WO2014005656A1

WO2014005656A1 - An arrangement for protection of hydraulic actuators of underground shield from dynamic overload with a mechanical rotary absorber

Info

Publication number: WO2014005656A1
Application number: PCT/EP2012/064617
Authority: WO
Inventors: Przemyslaw Lagiewka; Stanislaw Gumula; Mariusz WSZENDYBYL
Original assignee: Epar Sp. Z O. O.
Priority date: 2012-07-05
Filing date: 2012-07-25
Publication date: 2014-01-09
Also published as: PL399840A1

Abstract

A protective arrangement for hydraulic actuators of an underground shield from dynamic overload with a mechanical rotary absorber. It comprises a hydraulic actuator (103) mountable to the base (102) of the underground shield, to which there is connected a rotary device (110) for taking over and dissipating the energy of rocks falling on the hood (101), wherein the device (110) for taking over and dissipating energy comprises a ram element (1) mounted to the actuator (103), slidably coupled by means of ram guides (14) with side walls of a base plate (13) mountable to the hood (101), which cooperates with at least two serially connected racks (2, 3, 4) mounted slidably on a runner (15) and driving toothed wheels (9, 9a, 9b, 9c) of the kinetic energy rotary accumulators (10, 11, 12), wherein distances (5, 6, 7) are created between the ram element (1) and the first rack (2), as well as between the particular racks (2, 3, 4), said distances enabling the displacement of the ram element (1 ) in relation to racks (2, 3, 4), as well as the displacement of these racks (2, 3, 4) in relation to one another, such as to enable the moving ram element (1) to pass the kinetic energy of the translational movement to the kinetic energy rotary accumulators (10, 11, 12) in order to transform it to the kinetic energy of rotational movement.

Description

AN ARRANGEMENT FOR PROTECTION OF HYDRAULIC ACTUATORS OF UNDERGROUND SHIELD FROM DYNAMIC OVERLOAD WITH A MECHANICAL

ROTARY ABSORBER DESCRIPTION

TECHNICAL FIELD

The object of the present invention is an arrangement for protection of hydraulic actuators of underground shield from dynamic overload with a mechanical rotary absorber.

BACKGROUND ART

Underground vehicles are prone to falling rocks from the top parts of the heading. In order to effectively protect the personnel or equipment moving by the underground vehicle, the vehicle should have a robust hood. The hoods are usually mounted on stiff arms or arms with hydraulic actuators.

There are known powered underground shields protecting from fall of rock having a hood supported by means of a telescopic support on a base. Typical powered underground shields are disclosed in WO201 1/039693 or US7377727. These vehicles have telescopic supports configured to dampen the fall by hydraulic actuators, such as gas or oil dampers mounted within the supports. In order to effectively dampen the fall, the actuators must keep high efficiency. Keeping the efficiency and leakproofness of the actuators in the hard working conditions of the underground shields may cause problems.

It would be advantageous to provide an alternative mechanism for protecting the actuators of the underground shield from dynamic load.

WO2004028864 discloses a rotor device for taking over and dissipating impact energy, in which kinetic energy suddenly created by a collision is converted into kinetic energy of rotating masses. In this known solution a ram element is connected with two racks which drive by means of gears the rotors shaped as rods with movable weights sliding on them. Minimizing of percussive load of cooperating elements in the preliminary phase of the energy transfer is realized in the known solution by using movable weights situated possibly near a rotation axis of a bar-rotor so as to achieve a minimum moment of inertia of the rotor in this initial phase. In the further stage of this motion, when the rotor begins its rotation, these weights are moved by the centrifugal force increasing their distance from the rotation axis along the bar axis till reaching the extreme position near the end limiters. In this position the highest moment of inertia of the rotor is achieved, enabling the takeover of increased kinetic energy.

A rotor device for taking over and dissipating kinetic impact energy is also known from patent application WO2005121593, said device comprising a ram element cooperating with a rack making, by means of a toothed wheel, a kinetic energy rotary accumulator to rotate in order to convert impact energy into kinetic energy of rotary motion of the rotary accumulator. In one of embodiments of the known rotor device for taking over an impact energy a kinetic energy rotary accumulator cooperates with movable weights maintained in a suitable distance from a rotation axis by means of springs. Such a solution provides gradual increment of the ability of the device to take over kinetic energy during an impact.

WO2004053352 discloses a device for absorbing kinetic energy, comprising a rotor coupled with a bumper via a multiplying gear.

DE3141024 discloses a device for converting energy generated by an oscillating mass to an energy for driving a rotatable element by means of a rotatable shaft coupled with a hydraulic system.

The solutions described above do not provide efficient conversion of energy for various impact speeds and various masses of the impacting objects.

PCT/PL201 1/050060 (known to the inventors and not published before the priority date of the present application) discloses a rotary device for absorbing and dissipating energy of impact, used to convert kinetic energy of translational movement to kinetic energy of rotational movement. A ram element cooperates with at least two serially connected racks slidably mounted on a runner and driving the toothed wheels of the kinetic energy rotary accumulators. Distances are created between the ram element and the first rack and moreover distances are created between the racks to ensure the action of cushioning elements and to enable shifting of the ram element in relation to the racks, as well as shifting of these racks in relation to one another.

The invention presented in PCT/PL201 1/050060 is new and inventive over the solutions described before, as it allows gradual damping with increasing efficiency of energy dissipation in relation to the speed and mass of the objects under impact. By providing cushioning elements between the rotary absorbers, the load can be transferred gradually to successive absorbers and the moment of inertia can be gradually increased, thereby gradually adapting to the energy of impact. Such solution was neither known nor suggested by any of the previous publications.

The object of the invention is a new use of the rotary device for absorbing and dissipating energy of impact known from PCT/PL201 1/050060, in particular the use for absorbing impacts imparted to hydraulic actuators of an underground shield.

DISCLOSURE OF THE INVENTION

The object of the invention is a protective arrangement for hydraulic actuators of an underground shield from dynamic overload with a mechanical rotary absorber, characterized in that it comprises a hydraulic actuator mountable to the base of the underground shield, to which there is connected a rotary device for taking over and dissipating the energy of rocks falling on the hood, wherein the device for taking over and dissipating energy comprises a ram element mounted to the actuator, slidably coupled by means of ram guides with side walls of a base plate mountable to the hood, which cooperates with at least two serially connected racks mounted slidably on a runner and driving toothed wheels of the kinetic energy rotary accumulators, wherein distances are created between the ram element and the first rack, as well as between the particular racks, said distances enabling the displacement of the ram element in relation to racks, as well as the displacement of these racks in relation to one another, such as to enable the moving ram element to pass the kinetic energy of the translational movement to the kinetic energy rotary accumulators in order to transform it to the kinetic energy of rotational movement.

Preferably, the kinetic energy rotary accumulators have different energy accumulating abilities.

Preferably, the kinetic energy rotary accumulators have different moments of inertia.

Preferably, the kinetic energy rotary accumulator driven by the first rack has a smaller moment of inertia than the kinetic energy rotary accumulator driven by the second rack.

Preferably, the kinetic energy rotary accumulators are driven by transmissions increasing angular speed, which have different transmission ratios.

Preferably, the kinetic energy rotary accumulator has a one-way clutch. The protective arrangement according to the invention comprises a device for absorbing and dissipating energy of impact, wherein as a result of serial connection of the ram element with at least two serially connected racks which drive toothed wheels of kinetic energy rotary accumulators, with distances provided between the said racks, it is assured gradual driving in rotation of the subsequent kinetic energy rotary accumulators, what enables an abrupt increase of energy taking over ability of the device according to the invention. Cushioning elements fastened in the front of the racks in series decrease the percussive load of elements cooperating when starting the subsequent kinetic energy accumulators. The device according to the invention is suitable both for taking over small as well as great impact energy. In the first case the device ensures the effective and very gentle takeover of the impact energy because kinetic energy of progressive motion is carried out by kinetic energy rotary accumulators having the least moment of inertia. In the second case the device according to the invention provides also effective and uniform dissipation of the impact energy because taking over of kinetic energy of progressive motion is carried out by several kinetic energy rotary accumulators having ever greater energy taking over ability.

In a case of collisions of greater energy, in the device according to the invention there appears also an additional beneficial effect consisting in that kinetic impact energy, before being taken over by the kinetic energy rotary accumulators having the greater moment of inertia, is accumulated in its substantial part by kinetic energy rotary accumulators having the smaller moment of inertia. Such an order of taking over the energy provides the gentler operation of the device according to the invention during starting of next kinetic energy rotary accumulators, even those having the greatest moment of inertia.

By using a one-way clutch, the free rotation of the kinetic energy rotary accumulator is provided after taking over the impact energy until the energy accumulated in it is dissipated.

Therefore, it is possible to absorb impacts on the hood from rocks of different masses, falling from different heights. This allows to make the hood 101 from lighter materials than in case of hoods that are not so effectively dampened.

BRIEF DESCRIPTION OF DRAWINGS The object of the invention is shown by means of exemplary embodiments on a drawing, in which:

Fig. 1 shows an exemplary embodiment of an underground shield,

Fig. 2 shows schematically the protective arrangement according to the invention,

Fig. 3 shows the first embodiment of the rotor device for taking over and dissipating impact energy in a top view,

Fig. 4 presents the device from Fig. 3 in the side view,

Fig. 5 presents a cross section through the axis of the kinetic energy rotary accumulator along the line A-A marked in Fig. 4,

Fig. 6 presents the second embodiment of the device in a top view, having kinetic energy rotary accumulators of the differentiated moment of inertia, in which the rack transmissions with different gear ratios are used,

Fig. 7 presents an enlarged cross section of the rotary kinetic energy accumulator, and

Fig. 8 presents the device in its first embodiment during receiving impact energy where a rotation direction as well as shifting direction of particular parts of the device in action are marked. MODES FOR CARRYING OUT THE INVENTION

Fig. 1 shows schematically an embodiment of an underground shield with a hood 101 protected by hydraulic actuators, wherein protective arrangements, shown in details in Fig. 2, are used. The hood 101 is supported on the base 102 of the vehicle by means of hydraulic actuators 103, at the ends of which there is mounted a rotary device 1 10 for taking over and dissipating energy of impact of rocks to the hood 101 , described in details with reference to Figs. 3-8. The ram element 1 of the device 1 10 is mounted to the actuator 103 and the base plate 13 is mounted to the hood 101 .

As shown in the embodiment of Fig. 3, the rotor device for taking over and dissipating impact energy has a ram element 1 made as a beam and coupled with three racks 2, 3, 4 connected in series. Between the racks 2, 3, 4, as well as between the ram element 1 and the first rack 2 distances 5, 6, 7 are formed which enable an action of cushioning elements 8 and cause that the racks 2, 3, 4 shift in relation to one another, as well as in relation to the ram element 1 . Each of the racks 2, 3, 4 meshes with a toothed wheel 9 driving a kinetic energy rotary accumulator 10, 1 1 , 12, whereas in order to achieve greater effectiveness of impact energy receiving and dissipating, the first kinetic energy rotary accumulator 10 driven by the first rack 2 has the least inertia moment, the second kinetic energy rotary accumulator 1 1 driven by the second rack 3 has an average inertia moment, and the third kinetic energy rotary accumulator 12 driven by the third rack 4 has the greatest inertia moment.

The ram element 1 is slidably engaged with side walls of a body plate 13 by means of ram runners 14, whereas these ram runners 14 are fastened perpendicularly to the ram element 1 . Moreover, a runner 15 is fastened to the body plate 13, said guide ensuring shifting of the racks 2, 3, 4 in a suitable distance from the toothed wheels 9.

As it is shown in Fig. 4, the cushioning elements 8 are located in cylindrical openings 16 made in the racks 2, 3, 4. These openings cooperate with pressing mandrels 17 carrying impact energy from the ram element 1 onto the consecutive racks 2, 3, 4. In embodiments illustrated in the figure the cushioning elements 8 have a form of helical springs, however this solution does not limit the possibility of using other cushioning elements such as, in particular, fluid or elastomer absorbers.

As it is schematically shown in the cross section in Fig. 5, in an opening 18 formed in the body plate 13 there is an axle 19 tightly fastened, with the rotatably mounted toothed wheel 9 combined with an internal bush 20 of the kinetic energy rotary accumulator 12. The kinetic energy rotary accumulator 12 has furthermore a one-way clutch 21 of the known construction situated in the annular space around the internal bush 20.

In the second embodiment of the device according to the invention presented in Fig. 6, there are used the kinetic energy rotary accumulators 10, 1 1 , 12 having different moments of inertia and rack transmissions having different transmission ratios as the result of different pitch diameters of the used toothed wheels 9a, 9b, 9c. The kinetic energy rotary accumulator 10 having the least moment of inertia is driven by means of the toothed wheel 9a having the greatest pitch diameter, and the kinetic energy rotary accumulator 12 having the greatest moment of inertia is driven by means of the toothed wheel 9c having the least pitch diameter. This construction according to the invention makes it possible to obtain increased progressiveness of taking over the impact energy by successively started kinetic energy rotary accumulators. The characteristic of the progressiveness of taking over the impact energy by the consecutive kinetic energy rotary accumulators 10, 1 1 , 12 in the embodiment shown in Fig. 6 can be therefore shaped across by selecting pitch diameters of the driving toothed wheels 9a, 9b, 9c and by selecting moments of inertia of the consecutive kinetic energy rotary accumulators 10, 1 1 , 12.

The arrow which is perpendicular to the external surface of the ram element drawn in Fig. 3, Fig. 4 and Fig. 6 shows the expected direction of an impact load. Every angular deflection of the impact load from the expected direction increases the probability of the damage of the device and causes the reduction of the efficiency of taking over and dispersing impact energy. Therefore, the device according to the invention should be mounted in objects exposed to results of the unexpected collision in such a way that the expected impact load is substantially perpendicular to the external surface of the ram element 1 .

In the embodiment shown in Fig. 6 the ram element 1 is connected slidably with the body plate 13 by means of ram runners 14a which are mounted slidably in openings 22 made in the body plate 13 parallel to the runner 15 of the racks 2, 3, 4. Such a solution provides the increased shape rigidity of the whole device and can be used also in case of larger angular deviations of the impact load from the direction perpendicular to the external surface of the ram element 1 .

As it is shown in Fig. 7, one-way clutch 21 of the known construction is situated between the inner bush 20 and an inner surface of the kinetic energy rotary accumulator 1 1 .

The one-way clutch 21 is used to transmit the torque from the internal bush 20 to the kinetic energy rotary accumulator 10, 1 1 , 12. After taking over the impact energy, when the angular speed of the internal bush 20 is smaller than the angular speed of the suitable kinetic energy rotary accumulator 10, 1 1 , 12, the one-way clutch 21 is disconnected to enable free rotation of the kinetic energy rotary accumulator 10, 1 1 , 12.

Thanks to enabling the free rotation of the kinetic energy rotary accumulators 10, 1 1 , 12 the kinetic energy stored in a short time of an impact can be dissipated in a significantly longer time.

In Fig. 8 the device according to the invention is shown during taking over the impact energy. Sliding linear motions and rotary motions of particular parts of the device respectively are shown in this figure with arrow lines. To enable taking over of the impact energy by the device according to the invention, the body plate 13 is fastened to the hood 101 (not shown in the drawing) by fastening elements 23. Depending on energy taking over capacity of the device according to the invention, fastening elements 23 can be realized by welding, riveting, gluing, screwing and any other possible connections which can be used in a construction of an object protected against results of a collision.

The energy acting during the impact on the ram element 1 , transferred by racks 2, 3, 4 to the kinetic energy rotary accumulators 10, 1 1 , 12, is initially absorbed by the cushioning elements 8. Because of a serial connection of racks 2, 3, 4, the kinetic energy rotary accumulators 10, 1 1 , 12 begin their work one after another starting from the kinetic energy rotary accumulator 10 having the least moment of inertia, and finishing with the kinetic energy rotary accumulator 12 having the greatest moment of inertia. In the solution according to the invention the maximum idle stroke of the ram element 1 in relation to the last rack 4 which drives the kinetic energy rotary accumulator 12 having the greatest moment of inertia is equal to the sum of distances 5, 6, 7 between the ram element 1 and the first rack 2, as well as among particular racks 2, 3, 4.

In the device according to the invention, in the working position illustrated in Fig. 8 during taking over of the impact energy, the distances 5, 6, 7 existing in the rest state are decreased to the size 5a, 6a, 7a. At such position of the racks 2, 3, 4 all of the kinetic energy rotary accumulators 10, 1 1 , 12 are driven, whereas in this position the kinetic energy accumulator 10 having the least moment of inertia has the greatest angular speed, the kinetic energy accumulator 1 1 having the average moment of inertia has the average angular speed, and the kinetic energy accumulator 12 having the greatest moment of inertia has the least angular speed.

In case of taking over greater impact energies by the rotor device according to the invention, the distances 5a, 6a, 7a can reach the zero value and in this case linear speeds of the moving racks 2, 3, 4 are equal, and at equal ratios of the rack transmissions, the angle velocities of the kinetic energy rotary accumulators 10, 1 1 , 12 are also equal.

Claims

1 . A protective arrangement for hydraulic actuators of an underground shield from dynamic overload with a mechanical rotary absorber, characterized in that it comprises a hydraulic actuator (103) mountable to the base (102) of the underground shield, to which there is connected a rotary device (1 10) for taking over and dissipating the energy of rocks falling on the hood (101 ), wherein the device (1 10) for taking over and dissipating energy comprises a ram element (1 ) mounted to the actuator (103), slidably coupled by means of ram guides (14) with side walls of a base plate (13) mountable to the hood (101 ), which cooperates with at least two serially connected racks (2, 3, 4) mounted slidably on a runner (15) and driving toothed wheels (9, 9a, 9b, 9c) of the kinetic energy rotary accumulators (10, 1 1 , 12), wherein distances (5, 6, 7) are created between the ram element (1 ) and the first rack (2), as well as between the particular racks (2, 3, 4), said distances enabling the displacement of the ram element (1 ) in relation to racks (2, 3, 4), as well as the displacement of these racks (2, 3, 4) in relation to one another, such as to enable the moving ram element (1 ) to pass the kinetic energy of the translational movement to the kinetic energy rotary accumulators (10, 1 1 , 12) in order to transform it to the kinetic energy of rotational movement.

2. The protective arrangement according to claim 1 characterized in that the kinetic energy rotary accumulators (10, 1 1 , 12) have different energy accumulating abilities.

3. The protective arrangement according to claim 1 or 2 characterized in that the kinetic energy rotary accumulators (10, 1 1 , 12) have different moments of inertia.

4. The protective arrangement according to any of claims 1 - 3 characterized in that the kinetic energy rotary accumulator (10) driven by the first rack (2) has a smaller moment of inertia than the kinetic energy rotary accumulator (1 1 ) driven by the second rack (3).

5. The protective arrangement according to any of claims 1 - 4 characterized in that the kinetic energy rotary accumulators (10, 1 1 , 12) are driven by transmissions increasing angular speed, which have different transmission ratios.

6. The protective arrangement according to any of claims 1 - 5 characterized in that the kinetic energy rotary accumulator (10, 1 1 , 12) has a one-way clutch (21 ).