DE612823C - Electromechanical gearbox for driving diesel locomotives - Google Patents

Description

For locomotives and similar vehicles, such as B. railcars and buses that are driven by internal combustion engines, a gear is always required, which on the vehicle for starting off with slowly running internal combustion * machine transmits a speed that increases steadily from zero. Also is with Considering the highly variable driving resistance, an elastic line of traction is desirable. The aim should be that within the operational driving range, the maximum pulling force with falling speed and approximated constant power increases. Electrical energy transfer meets these requirements the next. However, the electrical intermediate gear is always relatively expensive and, above all, heavy, so that the service weight of the vehicles

ao is neatly large, which increases the scope this type of drive is restricted. In addition, this conditional transfer strong transmission losses, which result in the most favorable operating points between 15 and 30 ° / o move.

The purely mechanical multi-step transmissions have the main disadvantage that when over-shifting from one speed level to the other, the line of traction goes through zero, which is especially true when operating a locomotive can lead to malfunctions. There are electromechanical gears by means of a. Epicyclic gear, its links • connected to electrical machines operating either as motors or generators are known to have a stepless start-up, but not a satisfactory one in terms of weight Solution of the transmission problem. This is primarily due to the unfavorable Arrangement of electrical machines, ζ. Β. direct connection with the output shaft.

The invention relates to an embodiment of such an electromechanical transmission in which the required electrical machines are designed for only a fraction, for example ¹ J _{4, of} the engine power at favorable speeds.

This advantageous result is achieved as follows. With the prime mover is a Low power generator connected; in addition, the engine can have a switchable clutch work on the first link of an epicyclic gear, which is preferably has a braking device. The second link of this transmission can also be acted on by a low-power motor. Here, too, a brake is expediently arranged around this transmission part to be able to hold onto. The third link acts on the drive axis in a purely mechanical way of the vehicle.

Using an example (Fig. 1), the mode of operation of the gear unit will first be described. The engine a, the speed of which is controlled in a ratio of 1: 3, drives the generator b, whose output is equal to ¹ Z _{4 at the highest speed}

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Engine power is. The switchable clutch c and the brake d sit on the shaft that leads to the first link of the planetary gear. The motor f, whose output at normal speed is equal to ¹ J _{4 of} the engine output, is connected to the second transmission element via the brake g. The shaft h transmits the energy from the third link to the driving axle, not shown, of the vehicle.

The planetary gear is in a known manner, for. B. constructed so that when the second link is stationary and the first link is driven in a clockwise direction, the third link and thus the shaft h runs to the left. If the second link is also driven to the left *, the speeds and thus the powers add up.

Assuming this, the start-up proceeds as follows. The engine α runs at low speed with the clutch c switched off and the brake d applied, that is to say with the first transmission part braked, clockwise and only drives the initially unexcited generator b . The electrical connection from generator b to motor / is established so that when the excitation of the generator increases, the motor / starts up and drives the shaft h via the second and third gear parts. After the generator is fully excited, the engine _{speed is increased so that the vehicle receives a certain partial speed, which is, for example, * / 4 of} the highest driving speed, if the motor f was designed for about ¹ I _{4 of} the engine power. Now the clutch c is switched on and then the brake d is switched off, so that the engine speed decreases when the fuel supply is reduced, but the vehicle is accelerated further as a result of the energy taken from the centrifugal masses of the engine, despite the fact that the engine / is switched off and the brake is used g switches on. The speed compensation within the epicyclic gearing takes place extremely quickly, so that the clutch and brake only have to absorb little slippage work. Through increased fuel supply to the engine can again bring, whereby the vehicle is up to _^3/4 of its maximum speed driven from its lowest to its highest speed. A further increase in speed up to I is obtained after switching on the motor / again.

So there are three gaits, which are steplessly strung together, to be distinguished: Gait I electric motor / alone, temporarily overloadable,

Gait II purely mechanical transmission, gait III mechanical and electromotive Drive.

The maximum permissible torques decrease from I to III. It is possible in itself to produce yet another pace by working the motor as a generator on the generator acting as the motor leaves. Since this is connected to the engine shaft, their torques add up at a correspondingly reduced driving speed. In many cases one will do without the last-mentioned gait, because with the help of the charging process in internal combustion engines an extensive economic increase in Dnehmomejit with decreased Speed is easily possible. Should be with regard to ease of use and simple structure of the machine system both to the reversibility of the engine and to a reversing gear can be dispensed with, within gait I, taking into account the Short-term overload capacity of the electrical parts as good forwards as backwards be driven upwards, which is of the utmost importance for shunting and empty journeys. the One-sided main direction of travel is not a disadvantage for the vehicles in question, To which it should be mentioned that the economical cooler arrangement anyway calls.

The epicyclic gearing e (Fig. 1) can be constructed very differently depending on the requirements. Fig. 2 shows a light-weight transmission; the sun gear I works on three planetary gears 2. These are mounted with their axes in a cage 3, which can be driven by the pinion 4. The power supplied to the epicyclic gear is passed on to the shaft h via the ring gear 5.

As another indicated example (Fig. 3) shows, there is also an epicyclic gear can be used with two sun gears 1 ', 1 ". On the engine side, the cage 3 driven by the planetary gears 2 'and 2 ". The sun gear 1" can be driven by the electric motor / are driven; the sun gear 1 'sits on the drive shaft /}. The effect no wise this gear should be easily understandable.

In three-axle vehicles, it is desirable from the epicyclic gearbox at the same time to drive two axes in mechanical parallel connection. For this, Fig. 4 enters. Embodiment.

The sun gear 1, which is mounted on a well-supported hollow shaft, works on the im Cage 3 mounted planetary gears 2. The cage 3 has two ring gears 3 'and 3 "on its outer circumference, in which the

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Pinions 4 / and 4 / 'as well as 4 ₂ ' and 4 ₂ "intervene. These pinions can be driven by two electric motors ^ ₁ and f« via a further back gear J ₁ and / _{2 The gears O 1} 'and 6 ₂ "mesh with this gearing in order to transmit the drive power to the drive wheels via the shafts A ₁ and Λ _2.

The use of two electric motors and two drive shafts contributes significantly Relief of the gears and bearings, which is a big one despite the small dimensions of the gear unit Operational safety results. Of course, nothing stands in the way of the electric motor or the Electric motors instead of spur gears via worm and worm gear or the like to let the cage take effect.

The spatial arrangement shown here of clutch c and generator b behind the gearbox e has, in addition to the compact design, the advantage of better accessibility to the parts exposed to wear; the same applies to brakes ^ ₁ and g ₂ .

The construction of a heavy locomotive transmission could be done according to Fig. 5. With regard to the available space, the energy is supplied to the sun gear 1 via a bevel gear train 8. The planetary gears ζ are also arranged in a cage 3, Avelcher can be driven by the electric motor f via a countershaft 7 and further via the pinions 4 ″ and 4 ″ good support of the ring gear 5. This is achieved in that the three planetary gears each carry two rolling rings 9 'and 9 ″, the rolling rings 10' and 10 ″ or 11 attached in the ring gear 5 and on the sun gear 1 'and 11 "unroll. To improve the guidance, these four rolling rings each have a guide extension that corresponds to the guide shoulders of the six rolling rings 9 'and 9 ″ Both the guide approach of the rolling rings 11 'and 11 "could ultimately be dispensed with as well as these two rolling rings themselves, if the Uinlaufradachse both the radial pressure of the ring gear 5, for example provided with an external herringbone toothing, as well as any lateral forces, i.e. the axial pressures should. The remaining .Wälzringe are absolutely necessary, as are the guide lugs, which at the same time ensure that the internal toothing of the ring gear is filled with an oil ring while it is running. The oil is fed through the sun shaft to star-shaped oil channels in cage 3. These channels lead partly to the bearing shells of the planetary gears and partly to the three intermediate cage pieces 12. Nozzles are built into these intermediate pieces to guide the oil into the meshing sections of the sun gear and the planetary gears . The wheels 3 'and 3 "and the associated pinions 4' and 4" also have mutually inclined helical teeth in order to achieve smooth gear running. The blind shaft gear meshing with the external toothing of the ring gear 5 has not been drawn.

The transmission types shown can be varied in many ways according to the requirements to be placed on them; so it can z. For example, it may be desirable that from the ring gear 5 at two points at the same and different speeds of the output shafts Ji ₁ and L · energy is removed. The tool required for this is the well-known differential gear.

The type of coupling is essential for safe operation of the gearbox very essential.

In order to also be able to switch from gear I to II, i. H. from the purely electromotive To prevent overloading of the engine parts at the purely mechanical stage, the clutch is expediently used as a torque clutch educated. In the case of the known torque couplings, all of the work done by the prime mover Transfer work through the friction plates. Would you convert such a coupling into a Put partial energy flow, it would also only depend on the corresponding Control partial torque.

As such couplings with consideration of their type of work for the present special task are not very suitable, a torque coupling is specified below, which controls depending on the total torque of the work machine, nevertheless only a partial energy flow via the The friction surfaces of the clutch flow. This is achieved according to the invention in that = the 110 = all energy initially via the control elements of the torque clutch, which act as a spring clutch one part of which then flows to the electrical machine, which essentially works as a generator, while the other part is fed to the planetary gear via the clutch friction surfaces will. In this way, a full torque load on the drive machine and its overloading is conceivable in all cases not possible. Fig. 6 shows an embodiment.

Energy is supplied to the clutch through the shaft I ₀ on which the control disk 2 _{0 is} attached. In this disk, three concave grooves are milled on both sides on a pitch circle, the depth of which decreases from the deepest point in the direction of the pitch circle initially only slightly and then in a straight line, i.e. a section in the direction of the pitch circle shows two against ίο the development Surface of the disc at certain angles inclined straight lines, which are connected by a steady, slightly curved curve. Another three grooves similarly executed each have the 5 control rings 3 "and 4 _0, which bear teeth on its outer circumference. Between the control disk 2 ₀ and the control rings 3 ₀ and 4 "there are the control balls 5 ₀ ," which are guided through the grooves and which are supported by several springs 6 ₀ arranged on a pitch circle with the aid of the tie rods J ₀ and 7 ₀ 'and the two counter-rings 8 the socket O are charged to ₀ and 8. ₀ '. Due to the internal toothing ₀ energy \ ^r on is the control rings 3 ₀ and 4 ₀ adopted and to the part directly above the hollow shaft io ₀ and the Kettenradi I ₀ generator not shown to the . forwarded the remaining part of the clutch is a switchable multi-disc clutch;. it consists essentially of on the sleeve 9 ₀ axially displaceable lamellae I2 _O and displaceable in the outer cylinder I3 _O lamellae I4 _O Several compression springs I5 _O burden on the slats, provided that from outside 'to-use switching linkage i6 ₀ does not negate its effect. the shift linkage i6 _0' via the switching ring i6 _{0 0} i6 is in communication with an axially displaceable ring 17 _{is 0,} in which n the spring bushings i8 _{0 of} the springs I5 _{O are} screwed in. However, these sockets do not act directly on the disk pack, but rather via short springs Ia ₀ in order to achieve particularly smooth operation of the clutch. When the clutch is loaded, the self-control to constant torque is carried out by the pressure rings 4 ₀ and 3 ₀ , which act in the axial direction on the bushing ₀ , 0 and the shift linkage i6 ₀ when overloading begins and relieve the plates accordingly. The outer cylinder 13, which also serves as a brake disk, is in a fixed connection with the first link of the epicyclic gearing e.

For a more detailed explanation of the mode of operation of the clutch, the following is used: If a torque acts on the shaft I ₀ and thus on the disk 2 ₀ , the latter is rotated so far relative to the control rings 3 "and 4" and the rolling movement of the control balls 5 ₀ the control rings 3 ″ and 4 ₀ so far away from the disk 2 ₀ until the circumferential force corresponding to the torque generates an axial force component, the size of which is dependent on the respective groove inclination, which _{keeps the tension of the spring 6 0 in} balance. For each torque between zero and maximum, both positive and negative maximum, there is a certain angle of rotation of the control disk 2 "relative to the control ring 3" or 4 ₀ , for which the spring clutch is in equilibrium. The torque line as a function of the angle of rotation can look very different depending on the selection of the spring sizes and the shape of the control grooves. In general, efforts will be made to achieve the largest possible angle of rotation for the maximum torque, which results in a large energy storage capacity for the clutch. Resonance phenomena, which can lead to gear malfunctions, are to be avoided with certainty when using this coupling. If the maximum torque is reached, then, as already stated, the load on the lamellae is relieved to such an extent that the clutch slips. The tensioning force of the springs O ₀ is large compared to that of the springs 15, so that the slip torque of the clutch is practically independent of the variable magnitude of the coefficient of friction and is equal to the predetermined maximum torque of the prime mover.

Also noteworthy is the lubrication of the guide bearing 2o ₀ and the toothing: = - coupling. For this purpose, the guide bearing is given a larger diameter than the adjacent gear bearing e. Both bearings are hydraulically connected to each other through different axial bores 2i ₀ , so that part of the lubricating oil supplied to the gearbox bearing is sucked in by the guide bearing and thrown _{further into the toothing of the bushing O 0 via a spray ring.} The excess oil passes over the overflow _{ring 22 0} and is fed into the stationary Atiffangblech 23 ,,.

Instead of the mechanical switch-on and switch-off device of the clutch, an electromagnetic switching device can also be provided, for example in such a way that, as can be seen from Fig. 7, the action of the springs I5 _{O is} canceled by a likewise rotating ring magnet 25 ,,. The ring magnet obtained by the slip rings 27 ,, current, the ring armature connected to the switching rod i6 ₀ is tightened and released the clutch. The outer cylinder I3o here also carries a braking device d, consisting of the ring magnet 3O ₀ fastened to the gearbox housing e.

the I3o rotating armature 3I ₀ attracts and presses the brake plates 32 ,, together. With regard to the gear design similar to Fig. 4, the sun shaft connected to the outer cylinder 13 ,, is designed as a hollow shaft 2% . Here, too, the shaft I ₀ supplies the energy to the clutch c _{, while the shaft 2S 0} connected to the inner cylinder 9o already belongs to the generator b . Since the

to inner cylinder with its cover disks a hollow body closed on all sides forms, it can be filled with oil to a sufficient extent, in particular to protect the gear coupling to protect from wear and tear.

Between the control disk and the control ring 2 ₀ 3 'and 4o a cage is arranged per 33 ,, which ensures that the control balls 5o always occupy the correct position. Since the centrifugal forces press the control balls against the cage, it is advisable _{to guide the cages on the control disk 2 0} by means of inclined slots and pins so that no inadmissible frictional resistance occurs.

When the clutch is switched on, it is known as a gradual increase in normal pressure bring about that z. B. the mechanical actuation of the shift linkage with the interposition of another sufficient soft spring takes place. The magnetic control is due to gradual weakening or increase the excitation current, possibly combined with suitable damping devices achieve the same effect.

As shown, the torque coupling can be designed in very different ways. In all cases, however, the first part of the clutch serves both as a spring clutch and as a control element of the friction or multi-plate clutch in order to protect the epicyclic gear against overload. The more or less sharp or sudden operation of the sun or motor brake is irrelevant for proper work. Auxiliary motors, electromagnets, control cylinders, etc., are to be provided for brakes d and g in a manner known per se.

The sun brake d is operationally only

.. ventilated; If it does not serve as a service brake at the same time, its braking elements have no slip work to be taken up · Sun brake and clutch are expediently so closed lock so that the brake is only released when the clutch has already engaged, what in various ways, e.g. B. by direct or indirect mechanical or electrical dependency control, is feasible. More locking and Auxiliary contacts cause the generator-motor connection to be disconnected and the motor brake to be applied. Here is the Braking period very short, as both the gearbox and the brake apply a deceleration the motor armature act.

The friction plates of the clutch are stressed the most, so it is advantageous can be the switching period on the various gears, which in their effect on the jackshaft or drive shaft runs steplessly, do not extend it unnecessarily long. She · is the shortest when the fuel supply is switched off, which can be done manually or automatically can be obtained, such as B. by means of an auxiliary contact on the control linkage of the clutch and frequency relay depending on the ■ clutch slip. Because the speed limits (highest and lowest speed of the engine) are fixed for a certain type, it is only possible to reduce it the centrifugal masses constantly rotating with the engine shaft a further reduction to bring about the switching period. This is due to the existing spring clutch, which has an exceptionally large memory capacity, then executable, if harmful repercussions due to the increased degree of irregularity of the crankshaft are avoided, such as B. in a known way by attaching dampers to the controller. However, it is better to use in '' the drive shaft of the controller is resonance-free within the practical speed range Engage the spring clutch or have the regulator driven by the generator shaft.

For the design of the electrical machines - generator and motor - are different Points to consider, e.g. B. low weight, convenient control, simple setup - especially the field control -, Operational safety, type of auxiliary machine drives and choice of electrical ones Setup of the vehicle. At first it seems the most obvious, the generator to let work with controllable external excitation. With the help of a field and fuel regulator Any desired load condition can be achieved, taking into account the voltage and ammeter of the generator. At the same time, the ammeter provides information about the torque load.

Fig. 8 shows the characteristics of such a drive. The electrical machines are designed here for about ¼ of the engine power, although it was noted that they can briefly deliver twice the power. All lines are plotted as a function of the driving speed ν . The low losses of the electrical and mechanical transmission have not been taken into account for the sake of simplicity. The following mean: JV = engine power, JV '= power of the main

current motor, P = total torque or tensile force, η = engine speed.

During the first driving section (gear I) Vz =. O - 0.25 only the main current motor acts on the drive shaft. The speed of the engine remains constant at its lowest operating value until the field of the generator is gradually fully excited. The engine then accelerates to its highest speed, with the line of traction gradually falling from 2 to 1.5, taking into account the commutation ratios. After switching to a purely mechanical drive (gear II), the line of traction rises again to 2, in order to gradually decrease to 1 until ν ■ = ■ o.75. The thermal stress on the engine cylinders should form the boundary line here. In order to achieve the highest aircraft speed (gear III), the electric drive is switched on. The engine speed initially drops a little, in order to run up to ^ = 1.05 together with the motor after full field excitation of the generator has been established. At this point the line of tensile force is approximately = 0.7. A further increase in speed is only possible if the line of pulling force drops sharply, which is due to the characteristics of the engine. B. Downhill rides. The main course of the maximum tensile force line, which does not have any technically disadvantageous steps, changes from 2 to 0.7, ie the vehicle starts with approximately three times the torque. For electrical reasons, four times the starting torque can be achieved with the same machine sizes.

The power line N shows that the engine can be used extremely well in a wide speed range. It is also noteworthy that the electrical machines cannot be overloaded in the speed range 0.75 to 1.25. Overloading is only possible in the first section of the journey (gear I), which, however, is only used for a short period of time. In the case of empty and maneuvering journeys and a sufficiently low driving resistance, this section can expand up to ν = 0.5.

With the help of known devices, the field regulator of the generator can also be closed automatically control, e.g. B. depending on the armature current or the voltage of an accumulator battery, which can be used advantageously for starting the engine and driving a wide variety of auxiliary motors is.

In many cases, and especially when

if the generator does not serve as a loading machine at the same time, it is a self-regulating one The generator is preferable because of its ease of use. The generator receives for this purpose essentially next to the shunt or separately excited winding a counter-composite winding that makes it possible just by changing the fuel supply perform the cruise control for all driving sections. For the activation of the individual gears is a Control switch is not to be dispensed with under any circumstances. In addition to this gear selector, there is a clutch switch advantageously to be provided in order to disconnect the drive machine from the gearbox at any time and, if necessary, as quickly as possible to be able to restore the old operating state. During the gear change z. B. When starting up, the clutch is not operationally released because of the flow of energy must not be interrupted.

Claims (11)

Patent claims: i. Electromechanical transmission for driving diesel locomotives and similar vehicles by means of an epicyclic gear, the links of which are connected to electrical machines operating either as motors or generators, characterized in that the first link of an epicyclic gear (e), which preferably has a braking device (d) , has a switchable clutch (c) can be brought into mechanical connection both with the engine (α) and at the same time with the electrical machine (&) operating essentially as a generator, the second link of this transmission with one or more operating essentially as a motor electrical machines (/), which have appropriate braking devices (g) , is connected and the third link drives the drive wheels of the vehicle directly or via a mechanical transmission, and that the clutch (c) as well as the electrical machines (b, f) and braking devices (d, g) by means of switching devices by hand or similar which are switched automatically in the sequence required for the individual gaits. 2. Electromechanical transmission according to claim 1, characterized in that the first member of the planetary gear is designed as a sun gear (1), the second as a gear (3) carrying the axes of the planetary gears (2), on which the substantially as a motor working electrical machines (/) work with braking devices (g) , and the third link forms a gear (5) with internal and external teeth, in which the energy from the ring gear (5) directly or from the external toothing is removed by one or more gears. 3. Electromechanical transmission according to claim 1 and 2, characterized in that that the ring gear (5) is designed as a differential gear so that the energy supplied to the internal toothing is transmitted Differential gears 0. the like on two rotating at the same or different speed Sprockets is forwarded. 4. Electromechanical transmission according to claim 1, 2 and 3, characterized in that the engine (α), transmission (e), ' clutch (c) are arranged axially one behind the other in the order listed, that the sun gear (1) on a hollow shaft attached and the drive shaft leading to the coupling is guided through the hollow shaft. 5. Electromechanical transmission according to claim 1 to 4, characterized in that that the planetary gears (2) rolling rings (9 ', 9 ") with guide shoulders and the ring gear (5) rolling rings (10', 10") with Wear guide approaches to achieve good guidance and lubrication 'of the ring gear. 6. Electromechanical transmission according to claim 1 to 5, characterized in that that the intermediate cage pieces (12) as oil chambers are equipped with oil nozzles for lubrication. 7. Electromechanical transmission according to claim 1, characterized in that to achieve a smooth switching on and over the clutch (c) as a union of torsionally flexible spring clutch (2 ₀ to 8 ₀ ) with a switchable as well as torque _{-dependent self-controlling friction clutch (i2 0} to 19 ,,) is designed, in which the energy flow coming from the engine (a) is first passed through the spring clutch, one part of which then flows to the electrical machine (b) , which works essentially as a generator, while the other part flows through the Clutch friction surfaces (i2 ₀ , 14 ,,) is fed to the epicyclic gearing (e) and the clutch (c) is automatically controlled as a function of the total torque of the engine (α). 8. Electromechanical transmission according to claim 1 and 7, characterized in that short springs (190) are switched on in the clutch (c) between the spring-loaded ring (i7 ₀ ) and the friction plates (i2 ₀ , I4 _O), to make the controls smoother. 9. Electromechanical transmission according to claim 1 and 7, characterized in that the lubrication of the inner coupling parts is carried out by an outer bearing (e) via the guide bearing (2O ₀ ) provided with a larger bore. 10. Electromechanical transmission according to claim 1 and 7, characterized in that the control balls (S ₀ ) of the clutch (c) are guided _{by cages (33 0) to absorb the centrifugal forces.} which follow the movements of the balls (5o) by means of inclined slots and pins or the like in order to avoid damaging resistance to movement. 11. Electromechanical transmission according to claim 1, characterized in that for actuating the clutches (c) nnd brakes (d, g) and * for switching the electrical machines (5, f) in addition to a gear selector, a clutch switch is provided to be independent of at any time the position of the gear selector to be able to interrupt the flow of energy from the engine and electric motors. 1 sheet of drawings