DE29700988U1 - Hydrodynamic clutch - Google Patents

Description

G 05534GM / 297 OO 988.5 / Voith Turbo GmbH & Co. KG / ak/sp00176 /13 May 1997

Hydrodynamic coupling

The invention relates to a hydrodynamic coupling, in particular with the features from the preamble of claim 1. 5

Hydrodynamic couplings for torque transmission are available in a wide range of designs, for example as described in the publications 1.) CR 252

2.) J.M. Voith GmbH: "Hydrodynamics in drive technology"; Vereinigte Fachverlage Krauskopf Ingenieur Digest; Mainz 1987. Such couplings comprise at least two coaxially arranged impellers - a primary impeller and a secondary impeller, which together form at least one toroidal working space. The primary impeller functions as a pump wheel and the secondary impeller as a turbine wheel. The primary impeller can be connected in a rotationally fixed manner to a drive shaft that can be coupled at least indirectly to a drive machine. The secondary impeller can be connected in a rotationally fixed manner to an output shaft that can be coupled at least indirectly to a machine to be driven. To transmit torque, the working spaces can be filled with operating fluid. The operating fluid is circulated due to the primary impeller rotation during operation of the coupling and generates a reaction torque on the blades of the secondary impeller. This circuit of operating fluid between the primary and secondary impeller is also referred to as the working circuit. However, not all of the flow energy is converted into reaction torque, but only a part, while the rest is converted into heat. The cooling of the operating fluid during operation of the clutch can be achieved in different ways.

G 05534 / Voith Turbo GmbH & Co. KG / 'Overfill protection" / AK/sp00113 / 17 January 1&THgr;&THgr;7 Inventor B. Schust _&phgr;#

is a cooling circuit assigned to the working circuit, through which a portion of the operating fluid is continuously guided during operation. For example, the heated operating fluid can pass through corresponding openings in the impellers and through nozzles into a pump shell rotating at the speed of the primary impeller. There, the operating fluid is taken up by a pitot tube that is positioned against the direction of rotation. When installed, the pitot tube engages in the pump shell above the coupling axis. Due to the pressure conditions, the flow energy of the operating fluid taken up by the pitot tube is sufficient to return it to the coupling via a cooling device, cooler or heat exchanger without the need for additional aids. For this purpose, a closed coolant circuit is assigned to the working circuit during operation. In the stationary state, there is always a constant amount of operating fluid in the coupling and in the cooling circuit. No liquid is added to or removed from this circuit. The speed of the working machine can be increased or reduced by adding or removing operating fluid from the coupling. For this purpose, the work spaces are also assigned a supply line or channel and a drain or drain line or channel for the purpose of filling and emptying. The supply _and drain lines are coupled to an external operating fluid supply system, for example in the form of an operating fluid tank. The supply and drain lines can be assigned to the work spaces separately from the cooling circuit or using the lines or channels of the cooling circuit.

Other possibilities for exchanging or cooling the operating medium in the work area are conceivable, for example volumetric cooling, i.e. exchanging the operating medium in the working circuit by simultaneously removing a certain amount of heated operating medium

G 05534 / Voith Turbo GmbH & Co. KG/ "UberfullschutZ'/ AK/spOOHS/17 January 1887 Inventor B. Schust ·**.,*· ··

and feeding in lower temperature operating fluids in the appropriate quantity.

A major problem with hydrodynamic couplings is that, depending on the intended use, when starting up or activating the coupling, there is a risk of overfilling the coupling due to the rotation of the rotor parts of the coupling in a housing, as it is very difficult to maintain a certain filling level. In this case, additional splashing losses between the rotor parts themselves, i.e. the individual impellers, and the housing and the rotor parts, lead to a deterioration in efficiency and increasing leaks in the individual labyrinths, i.e. the operating fluid supply lines. A solution that provides an additional drain line from the housing to the tank to avoid these disadvantages is not desirable. To avoid overfilling, the inlet line or the control device for controlling the inlet is therefore controlled by a filling signal. The pressure in the outlet line, for example, acts as a filling signal. This is measured by a device for recording the current pressure value in the outlet line from the working area. If a certain pressure is exceeded, the system is electrically locked by a pressure switch, so that the supply of further operating fluid is prevented. The problem with such a solution, however, is that this signal is very inaccurate due to the different boundary conditions and is often not sufficient to prevent the coupling from being overfilled. The pressure switch itself must always be set very precisely when it is put into operation and is also exposed to pressure peaks caused by the open filling valve in the supply line. To clarify this problem: In detail, the device for recording the pressure continuously measures a certain pressure value in the pressure sensor during a period of time from the empty state of the coupling to the maximum filling of the coupling.

G 05534GM / 297 OO 988.5 / Voith Turbo GmbH & Co. KG / ak/sp00176 / 13 May 1997

the drain line. This pressure value increases steadily. A clear change in the increase in a characteristic curve for the pressure depending on the clutch filling only occurs in the area of overfilling, i.e. a clutch filling > 100%. Each pressure value is therefore proportional to a certain filling level. To determine a full filling, a corresponding pressure value must therefore be recorded. Tolerances can be incorporated into the determination. This leaves only a small pressure range in which overfilling can be concluded. The pressure switch must be controlled within this limited pressure range. However, since the determined pressure value in the line can still be influenced by a number of other marginal factors, the recorded pressure value often does not correspond to the theoretically assigned filling level. An early termination of the filling at a filling level < 100% or overfilling are then the result.

The invention is therefore based on the task of further developing a method for operating a hydrodynamic coupling in such a way that the disadvantages of the prior art are avoided. In particular, an effective protection against overfilling that is suitable for different installation conditions and can be responded to quickly is to be implemented. The solution according to the invention should be characterized by a low level of construction and control or regulation technology. The structural design for implementing the overfill protection should also be very resistant to failure and be able to detect and react to a maximum permissible filling level, which can correspond to the generally maximum permissible or a freely definable filling level, as accurately and very quickly as possible.

The solution according to the invention is characterized by the features of claim 1.

G 05534GM / 297 OO 988.5 / Voith Turbo GmbH & Co. KG / ak/sp0017e / 13 May 1997

Advantageous embodiments are described in the subclaims.

According to the invention, a hydrodynamic coupling comprising at least two impellers, a primary impeller and a secondary impeller, which together form at least one toroidal working chamber, is operated in such a way that only two filling levels are distinguished - a first filling level, which includes the state of non-filling and partial filling, and a second filling level, which describes the maximum permissible filling level, with a certain first, very low first pressure value being assigned to the first filling level, and a second pressure, which is higher than the first pressure value, being assigned to the second filling level. The working chamber is coupled to a storage chamber for this purpose. The operating fluid passes from the working chamber into the storage chamber in a certain ratio to the filling level of the coupling. In the storage chamber, the operating fluid level is tapped via a dynamic pressure generating device. This is at least indirectly coupled to a device for influencing the inflow quantity to the working chamber, generally an adjusting device of a valve device. The dynamic pressure generating device works according to the black and white principle. In a first filling level state, no pressure or only a very low, essentially constant pressure is generated and in a second filling level state, a pressure that is significantly higher than the first filling level is generated. Only when the increased pressure occurs is the device for at least indirectly influencing the inflow quantity, generally an actuator of a valve device assigned to the inflow line, activated and the supply of operating fluid reduced or interrupted. According to the invention, a corresponding pressure signal is thus only assigned to the operating states of non-filling or partial filling and full filling. It is important that there is a pronounced signal jump when transitioning from one state to the other.

G 05534 / Voith Turbo GmbH & Co. KG / "ClberfCillschutZ" / AK/sp00113 /17 January 1997 Inventor B. Schust ·*·..·· ··

is generated, which can be reliably identified. This ensures that - regardless of additional disturbances in the supply of operating materials - overfilling can be reliably identified. In particular, this system is not susceptible to pressure surges caused by the filling valve used to influence the inflow quantity. There is no need to set the pressure switch precisely when starting up. There is no need to optimize the system. The method is characterized by an easy-to-implement and precise determination of when a maximum filling level has been exceeded using a so-called black-and-white detection.

As a rule, the maximum permissible filling level will correspond to the actual, maximum permissible filling level. This is generally 100%. However, it is also conceivable to define the maximum permissible filling level in such a way that it corresponds to a certain filling level that can be predetermined and must be maintained for the specific application.

This filling level to be maintained can be described by any partial filling relative to the maximum permissible filling level.

In terms of the device, a collecting channel is assigned to the actual working space, which forms a storage space that is at least indirectly coupled to the working space for the purpose of supplying operating materials. The collecting channel is arranged on a diameter that, when the hydrodynamic coupling is in operation, allows at least one filling of the storage space that is proportional to the degree of full filling of the hydrodynamic coupling. A dynamic pressure generating device, preferably in the form of a dynamic pressure pipe, is introduced into this storage space, which communicates with the working space and is formed by the collecting channel, for the purpose of sensing the filling level in the storage space. The dynamic pressure generating device is arranged opposite the storage space in such a way that this or, in the case of a dynamic pressure pipe, its opening is above or outside the

G 05534 / Voith Turbo GmbH & Co. KG / 'Overfill protection· / AK/sp00113 / 17 January 1997 Inventor B. Schust ·· _aa

Operating fluid level in the storage space is such that it is not filled at this filling level. In this case, no operating fluid is discharged via the dynamic pressure pipe and therefore no pressure signal is generated. However, as soon as the filling level of the coupling reaches the maximum permissible filling level, ie usually full, the storage space also fills up in such a way that the dynamic pressure generating device, in particular the dynamic pressure pipe with its opening extends into the operating fluid, takes in operating fluid and thus generates a dynamic dynamic pressure of p _dyn = (ρ/2)χν ² .

'■'

What is essential to the invention is that the dynamic pressure pipe is arranged in the storage space in such a way that it only generates a high dynamic dynamic pressure when the operating fluid level in the storage space is proportional to the maximum filling level of the coupling. During the previous filling level states, which correspond to a non-filling or partial filling, the opening of the dynamic pressure pipe extends into a space in the storage space that is free of operating fluid. In this state, no pressure or only a very low pressure is generated via the dynamic pressure generating device. This low pressure corresponds, for example, to the pressure that occurs in an unfilled and open pipe in the atmosphere.

Since no pressure signal or only a very low pressure is generated in the area between the unfilled state of the hydrodynamic coupling and the maximum filling level, and only in the state of the maximum filling level is a dynamic back pressure of P^ _n = (ρ/2)χν ² generated, the state of the maximum filling level of the hydrodynamic coupling can be easily and immediately recognized without error influences, because only the two filling level states are distinguished, which differ by a strong pressure change in the form of a pressure increase. This or the pressure signal that can be formed from it can then be used to directly control an actuating device of a device for at least indirectly influencing the flow rate in the inlet to the working chamber of the

G 05534 / Voith Turbo GmbH & Co. KG / "Overfill protection" / AK/sp00i 13 /17 January 1987 Inventor 8. Schusl ·"*«.·· ·· ..

hydrodynamic coupling, in particular the actuator of a valve device.

The maximum filling level can correspond to an actual maximum permissible filling level, generally 100%. However, it is also conceivable to define the maximum filling level as a filling level to be maintained for a specific application. The maximum filling level, which corresponds to the specified filling level to be maintained, can then be defined by any filling level smaller than the actual maximum permissible filling level.

The degree of filling to be maintained can be defined by adjusting the position of the dynamic pressure generating device, in particular the opening for receiving the operating fluid in the storage space. This can be changed by moving it in a vertical direction, i.e. in the installed position by moving it in a radial and circumferential direction in the storage space or by swiveling it. The entire circumferential area can be considered the adjustment range for this. The position can be changed in a fixed way for a specific application or can be adjusted during operation.

This offers the advantage that with an overfill protection, different applications of a hydrodynamic coupling of a certain design and size can be covered by actively adapting to changing requirements.

An advantageous design consists in dispensing with a separate collecting channel and using the operating fluid collecting channel. This offers the advantage that existing components can be used. When arranging the pitot tube in the operating fluid collecting channel or when the pitot tube end extends into the operating fluid collecting channel, with the pitot tube in a separate filling segment which is arranged upstream of the operating fluid collecting channel, the knowledge is used that a

G 05534 / Voith Turbo GmbH & Co. KG / "Overtüllung protection" / AK/spOO113 / January 17, 1997 Inventor B. Schust ·· ·· . .

Drainage from the operating fluid collecting channel only occurs until the maximum filling, i.e. the state of full filling, has not yet been reached.

There are a number of options for the design of the storage space, which is essentially determined by the collection channel, and the allocation of the collection channel to the working circuit. The collection channel can be designed as a separate component that can be detachably connected to the corresponding rotor parts for allocation to the working space. However, the collection channel with a paddle wheel is preferably manufactured as a structural unit, i.e. in one piece.

The dynamic pressure generating device, which is preferably designed as a dynamic pressure tube, has a part that has an opening area. This part is preferably arranged essentially parallel to the operating fluid level that is established in the storage space. An arrangement inclined or perpendicular to this is also conceivable. The opening area extends at least partially perpendicular to the radial direction and in the circumferential direction, whereby the direction of rotation must be taken into account. The opening area preferably points completely in the circumferential direction and is arranged essentially perpendicular to this.

The solution according to the invention can be used with any type of hydrodynamic coupling with variable filling. The couplings can be designed as single-circuit couplings, which have a primary and a secondary impeller, which together form a toroidal working space, or as multi-circuit couplings, in which a plurality of primary and secondary impellers form a plurality of working spaces. In the former case, the collecting channel can be assigned to both the primary and the secondary impeller or to a shell. In the latter case, it is only necessary to assign it to one of the impellers.

G 05534 / Voith Turbo GmbH & Co. KG / "Overfill protection· / AK/spO0113 / January 17, 1997 Inventor 6. Schust *· ·· ..

In general, the externally arranged impellers are possible due to structural conditions.

The coupling between the storage space and the working space can be designed in a variety of ways. The connection between the interior of the catch channel and the working space is preferably made via at least one through-opening incorporated in the impeller. The through-opening enables operating materials to pass from the working space into the storage space. The design of the through-opening can be designed in different ways. Through-openings in the form of through-holes or elongated holes, each of which is arranged on a specific diameter of the impeller, are conceivable. Preferably, a large number of openings are arranged distributed over a diameter in the circumferential direction. An arrangement on different diameters and/or a combination of the individual types of through-openings is also conceivable.

The through openings can be arranged between the individual blades in the blade base or in an area radially inside the blade wheel which is free of the blading.

Depending on the design of the through-opening, the filling can also depend on the speed difference, i.e. the slip between the primary and secondary wheels, so that a short bridging of the pressure signal may also be necessary.

Preferably, the part of the pitot tube carrying the opening is arranged essentially parallel to the operating fluid level in the storage space. The opening itself can be designed perpendicular or inclined to the operating fluid level. Independence from the direction of rotation is achieved by providing at least two openings with respect to the orientation of the

G 05534 / Voith Turbo GmbH & Co. KG / "UberfullschutZ" / AK/sp00113 / January 17, 1997 Inventor B. Schust . ·· ·· ..

1 ·

supporting part of a dynamic pressure pipe, oppositely directed dynamic pressure pipes, which can be coupled to one another, for example, by a check valve. Another embodiment provides two dynamic pressure pipes, each of which is coupled to one another by a separate pressure switch. The dynamic pressure pipes are immersed in the storage space determined by the collecting channel and the external dimensions of the impeller to which the collecting channel is assigned, in such a way that, at a maximum filling level, a dynamic pressure is generated by immersing the dynamic pressure pipe in the operating medium in the collecting channel. This maximum filling level does not necessarily have to correspond to full filling. Any filling level, which is defined as the maximum filling level, is also conceivable. This maximum filling level can be defined according to the application of the hydrodynamic coupling. The dynamic pressure pipe can be designed to be adjustable for this purpose, so that the immersion height in the operating medium in the collecting channel can be varied. This offers the advantage of being able to easily adapt the overfill protection to different requirements.

A design of the component supporting the opening in a radial direction is also conceivable.

As already mentioned, the collecting channel can be designed as a separate channel on the coupling rotor, but it is also possible to use the operating fluid feed channel, i.e. the channel coupled to the feed line for the purpose of feeding the working area. In the latter case, no further structural measures are required on the impellers of the hydrodynamic coupling, but it is possible to use existing equipment.

G 05534 / Voith Turbo GmbH & Co. KG / 'Overtulping protection' / AK/spooi 13 /17 January 1997 Inventor B. Schust ..

The pressure signal generated by the dynamic pressure tube, which is used to control the actuator of a device for influencing the filling level, in particular a device for controlling the inflow quantity to the working chamber, can be processed in a higher-level control or regulating device. Another possibility

consists in the direct control of the actuator via the device for detecting a quantity that at least indirectly characterizes the degree of filling of the clutch. The actuating device is effective in such a way that the filling is either interrupted or reduced. Since in the ~ 10 normal case the pressure signal does not act directly on the actuating device,

A conversion device for converting the pressure signal into an electrical control signal is required between the device for detecting the degree of filling. A pressure switch is preferably provided for this purpose.
15

The solution according to the invention for implementing overfill protection can be used with any type of hydrodynamic coupling. It is preferably used with hydrodynamic couplings whose working spaces can also be emptied during operation of the coupling.

The solution to the problem according to the invention is explained below using figures. The following is also shown therein:

Figures 1a and 1b show an embodiment according to the invention of a

hydrodynamic coupling with overfill protection on

Example of a coupling with two working circuits and a diagram to illustrate the function of the overfill protection;

Figures 2a and 2b illustrate an example from the

State of the art and a diagram showing

Problems with the use of a circulating

G 05534/ Voith Turbo GmbH & Co. KG/'Overfill protection*/ AK/spOOH3/17 January 1987 Inventor B. Schust ·· ··

Figures 3a and 3b Figures 4a to 4b

Figures 5a and 5b Figures 6a and 6b

recorded pressure value to control the filling valve;

illustrates inventive designs of a gutter-pressure tube arrangement; illustrates concrete designs of inventive gutter-pressure tube arrangements;
illustrate a design of the connection of lines to the pitot tube; illustrate designs for
Pressure value recording in the area of the operating fluid collecting channel.

To clarify the problems of the designs according to the state of the art, Figures 2a and 2b show the functional diagram of a generic hydrodynamic coupling, here using the example of a coupling with two working circuits and an associated closed operating fluid cooling circuit, as well as a characteristic curve to show the dependence of the instantaneous pressure ρ in the drain lines on the degree of filling of the coupling.

Figure 2a shows a simplified functional diagram of a hydrodynamic coupling 1 of the type known from the prior art, which is designed as a double-circuit coupling with a closed operating medium circulation in a closed cooling circuit. In the case shown, this coupling 1 comprises two impellers, a primary impeller 2 and its secondary impeller 3, which together form at least two toroidal working spaces 4 and 5. The primary impeller 2 is connected via a drive shaft 6 at least indirectly to a drive machine, not shown in detail here.

G 05534 / Voith Turbo GmbH & Co. KG / "Overfill protection" / AK/spOO113 / 17 January 1&THgr;&THgr;7

Inventor B. Schust &idiagr;'&Iacgr;&idiagr;&Igr;'. f";·"·.".'"&Igr;

The secondary impeller can be connected to an output shaft 7 for rotationally fixed coupling to the output side.

The two toroidal working chambers 4 and 5 can be filled with an operating medium. Oil or water can be used as the operating medium.

When the hydrodynamic coupling is operating as a torque transmission device, the operating fluid is circulated in the toroidal working chambers 4 and 5 and thus forms a closed working circuit 9.1 and 9.2 between the two impellers, the primary impeller 2 and the secondary impeller 3.

To dissipate the heat generated in the working circuits 9.1 and 9.2, a coolant circuit 10 is assigned to the working circuit. The operating fluid is released into a pump shell 11, which is coupled in a rotationally fixed manner to the primary impeller 2, via openings (not shown in detail here) in the area of the outer diameter D _AS of the primary impellers during operation of the hydrodynamic coupling 1. The pump shell 11 is arranged in the radial direction relative to the coupling axis A in the area of the outer circumference U _AS of the two impellers 2 and 3. In the pump shell 11, the operating fluid is received by at least one dynamic pressure pipe 12 which is positioned against the direction of rotation. For this purpose, this projects into the pump shell 11 above the coupling axis A when the hydrodynamic coupling 1 is installed. This dynamic pressure pipe 12 is part of the coolant circuit 10 and opens into a line 13, which functions as an outlet line from the pump shell 11 and at the same time as an inlet line to a cooling device 14, which can be designed as a cooler or as a heat exchanger. The cooling device 14 is connected via a line 15 to an operating medium inlet channel 16 to the work spaces 4 and 5. In the case shown, the coolant circuit 10 is a closed circuit. The line course of this circuit

G 05534 / Voith Turbo GmbH & Co. KG / 'Clberfüllschutz' / AK/sp00113 / January 17, 1997 Inventor B. Schust ·· *

10 can also be used to fill and empty the toroidal working spaces 4 and 5. For this purpose, a supply line 17 and a discharge line 18, which are coupled to an operating fluid tank 19, are assigned to the working spaces 4 and 5 at least indirectly via the coolant circuit 10. The connection of these individual lines, here the supply line 17 and the discharge line 18, takes place via corresponding devices in the form of valve devices. The drain line 18 is connected by means of a switching valve that functions as an emptying valve, for example in the form of a 2-way valve 20. The connection of the supply line 17 takes place via a switching valve that functions as a filling valve in the form of a 2/2-way valve 21.

In the stationary state, there is always a constant amount of operating fluid in the coupling 1, i.e. in the two toroidal working chambers 4 and 5 and in the coolant circuit 10. No liquid is then added to or removed from this coolant circuit 10. An increase or decrease in the speed of the working machine is achieved by adding or removing operating fluid from the coupling through filling or emptying valves, here by connecting the individual supply and discharge lines 17 and 18. The filling takes place via the supply line 17 from an operating fluid tank 19 into the inlet line 15, which is coupled to the toroidal working chambers 4 and 5 via an operating fluid inlet channel 16. The filling quantity is influenced via the 2/2-way valve 21, which in a first switching position I ₂₁ decouples the supply line 15 to the operating medium inlet channel 16 from the inlet line 17 and in a second switching position M ₂₁ connects the inlet line 17 to the supply line 15.

To avoid exceeding a maximum permissible filling level of the hydrodynamic coupling 1, in particular the working chambers 4 and 5 the drain line, in particular the line 13 in the coolant circuit 10, is

G 05534 / Voith Turbo GmbH & Co. KG / "Top-fill protection' / AK/sp00113 / 17 January 1&THgr;&THgr;7 Inventor B. Schust · · · ·

to which, during operation, a part of the operating fluid is led from the working circuit 9.1 or 9.2 back into the working circuit via a cooler to dissipate heat, a device for detecting the pressure ρ is assigned. This device is designated here with 23. During operation of the hydrodynamic coupling 1, an increasing pressure ρ builds up as the speed of the drive machine increases by releasing the operating fluid into the pump shell 11. This pressure p, which is then present in the coolant circuit 10, in particular in the line 13, is used to implement overload protection. The prior art design makes use of the knowledge that if the permissible maximum filling level is exceeded, the pressure ρ in the line 13 is also increased. This pressure is tapped and used as a control signal to control a control device 25 on the 2/2-way valve 21. The pressure is used to control the supply of operating fluid from the operating fluid tank 19 via the inlet line 17 to the operating fluid inlet channel 16 on the hydrodynamic coupling 1. The control itself is usually electromagnetic, i.e. the pressure signal must be converted into a corresponding electrical control signal via a conversion device. The conversion function is carried out by a pressure switch, not shown in detail here. However, this must be set precisely when it is put into operation and is also exposed to pressure peaks caused by the open 2/2-way valve 21.

Figure 2b shows a diagram in which the pressure ρ is plotted as a function of the clutch filling or the filling level in %. From this it can be seen that only from a clutch filling that corresponds to the maximum filling level, which is usually 100 %, a change in the pressure values in the lines can be recorded in such a way that the pressure value curve shows an increased increase. In the range of a clutch filling level of 0% to 100 % the pressure ρ generated in the line system increases essentially continuously.

G 05534 / Voith Turbo GmbH & Co. KG / "ClberfCillschutZ" / AK/sp00113/17 January 1&bgr;&bgr;7 Inventor B. Schust

This constant increase is also present in the area of the maximum permissible clutch filling level of 100%. Only from this filling level, i.e. when overfilling, does the pressure ρ change in such a way that a steeper increase or a stronger rise is recorded. In order to be able to react actively even when the clutch is fully filled, the connecting link between the device for detecting the pressure ρ and the actuator for influencing the inflow quantity to the hydrodynamic clutch is limited to a small range in terms of its reaction. The actuating device is only activated when a pressure ρ occurs with a value that lies within the specified range. This pressure value must, however, be determined as precisely as possible by the detection device. Additional disturbances that can influence the pressure value in the system can already distort the result to be determined. With such a system, it is therefore difficult to determine the time at which the clutch is fully filled, i.e.

the maximum permissible filling level, to be determined precisely and at the same time to avoid overfilling through rapid reaction, in particular by controlling the actuator to influence the inflow quantity to the working chambers. This control is therefore very imprecise and is very error-prone.

Figure 1 shows a solution according to the invention for implementing overfill protection using a hydrodynamic coupling as described in Figure 2. The basic structure of the hydrodynamic coupling 1 essentially corresponds to that described in Figure 2a. The same reference numerals are therefore used for the same elements.

Here too, the hydrodynamic coupling 1 comprises a cooling circuit 10 assigned to the working circuit, as well as inlet and outlet lines 17 and 18 assigned to the working chambers 4 and 5, respectively.

According to the invention, the working space or the working spaces 4 and 5 are assigned a so-called collecting channel 26, which preferably runs in the direction of rotation

G 05534 / Voith Turbo GmbH & Co. KG / *ÜberfCillschu1z· / AK/sp00113/17 January 1887 Inventor B. Schust .. .

the hydrodynamic coupling 1 and is arranged in a region in the radial direction relative to the £ coupling axis A, which, in relation to the dimensions in the radial direction, extends at most over the maximum diameter of the working space 4 or 5.

This collecting channel 26 is connected to the working chamber 4 or 5 in a communicating manner. The connection is made, for example, in the form of a through-opening 27, which can be designed in various ways and is incorporated in the primary impeller 2 in the radial direction in an area between an outer diameter of the channel d _ra , which corresponds to the radially outer boundary of the collecting channel 26, and the area that delimits the collecting channel in the radial direction with the smallest diameter, for example the surfaces 29 and 30. The through-openings 27 can be arranged either in the blade-free, radially inner area of the primary impeller 2 or in the blade base of the bladed part 31 of the primary impeller 2. The arrangement of the collecting channel 26 and the through-opening 27 relative to the impeller depends on the desired filling depending on the degree of filling of the coupling 1. The through-openings 27 can be designed as through-bores which are circular or in the form of elongated holes which preferably extend over at least part of the circumference of the impeller at a certain diameter.

The filling level in the storage space 40 described by the collecting channel 26, which is determined by the filling level in the hydrodynamic coupling 1, in particular the working spaces 4 and 5 and the design of the through openings 27, is tapped by means of a dynamic pressure pipe 32. The dynamic pressure pipe 32 is designed and arranged in such a way that filling with liquid only takes place from a filling level 34 in the collecting channel 26, which corresponds to a maximum permissible filling level in the working spaces 4 and 5. By filling the

G 05534 / Voith Turbo GmbH & Co. KG / 'Cloverfill protection" / AK/sp00113 /17 January 1997 Inventor B. Schust .. .,

A so-called dynamic pressure P^ _n is generated in the dynamic pressure pipe 32, which serves as a control variable for the actuation of the 2/2-way valve 21 to influence the supply quantity of operating fluid to the working circuit 9.1 or 9.2. The maximum permissible filling level preferably corresponds to a maximum filling level of 100%.

In the case of partial filling, i.e. a filling level less than the maximum permissible filling level, a gap is formed between the collecting channel 26 and the

t'
&agr; Workrooms 4 and 5 also have an exchange of equipment, however

no dynamic pressure p _dyn is generated in the dynamic pressure pipe 32. In this case, no signal is emitted to actuate the actuating device of the 2/2-way valve 21. This signal is only generated when the maximum permissible filling quantity is reached.

The maximum permissible filling quantity can be determined by the upper filling limit, a filling level of 100%, or can be freely selected between a filling level > 0% and 100%. Depending on the filling level, the opening of the pitot tube 32 is always in the operating fluid fillable and has an operating fluid level 34

&bull; 20 reaching storage space 40.

In Figure 1b, the dependence of the determined dynamic pressure values on the clutch filling is plotted in a diagram for the embodiment according to the invention. It can be seen from this that in the case of partial filling, ie an operating state of the hydrodynamic clutch 1 in which the fluid level 34 in the storage space 40 of the collecting channel 26 is below the dynamic pressure pipe 32, a pressure value ρ is determined in the dynamic pressure pipe 32 which essentially corresponds to the air pressure. Only when the dynamic pressure pipe 32 is immersed in the operating medium in the storage space 40 and a dynamic dynamic pressure of P^ _n = (q/2)xv ² is generated, whereby the immersion of the dynamic pressure pipe 32 in the fluid in the collecting channel 26

G 05534 / Voith Turbo GmbH & Co. KG / 'ClberfCillschutZ" / AK/spO0113 /17 January 1897 Inventor B. Schust

If the operating medium is only filled to a certain level, for example 100%, a pressure value &rgr; or a strong change in the pressure value &Dgr;&rgr; is suddenly determined in the pitot tube, which is used as an identification feature for reaching the maximum permissible level of filling in the working chamber 4 or 5. The important thing here is the pronounced signal jump that can be seen in the diagram, which can also be seen under the influence of disturbances.

Figures 3a and 3b illustrate, in a section of a blade wheel, preferably the primary blade wheel 2, another possibility of designing the connection between the working space, here the working space 4, and the collecting channel 26 and the storage space 40 determined by the collecting channel 26 and the outer contour 37 of the primary blade wheel.

Figure 3a shows a section of a primary impeller 2, to which a collecting channel 26 is assigned. The collecting channel 26 is formed by a disk-shaped element 50, which can be detachably connected to the primary impeller 2. The outer contour 37 of the primary impeller and the collecting channel form a storage space 40. A device for detecting a variable that at least indirectly characterizes the degree of filling protrudes into this storage space 40 in the form of a dynamic pressure tube 32.

The collecting channel 26 extends in the radial direction into an area that is in the area of the working space 4 or at its height. The connection between the storage space 40 and the working space 4 is made via an inclined through-opening 27.1 that extends from the impeller g round 36 to the impeller outer side 37, which simultaneously forms an outer boundary surface for the collecting channel 26.

G 05534 / Voith Turbo GmbH & Co. KG / 'Overfill protection" / AK/spOO113/17 January 1987 Inventor 8. Schust .. .. .. .,

In the embodiment shown, the storage space 40 is arranged in the radial direction in an area that corresponds to the radial arrangement of the blading 44.

Figure 3b shows designs of a collecting channel 26 and a storage space 40, which are arranged in the radial direction in the radially inner area of the primary impeller 2. The collecting channel 26 is arranged in a radially inner area of the blading 44 of the primary impeller 2. In the installed position, the arrangement of the ram pressure pipe 32 depends on the degree of filling to be limited, in the case shown above the coupling axis A.

Further specific embodiments are shown in Figures 4a and 4b. Figure 4a1 illustrates a part of the primary impeller 2 which is assigned to a collecting channel 26 which is arranged in an area which lies between the inner diameter D _ls and the outer diameter D _AS of the blading 44. The collecting channel 26 extends in the radial direction into an area which lies in the area of the working chamber 4 or at its height. The connection between the storage chamber 40 and the working chamber 4 is made via an obliquely designed through-opening 27.1 which extends from the impeller base 36 to the impeller outer side 37, which at the same time forms an outer boundary surface for the collecting channel 26. The collecting channel 26 is formed solely by means of an annular component 38. The dynamic pressure pipe 32.2 extends through the annular component 38 and projects into the storage space 40 formed by the collecting channel 26. The dynamic pressure pipe 32.2 is designed in such a way that the opening area 41.2 is arranged in the installed position in the radial direction above the passage through the annular element 38. The part 42.2 carrying the opening area preferably extends essentially parallel to an operating fluid level 43 that is established in the storage space 40.

G 0S534 / Voith Turbo GmbH & Co. KG/ "Clberfullsctiutt'/ AK/spOOm/ January 17, 1987 Inventor B. Schust

Figure 4a2 shows a view l-l corresponding to Figure 4a1. This shows the course of the part 42.2 carrying the opening area 41.2. It can also be seen that due to the orientation of the opening area 41.2 in the circumferential direction in alternating operating modes, i.e. reversing operation, a second dynamic pressure pipe 32.1 is required, the opening area 41.1 of which extends in the opposite direction to the opening area 41.2 in relation to the circumferential direction. The two dynamic pressure pipes 32.1 and 32.2 are connected to a common line 49 via the line sections 47 and 48 assigned to them via a check valve 46.

Figure 4b 1 shows an embodiment of a collecting channel which is arranged in the radially inner region of the primary impeller 2.

The collecting channel 26 is arranged in a radially inner region of the blading 44 of the primary impeller 2. Here too, the storage space is limited by the inner diameter d _R of the collecting channel 26, the outer contour 37 of the primary impeller 2, and the surfaces 29 of the components connected to the primary impeller 2 in a rotationally fixed manner.

The coupling of the storage space 40 with the working space 4 takes place via through openings 27.2, which are arranged in the radially inner part of the primary impeller 2, which is free of blading 44.

The operating fluid level 43 is located here at the level of the opening area 41.2. of the pitot tube 32.2. The pitot tube 32.2 is also designed here in such a way that the opening area 41.2 is aligned in the circumferential direction and immerses in the operating fluid located in the storage space 40.

In the installation position, the arrangement of the dynamic pressure tube 32 is carried out according to the desired filling level to be limited in a certain

G 05534 / Voith Turbo GmbH & Co. KG / -Overfill protection" / AK/spOO113 / 17 January 1997 Inventor B. Schust

Distance to the coupling axis A. In the case shown, the pitot tube 32.2 is arranged above the coupling axis A.

Here too, due to the alignment of the component of the dynamic pressure tube 32.2 that carries the opening area, a second dynamic pressure generating device in the form of a second dynamic pressure tube 32.1 is required when the direction of rotation changes. This is shown in a view H-II in Figure 4b2. From this it can be seen that both opening areas 41.2 and 41.1 in the circumferential direction

ti

are directed in opposite directions to one another. Here too, both dynamic pressure pipes 32.1 and 32.2 are coupled to a common line 49 via a line 47 and 48, which are connected to one another via a check valve 46.

In both cases (Fig. 4a and 4b), the collecting channel 26 is formed by using a ring-shaped component 38, which is connected in a rotationally fixed manner to the primary impeller 2. However, it is theoretically also possible to create the collecting channel together with the primary impeller as an assembly.

Furthermore, the dynamic pressure tube in the versions shown in both figures is mounted in component 55 on the housing.

Figures 5a and 5b illustrate another possible design of the dynamic pressure tube 32. The component 55 supporting the dynamic pressure tubes 32.1 and 32.2 is attached to the housing. In contrast to the options shown in Figures 4a and 4b, the line from the dynamic pressure tube is routed via a pipe connection 56 attached to the housing wall. Figure 5b illustrates a view III-III according to Figure 5a.

The basic structure of impeller 2, working chamber 4 and the associated storage chamber 40, as well as the extension of the pitot tube in

G 05534 / Voith Turbo GmbH & Co. KG / "UberfullschutZ" / AK/sp00113/17 January 18&THgr;7 Inventor B. Schust

The gutter 26 corresponds to that described in Figures 4a1,2 and 4b1,2, which is why it will not be discussed in detail here. The same reference numerals have therefore been used for the same elements.
5

Figures 3 to 5 merely illustrate the design of the catch channel and the passage openings. Other options with which the same function can be fulfilled are also conceivable. According to the

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When designing the coupling with one or more working spaces, in the first case the catch channel can be assigned either to the primary impeller or the secondary impeller or to a shell, but in the latter case only to the primary impeller for structural reasons. The catch channel itself is designed as a separate component or as a component with the corresponding impeller.

An advantageous design, not shown in detail in Figure 6, consists in using the operating fluid collecting channel 22 in the working circuit 9.1 or 9.2 as a collecting channel or for recording pressure values. This preferably also runs over the entire circumference at a certain diameter. The dynamic pressure pipe 32 can be arranged in the operating fluid collecting channel 22, i.e. in an area below the coupling axis A in the radially inner area of the impeller, here the primary impeller 2. The knowledge is used that drainage from the collecting channel 22 only takes place until the coupling is filled, from which point onwards there is no more drainage from the operating fluid collecting channel 22. For this purpose, the dynamic pressure pipe can also be arranged in the filling segment 57, which is assigned to the operating fluid collecting channel 22. One possible arrangement is shown in Figure 6b. This only shows the filling segment 57 and a simplified schematic representation of the course of the pitot tube 32.

Claims (23)

G 05534GM / 297 OO 988.5 / Voith Turbo GmbH & Co. KG / ak/sp00178 /13 May 1997 Claims 1. Hydrodynamic coupling 1.1 with at least two impellers, a primary impeller and a secondary impeller, which together form at least one toroidal working chamber that can be filled with operating fluid; 1.2 the toroidal working space is assigned at least one supply line for operating materials; 1.3 the working space is provided with a device for recording a quantity that at least indirectly characterises the degree of filling; 1.4 the device is at least indirectly coupled to a device for influencing the amount of operating fluid in the supply line; characterized by the following features: 1.5 the device for detecting a quantity that at least indirectly characterizes the degree of filling comprises 1.5.1 a storage space assigned to a paddle wheel and coupled to the working space and 1.5.2 a dynamic pressure generating device which extends into the storage space, whereby the dynamic pressure generating device is assigned to the storage space in such a way that the dynamic pressure generating device only takes up operating fluid when there is a certain level of operating fluid in the storage space, which corresponds to a certain maximum filling level, and the dynamic dynamic pressure generated thereby is used as a signal for at least indirectly controlling the device for influencing the amount of operating fluid in the supply line in order to reduce the amount of operating fluid to be supplied or to decouple the supply line from the working space. G 05534GM / 297 OO 988.5 / Voith Turbo GmbH & Co. KG / ak/sp00178 / 13 May 1997 · 2. Hydrodynamic coupling according to claim 1, characterized in that the storage space is formed by a collecting channel associated with a paddle wheel. 3. Hydrodynamic coupling according to claim 2, characterized in that the collecting channel is formed by at least one separate component that can be detachably connected to the impeller. 4. Hydrodynamic coupling according to claim 2, characterized characterized in that the collecting channel is formed by the paddle wheel. 5. Hydrodynamic coupling according to one of claims 1 to 4, characterized in that the dynamic pressure generating device is designed to be adjustable in its position relative to the storage space. 6. Hydrodynamic coupling according to one of claims 1 to 5, characterized in that the dynamic pressure generating device is designed in the form of at least one dynamic pressure tube. 7. Hydrodynamic coupling according to claim 6, characterized by the following features: 7.1 the pitot tube comprises at least one component having an opening area for receiving operating fluids; 7.2 the component supporting the opening area is connected to a pipe part which, in relation to the coupling axis, is directed at least partially in the radial direction against the direction of gravity. 8. Hydrodynamic coupling according to claim 7, characterized in that the component carrying the opening area is designed essentially parallel to an operating fluid level which is established in the storage space. G 05534GM / 297 OO 988.5 / Voith Turbo GmbH & Co. KG / ak/sp00176 / 13 May 1997 9. Hydrodynamic coupling according to one of claims 7 or 8, characterized in that the component carrying the opening area extends in the direction of the impeller. 10. Hydrodynamic coupling according to one of claims 7 or 8, characterized in that the component carrying the opening area extends in the circumferential direction. 11. Hydrodynamic coupling according to one of claims 9 or 10, characterized by the following features: 11.1 the opening area is directed in the circumferential direction; 11.2 For reversing operation, two pitot tubes with opening areas facing opposite one another are provided; 11.3 The two pressure pipes can be connected to a common line via a valve device. 12. Hydrodynamic coupling according to one of claims 9 or 10, characterized by the following features: 12.1 the opening area is directed in the circumferential direction; 12.2 for reversing operation, two opening areas directed in opposite directions are provided on the pitot tube. 13. Hydrodynamic coupling according to one of claims 7 to 9, characterized in that the component carrying the opening area is formed by the tubular part which is directed at least partially against the direction of gravity in the radial direction relative to the coupling axis. 14. Hydrodynamic coupling according to one of claims 1 to 13, characterized in that the coupling between the working space and G 05534GM / 297 OO 988.5 / Voith Turbo GmbH & Co. KG / ak/sp00176 / 13 May 1997 Storage space is provided via at least one opening in the impeller. 15. Hydrodynamic coupling according to claim 14, characterized characterized in that the through openings are arranged in the radial direction in the area of the bladed part of the impeller. 16. Hydrodynamic coupling according to claim 14 or 15, characterized in that the through openings are arranged in the radial direction in the area of the part of the impeller free from the blading. 17. Hydrodynamic coupling according to one of claims 1 to 16, characterized in that the primary and secondary impeller form a working space with one another. 18. Hydrodynamic coupling according to claim 16, characterized in that the primary and secondary impellers form at least one further working chamber together. 19. Hydrodynamic coupling according to one of claims 17 or 18, characterized in that the storage space is assigned to the primary impeller. 20. Hydrodynamic coupling according to claim 17, characterized in that the storage space is assigned to the secondary impeller. 21. Hydrodynamic coupling according to one of claims 1 to 20, dcharacterized in that the storage space extends in the radial direction up to G 05534GM / 297 OO &THgr;88.5 / Voith Turbo GmbH & Co. KG / ak/sp00176 / 13 May 1997 an area that is arranged on a smaller diameter than the impeller outer circumference. 22. Hydrodynamic coupling according to one of claims 1 to 21, characterized in that the dynamic pressure generating device comprises a device for converting the dynamic pressure in the The pressure generated by the dynamic pressure generating device is converted into an electrical control signal for controlling an actuator of the device for influencing the amount of operating fluid supplied. 10 23. Hydrodynamic coupling according to claim 22, characterized in that the device for influencing the operating medium supply quantity is a valve device.