阅读说明：本技术 用于车辆的驱动装置、车辆和用于制动驱动装置的方法 (Drive device for a vehicle, vehicle and method for braking a drive device ) 是由 戈尔曼·席德洛斯基 菲利普·马特 罗兰·布尔 巴纳·西曼德尔 于 2020-02-26 设计创作，主要内容包括：一种用于车辆的驱动装置,包括：至少一个具有转子(R)和定子(S)的电机(1),特别是电动机、驱动轴(2)和主行车制动器(3),其中驱动装置配备有被配置为流体间隙制动器的附加行车制动器,该附加行车制动器包括被布置在转子(R)与定子(S)之间的流体间隙(6),其中为了获得制动效果,能够用流体注满流体间隙；一种车辆,包括具有流体间隙制动器的驱动装置；以及一种用于借助于流体间隙制动器制动驱动装置的方法,其特征在于以下方法步骤：-借助于溢流装置,用来自贮存器的流体注满流体间隙；-借助于泄流装置,将流体间隙的流体清空到贮存器中。(A drive device for a vehicle, comprising: at least one electric machine (1) having a rotor (R) and a stator (S), in particular an electric motor, a drive shaft (2) and a main service brake (3), wherein the drive device is equipped with an additional service brake configured as a fluid gap brake comprising a fluid gap (6) arranged between the rotor (R) and the stator (S), wherein the fluid gap can be filled with a fluid in order to obtain a braking effect; a vehicle includes a drive device having a fluid gap brake; and a method for braking a drive by means of a fluid gap brake, characterized by the following method steps: -filling the fluid gap with fluid from the reservoir by means of an overflow device; -emptying the fluid of the fluid gap into the reservoir by means of a draining device.)

1. A drive device for a vehicle, comprising: at least one electric machine (1) having a rotor (R) and a stator (S), in particular an electric motor, a drive shaft (2) and a main service brake (3), characterized in that the drive device is equipped with an additional service brake configured as a fluid gap brake comprising a fluid gap (6) arranged between the rotor (R) and the stator (S), wherein the fluid gap can be filled with fluid in order to obtain a braking effect.

2. Drive arrangement according to at least one of the preceding claims, characterized in that a transmission (4) is connected after the electric machine (1).

3. Drive arrangement according to at least one of the preceding claims, characterized in that the drive arrangement has a first drive shaft (2a), a second drive shaft (2b), wherein the transmission is arranged between the drive shafts (2a, 2b), and the electric motor (1) is coupled with the transmission (4), wherein a first main service brake (3a) is prearranged which can act on the first drive shaft (2a), wherein a second main service brake (3b) is prearranged which can act on the second drive shaft (2 b).

4. Drive arrangement according to at least one of the preceding claims, characterized in that the service brake (3) is configured as an inboard brake.

5. Drive arrangement according to at least one of the preceding claims, characterized in that the electric machine (1), the transmission (4), the service brakes (3a, 3b) and the additional service brakes configured as fluid gap brakes are arranged or mounted on or in a common housing (10).

6. The drive device according to at least one of the preceding claims, characterized in that the fluid gap brake is equipped with an overflow device (7a-d) for filling the fluid gap (6) with fluid, and in particular with a drain device (8a-e) for draining the fluid gap (6) and/or with a reservoir (9a-c) for storing the fluid.

7. The drive device according to at least one of the preceding claims, characterized in that the overflow device comprises a pump (7a), a pressure chamber (7b), an electric motor (1) at negative pressure, in particular a fluid gap (6) at negative pressure or a pre-chamber (7d) with a compartment (7c) with propellant.

8. The drive arrangement according to at least one of the preceding claims, characterized in that the drain arrangement comprises a pump (8a), a suction chamber (8d) at negative pressure, a self-emptying fluid gap (8c) and/or an impeller (8d) driven by the rotor.

9. The drive arrangement according to at least one of the preceding claims, characterized in that the reservoir (9a) comprises the transmission (4), the reservoir (9b) comprises the pressure chamber (7b) and/or the reservoir (9c) comprises the pre-chamber (7 d).

10. The drive arrangement according to at least one of the preceding claims, characterized in that the overflow arrangement comprises a first pump (7a) and the drain arrangement comprises a second pump (8a), wherein the reservoir (9a) comprises the transmission (4).

11. The drive arrangement according to at least one of the preceding claims, in particular according to claim 10, characterized in that the drain arrangement comprises a self-draining fluid gap (8c) and/or an impeller (8d) driven by the rotor.

12. The drive arrangement according to at least one of the preceding claims, characterized in that the overflow arrangement comprises a pump (7a) and a pressure chamber (7b), wherein the drain arrangement comprises a pump (8a), wherein the reservoir (9a) comprises a transmission (4) and the reservoir (9b) comprises the pressure chamber (7 b).

13. The drive device according to at least one of the preceding claims, characterized in that the overflow device comprises an electric motor (1) at a negative pressure, in particular a fluid gap (6) at a negative pressure, wherein the drain device comprises a suction chamber (8d) at a negative pressure, wherein the reservoir (9) is formed by the transmission (4).

14. The drive arrangement according to at least one of the preceding claims, characterized in that the overflow arrangement comprises a propellant compartment (7c), in particular an air reservoir, which is mounted in a fluid-filled prechamber (7d), wherein the leakage arrangement comprises a collecting chamber (8e) arranged gravitationally below the electric motor, in particular below the fluid gap, wherein the reservoir (9c) comprises the prechamber (7 d).

15. Drive arrangement according to at least one of the preceding claims, characterized in that gear oil, in particular present in the transmission, is used as fluid.

16. A vehicle comprising a drive arrangement according to at least one of the preceding claims.

17. Method for braking a drive device according to one of the preceding claims by means of the fluid gap brake, characterized by the following method steps:

-filling said fluid gap with fluid from a reservoir by means of said overflow means;

-emptying the fluid of the fluid gap into a reservoir by means of the draining means.

Technical Field

The invention relates to a drive for a vehicle according to the preamble of claim 1, a vehicle according to claim 16 and a method for braking a drive according to claim 17.

Background

The drive device for a vehicle mainly comprises an electric machine (in particular an electric motor), a drive shaft and a main service brake. If necessary, the driving force of the motor is transmitted to the drive shaft, which in turn drives the wheels, through the transmission. A main vehicle brake (overflow device) is a brake that ensures deceleration (negative acceleration) of a driven vehicle during driving operation. For this purpose, so-called friction brakes are generally used.

The service brakes for vehicles must be friction brakes by law. For extreme cases, the braking system is usually designed with a negative acceleration above the legal standard. Thus, for this range, other (non-friction) braking systems are also allowed to supplement the primary service brakes.

For this purpose, DE102009027478a1 proposes, for example, combining a conventional outboard brake system with a further brake system. The use of magnetic brakes and friction brakes mounted away from the wheels (inboard brakes) is explicitly proposed. The inboard brake may also be implemented electromechanically. Brakes located close to the wheels and remote from the drive are generally referred to as outboard braking systems. In contrast, brakes that are far from the wheels and close to the drive are referred to as inboard braking systems.

However, this combination of brakes results in a weight that cannot be ignored. Furthermore, for electromagnetic brakes, a large number of parameters, such as the conductivity of the brake disc, the direction of the magnetic field, the shape of the disc, etc., must be coordinated to achieve a sufficient braking effect.

Disclosure of Invention

The invention starts from here and has for its object to provide an improved drive unit, in particular a drive unit comprising a main service brake and an additional brake, which is of simple construction and which is of low additional expenditure.

According to the invention, this object is achieved by a drive device having the characterizing features of claim 1. Since the drive is equipped with an additional service brake configured as a fluid gap brake, which comprises a fluid gap arranged between the rotor and the stator, wherein the fluid gap can be filled with fluid in order to obtain a braking effect, an additional brake is provided which is simple in construction and can be implemented with little additional expenditure in order to assist the main service brake. Depending on the control, the fluid gap brake can be used as a brake in extreme situations (emergency braking, mountain driving, etc.) or as an auxiliary service brake. In both cases, this helps to reduce brake lining wear and brake particle emissions of the primary service brakes. In particular, the conventional outboard brake can be dispensed with.

Here, "filling the fluid gap with fluid" is to be understood primarily as filling with a liquid, such as oil, which displaces a preferably gaseous fluid, such as air, which may have been present in the fluid gap beforehand. The fluid may also be referred to as brake fluid. It is also possible that the fluid gap is free of fluid or (in the technical sense) emptied before filling.

In particular, further advantageous embodiments of the proposed invention result from the features of the dependent claims. The subject matter or features of the different claims can in principle be combined with one another in any desired manner.

In an advantageous embodiment of the invention, provision can be made for a transmission to be connected downstream of the electric machine. In addition to the usual functions of the transmission, in particular the distribution of the rotational speeds or torques, the transmission ratios, the reduction ratios, etc., which are associated with the electric machines, gear oil (transmission oil) which is generally present in the transmission can be used as fluid for the fluid gap brakes. To some extent, the transmission can be used as a reservoir for fluid and can be removed therefrom and in particular also be restored again. In most cases, the gear oil circulation pumps which are present anyway can also be used for the fluid gap brake, in particular as overflow devices.

In a further advantageous embodiment of the invention, it can be provided that the drive device has a first drive shaft and a second drive shaft, wherein a transmission is arranged between the drive shafts, and the electric machine is coupled to the transmission, wherein a first main service brake acting on the first drive shaft is provided, and wherein a second main service brake acting on the second drive shaft is provided.

The first drive shaft and the second drive shaft are in particular half shafts which are connected to one another via a differential, wherein the electric machine is designed for driving both half shafts. However, it is also conceivable and likewise possible for each half shaft to have a respective drive, which in each case comprises an electric machine and preferably in each case a transmission.

In a further advantageous embodiment of the invention, it can be provided that the main service brake is configured as an inboard brake. In particular, in order to reduce the sprung mass, it is advantageous to position the brake away from the wheel and as close to the drive as possible.

In a further advantageous embodiment of the invention, it can be provided that the electric machine, the transmission, the main service brake and the additional service brake, which is configured as a fluid gap brake, are arranged or mounted on or in a common housing. A compact drive unit can thereby be provided, which drive unit can in particular be constructed as a compact unit in a vehicle.

The basic principle of a fluid gap brake consists in introducing a fluid into the region between the rotor and the stator in order to brake the rotor during rotation of the electric machine. Overflow means are used for this purpose. In the flooding situation, energy is converted into heat in the fluid gap between the stator S and the rotor R due to viscous friction. The braking effect is released by draining the introduced fluid from the region between the rotor and the stator via a drain. In the following, the region to be filled with fluid or emptied of fluid shall be referred to as fluid gap. Fluid gap brakes usually have a reservoir into which fluid can be stored for output to the fluid gap and/or in which fluid can be received for recirculation from the fluid gap.

In this connection, it is preferably provided that the fluid gap brake is equipped with an overflow device for filling the fluid gap with fluid, and in particular with a drain device for draining or emptying the fluid gap, and/or a reservoir for storing fluid.

Various possibilities are conceivable for the design of the overflow, the drain and/or the reservoir.

Thus, for example, it can be provided that the overflow device comprises a pump, a pressure chamber, an electric motor at negative pressure, in particular a fluid gap at negative pressure, or a prechamber with a chamber with propellant.

Further, it may be provided that the drainage means comprise a pump, a suction chamber at negative pressure, a self-emptying fluid gap and/or an impeller driven by a rotor.

Further, it is preferably also provided that the reservoir comprises a transmission, a pressure chamber and/or a prechamber. Thereby, already existing components are also used for the fluid gap brake, whereby a weight saving in particular is possible.

In a preferred embodiment of the drive device, it can be provided that the overflow device comprises a first pump and the drain device comprises a second pump, wherein the reservoir comprises a transmission. By the use of a pump, the fluid flow can be accurately controlled and thereby the additional braking effect to be achieved can be accurately quantified.

In a preferred development of the drive device and in particular of the drive device described above, it can be provided that the drain device comprises a self-emptying fluid gap and/or an impeller driven by the rotor. In particular, a self-emptying fluid gap and/or an impeller driven by the rotor can preferably be used to assist the drainage device configured as a pump. In particular, the leakage flow can be accelerated thereby, which results in better suitability, in particular when used in a vehicle, since the additional braking effect can be used for shorter time intervals. At the same time, the impeller can also be used as an additional flow-blocking device when the fluid gap or the engine interior is filled, in order to increase the braking effect.

In an advantageous embodiment of the invention, it can be provided that the overflow device comprises a pump and a pressure chamber, wherein the drain device comprises a pump, and wherein the reservoir comprises a transmission and a pressure chamber. By means of the pressure chamber, a high overflow efficiency can be provided in a short time, wherein the pressure can be provided with a relatively low efficiency over a longer period of time.

In a preferred embodiment of the drive device, it can be provided that the overflow device comprises an electric motor which is at a negative pressure, in particular a fluid gap which is at a negative pressure, wherein the drain device comprises a suction chamber which is at a negative pressure, and wherein the reservoir comprises a transmission. The reaction time for switching on or off the fluid gap brake can be shortened by the vacuum, since the vacuum provides a high efficiency with a short activation time (valve switching). Furthermore, it is possible to build up a negative pressure over a longer period of time, so that a very inefficient device can be selected to produce the negative pressure.

In a preferred embodiment of the drive device, it can be provided that the overflow device comprises a propellant compartment, in particular an air reservoir, which is mounted in a fluid-filled prechamber, wherein the drain device comprises a collecting chamber arranged in the direction of gravity below the electric motor, in particular below the fluid gap, wherein the reservoir comprises the prechamber. Such a drive or fluid gap brake can be constructed very inexpensively, in particular because no expensive components such as pumps are required. On the other hand, this embodiment is preferably intended for emergency braking, since it cannot be easily put into use again.

In a further advantageous embodiment of the invention, it can be provided that gear oil, in particular the gear oil present in the transmission, is used as the fluid. Such fluids are inherently contained in the transmission and may be advantageously used as a fluid for a fluid gap brake.

In a further advantageous embodiment, the fluid gap brake can be designed with additional flow blocking devices, in particular with individual paddles or with vanes arranged on the rotor shaft on the rotor end face side. When the fluid gap or the engine interior is filled, the flow blocking device is immersed in the brake fluid and thus increases the braking effect.

Another object of the invention is to propose an improved vehicle, preferably a vehicle comprising an improved drive device, in particular an improved fluid gap brake.

According to the invention, this object is achieved by a vehicle having the characterizing features of claim 16. By using the drive/fluid gap brake according to the invention, the advantages outlined above can be used for a motor vehicle.

Another object of the invention is to propose a method for braking a drive device according to any one of the preceding claims by means of a fluid gap brake.

According to the invention, this object is achieved by the following method steps:

-filling the fluid gap with fluid from the reservoir by means of an overflow device;

-emptying the fluid of the fluid gap into the reservoir by means of a draining device.

In particular, the device outlined below can be used as an overflow or as a drain. "filling the fluid gap" is understood to mean a sufficient overflow for the braking effect to be achieved. "bleed flow" can also be understood as a purge for stopping the braking effect as required. It cannot be excluded that residual fluid remains in the fluid gap, but that no braking effect can be achieved anymore.

Furthermore, the fluid does not have to be forcibly directed back to the same reservoir from which it was removed. However, this is desirable in a closed loop.

Drawings

Further features and advantages of the invention will become apparent from the following description of preferred embodiments with reference to the accompanying drawings. In the drawings:

fig. 1 shows a drive device according to the invention in a schematic view;

fig. 2 shows a drive device according to the invention in a schematic view;

fig. 3 shows a drive device according to the invention in a schematic view;

fig. 4 shows a drive device according to the invention in a schematic view;

fig. 5 shows a drive device according to the invention in a schematic view;

FIG. 6 shows a measurement curve from a test in which the additional brake is activated;

fig. 7 shows a measurement curve from a test in which the additional brake is activated.

The following reference numerals are used in the drawings:

r rotor

S stator

1 electric machine

2 (a, b) drive shaft

3 (a, b) Main Driving brake

4 speed variator

5 (a, b) drive wheels

6 fluid gap

7 (a-d) overflow device

8 (a-e) draining device

9 reservoir

7a pump

7b pressure chamber

7c propellant cabin

7d precombustion chamber

8a pump

8b impeller

8c self-emptying fluid gap

8d suction chamber

8e collecting chamber

9a reservoir in a transmission

9b reservoir in pressure chamber

Reservoir in 9c precombustion chamber

10 casing

11 brake control element

12 valve

13 valve

14 valve

15 valve

16 pump

17 film.

Detailed Description

The drive for a vehicle, in particular a motor vehicle, comprises at least one electric machine 1, a drive shaft 2a, a main service brake 3a and an additional service brake configured as a fluid gap brake according to the invention. The additional brake or the additional service brake refers to a brake which assists the main service brake, and not, for example, a parking brake. Rather, the additional brake should serve as an auxiliary main service brake, i.e., should ultimately allow an additional deceleration of the drive wheels during a movement of the vehicle or of the drive.

Preferably, the drive device has a transmission 4, a first drive shaft 2a together with a first drive wheel 5a and a second drive shaft 2b together with a second drive wheel 5 b. The first drive shaft 2a is preferably arranged between the transmission 4 and the first driving wheels 5a, while the second drive shaft 2b is preferably arranged between the transmission 4 and the second driving wheels 5 b.

Preferably, a first main service brake 3a and a second main service brake 3b are provided. A first main service brake 3a acts on the first drive shaft 2a and a second main service brake 3b acts on the second drive shaft 2 b.

The electric machine 1, the transmission 4 and the main service brakes 3a, 3b preferably form a compact unit and are further preferably accommodated in a common housing 10.

The primary service brakes 3a, 3b may be referred to as inboard brakes due to their placement away from the drive wheels, close to the housing, or within the housing. As regards the principle of action, the main service brakes 3a, 3b are preferably so-called friction brakes, in particular disc brakes or drum brakes. The control may be achieved electromechanically.

As already explained, it is provided according to the invention that the drive is equipped with at least one additional service brake in the form of a fluid gap brake.

The basic principle of a fluid gap brake is to introduce fluid into the region between the rotor R and the stator S in order to brake the rotor R during rotation of the electric machine 1. In the illustration, the fluid is marked with wavy hatching. Overflow means are used for this purpose. In the flooding situation, energy is converted into heat in the fluid gap between the stator S and the rotor R due to viscous friction. The braking effect is released by draining the introduced fluid from the region between the rotor R and the stator S via a drain. In the following, the region to be filled with fluid or emptied of fluid shall be referred to as fluid gap. Fluid gap brakes usually have a reservoir into which fluid can be stored for output to the fluid gap and/or in which fluid can be received for recirculation from the fluid gap. When the fluid gap brake is not activated and no braking effect is required, the fluid used to fill the fluid gap (brake fluid) is different from another fluid that may be present in the fluid gap. In particular, the brake fluid can be a gas, if the fluid gap is fluid-free or (technically) evacuated if the fluid gap brake is not activated. The brake fluid may also be a liquid that displaces fluid, such as air, that may be present in the fluid gap when the fluid gap is filled with brake fluid.

Different embodiments are conceivable for the drive device, in particular for its fluid gap brake, in particular with regard to the design of the overflow device, the drain device and/or the reservoir. It is also possible to combine functions in a plurality of devices, or one device may perform a plurality of functions. In the following, a non-exhaustive list of several variants shall be presented.

The overflow means may comprise, for example, a pump 7a, a pressure chamber 7b, the electric machine 1 at negative pressure, in particular the fluid gap 6 at negative pressure and/or a propellant chamber 7c in the prechamber 7 d.

The draining means may comprise a pump 8a, an impeller 8b connected to the rotor R, a self-emptying fluid gap 8c, a suction chamber 8d at negative pressure and/or a collection chamber 8e arranged below the motor 1 in the direction of gravity, in particular below the fluid gap 6.

The reservoir 9b or 9c can be formed by the pressure chamber 7b or the prechamber 7d itself, or by the transmission 4. In principle, however, any container can be used as a reservoir for the fluid filling the fluid gap 6. Especially when the transmission 4 is used as the reservoir 9a, gear oil may be considered as the fluid. In principle, however, other suitable fluids are also conceivable.

The aforementioned variants can in principle be combined with one another as desired. Further, it is clear to the person skilled in the art that the devices outlined above are supplemented as necessary by further components such as valves, control technology, in particular the brake control unit 11, lines, etc.

In the following, several (but not all) combinations of the above-mentioned overflow and drain or reservoir shall be described in detail.

In fig. 1 a drive is shown in which the overflow means comprises a first pump 7a and the drain means comprises a second pump 8 a. The reservoir 9a is formed by the transmission 4. Correspondingly, gear oil originally preset in the transmission 4 is used as the fluid. As the pump 7a for filling the fluid gap 6, a gear oil circulation pump which is originally provided for circulation of gear oil may be used, but a separate pump may be used if necessary.

The function of the drive device, in particular the fluid gap brake, is outlined below. In the case of braking, the brake control unit 11 opens a valve 12 between the transmission 4 and the electric machine 1 (in particular the fluid gap 6). The fluid gap 6 is actively filled by the pump 7 a. For pumping, the pump 8a is activated, which pumps fluid from the fluid gap 6 back into the transmission 4 or the gear oil circuit. Between the pump 8a and the transmission 4, a valve 13 can be foreseen, which is opened before pumping.

In the following exemplary embodiments, overflow device 7 or drain device 8 is also controlled by brake control unit 11.

Fig. 2 shows a variant of the embodiment according to fig. 1, in which the drain additionally comprises an impeller 8 b. The impeller is formed, for example, by a paddle wheel that is disposed on the rotor R from the end face side.

The impeller 8b is arranged to remove fluid from the fluid gap 6 when the valve 13 is open. Additionally or alternatively, the draining means may also comprise a self-draining fluid gap 8 c. For this purpose, the rotor R can be provided with corresponding blades, for example, in the fluid gap 6. Both the impeller 8b and the self-emptying fluid gap 8c are alternatively used as a drain. At the same time, when the valve 13 is closed, the impeller 8b acts as a flow blocking device and increases the braking effect of the fluid gap brake.

Fig. 3 shows an embodiment variant in which the overflow means comprise a pump 7a and a pressure chamber 7b which may comprise a pressure bladder. The use of a pump 8a as a drainage device is also conceivable here. The reservoir 9 is formed here both by the transmission 4 and by the pressure chamber 7 b.

The function of the drive device, in particular the fluid gap brake, is outlined below. A valve 12 is provided between the transmission 4 and the pressure chamber 7 b. The valve 12 is opened and the pressure chamber 7b is pre-filled by means of the pump 12, wherein also a nearly incompressible fluid, such as oil, can be pre-pressurized by means of the pressure bag. The pump 12 may be an in-house existing gear oil circulation pump.

In the case of braking, the valve 13 between the pressure chamber 7b and the electric motor 1 (in particular the fluid gap 6) is opened, so that pressurized fluid flows from the pressure chamber 7b into the fluid gap 6. The valve 12 is blocked to prevent brake fluid from flowing back into the reservoir 9 a. Similarly to the embodiment according to fig. 1, the pump 8a is activated for the draining, which pumps the fluid back into the transmission 4 or the transmission circuit again. A valve 14 can be provided between the pump 8a and the transmission 4.

Fig. 4 shows an embodiment variant in which the overflow device comprises the electric machine 1, in particular the fluid gap 6, which is at a negative pressure. The drainage means comprise a suction chamber 8d at negative pressure. The reservoir 9 is formed by the transmission 4.

The function of the drive device, in particular the fluid gap brake, is outlined below.

A valve 12 is provided between the electric motor 1 (in particular the fluid gap) and the transmission 4. A suction chamber 8d and a pump 16 are connected to the motor 1, in particular to the fluid gap. Further, a valve 13 is foreseen between the suction chamber 8d and the motor 1 (in particular the fluid gap), and a valve 14 is foreseen between the suction chamber 8d and the pump 16. Preferably, a valve 15 is foreseen between the pump 16 and the transmission 4.

First, valve 12 is closed and valves 13 and 14 are opened. The motor 1 (in particular the fluid gap 6) and the suction chamber 8d are evacuated or a negative pressure is generated by the pump 16. This reduces unnecessary friction loss of the motor 1. After the technically necessary underpressure has been reached, the valves 13 and 14 are closed and the pump 16 is switched off. The valve 12 remains closed.

In the event of braking, the valve 12 between the transmission 4 and the electric machine 1 (in particular the fluid gap 6) is opened, so that fluid in the transmission 4, in particular in the gear oil circuit, is drawn into the electric machine 1, in particular into the fluid gap 6. For the leakage, the valve 12 is closed and the valve 13 is opened, so that fluid flows from the motor 1, in particular from the fluid gap 6, into the suction chamber 8 d. By opening valves 14 and 15 and activating pump 16, suction chamber 8d is drained to transmission 4.

Fig. 5 shows an embodiment variant in which the overflow means comprise a propellant chamber 7c, in particular a gas reservoir, which is installed in a fluid-filled prechamber 7 d. The draining means comprise a collecting chamber 8e arranged below the motor 1, in particular below the fluid gap 6, in the direction of gravity. Further, it relates to a variant of embodiment that is compliant with not having the transmission 4 as a reservoir. In this regard, the pre-chamber represents a reservoir 9c for providing fluid.

The function of the drive device, in particular the fluid gap brake, is outlined below. In the case of braking, the air reservoir 7c is ignited and fluid is pressed from the prechamber 7d into the electric machine 1, in particular into the fluid gap 6. A membrane 17 can be provided between the prechamber 7d and the electric machine 1 (in particular the fluid gap 6), which membrane is broken by the pressure of the air reservoir and opens the passage. After applying the braking effect, the motor 1, in particular the valve 13 between the fluid gaps 6, is opened and fluid (preferably constrained by gravity) flows out into the collection chamber 8 e. This variant is preferably disposable and designed for emergency braking. The driving device is kept in an operable state through the drainage device; in particular, it can be restored again to the initial state by a corresponding repair or overhaul.

FIG. 6/7 shows an actual measurement curve from a test in which the engine gap was filled with fluid. The braking power depends on the speed. The concept according to the invention is therefore particularly suitable for emergency braking at high speeds.

The features and details described in connection with the method are of course also relevant for the device according to the invention and vice versa, so that, in the case of the disclosure of the inventive aspects, reference is always made or can be made to each other. In addition to this, the method according to the invention described as necessary can be carried out by the device according to the invention.

A main application for the drive according to the invention is the use in a vehicle. Furthermore, the motor is preferably an electric motor. However, generators or electric motors acting as generators are also conceivable.

The braking can be implemented as "combined braking" such that the braking power is provided by the main service brake, the fluid gap brake and possibly additional regenerative brakes, in particular of the electric machine.