DE1805329C - Hydrodynamic brake - Google Patents

Description

The invention relates to a hydromechanical Brake with a stator housing arranged in a housing that extends over its circumference having distributed stator blades, the liquid tasr.hen substantially radially inwardly directed which form an inlet duct located near the central axis of the housing and on or in contains outflow openings for the liquid arranged in the vicinity of its circumference, as well as with a rotatably mounted paddle wheel with rotor blades, which are directed approximately radially outward Form fluid pockets for interaction with the stator pockets.

Older brakes of this type had satisfactory braking properties in a certain, relatively small speed range of the rotor of the brake. In other speed ranges, however, the braking properties were unsatisfactory, since the turbulence of the working fluid in the rotor and stator pockets required to achieve a good braking effect could not be maintained over a wide speed range of the rotor, because under certain circumstances the working fluid, which is usually a light oil is like a frictionless bearing ^; The fluid between the stator and rotor acts and not as a turbulent braking medium, which results in a sudden loss of the braking effect. The cause of this has been found to be that oil becomes trapped in the stator and impeller pockets, with a stagnant oil condition and a loss of turbulence between the pockets. In other words, if at any speed the oil becomes trapped in the brake and has no flow between the rotor and stator pockets, the oil in the space between the ends of the rotor blades and the stator blades will be cut off in layers without turbulence. The paddle wheel rotates without resistance because the oil, which forms separated adjacent layers after the loss of its turbulence, cannot act as a delay medium, but only forms support surfaces that slide freely over each other and cause the brakes to run away.

To ensure an eddy-free state of the working fluid to avoid as much as possible, a gear has been arranged between the drive shaft and the rotor, that changes the speed of the rotor relative to that of the drive shaft, e.g. B. the speed of the Rotors increased to increase the turbulence.

In a known brake, a planetary gear is arranged between the drive shaft and the rotor. In addition, two friction disc brakes are arranged, which have the braking effect support in certain speed ranges (USA.-Patent 3 108 660). These measures have proven to be successful to some extent, but require substantial propagation of moving parts and therefore an increase in the cost of such a brake as well an increased susceptibility to failure of the same.

The invention is based on the object of avoiding these disadvantages and a hydrodynamic To train the brake of the type specified in such a way that an increase with simple means the turbulence of the working fluid in the rotor and stator pockets over a wide speed range to increase the braking torque can be achieved.

This is achieved according to the invention in that overflow openings in some of the rotor blades and / or at least in some of the stator blades in the vicinity of the outflow openings and overflow openings are arranged.

The overflow openings are a further development of the invention in the stator blades at an angle to the outflow openings of the stator housing arranged.

The passage openings in the base of the rotor blades are expediently adjacent to the liquid inlet the stator housing arranged.

According to another useful feature of the invention, the rotor blades are reversed Direction tapered to the direction of flow. This gradually increases the static pressure of the working fluid increased so that the liquid in this area is free from cavitation.

The stator blades expediently have radially inwardly extending ones at their front end Sections on.

In the description below is an exemplary embodiment of the invention described in connection with the drawings. In the drawings represents

F i g. 1 shows a side view of a towing vehicle equipped with the hydrodynamic brake system according to the present invention Invention is provided,

F i g. 2 shows a longitudinal section of the hydrodynamic brake according to the invention,

Fi. 3 is a rear view of the hydrodynamic brake, in which the rear end plate removed and the loading valve assembly is shown,

F i g. 4 shows a cross section along line 4-4 of FIG. 2, which shows the blade arrangement of the impeller and the stator housing shows

F i g. 4 a is a partial view of the tapered rotor blades,

FIG. 5 is a cross section along line 5-5 of FIG. 2, deT the cooperating pockets in the Detail shows

F i g. Figure 6 is an end view of the stator housing with parts broken away around the circumferential discharge means to show. ouch

In Fig. 1 shows a motor vehicle T which has a drive shaft 5 to which a hydrodynamic brake 10 is coupled, which embodies the principle of the present invention. Immediately behind the hydrodynamic brake 10 is a cooler unit 11. Immediately in front of the hydrodynamic brake 10 is a fan 12 for promoting the cooling effect, as will be described in detail later.

The brake 10 transmits a braking force to the rear wheels of the vehicle T via the drive shaft S when it is switched on by the driver. When the car T is to drive in a normal manner and unaffected by the brake, the brake is switched off. It is noted that the use of the brake 10 according to the present invention on the motor vehicle T is only one example of application of the invention and that the brake 10 is also used in other motor vehicles, such as buses, tractors, aircraft or any other with wheels provided vehicle can be used in which the aim is to brake high vehicle speeds in a controlled manner.

In Fig. 2 is a section through an outer housing 15 of the brake 10 shown, which has a Abschlcßplatte 16 and for receiving the Functional parts of the brake 10 is used. The end plate 16 is preferably at its periphery with the outer housing 15 welded at 17, so that the housing throughout the life of the Brake is locked. The welding can be done because the brake 10 is very simple is as well as has very few moving parts and therefore no maintenance during the service life of the vehicle is required. As shown, the housing 15 and the end plate 16 be provided with suitable cooling fins 18 to divert a portion of the heat directly to the outside air to dissipate.

Roller bearings 20, 20 α are arranged at the front and rear for mounting the drive shaft S. The bearings 20, 20 a are held in contact with shoulders 21, 21 a of the shaft by means of Mont2 -;>? Bushings 22, 22 α, which are held in contact with screws 23 are attached. The bearings 20, 20 α are held in contact with the shoulders 21,21a by threaded bushings 24, 24 a, which are secured against unintentional rotation tienen over the mounting bushes 22, 22 α by locking screws 25, 25 a.

In the housing 15, a stator housing 26 is concentrically attached by screws 23, 23 a , which is connected to an end plate 27, preferably by a weld 28 on its periphery, in order to form a sealed stator unit. In the space delimited by the stator housing 26 and the outer housing 15, a fluid container is formed for feeding the working fluid into the interior of the stator housing when braking is required (see the oil level shown in FIG. 8).

Under the oil level in this container there is a pair of bearing lubrication channels 30,30 a, svekhe lead to the bearings 20, 20 α in order to constantly lubricate and cool them with oil from said container. As can be seen in Fig. 2 and 3, the lubrication channel extends through the hub of the end plate 27 and the mounting sleeve 22 a. The connection of the two channel parts to one another is ensured by the arrangement of an arcuate transition extension 31 α. The bearing lubrication channel 30 is also provided with a widened transition 31. The flow path for the oil to the bearings 20, 20 a is completed by slots 32, 32 α in the threaded bushings 24, 24 a, and suitable oil seals 33, 33 α are arranged in the threaded bushings, so that the bearing lubricating oil in the direction of in Fig. 2 drawn arrows flows.

The paddle wheel 35 of the brake 10 has a central hub 36 which is expediently provided with a steel bushing which is connected to the drive shaft 5 by a wedge. The impeller 35 is fixed in the axial direction on the shaft S by snap rings 39 which bear against the ends of the hub 36, as in FIG. 2 shown. During the rotation of the shaft S and the impeller, the oil flowing downward through the bearings 20. 20 α tends to flow away due to the centrifugal force outside along the hub, so that there is a steady flow of bearing lubricating oil. A limiting ring 39 a can be arranged next to the roller bearing 20 α in order to restrict the flow path to the rear end of the impeller 35 and to prevent flooding of the bearing 20 α.

In the lower half of the end plate 27 there is arranged a loading valve device 40 through which oil is introduced from the container into the interior of the stator housing 26. The device 40 includes an inlet channel 41 at the top of which are a number of upwardly extending passages 42. A rotatable valve member 43 with through-flow bores 44 serves to close or open the passages 42 (see FIGS. 2 and 3). In the in F i g. 2, the valve 40 is open so that the oil can flow into the housing 26, since the passage channels 44 of the rotatable valve member are aligned with the channels 42. When the valve member is rotated so that the passage bore 44 is at the angle of the flow channel 42, the oil supply is progressively limited until the valve 40 is in the fully closed position ^{with one O u rotation.} With this setting, air can be admitted into one or more of the passages 42 through an air pipe 45 and a connecting groove 4 which extends along the rotatable valve member 43, in order to

Stator housing located ö! to push out and so the wings 50 entering and through the out of the

to make the brake ineffective. The air tube 45 activated passages 57 incoming rays

has an opening 47 that communicates with the air chamber, the liquid tends to be a substantial amount of

through the interior of the housing 15 above the oil turbulence in the form of radially expanding

mirror is formed in the container to have 5 spirals in connection. That further improves that

stands. Charging, generally causes an increase in turbulence

An inlet passage chamber 48 protrudes directly in the stator housing 26 and prevents any-

iibci the passages 42 (see Fig. 2) which, after a complete loss of

as in Fig. 4 can be seen extending upward to turbulence and after a no-flow condition

a wide area of communication between the ic of the liquid, as it may otherwise occur,

incoming liquid and the paddle wheel 35. As shown in Figs. 2 and 4a, the turbulent

admit. The pumping action for introducing the flow path along the rotor pockets 56 in general

Oil from the container through the valve device 40 from right to left or from the rear end, where

and the introduction through-flow chamber 48 to which the blade parts 50, 53 are arranged, on the other hand

Impeller 35 is directed in the throughflow chamber 48 15 end. That is, the total flow of the

Caused by the pump blades 50, the turbulent liquid takes place from right to left

extend from the hub 36. The blades 50 in FIG. 4 a, and to ensure that the liquid

be found at the same distance from each other on wedge in this area free of cavitation or air

the hub 36 and are opposite to the direction of rotation is blowing, the static pressure of the liquid

(Arrow 52) inclined backwards, the ao gradually increased by the fact that the wings 55 in

Velocity of the liquid moving radially in the opposite direction or from left to right

flowing through the impeller 35, are too tapered, as illustrated in this figure,

bigger. The arrangement of the rotor blades 55 is also connected to the pump blade parts 50

Trcibschaufelteile 53 to the liquid further _c j _n e such that the rotor pockets 56 close to the

to accelerate and after the outer handle ₃₅ front end expelling the liquid from

of the paddle wheel 35 /.u guide. the stator housing because of the increase in

The blades 50, 53 are connected to one another at their rearward fluid pressure support, which favors the radial outward end through a circular disc 54 (Fig. 4) upward movement au :, the rotor pockets 56, which serves Hnyu, the blades at the inner circumference of the Slatorgehäuses is arranged to stiffen a and the connection between the inputs ₃₀ plurality of spaced-distance laßkammer 48 and the spaces between Statorschaufcln 60, the pockets 61 form, the blades 50 (s. Fig. 4) delimited. All which interact with the rotor pockets 56. Vanes 50, 53 go up outwardly ER- turbulent _to Jen flow path to form, as shown in stretching rotor blades 55 via extending vertically F i g. 2 and 4 can be seen. As best extend right to the Schaufeln50,53, respectively, otherwise ₃₅ Fig. 5 can be seen, are the ends of words, the rotor blades 55 extend Rotorschaufcln 55 at a small distance from the parallel to the central axis of the brake 10 stator blades 60, so that during the rotation of the (see Fig. 2). These rotor blades 55 delimit a blade wheel from the liquid in the opposing numbers of elongated rotor pockets 56, as overlying pockets 61, 56 become turbulent as a result can best be seen in FIG. On the _4O mutual interference and separating the liquid operation thereof will be discussed later. Keitsmolekolekule to the brake 10 their necessary

According to one feature of the invention, braking force properties are to be given. Your function Let 57 at the base of each of the blades 50 is determined by some important design factors arranged to affect the flow of liquid between the blades 55, 60, as now adjoining, η to enable pump rooms and 45 is explained in detail.

thereby each subsequent space with a small amount of liquid across the surface in question extend around the ends of the rotor blades and the inlet chamber 48 to fill (Fig. 2). These form blade sections 62, as best shown in FIG. 2 Inlet passages 57 are at such an angle as can be seen. At the opposite end of the that they are facing outwardly from the inlet chamber 50 vanes 60 on the inner surface of the closure are as shown in FIG. If each plate vane sections 63.Both vane sections individual pump blade 50, the inlet chamber 48 at 62 and 63 are in alignment with the blades their rotation in the direction of arrow 52 overflows 60 (see FIGS. 4 and 5). As a result of the presence of the If a precisely determined jet of liquid through blade sections 62, 63 are separate Verdie Passages 57 in backward and outward 55 vortex areas 64,65 at the ends of the passage caused, which created the initial effect of the outflow path in the pockets 56,61, which with solves. This jet of liquid then causes a central vortex zone 66 to work together bring in more liquid when the blades 50 provide a particularly effective exchange of liquid Cross inlet chamber 48, and consequently speed back and forth on the flow path Call up the charging characteristics of the paddle wheel 35 60. In addition to this type of vortex effect strongly raised. The arrangement of the flow takes place over the length of the flow path let 57 ensure that the blades 50,53 have a significant vortex effect at 90 " are completely overflowed by liquid in the shortest possible time because of the movement of the ends of the rotor Time so that a maximum amount of shovel across the stator pockets, such as through the of fluid is available for shear and for 65 arrows 68 in FIG. 5 is indicated. It is established Turbulence in the rotor pockets 56, as explained later, that was seduced by the combination ilieccr is. It has also been found that the different eddy forces cause the turbulence in the brake in each of the successive spaces between 10 self-sustaining kind and very much

Ιό

It is more effective than that previously with known braking condition occurs at any rotational speed of the Dreherachbar was. / nhlbcreiclis for which the brake is designed. The

If the ends of the rotor blade are over the is very reliable by the present invention

Stalortaschcn 61 realized during the rotation of the impeller in that in each stator blade 60

35 bir. run away, there is of course a brief 5 a passage 75 is arranged, which has a con-

Increase in pressure in the individual stator trolled passage of oil between adjacent

taschen61 to trigger an impulse. To one at stator pockets61 admits. Wi <; shown in Fig. 2,

the simultaneous superposition of these individual passages 75 are in the vicinity of the front one

Pressure fluctuations occurring jerky work of the lindes of the flow path or in the neighborhood

To prevent impeller 35, the number of io of outflow openings 70 to 72 is arranged. This

Stator vanes from that of the rotor vanes, passages 75 allow the over-

55 different. This ensures that no liquid escapes between the stator pockets 61

all rotor blades 55 and stator blades 60 at the same time, so that this is not included therein,

align with one another at an early stage, but gradually. That could cause a state of no flow

her is in the illustrated preferred embodiment ₁₅ could. The exchange of fluid through the

form of the invention the number of rotor blades 55 passages 75 through it takes place around the stator

been chosen as an even number, while the number housing clockwise instead, as shown in Fig. 5

The stator blades 60 is an odd number, being evident, due to the action of the blades

the in F i g. 4 results in 55 moving over the pockets. the

with the result that when the paddle wheel 35 ao passages 75 are arranged so that they are from the front

moves past the pockets 61, the pressure in. to the rear as well as obliquely to the periphery of the

each of two successive stator pockets run towards Slatorgchäuses. This reverse

rises and falls at different times and the direction of the passages 75 with respect to the

it is ensured that an impact effect does not occur. flow path along the pockets 56, 61 reinforces the

The peripheral discharge means of the stator housing a ₅ vortex effect at 64 in the stator pockets 61, preferably consist of an upper group of _s0 that the turbulent state of the liquid further improves outlet openings 70 and two lower groups of and an undesirable laminar flow AnslaßöfTiuingen 71, 72. as can best be seen in Fig. 2 or a flowless state of the liquid vcr- and 6 can be seen. This arrangement prevents this. Furthermore, because of the flow through, the oil is drained out of the stator housing at three 30 of a certain amount of liquid through the mutually separated points on the periphery of the fermented 75 the liquid in the stator pockets 61 housing for the purpose of evenly discharging the liquid to the outflow openings 70 to 72 and around a constant flow in order to promote a better outflow of the stator flux through the brake. It is also to be done with housing 26.

Arrangement of a plurality of outlet openings by 35 The most favorable width of the passages 75 is fixed.

the periphery of the housing 26 around possible that has been put to the braking capacity of the brake

Lowering working pressures to around 0.35 kg per square cm, 10 having a positive effect on the larger ones

and there is a better pressure equalization at the inner passageway, the liquid is more unhindered from

Perimeter of the case held while the desired one pocket can flow to another and

Turbulence effect in the liquid is still maintained- 40 therefore less resistance when rotating the

is obtained. Impeller 35 causes. Generally has a

While the groups of outlet openings 70 in passage of about 6 mm a good crossing outer annular wall of the housing a.i- see the stator pockets 61 are given back, the outlets 71, 72 are in the stir *! - to prevent the liquid from holding and the high wall of the housing arranged (Fig. 2 and 6). En 45 no swirling effect of the liquid The pair of throughflow chambers 73, 74 are to be weakened with the Au «-. By dimensioning the passage openings 71, 72 connected so that the outputs 75 can easily change the characteristic Oil escaping from these openings can be changed within certain limits when the brake 10 is discharged Operation to a point above the oil level in adaptation to the particular conditions of a the container is transferred. The heated oil will be 50 special vehicle.

so cooled before it goes into the duty cycle. One of the advantages of the brake arises from the dei

Stator housing comes back. Due to the position of the arrangement of the passages 57 in the paddle wheel 3f

Inflow openings of the storage container is also and the passages 75 in the stator blades, the

a backflow of liquid through the opening - an effective and reliable working dei

gen 71,72 prevented when the brake 10 ur- 55 hydrodynamic brake 10 in the whole speed

is charged and turned off. ensure the brake area. Furthermore, through

The operation of the brake is as follows: the arrangement made according to the invention dei

When the valve device 40 is opened, ui, i rotor and stator blades 55, 60 have a high unc

Bringing oil into the stator housing, constant turbulence is achieved for the oil. It's gone

pumped outwards, as shown in Fig. 2 by the 60 that it is possible to raise the brake with

Flow direction arrows indicated, will then operate over dis Hch lower fluid pressures, al;

Path of the turbulent flow with the eddies - it was previously possible, namely as a result of the An

zones 64 to 66 and finally through the order of a multitude of outflow openings 7 (

Outlet openings 70 to 72 pushed out. While i to 72 around the periphery of the Staic-rgehäusei

this is the same process as it was with the Ei-65. Finally, the Verbesseningen ai

Purification of the injection openings 57 executed: the cooling and control combined with the brake

important that the turbulence along the flow path system an economical and reliable worker

is maintained so that no flow lock of the brake is safe.

For this purpose 213 Iatt drawings 309 617 / 2Z

Claims (5)

Patent claims: 1. Hydrodynamic brake with a stator housing arranged in a housing, the has distributed over its circumference stator blades, which are directed essentially radially inward Form pockets of liquid, one near the central axis of the housing lying inlet channel and on or in the vicinity of its circumference arranged outflow openings for the liquid, as well as with a rotatably mounted paddle wheel with rotor blades, the approximately radially outwardly directed fluid pockets for interaction with the Form Siatorlaschen, characterized in that at least in some of the Rotorschauie.n (50) Overflow openings (57) and / or at least in some of the stator blades (60) in the vicinity of the outflow openings (70, 71) overflow openings (75) are arranged. 2. Brake according to claim 1, characterized in that that the overflow openings (75) at an angle to the outflow openings (70, 71) are arranged. 3. Brake according to claim 1, characterized in that the through openings (57) in the base of the rotor blades (50) are disposed adjacent the liquid inlet. 4. Brake according to claim 1, characterized in that the rotor swings (55) in reverse Direction to the flow direction are tapered. 5. Brake according to claim 1, characterized in that the stator blades (60) at their front end have radially inwardly extending portions (62).