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Title:
A GEARBOX ARRANGEMENT
Document Type and Number:
WIPO Patent Application WO/2019/016769
Kind Code:
A1
Abstract:
The present invention relates to a gearbox arrangement (10) comprising an input mechanism (12), a first transmission shaft (14) and a second transmission shaft (16). The first and second transmission shafts (14, 16) are connected to the input mechanism (12) and are arranged to be simultaneously driven by a drive means (not shown) via the input mechanism (12) and to divide the torque, which receives the drive means, in use. The first and second shafts (14, 16) are fitted with first and second output drive gears (18, 20) respectively. The gearbox arrangement (10) also comprises an output mechanism (22) which is connected to the transmission shafts (14, 16) and is arranged to be driven by the first and second output drive gears (18, 20) simultaneously.

Inventors:
PIENAAR ABEL ALBERTUS (ZA)
Application Number:
PCT/IB2018/055411
Publication Date:
January 24, 2019
Filing Date:
July 20, 2018
Export Citation:
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Assignee:
PIENAAR ABEL ALBERTUS (ZA)
International Classes:
F16H1/22; B65G23/08; F16H57/02
Domestic Patent References:
WO2017012558A12017-01-26
Foreign References:
DE3725872A11988-09-29
DE10353927A12004-06-17
US20050011307A12005-01-20
US20150075325A12015-03-19
DE2826022A11979-12-20
DE2544045A11977-04-21
Attorney, Agent or Firm:
DM KISCH INC. (ZA)
Download PDF:
Claims:
A gearbox arrangement comprising:

first and second transmission shafts connectable to an input mechanism, for the first and second transmission shafts to be driven simultaneously by the input mechanism; and

an output mechanism connected to the first and second transmission shafts, for the output mechanism to be driven by the first and second transmission shafts simultaneously.

The gearbox arrangement according to claim 1 , including the input mechanism for receiving a drive means for driving the input mechanism.

The gearbox arrangement according to claim 1 or 2, wherein the first and second transmission shafts are fitted with first and second input driven gears respectively which are arranged to engage with the input mechanism to thereby, in use, be driven simultaneously by the input mechanism.

The gearbox arrangement according to any one or the preceding claims, wherein the first and second transmission shafts include first and second output drive gears respectively which are arranged to engage with the output mechanism to thereby, in use, simultaneously drive the output mechanism.

5. The gearbox arrangement according to any one of the preceding claims, wherein the output mechanism comprises an output shaft that is fitted with first and second output driven gears for to be driven by the first and second output drive gears respectively.

The gearbox arrangement according to any one of the preceding claims, wherein the input mechanism comprises an input drive gear.

The gearbox arrangement according to any one of the preceding claims, wherein an input axis of rotation, about which the input mechanism rotates, and an output axis of rotation, about which the output mechanism rotates, are perpendicular relative to each other.

The gearbox arrangement according to any one of the preceding claims, wherein the first and second transmission shafts are arranged in a parallel configuration and, in use, rotate at substantially identical angular velocities.

The gearbox arrangement according to claim 3, wherein any one of the first and second input driven gears is fitted onto the respective one of the first and second transmission shafts by means of an angularly adjustable fixing mechanism for facilitating adjustment of the first and second input driven gears angularly relative to each other without having to angularly adjust the transmission shafts.

0. The gearbox arrangement according to claim 9, wherein the angularly adjustable fixing mechanism comprises inner and outer sleeves and a wedge arrangement for urging the inner and outer sleeves respectively against the shaft and gear in order to fit the gear onto the shaft.

1 1 . The gearbox arrangement according to claim 2, wherein the drive means comprises one of an electrical motor, internal combustion motor, pneumatic motor, and hydraulic motor, and wherein the drive means directly drives the input mechanism.

12. The gearbox arrangement according to any one of the preceding claims, wherein the output mechanism drives a head sprocket of a conveyor chain.

13. The gearbox arrangement according to claim 1 1 , wherein the conveyor chain is provided on a shuttle car.

14. A vehicle comprising a vehicle body and a gearbox arrangement, according to any one of the preceding claims, fitted to the vehicle body.

15. The vehicle according to claim 14, wherein the vehicle is a shuttle car.

16. The gearbox arrangement according to claim 1 , substantially as herein described with reference to the accompanying figures.

17. The vehicle according to claim 14, substantially as herein described with reference to the accompanying figures.

Description:
A GEARBOX ARRANGEMENT

FIELD OF THE INVENTION The present invention relates to a gearbox arrangement. Particularly, but not exclusively, the present invention relates to a gearbox arrangement that forms part of a drive arrangement for a conveyor system forming part of a shuttle car used in mining operations. INTRODUCTION AND BACKGROUND

Shuttle cars are generally used in underground mining operations for transporting debris, rock, coal, muck, and other materials away from a working face. Due to limited air supply in the underground operation, the shuttle cars are generally driven by electric motors, which are could be powered by trailing cables.

The shuttle cars furthermore comprise conveyor chains or belts for receiving and conveying the materials. The operative end of the conveyor chain may comprise a pivotable boom. The conveyor chain is driven by a drive arrangement comprising an electrical motor and a reducer gearbox which is arranged to drive a head sprocket and shaft of the conveyor chain. The drive arrangement may be mounted on the pivotable boom, which means that, practically, the permissible size and weight of the drive arrangement is limited. The limited space of the underground surroundings of the mining operation pose further limitations to the shuttle car. Because of the volume and weight of the materials to be transported by the shuttle car, the head sprocket and shaft of the conveyor chain has relatively high torque requirements.

Because of the high levels of torque transmitted via the gearboxes, these are known to be maintenance intensive units, with the internal gears, especially driven brass worm wheels and worm gears, having fairly high failure rates. To deal with the high torque requirements, known shuttle cars provide either two motor and gearbox arrangements, one on either side of the boom, capable of transmitting the required torque. In both of these instances, the weight, cost and physical size of the motor and gearbox arrangement, pose disadvantages to the known systems.

OBJECT OF THE INVENTION

It is therefore an object of the present invention to provide a gearbox arrangement with which the applicant believes the aforementioned disadvantages may at least be alleviated or that may provide a useful alternative to the known gearbox arrangements. SUMMARY OF THE INVENTION

According to a first aspect of the invention, there is provided a gearbox arrangement comprising: - first and second transmission shafts connectable to an input mechanism, for the first and second transmission shafts to be driven simultaneously by the input mechanism; and

- an output mechanism connected to the first and second transmission shafts, for the output mechanism to be driven by the first and second transmission shafts simultaneously.

There is provided for the gearbox arrangement to include the input mechanism for receiving a drive means for driving the input mechanism.

The first and second transmission shafts may be fitted with first and second input driven gears respectively which are arranged to engage with the input mechanism to thereby, in use, be driven simultaneously by the input mechanism. The first and second transmission shafts may further include first and second output drive gears respectively which are arranged to engage with the output mechanism to thereby, in use, simultaneously drive the output mechanism.

The output mechanism may comprise an output shaft that is fitted with first and second output driven gears for to be driven by the first and second output drive gears respectively.

The input mechanism may comprise an input drive gear. The gearbox arrangement may be such that an input axis of rotation, about which the input mechanism rotates, and an output axis of rotation, about which the output mechanism rotates, are perpendicular relative to each other. The first and second transmission shafts may be arranged in a parallel configuration. In use, the first and second drive shafts may rotate at substantially identical angular velocities.

Any one of the first and second input driven gears may be fitted onto the respective one of the first and second transmission shafts by means of an angularly adjustable fixing mechanism. The angularly adjustable fixing mechanism may facilitate adjusting the first and second input driven gears angularly relative to each other without having to angularly adjust the transmission shafts. The angularly adjustable fixing mechanism may comprise inner and outer sleeves and a wedge arrangement for urging the inner and outer sleeves respectively against the shaft and gear in order to fit the gear onto the shaft.

The drive means may comprise one of an electrical motor, an internal combustion motor, a pneumatic motor and a hydraulic motor. The drive means may be arranged to directly drive the input mechanism.

The output mechanism may be arranged to drive a head sprocket of a conveyor chain which may be provided on a shuttle car. According to a second aspect of the invention, there is provided a vehicle comprising a vehicle body and a gearbox arrangement, as defined above, fitted to the vehicle body. The vehicle may be a mining vehicle. More specifically, the vehicle may be a shuttle car.

These and other features of the invention are described in more detail below. BRIEF DESCRIPTION OF THE ACCOMPANYING DIAGRAMS

The invention will now further be described, by way of example only, with reference to the accompanying diagrams wherein: figure 1 is a first isometric view of a gearbox arrangement in accordance with the invention; figure 2 is a second isometric view of the gearbox arrangement of figure 1 ; figure 3 is a first side view of the gearbox arrangement of figure 1 ; figure 4 is a second side view of the gearbox arrangement of figure 1 , wherein an internal gear train of the gearbox arrangement is visible; figure 5 is a rear view of the gearbox arrangement of figure 1 ; figure 6 is a section view on line VI-VI' as indicated in figure 5, wherein the internal components of the gearbox arrangement is visible; figure 7 is an isometric view of the gearbox similar to that of figure 2, wherein the casing is indicated in broken lines in order to reveal the internal components of the gearbox arrangement; figure 8 is an isometric view similar to that of figure 7, wherein only the internal gears and shafts of the gearbox arrangement are shown; figure 9 is an isometric view of the gearbox similar to that of figure 1 , wherein the casing is indicated in broken lines in order to reveal the internal components of the gearbox; figure 10 is an isometric view similar to that of figure 9, wherein only the internal gears and shafts of the gearbox arrangement are shown; figure 1 1 is the second side view as shown in figure 4, wherein the casing is indicated in broken lines in order to reveal the internal components of the gearbox arrangement; figure 12 is an exploded perspective view of an angularly adjustable fixing mechanism forming part of the gearbox arrangement of figure 1 ; and figure 13 is a schematic perspective view of a vehicle including the gearbox arrangement of figure 1 .

DETAILED DESCRIPTION OF INVENTION

Referring to the figures an example gearbox arrangement, in accordance with the invention, is generally indicated by reference numeral 10.

The gearbox arrangement 10 comprises an input mechanism 12, a first transmission shaft 14 and a second transmission shaft 16. The first and second transmission shafts (14, 16) are connected to the input mechanism 12 and are arranged to be simultaneously driven by a drive means (not shown) via the input mechanism 12, which receives the drive means, in use. The first and second shafts (14, 16) respectively include first and second output drive gears (18, 20). The gearbox arrangement 10 also comprises an output mechanism 22 which is connected to the transmission shafts (14,16) and is arranged to be driven by the first and second output drive gears (18, 20) simultaneously.

The input mechanism 12 comprises an input drive gear. The first and second transmission shafts (14, 16) are fitted with first and second input driven gears (24, 26) respectively which are arranged to engage with the input drive gear 12. Therefore, the input drive gear 12 meshes with both the first and second input driven gears (24, 26) to thereby, in use, drive the first and second input driven gears (24, 26) simultaneously. The output mechanism 22 comprises an output shaft 28 that is fitted with first and second output driven gears (30, 32). Therefore, the first and second output driven gears (30, 32) are driven by the first and second output drive gears (18, 20) respectively, to thereby drive the output shaft 28.

Turning to figure 6, it is shown that the first and second output driven gears (30, 32) are fitted onto the output shaft 28 via an intermediate cylinder 34, which extends about the shaft 28. Spacer sleeves (36.1 , 36.2) are located on opposing ends of the arrangement 10 and assist in holding the shaft 28 in position. The shaft 28 further includes an annular shear groove 38 that causes the shaft 28 to break at this weakened area in the event that the required torque output exceeds a predetermined maximum, to thereby protect the internal gearbox components against excessive forces. In the event that the shaft 28 needs to be replaced, an end plate 40 is taken off to enable removal and replacement of the sleeves (36.1 , 36.2) and shaft 28 through an end of the arrangement 10. This process can be executed relatively quickly and doesn't require removal of the arrangement 10 from the vehicle it is fitted onto. Furthermore, the arrangement 10 facilitates the shaft 28 to protrude from either end of the arrangement 10 by merely, amongst other steps, turning the shaft 28 around, switching the sleeves (36.1 , 36.2) and securing the plate 40 to a corresponding position on an opposing end of the arrangement 10.

As best shown in figures 8 and 10, the input drive gear 12 comprises a pinion gear, the first and second input driven gears (24, 26) comprise first and second spur gears respectively, the first and second output drive gears (18, 20) comprise first and second worms respectively, and the first and second output driven gears (30, 32) comprise first and second worm gears respectively. As is best shown in figure 10, the second spur gear 26 is fitted to the second shaft 16 by means of an angularly adjustable fixing mechanism 42. The angularly adjustable fixing mechanism 42 renders the first and second spur gears (24, 26) angularly adjustable A relative to each other about their respective axes of rotation, without having to angularly adjust A the shafts (14, 16). The first and second input drive gears (24, 26) need to be angularly adjustable relative to each other to take up any backlash, and ensure that the timing of the first and second input drive gears (24, 26) are similar. In this way, the first and second input drive gears (24, 26) starts transferring their respective portions of the load simultaneously, and thereby performs equal amounts of work.

Referring to figure 12, the angularly adjustable fixing mechanism 42 comprises an outer sleeve 44, having an adjustable diameter, that seats against the second spur gear 26, an inner sleeve 46, also having an adjustable diameter, that that seats on the second shaft 16, and a wedge arrangement 48 extending along an annular path in- between the inner and outer sleeves (46, 44) in order to space the sleeves (44, 46) from each other. The sleeves (44, 46) are v-shaped in section view with their respective tapered sides facing each other.

The wedge arrangement 48 comprises opposing first and second wedge elements (50, 52) being axially spaced from each other, and a plurality of fastener elements 54 extending through non-threaded holes 56.1 and threaded holes 56.2 provided in the first and second elements (50, 52) respectively to hold them in position relative to each other. In an assembled configuration, the elements (50, 52) are axially spaced a predetermined distance apart, the outer sleeve 44 seats against outwardly facing sides of the wedge elements (50, 52), and the inner sleeve 46 seats against inwardly facing sides of the wedge elements (50, 52). When the fasteners 54 are tightened, the wedge elements (50, 52) move towards each other, in turn, causing the inner and outer sleeves (46, 44) to be urged away from each other and respectively against the shaft 16 and gear 26 to thereby fix the gear 26 onto the shaft 16. When the angular position of the gear 26 needs to be adjusted, the fasteners 54 are loosened.

It will be understood that in other embodiments of the invention the angularly adjustable fixing mechanism 42 could alternatively be fitted between the first spur gear 24 and first shaft 14 to render the first and second spur gears (24, 26) angularly adjustable relative to each other in a similar manner as described above.

The first and second shafts (14, 16) are arranged substantially parallel, and rotate at substantially identical angular velocities in similar rotational directions in use. Thus, the gear ratios of the first spur gear 24, first worm 18 and first worm gear 30 are identical to the gear ratios of the second spur gear 26, the second worm 20 and the second worm gear 32. Thus, each of the first and second shafts (14, 16) transfers half of the torque received from the drive means via the pinion 12 to the output driven gears (30, 32), and ultimately the output mechanism 22. The gearbox arrangement 10 therefore firstly has an internal torque splitting capability and secondly an internal torque summing capability. The input axis of rotation B of the pinion 12 is perpendicular to the output axis of rotation C of the output shaft 28. The drive means may be one of an electrical motor, an internal combustion motor, a pneumatic motor and a hydraulic motor. The drive shaft of the motor is directly connected to the pinion 12.

The gearbox arrangement 10 is provided with a casing 58 which comprises an internal lubrication system (not shown), for lubricating all of the internal components. The gearbox arrangement 10 is a step-down gearbox, which could be driven in forward and in reverse, if required.

Figure 13 illustrates a shuttle car 100 whereby the gearbox arrangement 10 has been fitted onto its body 102.

The gearbox arrangement 10 is particularly suited for driving the head sprocket (not shown) of a conveyor chain (not shown), and in particular, the head sprocket of a conveyor chain on an underground shuttle car 102. By splitting the torque between the first and second shafts (14, 16), the size and failure rate of the first and second gears (30, 32) can significantly be reduced. The need for making use of two gearboxes to transfer the required torque is also negated. The gearbox 10 therefore overcomes the ergonomic difficulties of known shuttle car gearbox arrangements. Furthermore, the gearbox arrangement 10 is compact in design and takes up less space and is lighter than devices known in the art that are able to perform the same work. Also, one of the shafts (14 or 16), along with the corresponding drive gear (18 or 20) it includes and corresponding driven gear (24 or 26) being fitted thereto, as well as the corresponding driven gear (30 or 32) it engages with could be removed in lower torque applications. Last-mentioned feature ensures that with the arrangement 10 only one gearbox is required for a variety of applications, thus affording the user greater flexibility and cost- saving.

It will be appreciated by those skilled in the art that the invention is not limited to the precise details as described herein and that many variations are possible without departing from the scope and spirit of the appended claims. For example, the output drive gears (18, 20) may comprise spur gears while the output mechanism may comprise an output pinion gear. Alternatively, or in addition, the input mechanism 12 may comprise a shaft including two worms, and each of the first and second input driven gears (24, 26) may comprise worm gears. Further, the arrangement 10 could be used to drive a belt as well. Also, the arrangement 10 could be used to drive single or dual chain assemblies.

It will further be appreciated that the foregoing examples have been provided merely for the purposes of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to exemplary embodiments only, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. The present invention is also not intended to be limited to the particulars disclosed herein. Rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the invention.