The invention relates to a drive device for rotating tools operating with oscillation superimposition exhibiting a drive housing, a carrier sleeve mounted rotatably in the drive housing, a drive shaft mounted rotatably in the carrier sleeve, a tool carrier to receive working tools and an oscillation-generating arrangement for producing the oscillation superimposition for the tool carrier.
In the drive devices of the kind in question with impact superimposition, activation of the impact impulse takes place by means of appropriate striking mechanisms, imbalance generators and, in particular, eccentric shafts, which carry freely rotating or driven working tools. Tools operating with impact superimposition are used in particular in mining, in tunnel construction and in road building, for example when hard rock or other mineral-bearing rock must be loosened, cut or worked in some other way. Impact superimposition permits the necessary pressing forces to be applied to the material intended for loosening or excavation to be reduced to as little as 1/10 of the pressing forces that are necessary without impact superimposition, which permits the use of lighter and smaller tools and machines and, at the same time, increases the extraction performance or daily headway of the tools.
Drive devices of the kind in question for tools on which impacts are superimposed are previously disclosed in EP 329 915 A1 and EP 455 994 B1. The drive devices of the kind in question each comprise a carrier sleeve that is rotatably mounted and is driven by a carrier sleeve drive with an eccentrically arranged internal bore, in which a shaft is rigidly connected to the tool carrier, which shaft is designated in the prior art as an eccentric shaft. The carrier sleeve is provided with counterweights for the dynamic balancing of the drive device, and the eccentric shaft is driven by means of a second drive, which can consist of a separate drive or a reduction drive. In a reduction drive, the speed ratio between the speed of the eccentric shaft and the speed of the carrier sleeve is fixed; in drive devices with a separate drive for the eccentric shaft, the speed ratio is variable within limits. The offset of the eccentric shaft in the carrier sleeve can be 5 mm, for example, and the speed ratio of the faster-rotating eccentric shaft to the more slowly-rotating carrier sleeve can be in the order of 30:1, so that the working tools mounted on the tool carrier strike the material or rock to be mined or worked with a large number of radial impacts. The loosening or mining performance achieved in the case of the tools with impact superimposition of the kind in question is already many times higher than in conventional drive devices without impact superimposition.
However, the considerable vibrations that are introduced into the drive housing and tool housing, the imbalance masses that are required in particular for dynamic balancing, and the service life of the seals and bearings for the eccentric shaft and the carrier sleeve, continue to be problematical in eccentric-induced drive devices with impact superimposition of the kind in question.
The object of the invention is to make available a drive device for rotating tools operating with impact superimposition, in which the bearing and sealing of the drive shaft and carrier sleeve are improved in order to increase the service life of the drive devices and, in particular, of the tools equipped with these.
This and further objects are achieved in accordance with the invention in that the generating device for the impact superimposition is an oscillation-generating arrangement, which exhibits at least two intermediate shafts for each tool carrier, which shafts are connected in each case to the tool carrier via an eccentric component part and are capable of being driven in a synchronous fashion. In terms of their construction, the drive devices in accordance with the invention exhibit a fundamentally different design from that of the drive devices of the kind in question with impact superimposition. The impact induction, which is referred to as oscillation in the invention in order to distinguish it from the state of the art, no longer takes place by means of a single, eccentrically mounted and arranged eccentric shaft, but by means of at least two intermediate shafts, which are connected to the tool carrier in an appropriate manner eccentrically via an eccentric component part and are capable of being driven in a synchronous fashion. Since at least two intermediate shafts are assigned to the one tool carrier, or to each tool carrier, these can have significantly smaller dimensions than in the state of the art, as a consequence of which the sealing of the shafts and the support of the intermediate shafts in bearings are greatly simplified. Also dispensed with at the same time is a carrier sleeve of similar large dimensions, to which a counterweight of correspondingly large dimensions had to be allocated in the state of the art. This is no longer necessary, on the other hand, in the construction in accordance with the invention with a plurality of smaller intermediate shafts. The drive device in accordance with the invention can thus be used to drive tools which operate with oscillation superimposition, which tools can be of a significantly larger size and more versatile than in the state of the art, but without the bearing or the shaft sealing of the intermediate shafts, the carrier sleeve and/or the drive shaft being problematical. A further advantage, in accordance with the invention, is that the entire part on the drive side is not subjected to the oscillations of the tool carriers produced by the oscillation-generating arrangements.
In a particularly advantageous embodiment of the invention, all the intermediate shafts are supported in bearings concentrically to the axis of rotation of the drive shaft in the carrier sleeve. In this construction, therefore, not only the drive shaft is supported in bearings concentrically to the carrier sleeve, but also all the intermediate shafts are supported in bearings concentrically to their common axis of rotation. The plurality of intermediate shafts can then be distributed in particular symmetrically, and can be arranged and supported in bearings around the axis of rotation of the drive shaft arranged on a peripheral circle. In this construction, the driving of the drive shaft and the driving of the carrier sleeve can take place in a particularly simple manner, since both the carrier sleeve and the drive shaft rotate concentrically about a common axis of rotation.
In a further preferred embodiment of the drive device, the intermediate shafts can be connected to the drive shaft via a gear mechanism, and particularly advantageously via a toothed gear mechanism. The use of a toothed gear mechanism is made possible by the fact that the axes of rotation of the intermediate shafts exhibit a constant distance to the common axis of rotation of the drive shaft and the carrier sleeve, regardless of their instantaneous position.
In accordance with one advantageous embodiment, the toothed gear mechanism can exhibit a central toothed wheel that is rigidly connected to the drive shaft and planet wheels that are each rigidly connected to the intermediate shafts and are in toothed engagement with the central wheel. In an alternative embodiment, the toothed gear mechanism can exhibit a central toothed wheel that is rigidly attached to the drive shaft and planet wheels that are each rigidly attached to the intermediate shafts, in conjunction with which intermediate toothed wheels are arranged additionally between the central toothed wheel and the planet wheels, which intermediate toothed wheels are supported in bearings in the carrier sleeve in such a way that they are free to rotate. In the case of planet wheels that are connected directly to the central toothed wheel, relatively high speeds of rotation can be achieved for the intermediate shafts, whereas in the construction with intermediate toothed wheels, the speed of the intermediate shafts can correspond essentially or precisely to the speed of the drive shaft. The latter is particularly advantageous if a balancing weight that is rigidly connected to the drive shaft is allocated to an individual tool carrier. It will be obvious in this case to a person skilled in the art that the multiplication ratio or the reduction ratio depends on the constructive layout of the individual toothed wheels.
A further major advantage of the solution in accordance with the invention is that the eccentricity is formed directly between the tool carrier and the intermediate shafts and is achieved by means of the eccentric component parts. In an embodiment in accordance with the invention, the eccentric component parts can be constituent parts of the intermediate shafts and can be constituted by an eccentric pin arranged eccentrically to the central axis of the intermediate shaft. One-piece intermediate shafts, on which the eccentric pin is integrally formed, are provided in this embodiment, therefore. In an alternative construction, the eccentric component parts can be shaft prolongations arranged eccentrically to the central axis of the intermediate shaft, which are attached to the intermediate shaft in a detachable fashion. In the construction with detachable shaft prolongations, it is particularly advantageous if the intermediate shafts and the shaft prolongations are connected via a conical taper prolongation, which engages in a conical depression in the second part. Since the intermediate shafts normally exhibit a greater diameter than the shaft prolongations, the depression can preferably be executed in the intermediate shaft. The reverse arrangement is also possible, however. It is then particularly advantageous if the rigid connection between the taper prolongation and the depression is secured by means of a securing means.
As a further alternative, instead of intermediate shafts with eccentric shaft prolongations, intermediate shafts with concentric shaft pins can also be used, in conjunction with which the eccentric component parts are then formed by means of sleeves with an eccentric shaft seat. The shaft pins in this case engage in the shaft seats, whereby the eccentric arrangement between the intermediate shafts and the tool carriers is formed. In this case, too, it is advantageous if the shaft seat and the shaft pin are of conical execution and engage rigidly into one another, in conjunction with which the rigid connection is preferably secured with the help of a securing means. A connection with conical parts facilitates the dismantling of the one or mote tool carriers from the component part on the drive side, which comprises the carrier sleeve, the drive shaft and the bearing for the intermediate shafts. As an alternative to screwed connections as a securing means, the rigid connection between the conical parts can also consist of an oil press fit connection or a press fit that can be released by subjecting it to pressure with hydraulic means. Assembly is then effected by means of a pressing-on process, in conjunction with which oil or some other hydraulic means is forced into the joint gap between the conical parts in order to dilate the external part for assembly. The necessary pressing force can be achieved with a multiplier or a hydraulic press, for example. It goes without saying that dilation of the outer conical part by means of the hydraulic means must also take place for the purposes of dismantling.
One pivot bearing and, in the case of tool carriers with larger dimensions or depths, two or more pivot bearings, is/are appropriately arranged in each case between the eccentric component part and the tool carrier. Only these pivot bearings are required to handle the eccentric rotation of the shaft prolongations or the shaft pins on the intermediate shafts. However, since the dimensions of the sleeves, the shaft pins or the shaft prolongations are relatively small because of the plurality of intermediate shafts, the service life of the bearings and the shaft seals presents no problems in spite of the eccentricity.
The drive device or a tool with the drive device can be executed in numerous different ways. According to one preferred embodiment, the drive device or the tool exhibits a plurality of tool carriers, in conjunction with which at least two intermediate shafts are connected to each tool carrier. In one embodiment with a plurality of tool carriers, it is particularly advantageous if the vibration produced by the oscillation-generating arrangement for the first tool carrier is out-of-phase in relation to the one or more vibrations produced by the one or more additional oscillation-generating arrangements. In this embodiment, therefore, it is possible for the dynamic balancing of a tool carrier to take place exclusively via a phase-displaced oscillation of at least one additional tool carrier.
According to a particularly advantageous embodiment, an even number of tool carriers can be provided, in conjunction with which in each case the mutually opposing tool carriers are superimposed with an oscillation impulse having a phase displaced by 180° through the arrangement of the eccentric component parts of the intermediate shafts of the associated oscillation-generating arrangements. In the case of two tool carriers, for example, these tool carriers are superimposed with an oscillation impulse having a phase displaced by 180°, and the oscillation impulse is directed either to the outside or to the inside at a set time, for example in the case of both tool carriers. Two pairs are produced in each case, for example, in the case of four tool carriers, in conjunction with which, within one pair, two tool carriers are superimposed with an oscillation impulse having a phase displaced by 180° and, particularly advantageously, a phase displacement of 90° exists between the pairs. All four tool carriers can be arranged in a single plane in this case. According to a second advantageous embodiment, three tool carriers are provided, in conjunction with which the individual tool carriers are superimposed with an oscillation impulse having a phase displaced by 120°, through the arrangement of the eccentric component parts of the intermediate shafts of the associated oscillation-generating arrangements. In this case, too, the dynamic balancing takes place exclusively through the phase-displaced superimposition of the oscillation impulses of the three other tool carriers, without the need for additional balance weights.
According to a further, alternative embodiment, two tool carriers arranged in different planes can be provided, which are superimposed with an oscillation impulse having a phase displaced by 180° through the arrangement of the eccentric component parts of the intermediate shafts of the associated oscillation-generating arrangements. The embodiment with tool carriers arranged in different planes has the advantage, to the extent that the working tools attached to it also lie in different planes, that the pressing forces, which are applied by a feed drive mechanism, for example, are further reduced, since the individual tool carriers are not in simultaneous engagement with the rock to be excavated at any time. Especially in the case of the last-mentioned embodiment, it is particularly advantageous if three intermediate shafts are allocated to each tool carrier, which shafts are distributed alternately around the periphery. In order to permit the arrangement in two different planes, the associated tool carriers can be of a spade-shaped, propeller-shaped or star-shaped execution in particular. An arrangement with three intermediate shafts can also be effected, however, in the case of drive devices and tools with only two tool carriers, or even with only a single tool carrier, and/or in the case of spade-shaped or propeller-shaped tool carriers, the location areas for the working tools can also be executed on the tool carriers by means of interleaving or off-setting in such a way that the working tools lie and act in a single plane.
In an embodiment in accordance with the invention with only a single tool carrier, this can also be driven with a higher number, for example six, of synchronously rotating intermediate shafts. In the embodiment with only a single tool carrier, there is then actually a requirement for a balance weight, which preferably rotates in the same direction about the drive axis of the drive shaft with a phase displacement of 180° in relation to the oscillation impulse generated by means of the eccentric components of all the intermediate shafts.
The tools can be attached directly to the tool carrier. It is particularly advantageous, however, if single-component or multiple-component tool holders in the form of an annular segment are attached to each tool carrier with attachment devices for a plurality of working tools. The drive device in accordance with the invention can be used for boring, cutting or the excavation of rock and minerals. The working tools used can consist in particular of self-sharpening round chisel bits, flat chisel bits, discs or cross roller bits. It is also advantageous if the carrier sleeve is driven during operation at a considerably slower speed than the intermediate shafts, in conjunction with which the speed ratio preferably lies between the speed Nz of the intermediate shafts and the speed NT of the carrier sleeves >22 and in particular between 25:1 and about 31:1, depending on the nature of the rock to be excavated and the number of working tools, etc. The carrier sleeves can preferably also be driven with a carrier sleeve drive, and the intermediate shafts with an intermediate shaft drive allocated to the drive shaft, and a feed speed for the drive device is adjustable via a feed drive mechanism, in conjunction with which a control device controls the carrier sleeve drive and the feed drive depending on the intermediate shaft drive and thus on the drive for the drive shaft. The connection between the intermediate shaft drive and the carrier sleeve drive can also be effected by means of a gear mechanism with a fixed multiplication ratio.
Further advantages and embodiments of the invention can be appreciated from the following description of illustrative embodiments represented schematically in the drawing of drive devices in accordance with the invention and of tools on which impacts are superimposed having drive devices in accordance with the invention. In the drawing:
Represented in
The construction of the drive device 10 is now explained with reference to
The carrier sleeve 15 broadens out at one end into a carrier sleeve head 15A, to the front side of which a sealing disc 20 is attached, which also carries the front bearing 19 for the drive shaft 13. Both the head 15A and the sealing disc 20 are each provided in this case with a total of six seats 21 for intermediate shafts 30, to which the tool carriers 16A and 16B are attached in each case via an eccentric component part 32. In the illustrative embodiment according to
In the drive device 10 in accordance with the invention, neither the shaft seals 24 between the drive housing 11 and the carrier sleeve 15 nor the shaft seals 25 on the seats 21 in the sealing disc 20, nor the shaft seals 26 between the eccentric component parts 32 and the tool carriers 16A, 16B are subjected to eccentric movements. Every tool carrier 16A, 16B is rotatably connected to the intermediate shafts 30 by means of a plurality of, in this case three, eccentric component parts 32 and associated bearings 35 for the eccentric component parts, so that the bearings 18, 22 and 35 are also not exposed to any excessive impact loadings, which are produced with the oscillation superimposition in the drive device 10.
The arrangement of the tool carriers 216A, 216B and the arrangement of the eccentric component parts 232 of the intermediate shafts are represented schematically in
In the case of the illustrative embodiment of a fourth drive device 310 in accordance with the invention in
In the case of the fifth illustrative embodiment of a drive device 410 shown in
In the case of the seventh illustrative embodiment of a drive device 610 in
Numerous modifications, which should fall within the scope of the protection afforded by the dependent claims, will be evident from the foregoing description to a person skilled in the art. In the case of tools and drive devices with larger dimensions, three or more intermediate shafts can also be allocated to every tool carrier. This embodiment also retains in full the particular advantage that the intermediate shafts with the eccentric component parts possess significantly smaller dimensions than in drive devices with eccentrically broad carrier sleeves. The possibility of connecting the drives for the drive shafts and the drives for the carrier sleeve directly to one another via a suitable gear arrangement is not represented. Also not represented is the ability to regulate the speed of the intermediate shaft drive, the speed of the carrier sleeve drive and the rate of feed for the tool as a whole in a way in which they are matched to one another and in particular with reference to the speed of the intermediate shaft drive, via a superior control device. The eccentric offset can be 7.5 mm, for example, for a speed of rotation of the carrier sleeve of 100-150 revolutions/min, and for an impact superimposition or oscillation of around 3200/min, so that a speed ratio Nz for the intermediate shafts and NT for the carrier sleeve in the order of 20:1 to 35:1 can be obtained. The detachable attachment between the eccentric component parts and the intermediate shafts can also be effected by means of an oil press fit connection. For example, eight working tools with an angular offset of 45° in relation to one another can be attached to the tool carriers. Torsionally elastic couplings can be installed between the drive shaft and/or the carrier sleeve and their drives, for example consisting of electric motors, which couplings can be equipped additionally with an overload function in order to prevent damage to the drive devices or the drives in the event of blockages. The working tools, such as round chisel bits, discs, flat chisel bits and the like can also be attached directly to the tool carrier. The gap between the segment-shaped tool carriers can be covered with plates and the like.
Number | Date | Country | Kind |
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10 2005 028 277.6 | Jun 2005 | DE | national |
20 2005 028 277.6 | Jun 2005 | DE | national |