Abstract:
A separator including a rotatable centrifugal drum having a vertical axis of rotation and an inflow line for a material to be processed by the separator. Also included is a drive spindle for the drum rotatably mounted via a mounting to a housing supported elastically on a machine stand section. A drive device includes an electric drive motor having a stator and a rotor which is aligned with the drive spindle. A lubricant system is configured to lubricate the mounting and the lubricant system includes a lubricant circuit to convey lubricant and has a lubricant collecting container.

Description:
BACKGROUND OF THE INVENTION 
     This application is a National Phase Application based upon and claiming the benefit of priority to PCT/EP2008/066282 Application, filed on Nov. 27, 2008, which PCT Application is based upon and claims the benefit of priority to German Patent Application No. 10 2007 060 841.4, filed on Dec. 13, 2007, the contents of both of which applications are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     The present disclosure relates to a separator that includes a rotatable centrifugal drum with a vertical axis of rotation and an inflow line for a centrifugable material to be processed. A drive spindle for the centrifugal drum is mounted rotatably by a mounting in a housing which is supported elastically on a machine stand. A drive device includes an electric drive motor having a stator and a rotor which is in alignment with the drive spindle. A lubricant system is configured to lubricate the mounting. The lubricant system includes a lubricant circuit to convey lubricant and has a lubricant collecting container. 
     Separators of this type, suitable particularly for industrial use in continuous operation, are known per se from the prior art. Among the known systems, there are structures, in which the drum, the drive spindle and the electric drive motor are connected rigidly to form a structural unit which is then supported elastically as a whole on a machine stand. Examples of such prior art are disclosed in FR 1 287 551, DE 1 057 979 and DE 43 14 440 C1. 
     Moreover, with regard to the technological background, also see WO 98/57751 A1, DE 103 14 118 B4, FR 938 919 A, U.S. Pat. No. 6,428,460 B1 and U.S. Pat. No. 1,745,853 A. 
     DE 20 2005 001 539 U1 shows a separator having a drive belt, with a circulatory lubrication system for lubricating the spindle mounting. The system has a tube-like device, resembling a paring disk, for pumping away lubricant. The device serves for pumping lubricant, which emerges from the mounting of the drive spindle of the separator drive, via a treatment assembly into a lubricant sump, into which the drive spindle, designed as a hollow spindle, penetrates with its lower end. However, this arrangement still has a relatively long axial length. 
     WO 2007/125066 A1 discloses a generic separator with a direct drive. The drive device has an electric drive motor with a stator and a motor rotor which is in alignment with the drive spindle, the stator being connected rigidly to the machine stand, and the motor rotor, drive spindle, centrifugal drum and housing forming a unit which is supported elastically on the machine stand and which oscillates during operation. In this case, the bearing device is arranged between the motor and the drum. Furthermore, it is proposed therein to accommodate the lubrication of the bearing devices above a partition over the drive motor. 
     Against this background, the present disclosure relates to, among other things, to improving further the set-up and arrangement of the lubrication system of separators having a vertical axis of rotation. 
     The present disclosure thus relates to an embodiment comprising a separator that includes a rotatable centrifugal drum having a vertical axis of rotation and an inflow line for a material to be processed by the separator. Further included is a drive spindle for the drum rotatably mounted via a mounting to a housing supported elastically on a machine stand section. A drive device includes an electric drive motor having a stator and a rotor which is aligned with the drive spindle. A lubricant system is configured to lubricate the mounting. The lubricant system includes a lubricant circuit to convey lubricant and has a lubricant collecting container. The entire lubricant circuit and at least the lubricant collecting container is arranged axially above the rotor. The lubricant is conveyed out of the lubricant collecting container directly through a lubricant duct formed in the housing and extending into a region of or above a neck bearing of the mounting. The entire mounting of the drive spindle is arranged axially above a bottom of the lubricant collecting container. Another embodiment comprises a separator that includes a centrifugal drum having a vertical axis of rotation and an inflow line for a material to be processed by the separator. Further included is a drive spindle for the drum rotatably mounted via a mounting to a housing supported elastically on a machine stand section. A drive device includes a motor and a drive belt looping around the drive spindle. The entire mounting is arranged above the motor or the drive belt. A lubricant system is configured to lubricate the mounting and includes a lubricant circuit and has a lubricant collecting container. The entire lubricant circuit and at least the lubricant collecting container is arranged axially above one or both of a belt pulley or the drive belt that surrounds the drive spindle. The entire mounting of the drive spindle is arranged axially above a bottom of the lubricant collecting container. 
     This arrangement makes it possible to implement a form of construction of the drive device which is especially short in the vertical direction. Since the spindle is not used for lubricant circulation, it can be utilized for other tasks, such as a product supply, for example through a hollow spindle. 
     As noted above, the structures are suitable both for drive via a belt mechanism and for various types of direct drives with a drive motor arranged in an axial prolongation of the drive spindle or on the drive spindle. 
     The region of the motor can be separated in structural terms from elements of the lubricant system. 
     Moreover, the oil is conveyed in a confined space, directly in or sometimes also directly on the housing, to the neck bearing. 
     Moreover, the co-rotating lubricant collecting container affords an advantage that it can receive a relatively large oil volume in a confined space. That means, for the conveyance of oil, for example, a conveying member, resembling a paring disk, for the pumping of oil or a conveying tube for conveying into the mounting, can be integrated into said collecting container. 
     Other aspects of the present disclosure will become apparent from the following descriptions when considered in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a sectional view of a first separator drive, according to the present disclosure. 
         FIG. 2  shows a sectional view of a second separator drive, according to the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a part of a separator  1  including a centrifugal drum  2  indicated by broken lines and having a vertical axis of rotation D. The centrifugal drum  2  is connected to a drive spindle  3 . A cowl and a solids trap are not shown. 
     The drive spindle  3  is mounted rotatably in a housing  6  by a mounting. The mounting comprises a neck bearing  4 , or upper bearing, and a foot bearing  5  or lower bearing. For example, the neck bearing  4  includes two rolling bearings. It is within the scope of the present disclosure that other configurations, for example, with only one rolling bearing as a neck bearing  4  is conceivable (not shown). Furthermore, it is also be conceivable to provide two foot bearings  5 . 
     The housing  6  is supported on a machine stand section  9  by one or more elastic elements  7 ,  8 , for example, round bearings. The machine stand section  9  may be designed, for example, as part of an overriding machine stand or may be fastened to a ceiling of a building. 
     A separator drive serves for driving the centrifugal drum  2 . As shown in  FIG. 1 , the drive includes an electric motor  10  which has a motor housing  13  with a stator  11 , or stator winding, and a motor rotor  12 . The motor  10  may have a variety of mountings, thus making it possible to have more cost-effective designs. 
     The drive spindle  3  is connected to the motor rotor  12  directly. That is, without interposed elements, such as a coupling. By contrast, the motor housing  13  with the stator  11  is arranged rigidly, unsprung, on the machine stand section  9 . The motor housing  13  is directly attached, for example, screwed on by bolts  28  to the machine stand section  9  at the bottom. The motor housing  13  has a lower cover  29 . For ventilation, orifices and/or a fan may be introduced (not shown) into the cover  29 . 
     The mounting, or bearing devices  4 ,  5 , is arranged axially between the motor  11  and the centrifugal drum  2 . 
     The motor rotor  12  is thus arranged, suspended with respect to the drive spindle  3 , in a simple and advantageous way. 
     Separate bearings on the motor  10 , for implementing a rigid positioning of the motor rotor  12  with respect to the stator  11  of the motor  10 , are dispensed with. 
     The motor rotor  12 , which executes the oscillation and movement of the drive spindle  3  in accompaniment, can rotate freely in the stator  11 , without touching it. 
     The elastic elements  7 ,  8  comprise, distributed circumferentially, a plurality of elements, such as, for example, round bearings which may be oriented perpendicularly to one another. This results in an especially defined setting of the point of articulation or center of rotation of the system P 1 . 
     The arrangement of the pairs of elastic elements  7 ,  8  is selected in such a way that straight lines running through longitudinal mid-axes of the first elastic elements  7  intersect at the point P 1  which lies axially and radially in the middle, within the motor rotor  13 , on the axis of the rotation D of the drive spindle  3 . The selected arrangement affords the advantage of a good and easy coordination of the spring properties by a variation in the location and design of the first elastic elements  7 . 
     The second elastic elements  8  are arranged radially outside the first elastic elements  7 . Straight lines running through their longitudinal mid-axes intersect on the axis of rotation D at a point P 2  which lies above the mounting, or bearing devices  4 ,  5  and lies within the drive spindle  3 . 
     The separator drive, according to the present disclosure, is designed in a defined way such that the center of rotation P 1  of the oscillating unit lies in the axially and radially middle third, or, for example, at the axial and radial mid-point, of the motor rotor  12 . 
     The machine stand section  9  has a radially inner wall section  14  which tapers conically upward and which merges downwardly into a wall section  15  extending cylindrically vertically downward. The motor housing  13  is attached to this cylindrical wall section  15  at the bottom. The cylindrical wall section  15  merges upwardly and radially outwardly into a conically widening wall section  16  which merges in turn into a radially outer flange section  17 . A solids trap and a cowl, in accordance with the present disclosure, also being capable of being supported on the machine stand  9 . 
     The housing  6  has an upper flange-like region which has a wall section  18  widening outwardly and downwardly and, adjoining said wall section  18  radially outwardly is a wall section  19  widening outwardly perpendicularly with respect to the section  18 . The housing  6  is consequently designed to be stable and yet stiff and with optimized weight. 
     The top sides of the wall sections  14  and  15  serve lower supporting surfaces, and the undersides of the wall sections  18 ,  19  serve as upper supporting surfaces of the first and second elastic elements  7  and  8  which are oriented perpendicularly with respect to one another. 
     The flange-like region or wall section  18  has adjoining it a cylindrical housing region  20  which extends axially downwardly and which surrounds the drive spindle  3 . The neck and foot bearings  4 ,  5  are arranged, spaced apart, between the inner circumference of the housing  6  and the outer circumference of the drive spindle  3 . 
     In the space delimited upwardly and radially outwardly by the machine stand section  9  and downwardly by the rotor  12  of the motor  10 , and also inwardly by the housing region  20 , and, further below, by the drive spindle  3 , an annular-space or torus-like lubricant collecting container  21  is arranged. Container  21  has boundary walls  22 ,  23  tapering upwardly and downwardly. Furthermore, as shown in  FIGS. 1 and 2 , the lubricant collecting container  21  is connected fixedly in terms of rotation in its lower region to the drive spindle  3 , for example, in region  31 . Thus, during operation, oil is collected in it radially on the outside. The lubricant collecting container  21  bears upwardly, with an extension  30  extending partially parallel to the housing  6  and against the housing  6  in a virtually sealing arrangement. However, the container  21  is rotatable in relation to said housing  6 . 
     The lubricant collecting container  21  can, in accordance with the present disclosure, be integrated predominantly as a co-rotating element into the structure. Nonetheless, container  21  may advantageously have a large volume. 
     The rotating lubricant collecting container  21  also affords an advantage that heat can easily be diverted outward by it, for example via cooling ribs. A means for surface enlargement, such as the cooling ribs, can also be integrated into the container  21  or on the outside of the container  21 , in accordance with the present disclosure. 
     Furthermore, for cooling, for example, the lower cover  29  could have one or more orifices, and a further orifice could be provided in the region of the housing  6  or machine stand section  9 , above the motor  10 , so that, during operation, an air stream past the motor  10  occurs in the manner of a fan. In the cover  29 , a diameter would be selected for the orifices which diameter is smaller than the outside diameter of the collecting container  21 , in order to achieve the fan-like cooling action. A ribbing on the collecting container  21 , for example at the bottom, would further reinforce this effect. 
     It is within the scope of the present disclosure to integrate a cooling circuit for a fluid into the motor housing  13  or at another suitable location. 
     In an advantageous refinement, a tube-like extension  24  projects as a means for the conveyance of oil into the lower region of the lubricant collecting container  21  and is arranged and designed in such a way that, during operation, it penetrates into the lubricant, for example an oil, collected in the lubricant collecting container  21  on the outside. The extension  24  projects into a radial bore  25  in the housing  6 , which bore  25  merges into a lubricant duct  26  extending axially into the region above the neck bearing  4 . This arrangement, resembling a paring disk, serves for conveying the lubricant out of the lubricant collecting container  21  into the region between the inner circumference of the housing  6  and the outer circumference of the drive spindle  3 , above the neck bearing  4 . 
     For better guidance, the tube  24  may also be bent opposite to the direction of rotation. 
     During rotations of the drive spindle  3 , oil is routed outward and is pumped upward through the lubricant duct  26  at the oil level designated as OIL in  FIG. 1 . 
     Lubricant emerging from the lubricant duct  26  can then run downwardly through the neck and the foot bearings  4 ,  5  and from there downwardly back into the lubricant collecting space  21 , where it collects radially on the outside on account of the centrifugal action. 
     By way of the lubricant duct  26 , oil can be conveyed out of the lubricant collecting container  21  through the lubricant duct  26 , which is formed in the housing  6  and extends directly into or above the neck bearing  4 , passes axially through the housing  6 , directly into the region of the neck bearing  4  on or into the region above the neck bearing  4 . In accordance with the present disclosure, the oil no longer, as in WO 2007/125066, has to be routed through external lines or filter elements out of the region lying radially near the drive spindle  3 . 
     Thus, a complete lubricant circuit designed in a defined way and operating reliably is implemented in a most confined space for the purpose of lubricating the mounting, or the neck and foot bearing  4 ,  5 , of the centrifuge or separator  1 . The region of the drive motor  10  is separated from the lubricant system or lubricant circuit. The drive region beneath the mounting  4 ,  5  has only a minimal vertical extent. 
     In an embodiment according to the present disclosure, the motor rotor  12  is connected fixedly in terms of rotation directly to the drive spindle  3  or is formed in one piece with the latter. Elements, such a coupling, which lengthen the form of construction, may thus be dispensed with. Moreover, the production costs are also further reduced. 
     It is within the scope of the present disclosure to provide other types of motors on the spindle  3 . Thus, it is conceivable to connect the motor rotor  12  to the spindle  3  and the stator  11  to the housing  6  (not shown). 
     As shown in  FIG. 2 , the lubricant circuit of  FIG. 1 , with all its elements, may also be employed in a structure in which the drive spindle  3  is driven via a drive belt  27  lying beneath the lubricant collecting container  21 . This embodiment of separator construction, which is an especially compact form of construction, including, for example, being short in the vertical direction is implementable using the lubricant system according to the present disclosure. 
     The annular-space/torus-like lubricant collecting container  21  is arranged in the space delimited upwardly and radially outwardly by the machine stand section  9  and downwardly by the drive belt  27  and also inwardly by the housing region  20  and, further below, by the drive spindle  3 . The lubricant collecting container  21  can also be integrated predominantly into the structure at this point.  FIG. 2  also shows a machine stand foot  32  and belt pulley  33  which the drive belt  27  surrounds or with which the latter may be formed integrally. 
     The separator drive, according to the embodiment of  FIG. 2 , is designed in such a way that the center of rotation P 1  of the oscillating unit lies at the axial and radial mid-point of that region of the belt pulley  33  on the drive spindle  3  around which the drive belt  27  is looped. 
     Although the present disclosure has been described and illustrated in detail, it is to be clearly understood that this is done by way of illustration and example only and is not to be taken by way of limitation. The scope of the present disclosure is to be limited only by the terms of the appended claims.