EP2094945B1 - Fluid motor having improved braking effect - Google Patents

Description

The invention relates to a motor drivable by a fluid pressure medium. In particular, the invention relates to a motor in which a runner arranged in an engine compartment is drivable with a pressure medium and in which an axially movable spring-loaded brake element forms a friction pairing for braking the rotor with its end face.

Fluid motors are preferably operated with compressed air or with a hydraulic fluid. For the drive performed during the relaxation of the pressure medium used work is utilized.

One known type of engine is the vane motor. This comprises a rotating in an engine compartment rotor with radial lamellae. As the rotor rotates, the volumes of the interstices largely sealed by the fins and the wall of the engine compartment change. The introduced in these spaces print medium expands here and drives the runner so.

Such motors have proven to be very reliable for a variety of applications, for example. For use in hoists. For many purposes, a braking device is necessary, which can slow down and shut down the vane rotor when no pressure medium is supplied. In particular, when used in hoists such a crash of the load is avoided.

In a variety of known hoists, the braking device is coupled to the engine via a shaft, but is located as a separate part outside the engine compartment, d. H. outside the room where the pressure medium expands.

In the EP 1 099 040 is described a driven by compressed air vane motor. In a cylindrical motor sleeve is a vane rotor eccentrically rotatably mounted. The motor is driven by supplying compressed air, which relaxes when enlarging chambers formed between fins. On a shaft of the motor, a separate braking device is provided. For lubrication of the motor, the vane rotor contains longitudinal bores, which are filled with a lubricant of pasty consistency.

The DE 1 102 488 discloses a pneumatic motor for hoists, the drive shaft is braked when stopping or missing the driving compressed air by a friction brake. For this purpose is located on a motor shaft stub a brake disc having a centrally located pressure cylinder and is pressed by spring tension against a wear ring of the motor housing. The compressed air supplied from an inlet is fed into a pressure cylinder of the brake disk, whereby it lifts against the resistance of the springs from the wear ring and thus enables the operation of the engine.

In the WO95 / 02762 a hydraulic engine is shown. A rotor turns in an engine compartment. The rotor is axially movable and is pressed by springs with a conical portion against a housing-fixed friction surface. The engine compartment is connected to the conical friction pair via channels with valves arranged therein. In operation, the pressure medium from the engine compartment passes to the friction pair and causes an axial displacement of the rotor, which leads to the separation of the friction pair and thus to release the brake.

In the WO97 / 02406 The applicant is shown a vane rotor with integrated brake direction. A vane rotor can be driven by compressed air in an engine compartment. A braking element is displaceable and loaded by springs arranged axially directly next to the vane rotor. The vane rotor thus forms on its front side with the braking element a friction pairing. The friction pairing is arranged in the engine compartment so that the compressed air acting there during operation acts on the brake element and displaces it against the spring action in such a way that the brake is released. This construction has proven extremely successful in practice. It leads in particular to a compact design.

The publication US Pat. No. 3,125,200 describes a pneumatic hoist with a pneumatic motor that drives a gearwheel via a two-stage planetary reduction gearbox. The rotor of the motor is connected to the transmission via a shaft. In, the motor opposite to the arranged end of the housing, a brake mechanism is arranged with a brake disc on the shaft, which is braked on both sides between brake elements. One of the brake elements is acted upon by a spring-loaded brake piston which forms a ring-shaped, sealed chamber with a spacer plate. By introducing compressed air into the chamber, the brake piston can be displaced against the action of the spring, so that the brake is relieved.

In the publication US 2,927,669 A is described a compressed air motor for a hoist. A brake disc with a pressure cylinder is arranged axially movable spring-loaded. Compressed air for operating the motor is passed through a hole in the motor shaft to release the brake during operation.

In the US 4 434 974 A a pneumatic braking device for a compressed air hoist is disclosed. Axially next to the rotor of a multi-disk motor is provided as a separate unit, a braking device with a rotatably mounted on the motor shaft brake disc. The brake disc is pressed by spring force on a housing-fixed brake ring, so that forms a pressure chamber in the interior of the brake ring. By applying pressure to the pressure chamber with compressed air, the brake disk can be axially displaced on the shaft so that the friction pairing between the brake disk and a housing-fixed brake ring is released.

The publication WO0 / 04276 A shows a vane motor with a vane rotor. The vane rotor is connected via a motor shaft with a separate braking device for braking the rotor.

It is an object of the invention to provide a motor in which in a simple way the braking effect over known constructions is still improved.

This object is achieved by a motor according to claim 1. Dependent claims relate to advantageous embodiments of the invention.

The engine according to the invention has an inner engine compartment and a rotor rotatable therein. This is driven by a pressure medium. While the term "engine compartment" refers firstly to the entire outwardly closed inner region of the engine, the part (or the section of the axial length of the engine compartment) in which the pressure medium expands or relaxes (in the case of hydraulic pressure media, the designation "relaxes "more precisely, in the following, however, is always spoken of" expansion "for the sake of simplicity) and so the runner drives here referred to as the work area. The inner engine compartment is preferably cylindrical, d. H. it has - at least in sections - over its longitudinal axis a constant cross section, preferably (but not necessary) on a circular cross-section. The rotor is preferably a vane rotor; however, the concept may also be used for other types of fluid expansion motors with other types of rotors.

Axial next to the rotor, a brake element for braking the rotor is arranged. Brake element and rotor are axially movable against each other, d. H. that either the rotor is movable in the direction of a (fixed) brake element, or a brake element with respect to an axially fixed rotor, or both elements are axially movable. One or both elements have springs that urge the elements toward one another to form a spring-loaded friction pair. Since the brake element is not rotatable about the axis, causes the friction pairing a braking, with sufficient friction up to the stopping of the rotor.

The friction pairing is preferably formed on one or both end surfaces of the rotor. This need not be exclusively radial surfaces, but different fits, eg. B. a two-sided cone, are possible.

The considerations leading to the invention include the recognition that the braking effect depends on the friction force, and thus on the friction coefficient of the materials on the friction pair and the applied spring force. Of these, it is particularly preferred because of the good adjustability to increase the spring force. However, an increase in the spring force is limited by the fact that the pressure medium during operation of the engine must still be able to release the brake. The maximum force available for this purpose is determined by the pressure of the medium on the one hand and the effective area on the other hand. In order to achieve a higher force at constant pressure, it is proposed here to increase the area.

According to the invention, therefore, a special pressure chamber is provided. The pressure chamber is formed so that its extension in cross-section is greater than the cross-sectional extent of the engine compartment at its working area, so it is at least partially disposed further outward with respect to the longitudinal axis. To compare here are on the one hand, the cross section of the engine compartment at the point at which the pressure medium by expansion drives the rotor (working area), more preferably at least in its axially central region, and on the other hand, the outer extension of the pressure chamber, also viewed in cross section. For the - preferred - case of a circular-cylindrical engine compartment, this means that the internal diameter of the boundary of the engine compartment is to be regarded as the cross-sectional extension. The pressure chamber is preferably designed as an annular space, wherein its outer diameter is then greater than the diameter of the engine compartment. The pressure chamber is thus located radially outside the working area of the engine compartment, so that a significantly larger area is provided.

The pressure chamber is limited at least on one side by at least one of the elements of the friction pair (brake element / rotor). A pressure built up in the pressure chamber acts on this element or these elements and leads to a force on the brake element and / or the rotor. The pressure chamber is in this case arranged so that the applied force leads to the separation of the friction pair, that is directed against the spring force. Thus, by building up a pressure in the pressure chamber, a separation of the friction pair between the brake element and rotor can be achieved, so that the deceleration of the rotor is canceled.

The pressure chamber according to the invention is arranged so that the pressure medium passes during operation of the engine in the pressure chamber. So if pressure medium is supplied to drive the rotor, so this gets into the pressure chamber and causes the separation of the friction pair and thus the release of the brake. The pressure medium can pass from a suitable feed directly into the pressure chamber. It is also possible that the pressure medium passes through a connection from the working area of the engine compartment in the pressure chamber.

The pressure space created according to the invention can in this case support a pressure chamber already arranged directly on the friction pair (i.e., between the brake element and the adjacent end face of the rotor). With sufficient dimensions, however, he can also apply alone the force that is needed to release the brake.

With the motor according to the invention, a construction is achieved in which, on the one hand, large braking forces and, on the other hand, an automatic release of a friction brake is achieved by the pressure medium supplied to the engine during operation. Due to the large cross-section extent of the pressure chamber is an additional, relatively large area for the effect of the pressure medium available. So even for great braking performance does not have the benefit of the design after WO97 / 02406 be omitted, in which an automatic solution of the brake takes place when the rotor. Nevertheless, the construction is not significantly more complicated by the additional pressure chamber. There are no additional moving parts required and the overall axial length of the construction can even remain the same. Thus, the production of a compact, inexpensive engine with the described advantages is possible.

According to a significant development of the invention, a connection of the pressure chamber is provided in a manner that the function of the pressure chamber is ensured in a reversible motor when operating in both operating directions. In general, the engine initially has a fluid port to which the pressure medium is supplied, and an exhaust, at which the expanded medium is discharged. In a reversible motor (ie, a motor that is operable in two directions of rotation) are two different fluid connections (when using the motor in a hoist called "lift side" and sink side ") provided, wherein the pressure medium is supplied depending on the desired direction of rotation of the one or the other fluid port.

In order to ensure ventilation of the pressure chamber for proper release of the brake during operation and venting of the pressure chamber to engage the brake during interruption of the operation, the pressure chamber can in various ways with the fluid connections (or the fluid connection, if the engine has only one ):

On the one hand, a fluid connection of the pressure chamber with a fluid connection is possible, preferably via a direct, valve-free supply line. Such a valve-free connection should only be made with one of two fluid connections to avoid a short circuit.

The motor may be designed so that it is not symmetrical with respect to the two fluid ports, so that it provides a higher performance when operating on a first fluid port (in hoists this would be the lift side) than when operating on the second fluid port (drain side). It is possible to connect the pressure chamber with both the lift and the sink side. In this case, a connection with the sink side is preferred.

One of the fluid connections can be connected via a throttle element for limiting the volume flow with a fluid supply. Here, the pressure chamber can be connected to the corresponding supply line to the throttle element. In order to reduce running down of the engine, however, it is more advantageous to connect the pressure chamber upstream of the throttle element with the fluid supply, so that a possible backflow at the throttle element does not lead to a delayed venting of the pressure chamber and thus to running of the engine.

As a further alternative, the pressure chamber can be connected to both fluid connections, wherein at least one valve is provided in the connection to avoid a short circuit. Preferably, a shuttle valve is used here, so that the Pressure chamber is always connected to the connection at the highest pressure and when venting always with one of the connections, so that when venting both connections via the control valve an immediate venting is ensured.

According to a further embodiment, the pressure chamber is connected to the working area of the engine compartment. This results in operation in both directions, an overpressure. In this connection, the connection is preferably a direct, valve-free connection, for example a puncture channel, a line or even a targeted leak of a fit. When the pressure chamber is connected to the working area of the engine compartment (instead of the connection to the fluid connections), the function is performed without any additional expenditure the brake maintained even with Umsteuerbarkeit the engine.

It is preferred that the pressure chamber is connected to the engine compartment via a conduit with only one opening to the engine compartment. Thus, even without valves, it is ensured that there is no short circuit (i.e., the pressure medium flows from the inlet directly across the pressure chamber to the outlet without driving the motor).

As far as a line is provided for guiding the pressure medium from the engine compartment into the pressure chamber, it is preferred that this is connected to a connection opening which is arranged on the front side next to the rotor. Particularly preferably, this opening is formed in the brake element. As described, the conduit may preferably be a direct, valve-free conduit. For the arrangement of the connection opening is preferred that this - from the axial point of view - is arranged in the same quadrant of the engine compartment, as a (first) fluid connection. Particularly preferably, the opening is arranged in the region of +/- 30 ° from the fluid connection (measured in each case at the center of the fluid connection and the opening). It has been found that, even with reversible motors with two fluid connections, an arrangement of the connection opening near one of the fluid connections is sufficient for trouble-free operation in both operating directions. If the engine has a preferential direction (usually the lifting side for hoists), then it makes sense to arrange the connection opening in the region of the corresponding preferred fluid connection. In the case of loaded hoists, when a load is lowered, compression results in the fluid exit, thereby providing the brake release required Printing is supported. In a motor without preferential direction, it has proven to be useful to arrange the connecting opening in the center, ie at the same distance from the fluid connections for both directions of rotation.

As a further advantage of the arrangement of the connection opening on the front side next to the rotor, a good start-up behavior has been shown. The minimum time delay, which results from the action of the pressure medium initially on the working area of the engine surface of the brake element and then only by starting the engine in the pressure chamber, allows a gradual, stepless driving the motor.

According to one embodiment of the invention, the fit of the brake element with respect to a wall of the engine compartment so that the pressure medium passes between these two into the pressure chamber. In this case, a gap or a leak can be deliberately left to connect the pressure chamber with the working area of the engine compartment. In this way - without special channels are necessary - a connection can be created in a very simple way. The necessary cross-section is low anyway, since it does not come to a constant flow through the connection in operation, but the pressure in the pressure chamber is maintained static.

According to one embodiment of the invention, the pressure chamber is formed between the brake element (or an element connected with respect to the axial movement thereof) on the one hand and the housing (or a housing-fixed element) on the other. Thus, when exposed to the pressure medium, the brake element is moved relative to the housing.

Preferably, the pressure chamber is designed as an annular space. An annulus of relatively large diameter has the advantage that a uniform force is applied and thus the risk of a possible tilting of the thus displaced element is low. Due to the free choice of the diameter graduation of the stepped piston braking moments in the required size can be realized within achievable engine power.

According to one embodiment of the invention, it is proposed that a wall is provided which encloses at least the working area of the engine compartment and the brake element. This wall has in longitudinal section at least one step. In the preferred case of a cylindrical working area, the wall preferably comprises two juxtaposed cylinder sections of different diameter connected by the step. Also, the braking element received within the area enclosed by the wall has a matching step. The pressure chamber is then formed between radially arranged surfaces of the stages. Thus, a pressure chamber can be formed in a structurally very simple manner, which leads to an axial displacement of the braking element when acted upon.

Fig. 1

eine Ansicht eines Längsschnittes durch eine erste Ausführungsform eines Lamellenmotors;

Fig. 2

eine Ansicht eines Querschnittes durch den Lamellenmotor aus Fig. 1 entlang der Linie A .. A';

Fig. 3

eine Ansicht eines Querschnittes durch den Lamellenmotor aus Fig. 1 entlang der Linie B .. B' und

Fig. 4a, 4b

Prinzipskizzen zur Lösung der Bremse bei einem mit dem in Fig. 1 gezeigten vergleichbaren Lamellenmotor.

Fig. 5

in schematischer Darstellung als pneumatisches Schaltbild den Motor aus Fig. 1 mit einer Steuerung;

Fig. 6

eine Ansicht eines Längsschnittes durch eine zweite Ausführungsform eines Lamellenmotors;

Fig. 7-10

schematische Darstellungen als pneumatisches Schaltbild des Lamellenmotors aus Fig. 6 mit einer Steuerung in verschiedenen Verbindungsarten.

Hereinafter, embodiments of the invention will be described in more detail with reference to drawings. In the drawings show:

Fig. 1

a view of a longitudinal section through a first embodiment of a vane motor;

Fig. 2

a view of a cross section through the vane motor Fig. 1 along the line A .. A ';

Fig. 3

a view of a cross section through the vane motor Fig. 1 along the line B .. B 'and

Fig. 4a, 4b

Schematic diagrams for solving the brake in a with the in Fig. 1 shown comparable vane motor.

Fig. 5

in a schematic representation as a pneumatic circuit diagram of the engine Fig. 1 with a controller;

Fig. 6

a view of a longitudinal section through a second embodiment of a vane motor;

Fig. 7-10

schematic representations as a pneumatic circuit diagram of the vane motor from Fig. 6 with a controller in different types of connection.

In Fig. 1 is a motor (vane motor) 10 according to a first embodiment shown in longitudinal section. A housing 12 comprises a motor bush 14 and a front-side cover 16 and a further end-side cover 19 with a brake pad 21st

The engine bushing 14 defines an inner engine compartment 18. In an alternative embodiment (not shown), a separate engine bushing may be omitted and the inner engine compartment 18 may be formed by the housing wall. In the inner engine compartment 18, a vane rotor 20 and a brake member 22 are arranged.

The motor socket 14 comprises a step 24 which is formed between two circular cylindrical sections of different diameters. A first portion 26 has a larger inner diameter than a second, subsequent thereto section.

The vane rotor 20 is arranged in the region of the second portion with the smaller inner diameter. As is known to those skilled in the art of laminar motors, the vane rotor 20 is eccentrically located within this range. As in Fig. 1 shown is the axis of rotation 28, which has at one end a bearing pin 30 and at the other end a driven pin 32 relative to the longitudinal center axis of the motor bushing 14 downwardly displaced. This is also in the Fig. 2 shown cross section recognizable.

How out Fig. 2 also visible, the vane rotor 20 has a number of radially displaceable, outwardly spring-loaded blades 34. The lamellae abut the motor bushing 14 and thus delimit gaps 36. The lamellae are over the entire axial length of a working area 40 (see FIG Fig. 1 ) of the engine 10 is provided.

At the periphery of the working area 40, the motor bushing 14 has a first compressed air inlet 42, a second compressed air inlet 44 and an exhaust 46. When operating in the preferred direction (turn to the left in Fig. 2 ) compressed air is supplied through the compressed air inlet 42. Upon rotation of the vane rotor 20, the compressed air expands in the increasing with the rotation gaps 36 between the fins 34 until it is discharged at the exhaust 46 under a residual pressure.

When operating in the opposite direction of rotation (clockwise in Fig. 2 ) Compressed air is supplied through the compressed air inlet 44. How out Fig. 2 can be seen, the exhaust 46 is not arranged symmetrically between the compressed air inlets 42, 44, but in The result is that the first direction of rotation driven by this compressed air inlet 42 becomes the preferred direction (for example, in the case of a hoist: lifting direction), in which the power of the motor 10 is higher than in the opposite direction.

As in Fig. 1 shown, the brake element 22 is arranged axially adjacent to the vane rotor 20. With a mounted on the surface brake pad 48, it forms a friction pair with the end face 50 of the vane rotor 20. Spring elements 52, of which Fig. 1 only two can be seen acting on the brake member 22 and act on it with a force in the axial direction, which presses the elements of the friction pair 48, 50 to each other. The brake element is held by pins 51, so that it can move axially, but can not rotate relative to the housing 12. Another friction pair is formed between the axially displaceable vane rotor 20 and provided with a brake lining 21 cover 19, so that the vane rotor 20 is braked on both sides.

Matching to the provided in the motor socket 14 stage 24 and the recorded in the motor socket 14 brake element 22 is provided with a step 54. Between the axial surfaces of a stepped portion of the braking element 22 and the stage 24 of the motor bushing 14, a pressure chamber 60 is formed. The pressure chamber 60 has, as out Fig. 3 seen, the shape of a circumferential annular space. As from the comparison of Fig. 2, Fig. 3 shows, the pressure chamber 60 in the direction transverse to the longitudinal center axis of the motor bushing 14 has a greater extent than the working area 40 of the motor 10. The pressure chamber 60 extends to a radius R2 (FIG. Fig. 3 ), while in the working area 40, the motor bushing 14 has only a smaller inner diameter R1 (FIG. Fig. 2 ) having.

The connection of the pressure chamber 60 takes place in the first embodiment via a line 62 which is formed as a channel within the braking element 22. It connects the pressure chamber 60 with an opening 64 in the surface of the brake element 22 facing the slat rotor 20. The line 62 is designed as a direct, valve-free connection of only one opening 64 to the pressure chamber 60.

In Fig. 5 is shown in schematic form the engine 10 with its pneumatic circuit. The wiring is shown here for the sake of clarity reduced to the essentials; Further control functions such as emergency stop and overload shearing for a hoist are therefore not shown here.

The inner engine compartment 18 is connected with its first compressed air inlet 42 to the lifting side h of a control valve 70 and with its second compressed air inlet 44 on the sink side s. The vane rotor 20 is braked by the friction pairing between the brake pad 48 and the end face 50 shown symbolically here. The brake is released by compressed air supply to a gap 72 between the brake element 22 and the end face 50, which in Fig. 4b illustrated and explained below, and - through the channel 62 - to the pressure chamber 60, wherein in the two pressure chambers 60 _; 72 constructed pressure the brake element 22 against the spring 52 acts. The exhaust 46 of the engine is connected to a muffler 74.

The control valve 70 has in the example shown via an actuating lever 76 which is displaceable s in a medium idle position in the operating mode s or opposite in the lifting mode h, wherein in a slide valve 80 by shifting relative to the terminals different valve functions between a compressed air supply P and a Venting port R (connected to the muffler 74) on the one hand and a supply port A for the lifting side and B for the drain side are realized on the other hand:

In the illustrated idle ports A and B are vented, ie connected to R. In lifting mode (left valve function in Fig. 5 ), the compressed air port of the lift side A is connected to the compressed air supply P, while the drain side is vented (connection BR by crossing position of the valve 80). The supply A is connected to the valve output of the lifting side h via the parallel connection of a throttle element 82 with a check valve 84, wherein the check valve 84 acts so that in the lifting operation, the compressed air can flow through the check valve 84 to the lifting side h, so that the throttle 82 the Fluid flow is not limited, but next to the valve 84 acts as an additional connection.

In lowering mode (right valve function in Fig. 5 ), the drain side s is directly connected to the compressed air supply P, while the lift side h is vented via the throttle element 82 (connection AR, the check valve 84 blocks). The throttle element limits the volume flow of the pressure medium. It can be realized in a very simple way as a bottleneck in the conduction path, for example as a perforated plate. In the lowering mode, the throttle element 82 serves to limit the lowering speed. Because in this mode of operation, the motor is supplied with compressed air on the one hand by the compressed air connection 44, which expands to the outlet on the exhaust 46. On the other hand, the engine due to a load to be lowered on the hoist acts as a compressor that compresses the air from the exhaust 46 to the compressed air connection 42 (lifting side) with the decreasing blade interspaces 36. This compressed air is passed to the control valve to the port h and vented through the throttle element 82. Due to the limitation of the volume flow at the throttle element 82, this results in a braking effect due to the backflow, which leads to a braked lowering of the load.

When operating the motor 10 takes place upon application of one of the two compressed air inlets 42,44 with compressed air automatically releasing the brake, while decreasing compressed air supply the vane rotor 20 between the brake pad 48 of the brake element 22 and the brake pad 21 of the fixed lid 19 is automatically stopped. This mechanism will be described below with reference to the schematic diagrams Fig. 4a, 4b shown. It should be noted that the illustration in Fig. 4a, 4b is schematic in nature and should serve to explain the general operating principle. Therefore, some details are omitted and in particular the gap dimensions exaggerated.

Fig. 4a shows the braked motor 10. The vane rotor 20 is braked by contact of the braking element 22. By the force of the spring elements 52, the motor 10 is thus stopped.

For starting the engine, compressed air is now supplied via the compressed air inlet 42. How out Fig. 2 As can be seen, the compressed air enters a blade interstice 36. Since the vane rotor 20 is stopped, it does not initially turn the vane rotor 20. Instead, the pressure in the gap 36 (and by leaks on the blades soon on the entire surface) acts on the axially displaceable brake element 22 so that it begins to dissolve against the force of the spring elements 52 from the vane rotor 20, so that a pressure chamber 72 (s. Fig. 4b ).

However, acts by the spring elements 52 such a force on the brake member 22 that the force acting on the surface of the friction lining 48 alone pressure would not be sufficient to completely release the brake.

At the same time, however, the compressed air also enters the pressure chamber 60. This can be done in two different ways. On the one hand, leakages may remain in the fit between the motor bushing 14 and the brake element 22, through which the pressure medium enters the pressure chamber 60 (dotted arrows in FIG Fig. 4a ). In the preferred construction according to Fig. 1 in this case recordings for seals 65 are provided. If no seal is used at this point, so eliminates a seal at this point and it comes to the in Fig. 4a shown by dotted arrows path of the pressure medium in the pressure chamber 60th

Alternatively or additionally, the pressure medium passes through the opening 64 in the brake element 22 and the line 62 connected thereto in the pressure chamber 60. Although the opening 64 appears in the idle state ( Fig. 4a ) first closed. However, the pressure medium still passes through during operation, since on the one hand the contact between the vane rotor 20 and the brake element 22 is not completely sealed. On the other hand, the introduction of the pressure medium already causes a first movement of the brake element 22, so that then the opening 64 is free. In a preferred embodiment (in Fig. 1 can not be seen due to the small dimensions), a slightly raised ring can also be left in the manufacture of the vane rotor 22 on its end face 50, which ensures against the brake element 22 when it rests against the opening 64 (not shown). ,

The arrangement of the opening 64 is from the synopsis Fig.1 . Fig. 2 exactly visible. In the radial direction, it lies as if out Fig. 1 recognizable, in the interior of the braking element 22 through the work area 40 of the engine compartment facing surface, ie not right on the edge. The location of the opening 64 relative to the compressed air inlets 42, 44 and the exhaust 46 is off Fig. 2 seen. Here, the opening 64 is arranged in the region of the compressed air inlet 42 of the lifting side. As tests have shown, the arrangement is particularly well in the area of this compressed air inlet. It is therefore preferred that the opening 64 be as in FIG Fig. 2 is arranged in the same quadrant of the engine compartment as the compressed air inlet 42. More preferably, the angle between the center of the compressed air inlet 42 and the center of the opening 64 is not more than 30 °.

This arrangement of the opening 64 is particularly advantageous for operation in the lifting direction (compressed air on compressed air inlet 42). As tests have shown but results in a loaded hoist even when supplying the compressed air through the compressed air inlet 44, a sufficient pressure build-up in the region of the opening 64, so that the pressure chamber 60 is filled sufficiently quickly, because when lowering the load - almost by pumping action - Area of the opening 64, a higher pressure than at the compressed air inlet 44th

The pressure medium acts on the radial surfaces of the brake element 22, namely on the one hand on the inner, on the friction pair 48, 50 involved surface and on the other hand on the formed on the step 54 additional annular surface. The total force acting on the brake element 22 corresponds to the product of the pressure of the pressure medium and the surface. By suitable sealing measures (seal seat 66 in Fig. 1 ) prevents the pressure medium also passes behind the brake element 22. Thus, it is altogether possible that the brake element 22 is released solely by the pressure of the pressure medium.

The lifting of the braking element 22 - and the start of the engine 10 - takes place even with rapid application of the compressed air inlet 42 always gradually. Because first, the brake element 22 is slightly displaced solely by the pressure on the front side of the vane rotor 20 and thus reduces the braking effect. Only with (slight) time delay, the compressed air also flows into the pressure chamber 60, so that the braking effect can then be completely canceled.

In operation, the brake element 22 remains spaced from the vane rotor 20 as long as the pressure medium is supplied. When switching off the pressure medium falls automatically by the force of the spring elements 52, the brake again.

By the pressure chamber 60 thus an enlargement of the area is created on which the pressure of the pressure medium can act on the brake element 22. It is thus possible to specify a desired, increased braking force by means of suitable, stronger springs 52.

In Fig. 6 is a second embodiment of a vane motor 100 is shown, which has proven in experiments to be particularly advantageous. The motor 100 according to the second embodiment largely corresponds to the motor 10 according to the first embodiment. It has predominantly the same elements as the motor 10. These elements are therefore designated by the same reference numerals. Reference is therefore made to the above description for these elements. In the following, only differences between the embodiments will be mentioned.

The engine 100, unlike the engine 10, does not have an opening 64 in the end face of the brake member 22, and correspondingly, does not have a passage 62 connecting the engine inner space 18 to the pressure space 60. Instead, the pressure chamber 60 is closed by the fit and in particular the seals 65 with respect to the inner engine compartment 18.

When the engine 100, the ventilation of the pressure chamber 60 by an external supply line (not shown in FIG Fig. 6 ). This supply line can, as in Fig. 7 - 10 represented and explained below be connected in various ways.

The subject of the considerations here is the operation of the engine of a hoist in the operating mode sinks with appropriate load. In this case, it should be ensured that, in the event of an interruption of the lowering operation (ie switching over of the slide valve 80 from the "lowering" position to the middle position), braking is applied immediately when the load is attached and, as far as possible, the engine does not run after it. In the case of the above-discussed first embodiment, in the case of insufficient connection of the pressure chamber 60 with the interior 18 of the engine, this may lead to a too slow venting of the pressure chamber 60, and a correspondingly delayed engagement of the brake come. To avoid this, is in the various connection types Fig. 7 - 10 an external ventilation for the pressure chamber 60 is provided.

For the first connection according to Fig. 7 the pressure chamber 60 is directly connected to the lifting side (compressed air connection 42). In the lifting operation of the pressure chamber 60 is vented from there and also vented when switching back to idle. In lowering mode, the release of the brake is initially carried out mainly by venting the pressure chamber 72, and then by venting the pressure chamber 60 due to the backpressure arising before the throttle element 82. When interrupting the operating mode lowering the slide valve 80 is moved to the middle position, thus creating a vent before lifting and lowering side. In this case, a venting of the pressure chamber 60 via the lifting side, as soon as the backwater is reduced in front of the throttle element 82.

For applications in which the backpressure before the throttle element 82 proves to be too large, so that there is an after-running of the engine after interrupting in the operating mode sinks, as in Fig. 8 alternatively shown the pressure chamber 60 are also connected in front of the throttle element 82, so that a venting takes place directly when switching the slide valve 80.

Alternatively, and currently preferred, the pressure space 60 (as in FIG Fig. 9 shown) connected to the sink side. In lifting mode, the ventilation then takes place via the drain side as soon as the brake has released itself slightly due to pressure build-up in the pressure chamber 72. In lowering mode takes place when interrupting and switching the slide valve 80 in the middle position a direct vent, since there is no throttle element on the sink side, but the sink side is vented directly to the exhaust 46 in the middle position.

As another possible connection type is in Fig. 10 the connection of the pressure chamber 60 shown on both the lifting and the sink side. To avoid a short circuit, a shuttle valve 86 is provided here. In lifting mode, the Ventilation of the pressure chamber 60 directly from the lifting side, wherein the valve 86 prevents a short circuit to the drain side. In the lowering mode, on the other hand, the ventilation takes place directly from the drain side, whereby in turn the valve 86 prevents a direct short circuit to the lifting side. When interrupting the lowering operation, the venting of the pressure chamber 60 via the lifting or the sink side, which are both directly vented at mid-position of the slide valve 80.

• Bei der Konstruktion eines Motors gemäß Fig. 1 ist eine gestufte, einstückige Motorbuchse 14 vorgesehen. Alternativ kann das Gehäuse des Motors auch anders aufgebaut sein, um einen inneren Motorraum zu schaffen.
• Während vorstehend ein mit Druckluft beschriebener Lamellenmotor beschrieben wurde, kann das Erfindungsprinzip für den Fachmann ohne weiteres erkennbar auch auf andere Motortypen (z. B. Zahnradmotor) und andere Antriebsmedien (bspw. Hydraulikflüssigkeit) angewendet werden.
• Während vorstehend der Druckraum 60 jeweils alternativ über den Kanal 62 oder über eine externe Zuleitung angeschlossen ist, können auch beide Anschlussarten kombiniert werden.
• Die in Fig. 5 und 7-10 schematisch gezeigte Hebelsteuerung kann durch andere Steuerungsarten, bspw. eine Druckluftsteuerung ersetzt werden, mit der das Schiebeventil 80 in die entsprechenden Schaltstellungen verschoben wird.

As can be appreciated by one skilled in the art, the invention is not limited to the embodiments shown and described. In particular, the following modifications are conceivable:

• In the construction of an engine according to Fig. 1 a stepped, one-piece engine bushing 14 is provided. Alternatively, the housing of the engine may be constructed differently to provide an internal engine compartment.
• While a vane motor described above with compressed air has been described above, the principle of the invention can readily be applied to other types of motor (eg gear motor) and other drive media (eg hydraulic fluid).
• While above, the pressure chamber 60 is alternatively connected via the channel 62 or via an external supply line, both types of connection can be combined.
• In the Fig. 5 and 7-10 schematically shown lever control can be replaced by other types of control, eg. A compressed air control, with the slide valve 80 is moved to the corresponding switching positions.

Claims (14)

1. Motor with

   - an internal motor chamber (18),

   - and a rotor (20) rotatable therein, wherein the rotor is drivable by having a pressure medium applied to it, wherein the pressure medium expands in a working area (40) of the motor chamber,

   - and a braking element (22) for braking the rotor (20), which is axially arranged directly adjacent to the rotor (20), wherein the braking element (22) and the rotor (20) are axially moveable with respect to each other and form a spring-loaded friction pair (48, 50), at least at one front end face of the rotor (20),

   - a pressure chamber (60) having an extension in cross-section larger than the cross-sectional extension of the motor chamber (18) at its working area (40),

   - wherein the pressure chamber (60) is at least unilaterally axially delimited by the braking element (22) and/or the rotor (20), so that a pressure in the pressure chamber (60) results in a force to separate the friction pair (48, 50) against the spring force,

   - and wherein the pressure chamber (60) is arranged in such a way that the pressure medium passes into the pressure chamber (60), when the motor is in operation.
2. Motor according to claim 1, wherein

   - when feeding the pressure medium to the rotor (20), the pressure medium acting on the braking element (22) being in contact with the front end face of the rotor (20) provides a force for separation of the friction pair (48, 50)

   - and the pressure in the pressure chamber (60) provides an additional force for separation of the friction pair (48, 50) opposite to the spring force.
3. Motor according to claim 1 or 2, wherein

   - at the motor chamber (18) a first fluid port (42), a second fluid port (44) and an exhaust (46) are provided, which are arranged over the circumference of the working area (40) of the motor chamber at a distance to each other, wherein the motor (10) is drivable in a first sense of rotation by supplying fluid to the first fluid port (42) and in a second sense of rotation by supplying fluid to the second fluid port (44),

   - wherein the pressure chamber (60) is connected with the first fluid port (42) and/or the second fluid port (44) in such a way that in the operation of the motor (10) the pressure medium passes into the pressure chamber (60).
4. Motor according to claim 3, wherein

   - the connection of the pressure chamber (60) with either the first or the second fluid port (42, 44) is a valve-free supply line.
5. Motor according to claim 3 or 4, wherein

   - a supply line (A) is connected with one of the fluid ports (42) via a throttling element (82) to limit the volume flow of the pressure medium,

   - and the pressure chamber (60) is connected to the supply line (A) upstream of the throttling element (82).
6. Motor according to claim 3, wherein

   - the pressure chamber (60) is connected with the two fluid ports (42, 44),

   - wherein at least one valve (86) is provided in the connection to avoid shorting.
7. Motor according to one of the preceding claims, wherein

   - at the motor chamber (18) a first fluid port (42), a second fluid port (44) and an exhaust (46) are provided, which are arranged over the circumference of the working area (40) of the motor chamber at a distance to each other, wherein the motor (10) is drivable in a first sense of rotation by supplying fluid to the first fluid port (42) and in a second sense of rotation by supplying fluid to the second fluid port (44),

   - wherein the pressure chamber (60) is connected with the working area (40) of the motor chamber (18) via a direct, valve-free connection (62, 64), so that the pressure medium passes into the pressure chamber (60) in the operation in both senses of rotation.
8. Motor according to claim 7, wherein

   - the fit of the braking element (22) with respect to a side wall (14) of the motor chamber (18) is such that the pressure medium can pass between the braking element (22) and the side wall (14) into the pressure chamber (60).
9. Motor according to one of claims 6, 7, wherein

   - at least one line (62) is provided for feeding the pressure medium from the working area (40) into the pressure chamber (60),

   - wherein the line (62) is connected to a connecting opening (64) arranged in the braking element (22) at the end face adjacent to the rotor (20).
10. Motor according to claim 9, wherein

    - the line (62) has only one connecting opening (64).
11. Motor according to claim 9 or 10, wherein

    - at the working area (40) at least one first fluid port (42) is provided for supplying the pressure medium to be applied to the rotor (20),

    - wherein the connecting opening (64) is arranged in the same quadrant of the motor chamber (18) as the first fluid port (42) as seen in the axial direction.
12. Motor according to one of the preceding claims, wherein

    - the pressure chamber (60) is formed between the braking element (22) and the housing (12, 14).
13. Motor according to one of the preceding claims, wherein

    - the pressure chamber (60) is an annular space axially delimited by the braking element (22),

    - wherein the annular space (60) has an outer diameter (R2) greater than the transverse extension (R1) of the working area (40) of the motor chamber.
14. Motor according to one of the preceding claims, wherein

    - a side wall (14) is provided surrounding the working area (40) of the motor chamber and the braking element (22),

    - wherein the side wall (14) has at least one step (24) in the longitudinal section,

    - wherein the pressure chamber (60) is formed in the area of the step (24).

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