speed is reduced and the next higher frequency range is switched, the hydraulic 9 66318 clutch then softly slips and pulls with the rotor wheel set for normal asynchronous motor operation. Method according to one of the preceding claims, characterized in that the frequency of the alternating current generated by the generator is low, e.g. about 25 Hz, when starting, and the rotors of the short-circuit motors connected to this network can start asynchronously within a reasonable start time when the locomotive starts. Fig. 4) after which increasing the speed of the diesel engine increases the frequency whereby the locomotive speed correspondingly rises to its maximum value in this "I gear" and then the engine speed, AC mains frequency and power are reduced and a larger frequency range is connected, e.g. return to asynchronous operation, after which increasing the speed of the diesel engine and the frequency of the alternating current network gives a "speed range II" and thus further proceeds to obtain the desired maximum speed of the locomotive. Apparatus for carrying out the AC transmission procedure according to claims 1, 2, 3, 4 or 5, characterized in that the rotor of the alternator is provided with several windings or connections so that the stator provides the frequency corresponding to each winding or connection on top of each bogie, there is a 3-phase short-circuit motor in the engine room, which uses the hydraulic clutch to drive the bogie wheels at the same time. Apparatus according to claim 6, characterized in that a hydraulic clutch is built inside the short-circuit motor, the primary wheel of which is fixedly connected to the short-circuit motor rotor at rotor speed n1 and the secondary wheel rotates the short-circuit motor output shaft at speed n2 and increases after the acceleration time (e.g. in Figure 4 30 sec) such that n2 = n1. 11 6631 8