AU2007293868B2

AU2007293868B2 - Vibration mill having sliding guide

Info

Publication number: AU2007293868B2
Application number: AU2007293868A
Authority: AU
Inventors: Lilli Elies; Ernst Michael Haas
Original assignee: FLSmidth AS
Current assignee: FLSmidth AS
Priority date: 2006-09-08
Filing date: 2007-09-04
Publication date: 2011-04-21
Anticipated expiration: 2027-09-04
Also published as: CN101553316A; ATE462497T1; EP2063993A1; DE502007003348D1; WO2008028897A1; DE102007017131A1; AU2007293868A1; EP2063993B1; CN101553316B

Abstract

The mill (1) has a grinding unit (4), and an oscillating drive provided for oscillating the grinding unit. The oscillating drive is fastened to a holding device (2) for transmission of forces acting parallel to a vibration plane to the holding device, and the grinding unit is displaceably mounted plane-parallel to a vibration plane (S) by using a sliding guide (12) that engages the grinding unit. The sliding guide has a guiding unit that projects over a housing base contour of the grinding unit and connected fixedly with the grinding unit.

Description

1 Vibration mill with sliding guide The invention relates to a vibration mill, preferably a disk vibration mill, having a grinding unit and a 5 vibratory drive, by means of which the grinding unit can be caused to vibrate. The discussion of documents, acts, materials, devices, articles and the like is included in this specification solely for the purpose of providing a context for the 10 present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application. 15 Throughout the description and claims of this specification, the word "comprise" and variations of the word, such as "comprising" and "comprises", is not intended to exclude other additives, components, integers or steps. 20 In an existing vibration mill of this type, the type of suspension or method of positioning according to the art on a fixed standing surface may result not just in desirable vibration of the grinding vessel in a vibration 25 plane parallel to the grinding base of the grinding vessel but also in vibration and tilting movements perpendicular thereto. In the case of so-called disk-type vibration mills, in which the grinding chamber bounded by a lateral grinding wall, a lower grinding base and an 30 upper grinding cover usually has a grinding stone, and/or a grinding ring which encloses the grinding stone, accommodated in it, with lateral (vibratory) play in each case, for the purpose of comminuting material to be ground, it is nevertheless possible, on account of the 2 small amount of vertical play also required for the vibratory movement of the grinding elements, for vertical vibration and tilting movements of the grinding unit brought about by the vibratory drive to have a 5 disadvantageous effect. It would therefore be desirable to develop in an advantageous manner a vibration mill of the type mentioned in the introduction so that in particular 10 vertical vibration and tilting movements of the grinding unit and disadvantages associated with this are as far as possible avoided. According to the present invention, there is provided a 15 vibration mill having a grinding unit and a vibratory drive, by means of which the grinding unit can be caused to vibrate, wherein by the provision of a mounting arrangement on which the vibratory drive is fitted and on which the grinding unit is mounted such that it can be 20 moved, by means of at least one sliding guide acting on the grinding unit, in a plane-parallel manner in relation to a vibration plane, and wherein the grinding unit is mounted such that it can be moved in a plane-parallel manner in relation to a reference plane defined by the 25 grinding base of the grinding unit. It can thus be ensured that the grinding unit merely executes movements which are plane-parallel in relation to the vibration plane, i.e. displacement movements and, 30 in particular, rotary movements, for all practical purposes without any movement component perpendicular to the vibration plane. The mounting arrangement may be a frame-like arrangement or a mounting frame which has a high degree of stiffness and on which both the vibratory 35 drive and at least one mating guide element of the sliding guide can be fitted. Within the context of the 2a invention, the vibration plane constitutes a reference plane which, for all practical purposes, is fixed in space, it being possible for the grinding unit to move, as a result of being caused to vibrate, solely within, 5 and/or parallel to, the reference plane. This movement capability thus includes displacements and rotations which do not contain any significant movement component perpendicular to the said vibration plane. The sliding guide is adapted thereto to the extent that the grinding 10 unit cannot execute any rotary or tilting movements about axes of rotation parallel to the vibration plane or any movements perpendicular to the vibration plane. The term sliding guide covers all types of suitable plane parallel guides. Possible sliding guides are ones, in 15 particular, which are formed from surfaces of two or more guide or sliding elements sliding directly along one another and which, with a suitable coating (for example using plastics material, for example PTFE), can slide either in the dry state or using a lubricant. Possible 20 sliding guides in addition to those with abutting surfaces are ones in which separate sliding or rolling bodies are inserted between the elements which are guided in relation to one another. It is preferred if the grinding unit is mounted such that it can be moved in a 25 plane-parallel manner in relation to a 3 reference plane defined by the grinding base. As an alternative, or in combination with this, it is possible for the grinding unit to be mounted such that it can be moved in a plane-parallel manner in relation 5 to an eccentric drive plane defined by an eccentric rotation of the vibratory drive. It is considered to be advantageous if the vibratory drive is secured to the mounting arrangement, preferably flanged thereto, in a manner suitable for transmitting to the mounting 10 arrangement forces which act parallel to the vibration plane. A possible configuration may be one in which the sliding guide has at least one guide element, which projects laterally beyond the basic contour of the housing of the grinding unit and is fixedly connected 15 to the grinding unit, and at least one mating guide element, which is fixedly connected to the mounting arrangement, overlaps the guide element with respect to a projection onto the vibration plane, and is parallel to the guide element. In this context it is also 20 preferred if the grinding wall is enclosed by a housing part, preferably by a housing ring, of the grinding unit, and if the housing part is fixedly connected to an upper plate-like guide element and to a lower plate like guide element, which is spaced apart from and 25 parallel to the first guide element, the plate-like guide elements engaging around the mating guide element to form the sliding guide. This constitutes a stable and, at the same time, functionally reliable construction. It is possible for a first guide surface 30 to be provided on the underside of the upper guide element and for a second guide surface, which is parallel to the first, to be provided on the upper side of the lower guide element, respectively parallel mating guide surfaces on the mating guide element being 35 associated with the guide surfaces. In order to achieve a, for all practical purposes, play-free slideway, the vertical spacing between the first and second guide surfaces can correspond approximately to the vertical spacing between the associated first and second mating 4 guide surfaces. Conditions which are advantageous for guiding purposes are achieved if the sliding guide acts on the grinding unit at least approximately level with the center of gravity of the grinding unit and/or 5 approximately level with the center of gravity of the grinding wall and/or of a grinding ring and/or of a grinding stone. A preferred embodiment is one in which the upper guide surface is disposed level with, or above, the grinding chamber, and the lower guide 10 surface is disposed level with, or beneath, the grinding chamber. A particularly operationally reliable embodiment is possible by the mating guide element enclosing a housing region of the grinding unit, preferably the housing ring thereof, with respect to 15 the guide plane, to leave a lateral interspace sufficient for the vibratory drive, preferably along the entire circumference. In this context, it is further preferred if the housing ring, which may have a cylindrical outer wall, is arranged with lateral play 20 in a preferably round or likewise cylindrical central opening of the mating guide element, and the plate-like guide elements project beyond the periphery of the central opening in- every- -poss-ib--e-vibr-atory -pos-i-t-i-en--of the grinding unit. In respect of the vibratory drive, 25 it is possible for the latter to have a drive motor which is secured to the mounting arrangement and drives an eccentric in rotation in an eccentric drive plane, and for the eccentric to act on the grinding unit to cause vibration. Specifically, the eccentric may have 30 an eccentric pin which engages in a rotary bearing, for example a ball bearing, accommodated on the grinding unit, preferably on the underside. In order to avoid an increase in temperature brought about by the frictional heat, particularly during a relatively long period of 35 operation, the grinding unit may comprise a cooling arrangement which acts on the grinding wall and has preferably at least one cooling channel bordering directly on the grinding wall on the outside. In order for it to be possible to remove the comminuted ground 5 material from the grinding chamber following the grinding operation, a discharge channel may be present, the discharge channel enclosing the grinding base along its circumference, in the process adjoining the latter 5 such that it is offset in the radially outward and downward directions in cross-section. During grinding operation, the grinding base can have its periphery positioned directly adjacent to the lateral grinding wall; on the other hand, in order to direct the 10 comminuted ground material away into the discharge channel, the grinding base can be displaced into a position which is set back from the grinding wall, this resulting in a through-passage from the grinding chamber to the discharge channel. It is preferred if 15 the grinding base can be adjusted in position in the grinding unit, perpendicularly in relation to the movement or vibration plane of the grinding unit, by means of a double-action lifting arrangement, preferably by means of a double-action pneumatic or 20 hydraulic cylinder/piston unit. According to a further aspect of the invention, the rotary bearing may be connected, on the upper side, to a base plate of the grinding unit, the base plate forming a base for the double-action lifting element. In order to achieve a 25 tilting-free adjusting movement, the piston here may be supported in a flexurally stiff manner in relation to the housing of each of the grinding unit and the grinding base. In order to achieve mass balancing in respect of the grinding unit being caused to vibrate 30 eccentrically, an eccentric counterweight, driven by the drive motor, may be provided, it being possible to adjust the counterweight, preferably for adaptation to different operating conditions. 35 The invention is further described hereinbelow with reference to the accompanying figures, in which a preferred exemplary embodiment is illustrated and in which: 6 Figure 1 shows a sectional view through a vibration mill according to the invention according to a preferred embodiment, 5 Figure 2 shows an enlargement of the detail II in Figure 1, Figure 3 shows a side view as seen in direction III according to Figure 1, and 10 Figure 4 shows the partial section IV according to Figure 3. Figure 1 shows in sectional view a vibration mill 1 15 specifically a disk vibration mill, according to a preferred embodiment. This vibration mill has a frame like, i.e. inherently stiff mounting arrangement 2, a vibratory drive 3, which is fitted on the mounting arrangement, and a grinding unit 4, which can be caused 20 to vibrate in rotation by the vibratory drive. The grinding unit 4 constitutes a subassembly which is intended for accommodating and comminuting material to be ground and can be caused to vibrate by a separate vibratory drive acting on the grinding unit. The 25 grinding unit comprises a grinding wall 5, a grinding base 6 and a grinding cover 7 and these together surround a grinding chamber 8. A material to be ground which is to be comminuted in the vibration mill but has not been illustrated, for example a granular material 30 sample made up of rock, ore or slag, can be introduced into the grinding chamber through an opening 9 which leads through the grinding cover 7. Comminution can be carried out preferably down to a particle size in the order of magnitude of micrometers and can be used, for 35 example, for preparing the material to be ground for material analyses, for example for examining the composition by means of an X-ray spectrometer. The comminution of material to be ground is effected by the vibratory drive causing a grinding stone 10 to carry 7 out movements in the grinding chamber 8, the grinding stone being movable in said grinding chamber on account of its lesser dimensions in relation to the grinding base 6, the material to be ground being comminuted in 5 the grinding gap 11, the width of which changes continuously, between the grinding wall 5 and grinding stone 10. In order to achieve small particle sizes and as uniform a size distribution as possible, it is preferred (as is illustrated) to have a grinding gap 10 with, as far as possible, parallel boundaries. As an alternative to, or in combination with, the grinding stone 10 which is shown in Figure 1, and is in the form of a solid body, a so-called grinding ring (not illustrated) may be accommodated in the grinding 15 chamber. In the case of combined usage, the dimensions or diameters are coordinated so that the grinding ring lies on the grinding base 6 such that it can be displaced within the grinding wall 5, and the grinding stone lies on the grinding base 6 such that it can be 20 displaced within the grinding ring. During grinding operation, the vibratory drive 3 causes the grinding unit 4 to vibrate in rotation in the manner which will be described in more detail with reference to Figure 2. In order to achieve a situation here where the 25 components of the grinding unit which surround the grinding chamber 8 can be moved, i.e. displaced and/or rotated, only in a plane-parallel manner in relation to a reference plane perpendicular to the grinding-base surface, a sliding guide, which is designated overall 30 by 12, acts on the grinding unit 4. This ensures that the grinding unit 4 is mounted on the mounting arrangement 2 such that it can be moved only in a plane-parallel manner in relation to a vibration plane, in the form of a reference plane which is intended to 35 be fixed in space in this respect in relation to the mounting arrangement. The direction of the vibration plane is predetermined by the sliding guide 12, or by the direction of the sliding surfaces thereof, and, in the exemplary embodiment shown, the vibration plane .8 extends in the direction of, or parallel to, the surface of the grinding base 6. In order to indicate this schematically, the direction of the vibration plane S is indicated in Figure 1 by way of example 5 (displaced upward from the grinding base for the purpose of illustration) . In the example shown, the frame-like mounting arrangement 2 is formed from a number of supports 14 which are fixedly upstanding on a base 13, from a bearing plate 15 which is secured to 10 these supports, e.g. screw-connected thereto, and from a further group of supports 16 which project upward in a substantially flexurally stiff manner from the bearing plate 15 and which are extruded sections in the example selected, although this need not necessarily be 15 the case. A carrier 18 in the form of an L-section is fitted, by means of screws 17 in each case, to those vertical surfaces of the supports 16 which are directed toward the grinding unit 4. Each leg of the carrier which projects from the support 16 to the grinding unit 20 4 is screw-connected in the region of its free end to an outer annular flange 19 of an annular part which thus holds the grinding unit 4 in the vertical direction. This annular part at the same time is the mating guide element 20, which, together with a 25 respective upper and lower guide element 21, 22, forms the slideway 12. The mating guide element 20, which is preferably closed along its circumference, encloses a housing region of the grinding unit 4, specifically a housing ring 23 in the example shown, with respect to 30 the guide plane S to leave a lateral interspace 24 sufficient for the vibratory drive. The housing ring 23, which is fixedly connected to the upper and lower plate-like guide elements 21, 22 by means of screws 25, is forcibly guided within the through-passage opening 35 26 of the mating guide element 20 in a plane-parallel manner in relation to the vibration plane S, by means of the sliding guide 12. As a result, the entire grinding unit 4 can only execute movements, i.e. displacements and rotations, in a plane-parallel manner 9 in relation to the vibration plane S, i.e. without any movement component perpendicular thereto. A corresponding vibratory movement is generated by the vibratory drive 3, which is also illustrated in 5 Figure 1. In the example shown, this vibratory drive comprises a drive motor 27 (in this case an electric motor), which is flanged to the bearing plate 15 from beneath by means of a bearing flange 28. Mounted with a rotary form fit on the motor shaft 29 is a component 10 which is designated as a whole as drive eccentric 30 and of which the sleeve portion 31, which is directed toward the motor and is concentric with the motor shaft 29, is mounted in a rotatable manner in a motor bearing 32 accommodated by the bearing flange 28. An eccentric 15 pin 33, which continues in prolongation of the portion 31 but eccentrically (see eccentricity e in Figure 2), engages in a rotary bearing 35 accommodated in a bearing mount 34 on 'the underside of the grinding unit 4. The rotation of the eccentric pin 33 defines an 20 eccentric drive plane E (see Figure 2) which is perpendicular to the motor shaft 29 and is spaced apart from and parallel to the vibration plane S. Clearly the vibratory drive 3 is fitted to the mounting arrangement 2 in a manner suitable for transmitting to the mounting 25 arrangement 2 forces which act parallel to the vibration plane S. Figure 2 uses an enlargement of the detail II from Figure 1 to illustrate some further design details. In 30 respect of the sliding guide 12, a guide surface 36 is provided on the underside of the upper guide element 21 and a further guide surface 37, which is parallel to the first, is provided on the upper side of the lower guide element 22. Parallel mating guide surfaces 38, 39 35 respectively on the upper side and underside of the mating guide element 20, which functions as a sliding ring, are associated with the surfaces 36, 37. A center of gravity 40 is indicated merely schematically in order to show that the slideway 12 acts on the grinding 10 unit 4 approximately level with this center of gravity 40. This is because, specifically, the upper guide surface 36 is disposed above the grinding chamber 8 and the lower guide surface 37 is disposed approximately 5 level with the height-adjustable grinding base 6. In this respect, Figure 2 shows (in contrast to Figure 1 for the grinding operation) the grinding base in the lower displacement position, which can be selected in order for comminuted ground material to be emptied out 10 of the grinding chamber 8. In this position, the grinding base 6 and the grinding wall 5 surround a peripheral gap 41, through which the comminuted ground material passes, on account of centrifugal forces, into the likewise annularly extending discharge channel 42, 15 which is offset in the radially outward and downward directions in cross-section. The ground material is transported along the discharge channel 42, by the vibratory movement, to a discharge region 43 and, finally, to an outlet 44. The grinding base 6 can be 20 adjusted in position by means of a double-action lifting arrangement 45, in the example a pneumatic cylinder/piston unit, by way of an upper or lower pressure chamber 46, 47 optionally being subjected to pressure. The rotary bearing 35 is connected, on the 25 upper side, to a base plate 51 of the grinding unit 4, the base plate forming the base for the said cylinder/piston unit. The piston 45' guided therein is supported in a flexurally stiff manner on its offset cross-section in relation to the housing of the 30 grinding unit and to the grinding base in order to achieve an, as far as possible, tilting-free adjusting movement. Figure 1 also shows that there is a gap (see spacing A) which is sufficient for the lateral movement of the grinding element (also in respect of the 35 material to be ground which is present) remaining between the upper side of the grinding stone 10 and the underside of the grinding cover 7, which is inserted into the guide element 21 with a peripheral seal. Preventing tilting of the grinding elements in relation 11 to one another and in relation to the grinding wall keeps the boundaries of the grinding gaps formed parallel, which has, during grinding operation, an advantageous effect on the particle size which can be 5 achieved and on achieving uniformity of the particle size. Nevertheless, on account of the sliding guide 12 being configured with a comparatively small amount of play, the sliding stone 10 is caused to execute only vibrations which are parallel to the vibration plane S, 10 rather than jumping or tilting movements. In order to achieve mass balancing in relation to the grinding unit, which is caused to vibrate eccentrically in rotation, an eccentric counterweight 48, the shape of which can be gathered from Figure 4, is pushed onto an 15 eccentric length portion of the drive eccentric 30 and can be secured in an adjustable circumferential position by a screw 49. Finally the grinding unit 4 also comprises a cooling arrangement which acts on the grinding wall 5 and, in the exemplary embodiment, has a 20 cooling channel 50 bordering directly on the grinding wall 5 on the outside. This cooling channel can have a coolant, for example, water, which is directed through inflows and outflows (not illustrated), flowing through it, so that specific temperature management is possible 25 in particular in conjunction with an external cooling subassembly with a control or regulation feature. All features disclosed are (in themselves) pertinent to the invention. The disclosure content of the 30 associated/attached priority documents (copy of the prior application) is hereby also included in full in the disclosure of the application, also for the purpose of incorporating features of these documents in claims of the present application. 35

Claims

1. Vibration mill having a grinding unit and a vibratory drive, by means of which the grinding unit can be caused to vibrate, 5 wherein by the provision of a mounting arrangement on which the vibratory drive is fitted and on which the grinding unit is mounted such that it can be moved, by means of at least one sliding guide acting on the grinding unit, in a plane-parallel manner in relation to a vibration plane, and wherein the 10 grinding unit is mounted such that it can be moved in a plane parallel manner in relation to a reference plane defined by the grinding base of the grinding unit.

2. Vibration mill according to claim 1, wherein the grinding unit 15 is mounted such that it can be moved in a plane-parallel manner in relation to an eccentric drive plane defined by an eccentric rotation of the vibratory drive.

3. Vibration mill according to any one of the preceding claims, 20 wherein the vibratory drive is secured to, in particular flanged to, the mounting arrangement in a manner suitable for transmitting to the mounting arrangement forces which act parallel to the vibration plane. 25

4. Vibration mill according to any one of the preceding claims, wherein the sliding guide has at least one guide element, which projects laterally beyond the basic contour of the housing of the grinding unit and is fixedly connected to the grinding unit, and at least one mating guide element, which is fixedly 30 connected to the mounting arrangement, overlaps the guide element in respect of a projection onto the vibration plane, and is parallel to the guide element.

5. Vibration mill according to any one of the preceding claims, 35 wherein the grinding wall of the grinding unit, which wall delimits the grinding chamber, is enclosed by a housing part, in particular by a housing ring, of the grinding unit, and in CApoftemp\SPEC-649441.doc 13 that the housing part is fixedly connected to an upper plate like guide element and to a lower plate-like guide element, which is spaced apart from and parallel to the first guide element, the plate-like guide elements engaging around the 5 mating guide element to form the sliding guide.

6. Vibration mill according to any one of the preceding claims, wherein a guide surface is provided on the underside of the upper guide element and a further guide surface, which is 10 parallel to the first, is provided on the upper side of the lower guide element, and in that respectively parallel mating guide surfaces on the mating guide element are associated with the guide surfaces. 15

7. Vibration mill according to any one of the preceding claims, wherein the sliding guide acts on the grinding unit at least approximately level with the center of gravity of at least one of the grinding unit, the grinding wall, a grinding ring, or of a grinding stone. 20

8. Vibration mill according to any one of the preceding claims, wherein the upper guide surface is disposed level with, or above, the grinding chamber, and in that the lower guide surface is disposed level with, or beneath, the grinding 25 chamber.

9. Vibration mill according to any one of the preceding claims, wherein the mating guide element encloses a housing region of the grinding unit, in particular the housing ring thereof, with 30 respect to the guide plane, to leave an interspace sufficient for the vibratory drive, in particular along the entire circumference.

10. Vibration mill according to any one of the preceding claims, 35 wherein the housing ring is arranged with lateral vibratory play in a, in particular, round through-passage opening of the mating guide element, and the plate-like guide elements project C:ooftemp\SPEC-649441 doc 14 beyond the periphery of the through-passage opening in every possible vibratory position of the grinding unit.

11. Vibration mill according to any one of the preceding claims, 5 wherein the vibratory drive has a drive motor which is secured to the mounting arrangement and drives a drive eccentric in rotation in an eccentric drive plane, and in that the drive eccentric acts on the grinding unit to cause vibration. 10

12. Vibration mill according to any one of the preceding claims, wherein the drive eccentric has an eccentric pin which engages in a rotary bearing, in particular a ball bearing, accommodated on the grinding unit, in particular on the underside. 15

13. Vibration mill according to any one of the preceding claims, wherein the grinding unit comprises a cooling arrangement which acts on the grinding wall and has, in particular, a cooling channel bordering on the grinding wall on the outside. 20

14. Vibration mill according to any one of the preceding claims, wherein the grinding base can be adjusted in position in the grinding unit, perpendicularly in relation to the movement plane of the grinding unit, by means of a double-action lifting arrangement, in particular by means of a double-action 25 pneumatic or hydraulic cylinder/piston unit.

15. Vibration mill according to any one of the preceding claims, wherein the rotary bearing is connected, on the upper side, to a base plate of the grinding unit, the base plate forming a 30 base for the double-action lifting arrangement, and in that the piston is supported in a flexurally stiff manner in relation to the housing of the grinding unit and to the grinding base, in order to achieve a tilting-free adjusting movement. 35

16. Vibration mill according to any one of the preceding claims, wherein the drive motor drives at least one, in particular adjustable, counterweight for mass-balancing purposes. C:\poftnmp\SPEC-849441.doc 15

17. Vibration mill according to any one of the preceding claims comprising a disk vibration mill. 5

18. Vibration mill substantially as herein described with reference to the accompanying drawings. 10 C:pofemp\SPEC-84944t .doc