WO2007132065A1

WO2007132065A1 - Screen scoop and power transmission module for screen scoop

Info

Publication number: WO2007132065A1
Application number: PCT/FI2007/050270
Authority: WO
Inventors: Benjami PITKÄSALO; Veikko Janhunen; Ilkka JÄRVINEN
Original assignee: Ramtec Oy
Priority date: 2006-05-15
Filing date: 2007-05-14
Publication date: 2007-11-22
Also published as: FI20065326A; FI121820B; FI20065326A0; EP2018457B1; EP2018457A4; NL1033853A1; ITMI20070975A1; NL1033853C2; EP2018457A1

Abstract

The invention relates to a screen scoop and a power transmission module for screen scoop. The screen scoop comprises at least one separate power transmission module (4), which includes a body (4') forming a closed space 5 and a power transmission wheel for each screen shaft (2; 2a, 2b) of the screen scoop (1) which may be connected to be rotated by a separate rotating motor (3), in which case the shaft (9) of each power transmission wheel is provided with coupling members (13) which connect the screen scoop irrotatably to the ends of the screen shafts (2; 2a, 2b).

Description

SCREEN SCOOP AND POWER TRANSMISSION MODULE FOR SCREEN SCOOP

BACKGROUND OF THE INVENTION

[0001] The invention relates to a screen scoop intended to be attached to a boom of a machine, such as an excavator, wheel loader or the like, the screen scoop having a scoop-like body portion whose one side is provided with an opening whose length substantially corresponds to that of the body portion and where one or more parallel screen shafts being arranged in the opening rotate about parallel axes, the screen shafts being provided with crushing blades arranged at a distance from one another, a rotating motor for rotating the screen shafts, and power transmission means for transmitting the rotational movement from the rotating motor to the end of each screen shaft. The invention further relates to a power transmission module for screen scoop. [0002] Screen scoops are used to sort and crush various earth materials and also harder materials, such as soft rock types, pieces of light con- crete, frozen earth blocks, etc. Such solutions are known from Finnish publications 101819, 104081 and 1171031 , for instance. Screen scoops of this kind include a scoop-like body portion whose bottom is, instead of a solid plate, formed of one or more parallel screen shafts provided with crushing blades and rotated by rotating motors, typically by hydraulic motors. In that case, the material in the scoop is screened and frozen or hard earth blocks, for example, are crushed into smaller pieces. Instead, rocks, for example, remain in the scoop and are thus screened from the material to be handled.

[0003] In prior art solutions, the crushing blades are rotated by chain wheels and a chain mounted at the end of each screen shaft, by means of which a hydraulic motor attached to the body of the device rotates the shafts. For power transmission, the screen scoop is provided with a casing space which is covered by a cover plate so as to protect the cog wheels and the chain from dust. To provide lubrication during use, this space is typically filled with oil and a seal is arranged between the cover plate and the body. [0004] A problem associated with the prior art solutions is that during use, the scoop is subjected to forces that make it twist, and thus, in the course of time, the oil in the power transmission casing may flow out. A further problem is that when the chain, cog wheel or hydraulic motor is damaged, the device can no longer be used but has to be taken to repair or repaired on site, which usually takes a significant amount of time. BRIEF DESCRIPTION OF THE INVENTION

[0005] The object of the invention is to provide a screen scoop where the damaging of the power transmission apparatus is less likely than in prior art solutions and where, in case of damage, the repair time is shorter than in prior art solutions.

[0006] The screen scoop according to the invention is characterized in that the power transmission means comprise at least one separate power transmission module, which includes a body forming a closed space and power transmission wheels for screen shafts, the power transmission wheels being connectable to be rotated by the rotating motor, arranged rotatably with respect to the body of the power transmission module and provided at least alternately with coupling members for connecting the power transmission wheel irrotatably to the end of the screen shaft so that each screen shaft connects to the respective power transmission wheel when the power transmis- sion module is pushed into its place in the direction of the screen shafts.

[0007] The power transmission module for screen scoop according to the invention is characterized in that it comprises a body and power transmission wheels for screen shafts of the screen scoop inside the body, the wheels being connectable to be rotated by a separate rotating motor, in which case the shafts of the power transmission wheels are provided with coupling members that connect the ends of the screen shafts in the screen scoop irrotatably to each other, in which case the power transmission module is mount- able in the screen scoop by pushing it into its place in the direction of the screen shafts so that the ends of each power transmission wheel and the re- spective screen shaft connect to each other, after which the power transmission module may be attached to the screen scoop by suitable fastening means, such as bolts.

[0008] The basic idea of the invention is that the power transmission apparatus is formed as a separate power transmission module which is quick and simple to detach and attach. In an embodiment according to the invention, the power transmission apparatus comprises a cog wheel for each shaft, the cog wheels being connected to rotate each other and the rotating motor being connected to rotate the cog wheels by a cog wheel.

[0009] An advantage of the invention is that since the power trans- mission apparatus is a separate power transmission module, it may be attached to the screen scoop so that the twisting of the screen scoop does not twist the body of the power transmission module and cannot thus damage the sealing structures. In that case, the lubricating oil inside the power transmission module stays there and the power transmission members do not have to suffer from lack of lubrication. A further advantage of the invention is that in case of damage, the power transmission module may be quickly detached and replaced by a corresponding power transmission module, in which case the damaged power transmission module may be repaired totally separately from the apparatus and the use of the apparatus is discontinued only for a short period. A further advantage of an embodiment of the invention is that when cog wheels are used for power transmission, stretching of chains typical in chain mechanisms can be avoided as well as interruptions and damage caused by this to the use of the device.

BRIEF DESCRIPTION OF THE FIGURES

[0010] The invention will now be described in greater detail in the accompanying drawings, in which

Figure 1 schematically illustrates a perspective view of a screen scoop,

Figures 2a and 2b schematically illustrate a perspective view and a direct side view of an embodiment of a power transmission module, respec- tively,

Figures 3a and 3b illustrate a more detailed top view of the embodiment of the power transmission module shown in Figures 2a and 2b cut along line A-A and a detailed enlargement of the installation of one cog wheel in the power transmission module, and Figures 4a and 4b illustrate a cross sectional top view of another embodiment of the power transmission module shown in Figures 2a and 2b and a detailed enlargement of the installation of one cog wheel in the power transmission module.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION [0011] Figure 1 schematically illustrates a perspective view of a screen scoop 1 according to the invention. As shown in the figure, the screen scoop 1 comprises a body portion 1a having the shape of a scoop of an excavator, wheel loader or the like. However, instead of solid material, its bottom is formed of one or more parallel screen shafts 2 provided with crushing blades and rotated by rotating motors 3, typically by power transmission mechanisms driven by hydraulic motors and illustrated in greater detail in Figures 2a and 3a to 3c. The power transmission mechanisms are arranged as separate power transmission modules 4 attached to the screen scoop. In principle, there may be only one power transmission module but preferably both ends of the screen scoop are provided with one module. The screen scoop further comprises fastening lugs 5 and 6 for fastening the screen scoop in a manner known per se to the boom of a machine, such as an excavator, wheel loader or the like, so that the screen scoop can be used.

[0012] There is one power transmission module 4 at both ends of the screen scoop and they both are provided with a dedicated rotating motor 3. The screen shafts 2 may be either uniform shafts extending from one end of the screen scoop to the other or they may be formed of separate shaft portions by arranging two shaft portions 2a and 2b one after the other so that they together extend from one end of the screen scoop to the other. In that case, the screen scoop must be provided with a separate support beam 1a, which travels in the transverse direction of the shafts and where the ends of the shaft portions 2a and 2b are mounted rotatably by bearings. The use of a support beam 1a in connection with uniform shafts extending from one end of the screen scoop to the other is also preferable because it supports the shafts and reduce their bending during use. Crushing blades 2c are attached to each screen shaft at a distance from one another so that the crushing blades 2c of adjacent screen shafts 2 are interlocked. A structure formed of two separate screen shaft elements could also be used, in which case the screen scoop would be formed by shaft elements covering about half of the bottom, and each element would have a dedicated power transmission module and naturally a dedicated rotating motor.

[0013] Figure 2a schematically illustrates a perspective and partly cross-sectional view of a power transmission module 4 of a screen scoop according to the invention. The figure shows power transmission wheels mounted in the body 4' of the power transmission module 4 by bearings. In this example, the wheels are cog wheels 7 which are connected to each other by means of cogging so that all wheels rotate when one wheel rotates and adjacent cog wheels rotate in opposite directions. Figure 2a further illustrates a cog wheel 8 which is intended to be connected to the rotating motor and which rotates the cog wheels 7 when the rotating motor rotates it. Other components of some embodiments of the power transmission module are illustrated in greater detail in connection with Figures 3a to 3 and 4a and 4b. Figure 2b illustrates a side view of the power transmission module 4. In this example, the power transmission module comprises four cog wheels 7 which are connected to one another and whose shafts are intended to be connected to the end of one screen shaft after the power transmission module has been installed. Figure 2b further illustrates a cog wheel 8 to be connected to the rotating motor. For connecting the cog wheel 8 to the rotating motor, it may be provided with a hole 8a for the shaft of the rotating motor and a wedge groove 8b for the wedge. Other prior art manners of implementing the connecting may naturally also be used. [0014] Figures 3a and 3b illustrate a top view of an embodiment of the power transmission module shown in Figures 2a and 2b in greater detail cut along line A-A and a detailed enlargement of the installation of one cog wheel in the power transmission module.

[0015] Figure 3a illustrates a top view of the power transmission module. It shows how the cog wheels 7 are mounted in the power transmission module 4 by bearings, which are illustrated in greater detail in connection with Figure 3b. It further shows how the shafts extend outside the body 4' of the power transmission module 4 at the cog wheels 7. This provides a situation where the rotating force is transmitted from one cog wheel to another rotated by the rotating motor and correspondingly to shafts 9 connected irrotatably to the cog wheels. In this embodiment, only one power transmission module would be sufficient for rotating all the shafts. To achieve a more even load and power distribution, both ends of the screen scoop may be provided with a power transmission module. Correspondingly, if screen shafts formed of two shaft portions 2a and 2b or of two separate screen shaft elements are used, also two power transmission modules will be needed.

[0016] Figure 3b illustrates section B in greater detail, i.e. installation of a cog wheel in the power transmission module 4. The cog wheel 7 is mounted irrotatably on the shaft 9 so that the rotational movement of the cog wheel 7 is transmitted forward through the shaft 9. Any prior art method may be used in mounting the cog wheels 7 irrotatably on the shafts 9, such as wedges and wedge grooves in the shaft and in the cog wheels, respectively, openings with a cross section different from a circle in the cog wheels and shafts with a corresponding cross-sectional shape, fastening the cog wheels to the shafts in a prior art fastening method, etc. The power transmission module is provided with openings for mounting the cog wheels and the openings are provided with cover plates 4a. On both sides of the cog wheel 7, there are bearings 10 and 11 for mounting the cog wheels rotatably with respect to the cover plates 4a and the side plate 4c or side plates 4b and 4c of the power transmission module 4. On the side where the shaft 9 exits the module, there is also a seal 12 for sealing the shaft so that the lubricating oil inside the power transmission module 4 stays inside the power transmission module and cannot flow out through the openings in the shaft 9. The shafts are also provided with recesses 13 having a cross section different from a circle, for example a quadrangular cross section. The ends of the screen shafts in the screen scoop 1 have a similar cross section and are dimensioned so that they are easy to push into the holes 13. In that case, the power transmission module 4 is installed simply by pushing it in the direction of the shafts, after which it is easy to fasten the module to the body portion 1a of the screen scoop 1.Correspondingly, it is easy to detach the power transmission module 4 by only unscrewing the fastening bolts and by withdrawing the module. The structure of the power transmission module 4 may also differ from what was described above and instead of the cover plates 4a, another kind of structure may be used.

[0017] Figures 4a and 4b illustrate in greater detail a top view of an- other embodiment of the power transmission module shown in Figures 2a and 2b cut along line A-A and a detailed enlargement of the installation of one cog wheel in the power transmission module. For the sake of clarity, only the features differing from the solution of Figures 3a and 3b will be described in detail, while other parts and their function correspond to the ones shown in Figures 3a and 3b.

[0018] Figure 4a illustrates a top view of another embodiment of the power transmission module. In this solution, the screen shafts should rotate in the same direction. Thus it comprises two cog wheels 7a connected to the shafts 9a irrotatably so that the cog wheels 7 rotate the shafts 9a. It also com- prises a second set of cog wheels 7b which alternate with the cog wheels 7 and which are mounted to rotate about their shafts 9b. Between the cog wheels 7b and the shafts 9b, there are bearings 14 that allow the cog wheels 7b and the shafts 9b to rotate with respect to each other. This structure is described in greater detail in connection with Figure 4b. This provides a situation where the rotational force is transmitted from one cog wheel to another rotated by the rotating motor and correspondingly to the shafts 9a connected irrotata- bly to the cog wheels. When there is another power transmission module 4 at the other end of the screen scoop, the connection between the cog wheels and the shafts is opposite, i.e. the cog wheels corresponding to the cog wheels 7a of the power transmission module illustrated by Figure 4b are mounted rotata- bly about their shafts and the cog wheels corresponding to the cog wheels 7b are connected irrotatably about their shafts so that uniform shafts 2 of the screen scoop extending from one end to the other can be made, if desired, to rotate in the same direction or, by changing the rotational direction of the other rotating motor, adjacent shafts can be made to rotate in the opposite direc- tions.

[0019] The power transmission module 4 is installed in the screen scoop illustrated by Figure 1 by fastening it with only a few bolts. Between the power transmission module 4 and the body portion 1a of the screen scoop, there may be spring members which allow the body portion 1a of the screen scoop to bend without substantially twisting the power transmission module. The casing of the power transmission module 4 may also be made of a sufficiently thick material so as to obtain sufficient rigidity.

[0020] The invention was only described by examples in the above specification and drawings and it is by no means limited to them. Instead of the cog wheels, chain wheels and a chain mechanism may naturally be used to generate the rotational movement. The shafts of the cog wheels, or alternatively the chain wheels, do not need to extend outside the power transmission module but the shafts may be shorter and the recess 12 may also be provided inside the power transmission module. Correspondingly, the coupling between the shafts 9 and the screen shafts may be implemented so that the recesses are at the end of the screen shafts and the projections to be pushed into them are at the end of the shafts 9. Furthermore, the bearings of the cog or chain wheels in the power transmission module may be implemented in various ways and the seals and bearings may also be arranged in the reverse order.

Claims

1. A screen scoop intended to be attached to a boom of a machine, such as an excavator, wheel loader or the like, the screen scoop having a scoop-like body portion (1 ) whose one side is provided with an opening whose length substantially corresponds to that of the body portion (1) and where one or more parallel screen shafts being arranged in the opening rotate about parallel axes, the screen shafts being provided with crushing blades (2c) arranged at a distance from one another, a rotating motor (3) for rotating the screen shafts, and power transmission means for transmitting the rotational movement from the rotating motor to the end of each screen shaft, characterized in that the power transmission means comprise at least one separate power transmission module (4), which includes a body (4¹) forming a closed space and power transmission wheels for screen shafts (2; 2a, 2b), the power transmission wheels being connectable to be rotated by the rotating motor (3), ar- ranged rotatably with respect to the body (4¹) of the power transmission module and provided at least alternately with coupling members (13) for connecting the power transmission wheel irrotatably to the end of the screen shaft (2; 2a, 2b) so that each screen shaft (2; 2a, 2b) connects to the respective power transmission wheel when the power transmission module (4) is pushed into its place in the direction of the screen shafts.

2. A screen scoop according to calim 1 , characterized in that all power transmission wheels (7a) are connected to their shafts (9a) irrotatably so that all screen shafts (2) are connected to be rotated by the power transmission wheels of the same power transmission module (4).

3. A screen scoop according to claim 2, characterized in that it comprises one power transmission module (4) at both ends of the screen scoop and that all screen shafts (2) are connected to be rotated by the power transmission wheels of both power transmission modules (4).

4. A screen scoop according to claim 1 , characterized in that it comprises one power transmission module (4) at both ends of the screen scoop and that the power transmission module (4) at one end is provided with alternate power transmission wheels (7a) that are connected to their shafts (9a) irrotatably and correspondingly alternate power transmission wheels (7b) that are connected to their shafts (9b) rotatably, and correspondingly the power transmission module (4) at the other end comprises alternate power transmis- sion wheels (7a) that are connected to their shafts (9b) rotatably and correspondingly alternate power transmission wheels (7b) that are connected to their shafts (9b) irrotatably, in which case adjacent screen shafts (2) are connected to be rotated by the power transmission module (4) at the different end of the screen scoop.

5. A screen scoop according to claim 4, characterized in that the adjacent screen shafts (2) are connectable to rotate either in the same direction or in opposite directions by changing the rotating direction of the rotating motor (3) of one power transmission module (4).

6. A screen scoop according to claim 1 , characterized in that the power transmission wheels are cog wheels (7, 8) connected to adjacent cog wheels (7, 8) through cogging so that the rotational force of the rotating motor (3) is transmitted from one cog wheel (8, 7) to the next.

7. A screen scoop according to claim 1 or 2, characterized in that the shafts (9) of the power transmission wheels extend outside the body (4¹) of the power transmission module (4) and that coupling members are provided in the part of the power transmission module (4) that is outside the shafts (9).

8. A screen scoop according to any one of the preceding claims, characterized in that the shafts (9) of the power transmission wheels are sealed with respect to the body (4¹) of the power transmission module (4) by seals (12) so that the power transmission module (4) is substantially tight.

9. A screen scoop according to any one of the preceding claims, characterized in that the coupling members (13) comprise a recess whose cross section differs from a circle at the end of the power transmission shaft (9) and a shaft that fits in the recess.

10. A screen scoop according to any one of the preceding claims, characterized in that the power transmission means include one power transmission module (4) at both ends of the screen scoop.

11. A power transmission module for a screen scoop, character- ized in that it comprises a body (4¹) and power transmission wheels for screen shafts (2; 2a, 2b) of the screen scoop (1) inside the body, the wheels being connectable to be rotated by a separate rotating motor (3), in which case the shafts (9) of the power transmission wheels are provided with coupling members (13) that connect the ends of the screen shafts (2) in the screen scoop irrotatably to each other, in which case the power transmission module (4) is mountable in the screen scoop by pushing it into its place in the direction of the screen shafts (2; 2a, 2b) so that the ends of each power transmission wheel and the respective screen shaft (2; 2a, 2b) connect to each other, after which the power transmission module may be attached to the screen scoop by suitable fastening means, such as bolts.

12. A power transmission module according to claim 8, characterized in that the power transmission wheels are cog wheels (7, 8) connected to adjacent cog wheels (7, 8) through cogging so that the rotational force of the rotating motor (3) is transmitted from one cog wheel (8, 7) to the next.

13. A power transmission module according to claim 11 or 12, characterized in that it comprises alternate power transmission wheels (7a) that are connected to their shafts (9a) irrotatably and correspondingly alternate power transmission wheels (7b) that are connected to their shafts (9b) rotata- bly.