DE2716126A1 - HYDRODYNAMIC BRAKE - Google Patents

Description

Licht Schmidt Hansmann & Herrmann patent attorneys

* 2713126

Light. Schmidt. Hanjmann. Herrmann- Postfach 701205 8000 Munich 70 ' Dipl.-Ing. Martin light

Dr. Reinhold Schmidt Dipl.-Wirtsch.-Ing. Axel Hansmann Dipl.-Phys. Sebastian Herrmann

Albert-Roßhaupter-Str. 8000 Munich 70

Telephone: (089) 7603091 Telex: 5 212 284 pats d Telegrams: Lipatli Munich

April 12, 1977

Ke / z / Jo

PARMAC, INC.

(a society after the

Laws of the State of Delaware)

P. 0. Box 573

Coffeyville, Kansas

V. St. A.

"HYDRODYNAMIC BRAKE"

709843/0862

Deutsche Bank Munich, account no. 82/08050 (BLZ 70070010) Postcheck Munich No. 163397-802

The invention relates to a hydrodynamic or hydrokinetic brake, as used as a dynamometer, braking device for vehicles and hydrodynamic brake for drill pipe use. In particular, deals the invention with a hydrodynamic or hydrokinetic brake that serves to absorb energy, by regulating or controlling the fluid circulated through the brake.

It is known that such hydrodynamic brakes consist of a rotor and a stator which are opposite to each other Have pockets. The shape of the pockets in the rotor and stator varies from design to design various, with spherical pockets in some cases and elliptical or rectangular pockets in others Application. However, the same working principle applies to all constructions of this type.

When the rotor rotates, the fluid in the brake is caused by the inside diameter of the Rotor pocket to flow to the outer diameter of the rotor pocket. Due to the rotating movement of the rotor, the liquid becomes Energy is supplied, and the kinetic energy of the liquid increases. When the liquid comes out of the Brake could kick out after it has left the rotor, then the force that increases the kinetic energy the fluid required is the same as the energy required by a hydraulic pump, and a very small force or energy would be absorbed by the brake, i.e. converted into another form of energy.

In the case of a hydrodynamic brake, however, the liquid emerging from the rotor flows through the between the Rotor and the stator located gap in the stator

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27 IGI

pocket inside. The liquid is determined by the outside diameter the stator pocket is directed to the inside diameter of the stator. When the liquid leaks from the stator, it hits the Kotorflügel in a direction that is opposite to the direction of rotation.

The fact that energy is absorbed by the brake is due to the fact that the rotor acts on the fluid a movement quantity or an impulse is transmitted that also flows into the rotor and stator pockets Fluid suffers frictional loss, and that energy is consumed when the fluid opposes it the direction of rotation flows from the stator into the rotor.

The friction loss due to the fluid flow within the rotor / stator pockets is compared to the momentum transmitted by the rotor to the liquid and the subsequent flow of liquid which consequently directed from the stator towards the rotor, only minimally.

In most hydrokinetic braking devices, the amount of energy absorbed is determined by the Controlled the amount of fluid that is in the brake and that is regulated by the Amount of fluid flowing through the brake. The energy absorption is maximum when the brake is completely filled with liquid and decreases as the amount of fluid in the brake or flow rate or speed is reduced.

The amount of liquid or flow rate or rate is controlled by adjusting a valve located in the inlet opening to the brake, or through a level tank. The brake is so

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builds that when the inlet line is fully open, it works full of liquid. By Closing a valve in the inlet opening will the flow of fluid to the brake is reduced due to the outflow effect of the inlet opening through the valve This also reduces the amount of fluid that flows into the brake pockets. The fluid level in the container can be reduced, so that the pressure head at the inlet opening of the brake prevails and which represents a further control means is reduced in size.

Of particular interest at present is the use of a safety brake device for oil well drill pipes. The brake is attached to the winding drum of the rotating drill pipe and is used to prevent the To delay lowering of the hook when it enters the borehole. As the weight on the hook varies, it must be possible to change the energy absorption capacity of the brake so that the hook can be used for different hook weights can be braked to the same speed.

In the past, two methods of flow regulation and level control were used to regulate the absorption capacity of the brake, but they have never worked to complete satisfaction. The drill pipe is designed in such a way that that it is able to handle maximum loads or weights as a function of drilling depth. The brake is then selected for the drill pipe so that a brake is installed that can handle the maximum hook load to a safety lowering speed of, for example, 65 m / min, decelerates when operating with

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full of liquid.

When the drill pipe used when drilling the oil well is connected, the hook load increases from a minimum value to the maximum value, when the drilling depth increases. With most linkages, the hydrodynamic brake is not used until until the hook load reaches a certain value, because the friction brake of the elevator drum is used to brake and stop of the hook can be used. After a certain hook load is reached, the hydrodynamic occurs Brake in action to slow the load to a safe rate of descent. At this point it is a very small amount of fluid is necessary in the brake. As the load increases, that on the brake increases Amount of liquid present so that the brake decelerates the growing hook load to the same speed can. To enable the brake to decelerate a load to a constant speed, the in the brake fluid can be kept constant. In other words, the amount of fluid that is in the brake is applied must be equal to the amount of fluid leaving the brake. Should the fluid outflow be greater than the amount of fluid entering the brake, then the speed of the brake increases to, causing the brake to slip and the rate of descent to become too great.

All hydrodynamic brakes have a minimum operating point, in which the brake at a certain light load with a certain constant speed is working. When the speed of the brake by reducing the amount of fluid in the If the brake increases, this results in an unstable condition, since the brake does not have the same amount of fluid

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can receive that is carried out of it. The above Problem arises with the drill rods used nowadays because of the greater drilling depths and thus of the wider operating load range in which the brake is working.

If the hydrodynamic brake is by a hydraulic pump is supplied with fluid and the braking process through a manually operated inlet valve between the brake and the pump is controlled, another control problem arises.

While a drill pipe frame is connected to a drill string, the hydrodynamic brake is not rotated, but rather is in the idle state. During this time, the pump completely fills the brake with fluid. However, because of the load acting on the hook, the brake must be operated partially filled with liquid to achieve the desired lowering speed. The brake must therefore dispense a certain amount of liquid to move between the inlet and the outlet to maintain a flow equilibrium. During the period of discharge of excess liquid the Ilaken is lowered at a slower speed than desired. About this slow lowering speed To compensate for the beginning of the lowering, the drill reduced the opening in the inlet valve to thereby to prevent the brake from being filled with liquid during the rest period. During operation the brake is then narrowed the inlet opening so that the brake does not have a balance between the entering and exiting the amount of liquid can be maintained, and the load then runs in the above described way away.

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In order to avoid the above problems in controlling the braking effect, the brake should be controlled inside will. With such brake control inside, the fluid system outside of the brake housing would not Influence the control of the brake.

A well-known method of internal control is to to constrict the flow of liquid in the stator pockets. By preventing the liquid from getting into the stator pockets enter, it cannot strike the rotor.

In US-PS 1 992 911 movable plates are arranged between the end faces of the rotor and the stator. When the liquid exits the rotor, it is on entering the stator through the adjustable plates prevented. To enable braking, the plates are removed from the area between the rotor and stator, and the fluid circulation is started again.

The adjustable plates used hitherto suffer from various disadvantages. It is well known that The braking effect that can be achieved is less, the larger the gap between the rotor and stator end faces. Around To achieve a maximum braking effect, the rotor surface should be as close as possible to the stator surface, so that the liquid can enter the stator pocket when it leaves the rotor pocket. When the gap between the rotor and the stator is large, the liquid does not flow into the stator pocket but instead its out of the exit opening of the brake and is lost.

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The installation of the adjustable plates between the rotor and the stator enlarges the gap, thereby increasing the maximum Braking efficiency decreases as the plates are withdrawn.

If the panels are made thin in order to keep the gap to a minimum, they lose their rigidity, so that they can be found under the impacting water bend and rub against the stator surface. Thus, the friction occurring between the plate and the stator requires a considerable force so that the adjustable Plates can be moved.

When the adjustable plates are moved in or out of perpendicular to the center line of the brake, this will Brake housing quite large so it can accommodate the adjustable plates.

Some of the inlet tubes of the brake are located in the blades of the stator and exit at the end of the stator blade . When the brake is turned and a very small amount of braking is required, the adjustable plates are moved inward and cover the entry pipes. Since the fluid supply to the brake is blocked by the adjustable plates, the rotor runs dry and too much heat is generated due to the turbulence of the air in the pocket, so that an operating state occurs in which the brake runs out.

Furthermore, it has become known in this field of technology to effect the adjustment of the braking force by throttling the pocket circulation, as is shown, for example, in FIG Italian Patent No. 423 510, GB-PS 589,790 and US Pat. No. 3,572,480 "This However, devices are not able to

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measurement speed or amount in the brake in one Set dimensions sufficient to operate the brake in the wide operating range required for use is required on drill pipe drum equipment.

The prior art is also made on the following patents referenced:

U.S. Patent 2,890,661; 3,572,480; 1,992,911;

3,072,222; 3,371,890; 3,399,747;

3,414,333; 3,489,252; 3,467,225;

1,685,735; 1,992,912;

Italian patent: 423 510;

NL-PS: 88,615;

DT-PS: 802 030;

GB-PS: 589 790.

The most important of these patents were mentioned above already dealt with.

The object of the invention is therefore to create a hydrokinetic or hydrodynamic brake, which has a flat operating characteristic, i.e. a flat curve of the speed over the load, in a selected load area. In this context, a controlled brake of the type mentioned be created, which is provided with a device through which the flow rate or amount of the Liquid can be controlled in a large pocket of the stator, while in a small stator pocket one continuous flow is maintained. Furthermore, the load characteristics should be controlled by controlling the Flow rate of the liquid both in one

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large pocket as well as in a small pocket of the stator.

This object is achieved according to the invention in that in the case of a brake of the type mentioned, the flow from the rotor is directed in an essentially axial direction with both the rotor and the stator having a large annular pocket in their matching one Have surfaces as well as a small annular pocket within the large annular pocket. Further a device is provided, for example in the form of a circular coaxial groove or a circular one coaxial slot running on a medium radius from the back of the stator through the large pocket and extends to the rear of the small pocket and contains a corresponding cylindrical baffle plate the axial position of which is the fluid passage in the radial direction within the large pocket of the stator can be controlled.

According to another embodiment of that described herein Invention, the cylindrical slot is continued not only through the space of the pocket but also through the Wall of the small pocket and runs down to the face of the small and large pockets, so that the entire flow of liquid within both pockets, i.e. both the large and the small pocket in the blocked or desired way by adjusting the axial position of the cylindrical baffle plate in the slot can be opened. To control the axial position of the cylindrical baffle plate, mechanical, use pneumatic or hydraulic means in conjunction with a spring device.

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2715126

Another important feature of the invention can be seen in the fact that the control of the hydrokinetic brake is achieved by controlling the flow of liquid within the stator pocket or pockets, while a essentially constant amount of fluid in the brake is fed.

Finally, the construction according to the invention rapid control of the brake regardless of the location of the operator on the drill string and / or reached the location of the drawing tools.

The invention is explained in more detail below with reference to the exemplary embodiments shown in the drawing. In the drawing show:

Figure 1 is a vertical sectional view of an embodiment of the hydrodynamic brake,

Figure 2 is a vertical cross-sectional view taken along line 2-2 in Figure 1;

Figure 3 is a vertical partial sectional view through the axis showing a second embodiment of the hydrodynamic represents or hydrokinetic brake control device,

Figure k shows a third embodiment of a brake with two rotors and stators, both stator pockets having a fluid control,

Figure 5 is a diagram showing the load speed over the Load for a double pocket brake with a control device for controlling the flow rate which represents liquid in the large pockets,

Figure 6 is a schematic view of the invention Device when used on a drill pipe

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Drawing tool system, and

Figure 7 is a partial sectional view showing the relationship between liquid flow and the pocket flow adjuster.

Before the invention is described in detail, it should be noted that its usefulness is not limited to the is limited to the circumstances shown in the drawing, but that they can also be used for other embodiments which can be used in various ways.

In Figures 1 and 2, a brake generally designated IO is shown. This brake has a housing 12 and 14 on. A shaft 18 is supported in bearings 17 in one portion of the housing 12 as described in pending U.S. Patent Applications Nos. 277,669 and 4,740,445. A rotor 20 is carried by the shaft 18 and is wedged with her. It has a circular arrangement with a large number of annular pockets 30, the a rear wall 31 and a front 34 have. One small annular pocket 32 is provided with a rear wall 33 and has a front side in plane 34. the Pocket 30 is geometrically identical to pocket 32, except for the fact that the latter is smaller. The pockets 30 and 32 are preferably about spaced apart a substantially constant distance. This is done for the purpose of large pocket to produce a substantially constant flow, i.e. between the inner wall of the large pocket 30 and the back of the smaller pocket 33 · Further is a coaxial stator 22 with a large annular Bag 45 available. The stator also has a small one annular pocket 47 which has a rear side 51.

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The large and small pockets in the rotor and stator are in sectional view as shown in FIG is essentially mirror images of each other.

In the rotor 20 and stator 22 are several vanes 40 or intended. The blades in the rotor are arranged at an acute angle to the surface 34 and point in the direction of rotation of the rotor. The blades 42 in the stator are separated from each other by the same distance as the blades in Rotor, but at an angle opposite to that of the rotor blades. In other words, the Liquid thrown out of the pockets by the rotor is directed into the pockets of the stator.

Figure 2 is a cross-sectional view taken along line 2-2 in Figure 1 showing the end face of the stator. The wings are indicated at 42 and the outer and inner boundaries of the small pocket are through the rods 44 indicated across the face of the stator.

Each wing in the stator has a line, which is designated and is drilled through it. These Line leads from the rear surface 22 of the stator into the end face 36 of the stator. liquid for the hydrokinetic brake occurs through the opening according to the arrow 25 and flows accordingly the arrows 29 from a chamber 52 through the lines 28 to the end face 36 of the stator. This is why important because the brake is continuously supplied with fluid in this way, regardless of the position of the cylindrical flow control body 59. The liquid flows through the gap 38 between the both end faces 34 and 36 of the rotor and stator, so that they are the spaces within the large and small

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Fills pockets. The flow of liquid in the rotor and stator pockets is directed radially outward, as shown by the arrows k9 , and then moves back in the stator according to the arrows 53. The excess liquid to compensate for that which enters through the opening 2k flows out through the gap 38 between the rotor and stator end faces and then moves axially through the annular gap 5k between the outer circumferential surface of the rotor and the inner urinary surface of the housing 12 according to the arrow 39. It then flows into the chamber 50 and through the opening 26 according to the arrow 27 to the outside.

As stated in the pending patent applications, the radial dimension of the gap is 5 ^ at important in controlling the flow of fluid through the brake. If the control is at the outlet opening of the Uremse takes place, it ensures that the pockets all are filled with liquid at all times so that a stable load-speed condition is established.

The stator 22 is carried by a flat flange 23 which is clamped by screws 16 between the parts 12 and 14 of the housing. Suitable seals are provided between the stator and the housing so that the liquid can flow from the inlet openings 2k through the line 28 into the gap 38 between the two sets of pockets and through the annular gap 5k and then through the outlet opening 26.

Furthermore, there is a coaxial annular groove or a coaxial annular slot 56 which is cut at a radius which corresponds to the maximum axial dimension of the small pocket. This slot runs from the rear

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Kt

side surface 22 of the stator to the rear surface 43 of the small pocket kl. The slot is preferably located at a location within the streamline field so that it is perpendicular to the flow of fluid in the outer pocket. In addition, the slot 56 is located such that its outer circumference is within the radial position of the lines 28. The importance of the position of the cylindrical groove and the cylindrical device located in it lies in the fact that the impinging stream of liquid strikes the cylinder at a right angle. Otherwise, the force of the impinging liquid would cause the cylindrical body 59 to move axially into or out of the slot. The cylindrical body 59 is provided in the form of a tube which can slide in the slot 56. This tube has a transverse wall or plate 58. A spring device 6k can be provided in the space between the stator and the plate 58 and then serves to push the wall outwards so that a free passage is created within the large pocket of the stator . In the space 60 between the plate 58 and the outer wall Ik of the housing, a pneumatic or hydraulic means is introduced through an opening 62, which presses the piston axially to the left, so that the cylindrical body or tube 59 slides in the slot 56 and thereby blocks the entire cross-section or part of the cross-section of the large pocket, as a result of which the liquid cannot flow in the direction of arrow 53. After the pneumatic or hydraulic pressure acting on the plate 58 has been released, the spring forces lead the plate 58 to the right, whereby the passage is opened so that the liquid can flow in the direction of the arrow 53 again. If no flow through

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the stator pocket takes place is the braking effect the large stator pocket eliminated. When the cylindrical body 59 'has also been referred to above as a pipe is, is withdrawn, so that the flow of liquid begins again according to the arrow 53, then that of maximum braking effect generated by the large pocket.

In Figure 3 is another embodiment of the arrangement of Figure 1, in which the groove or cut 56 does not only run through the space in the large pocket, but also extends through the rear wall 43 of the small pocket, as an extension 56a, down to the bottom to the end face 36 of the stator. Thus, in Figure 3 a cylinder 72 is shown which now has a greater length compared to the cylindrical body of Figure i, so that it can move as far as the end 71 is flush with the end face 36 of the stator. In this position he can control the flow of liquid in the Block the stator through both the large and small pockets; . ^ thereby the braking effect the hydrokinetic brake to a minimum.

The cylinder 72 of FIG. 3 differs from the cylindrical body of FIG. 1 in that the circular plate 58 here forms an annular plate 70 which is fastened to the tube 72. This ring plate 70 acts like a piston in an annular space 79. Behind the piston 70 there is a fluid space 78, into which pressurized fluid can enter through the opening 80, thereby facing the piston 70 and the tube 72 attached to it to the left press against the force developed by the spring Ik.

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This allows the tube 72 to be inside the two spaces completely or partially block the large and small pockets. Various seals, for example O-rings can be used to seal the stator in the housing and also to seal the To effect piston 58 and 70 in their cylindrical working space. All of this is in this branch of technology known. Although the actuation of the piston 70 and the Tube 72 in slot 56 to pneumatic or hydraulic As described in connection with a return by spring force, it can also be entirely be effected mechanically by means of levers acting on the tube 72 and the cylindrical body 59.

A comparison of Figures i and 3 shows that in a single rotor and stator system, a single cylinder and a single tube can be used to control the flow both in the large bag alone or in the control the large pocket and the small pocket of the stator together.

In Figure k , an embodiment is shown which is similar to that in Figure 1, except for the fact that two rotors 120, 120A are used, which are spaced apart and facing each other, and two stators 122, 122A, which are in the Space between the two rotors, with the end faces 136 and 136a of the stators being separated from the two rotor end faces at the desired gaps 138, 138A. The stators are spaced back-to-back, and in the space between them are two axial annular grooves 156 and 156A between the rear surfaces of the large pockets of the stators and the rear surfaces of the small pockets.

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cut. Furthermore, two tubes 206 and 206a are attached to the pistons 208 and 218. Both pistons are located in a single cylinder face to face, so that the through an opening 200, 202 in the cylindrical barely 204, which has the shape of an annular Has cylinder, pressure medium entering the two pistons and their cylindrical tubes 206 and 206a simultaneously can move outwards, against the force developed by the coil springs 214 or 222, in order to thereby control the flow of liquid in the stator pockets. Of course, the grooves 156, 156a can also cut only through the large pocket space or through both the large and small pocket spaces be.

The one tube 2ü6 is, for example, by welding attached to an annular plate 208 which forms the piston. The piston also carries a smaller one tubular body 210. The tubular body 210 and the fixed cylindrical part 222 form an annular Cylinder for the piston 218 which carries the tube 2O6A in the second stator. The coil springs 214 and 222 guided by rings 216 and 224 generate the holding force and the force that pulls the pistons back when the fluid pressure is out of space 204 escapes.

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-Vr- Ke / z

In the operating state of a hydrokinetic brake the operational stability improves when the pockets, both large and small, which are always filled with liquid, and the exit control the flow is effected by means of the annular gaps 154 and 154a. When the rotor turns, the Liquid in the rotor pockets, according to arrows 149 and 149A, as in a centrifugal pump radially flung outside. When the flow channel is open inside the large stator pockets and small stator pockets the flow of liquid moves out of the rotor into the stator pockets and then migrates radially inward, according to arrows 153 and 153A. Just the bump of the liquid entering the rotor pockets from the stator, with the corresponding generation of turbulence and heat represents lost energy and limits the movement of the rotor, i. H. the braking effect. But when there is no flow through the stator pocket, this heat generation is limited to a minimum, and you would only have to do with the friction that flows into and out of the rotor through the control gaps 154, 154A causing leakage of liquid. Accordingly, by controlling the flow rate or speed the liquid in the stator pockets vary the braking effect, with the whole brake in a stable Operating state.

As can be seen from Fig. 1, there is the possibility that Control so build the coaxial tube and groove so that it can only pass through the gap in the large pocket is working. As shown in Fig. 3, the operation of the flow control element can through the large pocket and also the small pocket, whereby maximum control of the braking effect is achieved.

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5 shows a diagram in which the ordinate represents the load speed, for example the speed of the lifting hook in a rotary drilling device, while the abscissa represents the hook load, that is to say the load carried by the drilling ropes. 6 schematically shows the brake 10 which is attached to the drum 302 via the shaft 18 and the coupling 300. The drum contains a helically wound wire rope 304 which is steered with the aid of a rope pulley at the tip of a drilling crane to a hoist hook and / or elevator for raising and lowering the drill pipe, which is not shown here. The elevator drum is driven by a drive machine 306 via either a slow drive 308 and a coupling 310 or a high-speed drive 312 and a coupling 314. Water from a supply container 320 is pumped via the line 322 to the inlet opening of the pump 10 and returned to the container 320 through the outlet line 324. Most of the rods have a pressure medium supply 330 (in the present case air) which is controlled by the drill with the aid of the valve 332, whereby it reaches the connection opening 62 of FIG. 1, so that the movable plate 58 is moved into the stator pockets . The purpose of the hydrokinetic brake in this application method is to inhibit the rotation of the cable drum so that the load carried by the hook or the elevator does not go faster than a selected speed, for example 65 m / min. _{t is} moved, namely in a selected load range, for example between 37 and 100 tons.

The small pocket alone is suitable for braking the hook when the loads are below 37 t. The part of Characteristic curve, which is drawn out and labeled 240 (Fig. 5),

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represents the hook speed when the load is from 7.5 to 37 t increases, while the speed increases from 30m / min. up to 65m / min. varies. It was determined that the speed of 65 m / min. should be the selected operating speed. It goes without saying that then, when the small bag is used alone, the hook speed changes according to the dashed line Extension 242 of the characteristic curve for the small pocket cross-section increases as soon as the load rises above 37 t This is undesirable. The large bag was used during the time when the hook loads were below 37 t, i.e. for the characteristic curve region 240 up to the point 246, closed by the control device 332. Once the load is over 37 t increases, the control device is then withdrawn, causing an increasing amount of liquid through the big bags can flow. This control movement is synchronized with the load, so that the characteristic load speed at about 65m / min. lies, namely up to a point 248, which corresponds to a load of 100 tons. At this point the control device is complete withdrawn from the large pocket and there is no further possibility of controlling the flow of liquid. As a result, the speed of the hook increases according to the curve 252 over 65m / min., if the load becomes larger than 100t. The curves 250 and 252 represent the speed as a function of the load both for both small and large pocket cross-sections.

It would be possible to extend the section 244 to the left and a speed of 65 m / min. for smaller ones Maintain loads as 37t using the embodiment of FIG. 3 when part of the flow is in the small Bag would be cut off. The end part 71 of the in FIG

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The tube 72 shown can, as shown, be square, but it can also be rounded and have any chosen shape, so that the turbulence due to the Liquid flow around the end of the tube when this partially in the liquid flow in the large Bag protrudes, is kept to a minimum.

An important feature of the construction described here is the displacement of the cylindrical tube 59 with respect to the flow of liquid. As can be seen from Fig. 7, the circumference should be arranged with respect to the pocket so that it is perpendicular to the flow, as shown by the arrows, so that the forces acting on the cylindrical tube 59 are in equilibrium.

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Claims (12)

2715126 PATENT CLAIMS: 1. Hydrodynamic brake with at least one single "rotor and one single stator, each one of which Has fluid pocket which are opposite to each other at the same circumferential distance from the axis of rotation, wherein the rotor and the stator are separated from each other at a selected distance and each pocket has several planes Has vanes which extend in the radial direction over the pockets and in the rotor in the direction of rotation of the rotor are inclined and are inclined in the opposite direction in the stator, characterized in that each of the annular pockets (45, 47; 30, 32) in the stator (22) and rotor (20) from a wall surface (33) to an inner one smaller pocket (47, 32) and an outer larger pocket (45, 30) is divided that the distance between the outer wall surface of the inner pocket (47, 32) and the inner wall surface of the outer pocket (45, 30) what is constant is that the inner and outer pockets have the same curved configuration that in the outer pockets (45, 30) wings (42) are provided which continue over the inner pockets (47, 32) that in the wings (42) in the stator pockets (45, 47) a line (28) is provided which on the rear side (22) the outer pockets of the stator has a liquid inlet opening, and its liquid outlet opening in radial direction in the space (38) between the rotor and the Stator (20, 22) is arranged within the inner pockets (47, 32) so that during the rotational movement of the rotor (20) a constant flow of liquid into the inner pockets (47, 32) through the space (38) between the stator and Rotor passes through and thus into each outer pocket (45, 30) that a cylindrical groove (56, 156, 156A) co- 709843/0862 ORIGINAL INSPECTED axially to the axis of rotation through the rear surface (22) of the stator (20) and the blades (42) in the outer pocket is cut, which is arranged so that the outer circumference of the groove was within the radial from the outlet openings of the line (28 ) is that a circular, cylindrical device (59, 72, 206, 206A) is present, which is located in the groove, is not rotatable and moves back and forth in the axial direction in the groove , that the inner and outer pockets (45, 47, 30, 32), the groove (56, 156, 156A) and the cylindrical device (59, 72, 206, 206A) are arranged with respect to one another so that a tangent to the curved outer wall surface of the inner pocket and a tangent to the curved inner wall surface of the outer pocket at its intersection with the outer surface of the cylindrical device (59, 72, 206, 206A) is perpendicular to the outer surface, and that means (64, 74, 214, 222) to move the cylindrical device is provided. 2. Hydrodynamic brake according to claim 1, characterized in that the device (64, 74, 214, 222) for moving the cylindrical device to and fro has a fluid-operated device (53, 70, 218). 3. Hydrodynamic brake according to claim 1, characterized in that the means (64, 74, 214, 222) for reciprocating the cylindrical device forms a spring which is normally so tensioned that the cylindrical device from the groove ( 56, 156, 156A) is kept out. 4. Hydrodynamic brake according to claim 1, characterized 70S8A3 / 0862 by two stators (122, 122A) and two rotors (120, 120A). 5. Hydrodynamic brake for the rods of a derrick, with a driven, rotatable drum for Winding up of the rope used for lifting in the derrick to which the hydrodynamic brake is attached. the is brought, braked with the rotary movement of the drum is, wherein the brake is at least a single rotor and a single stator each provided with an annular fluid pocket which extends opposed to each other at the same circumferential distance from the axis of rotation, and wherein the rotor and the stator in a selected distance next to each other and each pocket is equipped with several flat wings that extend in the radial direction through the pockets and are inclined in the rotor in the direction of rotation of the rotor and the stator are inclined in the opposite direction, characterized in that each of the annular pockets (45, 47, 30, 32) in the stator (22) and rotor (20) from a wall surface (33) into an inner smaller pocket (47, 32) and an outer larger pocket (45, 30) is divided that the distance between the outer wall surface of the inner pocket (47, 32) and the inner wall surface Al outer pocket (45, 39) is constant, that the inner and outer pockets have the same curved configuration that in the outer pockets (45, 30) wings (42) are provided, which continue over the inner pockets (47, 32) that in the wings (42) in the stator pockets (45, 47) a line (28) is provided on the back (22) of the outer pockets of the stator a Has liquid inlet opening, and its liquid outlet opening in the radial direction in the space (38) 70 ° 843/0862 is arranged between the rotor and the stator (20, 22) within the inner pockets (47, 32) so that during the rotation of the rotor (20) a constant flow of liquid into the inner pockets (47, 32) passes through the space (38) between stator and rotor and thus into each outer pocket (45, 30), that a cylindrical groove (56, 156, 156A) coaxial with the Axis of rotation through the rear surface (22) of the stator (20) and the blades (42) in the outer pocket is incised, which is arranged so that the outer The circumference of the groove lies within the radial distance between the outlet openings of the line (28) so that a circular, cylindrical device (59, 72, 206, 206A) is present which is located in the groove and cannot rotate is and back and forth in the axial direction in the groove moved that the inner and outer pockets (45, 47, 30, 32), the groove (56, 156, 156A) and the cylindrical Device (59, 72, 206, 206A) are arranged in relation to one another so that a tangent to the curved outer wall surface of the inner pocket and a tangent to the curved inner wall surface of the outer pocket at its intersection with the outer surface of the cylindrical device (59, 72, 206, 206A) perpendicular extends on the outer surface, and that means (64, 74, 214, 222) are provided for reciprocating the cylindrical device. 6. Hydrodynamic brake according to claim 5, characterized in that the device (64, 74, 214, 222) for reciprocating the cylindrical device a fluid-operated device (58, 70, 218). 7. Hydrodynamic brake according to claim 6, characterized in that a control device is provided for supplying pressure medium to the brake. 709843/0862 271G126 8. Hydrodynamic brake according to claim 7, characterized characterized in that the control device is arranged on a control panel next to the elevator drum. 9. A hydrodynamic brake according to claim 6, characterized in that the groove (56, 156, 156A) extends from the rear (22) of the stator to the front of the inner pockets, and that the fluid operated device controls the flow of fluid in both the outer and the outer pockets controls the inner pockets (45, 30; 47, 32). 10. Hydrodynamic brake according to claim 5, characterized in that the device for reciprocating the cylindrical device (59, 72, 206, 206A) has a spring device which is normally so is tensioned that it holds the cylindrical device out of the groove (56, 156, 156A). 11. Hydrodynamic brake according to claim 5, characterized by two stators (122, 122A) and two rotors (120, 120A). 12. Hydrodynamic brake with at least one single Rotor and a single stator, each provided with an annular fluid pocket, which face each other at the same circumferential distance from the axis of rotation, the rotor and the stator in one selected distance are next to each other and each pocket has several flat wings that extend radially through the Pockets extend and are inclined in the rotor in the direction of rotor rotation and in the Staotr in the opposite direction are inclined, characterized in that each of the annular pockets (45, 47; 30, 32) in the stator (22) and 709843/086 the rotor (20) through wall surfaces (33) into the interior smaller pockets (47, 32) and outer larger pockets (45, 30) is divided that the distance between the outer wall surface of the inner pocket and the inner Wall surface of the outer pocket is constant that the inner and outer pockets are the same curved Have configuration that the wings (42) in the outer pockets (45, 30) extend through the inner pockets (47, 32) continue that a line (28) is present in the wing (42) in the stator pockets, the one Liquid inlet opening on the rear surface (22) of the outer pockets in the stator, and their liquid outlet opening in the radial direction is arranged in a space (38) between the rotor (20) and stator (22) within the inner pockets in order to thereby initially a continuous flow of liquid into the inner pockets and through the space (38) between the stator (20) and rotor (22) and thus in each outer pocket, as the rotor rotates, causing a cylindrical groove (56, 156, 156A) is provided, which is coaxial with the axis of rotation through the wall surfaces of the stator and the vanes (42) outer and inner pockets are incised and so arranged is that the outer diameter of the groove lies within the radius of the outlet openings of the line (28), that an exactly circular, cylindrical device (59, 72, 206, 206A) in the groove (56, 156, 156A) is present is, which is rotationally fixed and is located in the axial direction in the groove to control the flow of liquid in the outer and inner pockets (45, 47, 30, 32) reciprocate that the inner and outer pockets, the groove and the cylindrical device is arranged in relation to one another so that a tangent to the curved outer Wall surface of the inner pocket and a tangent to the curved inner wall surface of the outer pocket its intersection with the outer surface of the cylindrical device (59, 72, 206, 206A) perpendicular to the 709843/0862 outer surface that a spring means (64, 74, 214, 222) is provided which normally holds the cylindrical device out of the pockets, and that a pressure medium operated device (58, 70, 218) is present with which the cylindrical device can be moved into the pockets. 709843/0862