Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
  • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
  • B02C17/00—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls
  • B02C17/04—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls with unperforated container
  • B02C17/08—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls with unperforated container with containers performing a planetary movement
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
  • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
  • B02C17/00—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls
  • B02C17/18—Details
  • B02C17/24—Driving mechanisms

Definitions

• the invention relates to a planetary mill on a laboratory scale, sometimes also referred to as a planetary ball mill, in particular with an inclined planetary axis and a three-dimensional or limited toothed belt drive for driving the grinding station or the grinding bowl holder, as well as a three-dimensional or limited toothed belt drive for such a planetary mill or possibly for other applications .
• Laboratory-scale planetary ball mills are used, for example, in process analysis for grinding samples.
• Planetary mills sometimes also referred to as ball mills or planetary ball mills, are e.g 2006 047 479 A1.
• DE 10 2006 047 498 A1 describes a ball mill with cooling, in which cooling channels extend at least partially within the bottom and/or the annular wall of a cup-like receiving device.
• Newer planetary mills are described, for example, in DE 10 2010 044254 A1, DE 10 2012 009 983 A1, DE 10 2012 009 985 A1, DE 10 2012 009 982 A1, DE 10 2012 009 984 A1, DE 10 2012 009 987 A1
• An overview of currently marketable planetary mills on a laboratory scale can also be found on the applicant's website at www.fritsch.de.
• grinding bowls are arranged as planets eccentrically to a sun axis, sometimes also referred to as the central axis, and run on the one hand on a circular path around the sun axis and on the other hand rotate around their own axis, the eccentric planetary axis. Due to the circulation and rotation of the grinding bowls, a changing centrifugal force directed radially outwards is exerted on the material to be ground that is filled into the grinding bowl.
• grinding media for example grinding balls, are added to the material to be ground, which comminute the material to be ground with high efficiency through the impact and friction effect.
• trajectories for the material to be ground and the grinding bodies can be generated in a planetary ball mill.
• the material to be ground and the grinding beads then move transversely through the grinding jar until they strike the inner wall of the grinding jar.
• the material to be ground with the grinding media can then be carried along a bit along the inner circumference of the grinding bowl until the resulting force again ensures that the transverse acceleration described above takes place and the material to be ground and the grinding media perform a flight movement through the grinding bowl. This is also referred to as the "throw regime". If a ball mill works in the throw regime, a particularly high grinding effect can be achieved at high speeds.
• planetary ball mills are characterized by fast and effective comminution. They can be used in a variety of ways and are ideal for loss-free fine comminution down to final fineness in the nanometer range. Depending on the task, grinding can be carried out dry, in suspension or under inert gas. They are also ideal for homogenizing emulsions and pastes or for mechanical alloying in materials research.
• nano-comminution requires a relatively high energy requirement and can lead to undesired heating of the material to be ground as a result of the grinding process.
• some substances are so temperature-sensitive that they cannot be crushed in the current planetary ball mills. Other materials can only be crushed after they have become brittle.
• the axis of the sun and the axis of the planet usually run parallel.
• a centrifuge is known from EP 2 457 645 A1, in which the axis of rotation of the container holder is inclined. The entire rotating arrangement is arranged in a compartment which is provided with cooling/heating tubes. The container holder is driven by a bevel gear drive. Effective cooling of the grinding bowls does not appear possible with this. The drive shown there also appears complex, maintenance-intensive and not very smooth-running. Furthermore, the rotating system has a high mass.
• a planetary ball mill is known from US Pat. No. 7,744,027 B2, in which the buckets circulate in a ring made of elastic material at the upper end of the buckets and are apparently set in rotation by friction between the buckets and the encircling elastic ring.
• Such a drive does not appear to be very reliable and is likely to exhibit slip and high wear. There is no synchronicity and it is assumed that in practice the speeds and power are tightly limited.
• a centrifugal processing device for stirring and defoaming is known from EP 2 722 088 B1.
• the drive takes place via a gear train, which is located above the storage container.
• the construction appears complex, cost-intensive and not very smooth-running. Furthermore, attachment of the container appears difficult and access to the container is limited. Such an arrangement of the gear train appears to be unfavorable in principle.
• DE 11 2004 001 671 B4 discloses a stirring/deaerating device which stirs and deaerates an object to be kneaded by simultaneously rotating and revolving a container, the device comprising a hermetically sealable container which is connected to a vacuum pump via a suction pipe.
• a second rotation drive mechanism includes an idler pulley and a pulley and a Round belts with a pulley ratio of 1:1.
• a similar drive with such a round belt is shown in JP 2009-268955 A.
• the round belt seems to be a custom-made product, which is expensive and unfavorable in terms of spare parts supply. Furthermore, such a drive does not appear to be suitable for high performance requirements.
• the drive is designed for a speed ratio of 1:-1.
• a step-up or step-down is neither intended nor readily possible.
• such a drive seems susceptible to wear and the transmittable power appears low. It is also assumed that the speed and power are severely limited, which may be sufficient for this device, namely for stirring and venting or kneading.
• cryogenic vibratory mills and cryogenic mills with a magnetic drive are known, which, however, can only grind very small amounts of sample and whose grinding performance leaves something to be desired.
• magnetically driven mills have the disadvantage that they are ground with special magnetic pestles and the material to be ground should not be magnetic.
• the object of the present invention is to provide a planetary mill with an inclined planetary axis, the drive of which avoids or at least mitigates the disadvantages described above.
• Another aspect of the task is to provide a planetary mill with an inclined planetary axis, which has a reliable synchronous drive between the carrier device as a sun element and the grinding bowl, which works slip-free and largely uses commercially available construction elements.
• Another aspect of the task is to provide a planetary mill with an inclined planetary axis, which has a synchronous drive between the carrier device as a sun element and the grinding bowl, which is smooth-running, low-wear, robust and inexpensive and with which a high grinding capacity can be achieved at the same time can.
• a further aspect of the task is to provide a planetary mill with an inclined planetary axis, which has a synchronous drive between the carrier device as a sun element and the grinding bowl holder, with the grinding bowl holder being driven directly by the rotation of the carrier device and the grinding bowl holder being driven directly input and output shafts running at an angle to each other and an over- or reduction ratio not equal to one combined directly in one and the same drive, in particular with a single drive element.
• a further aspect of the task is to create a smooth-running, low-wear and reliable synchronous drive that is suitable for spatially complex drive geometries, in particular with axes running obliquely, comprehensively obliquely in a common plane or skewed to one another and/or step-up or step-down ratios.
• a further aspect of the task is to provide a planetary mill which enables effective and, in particular, permanent cooling of the material to be ground during the grinding process.
• Another aspect of the task is to provide a planetary mill with which unwanted heating of the material to be ground during the grinding process can be prevented or at least reduced, e.g. to grind temperature-sensitive samples with high quality and/or high grinding capacity, and preferably for permanent cryogenic grinding with to enable a planetary mill, i.e. to make a cryo-planetary mill available.
• Another aspect of the task is to provide a planetary mill which has a high grinding capacity and at the same time allows insight into and/or access to the interior of the grinding jar receptacle and/or the grinding jar during the rotation of the carrier device and the grinding jar receptacle, e.g. to liquid cryogenic cooling medium drip into the grinding bowl or the grinding bowl holder or to be able to monitor the grinding process with a camera.
• the laboratory-scale planetary mill sometimes also referred to as a planetary ball mill or laboratory planetary ball mill, comprises a support device as a sun element which rotates about a sun axis and at least one grinding bowl receptacle which is axially offset from the sun axis on the support device and arranged about a planetary axis rotates relative to the carrier device. At least one grinding bowl can be inserted into the grinding bowl receptacle and clamped or latched so that it performs a combined rotating and revolving movement.
• the grinding bowl receptacle and the grinding bowl clamped or latched therewith revolve around the sun axis at the rotational speed of the carrier device and simultaneously rotate around their own axis, ie the planetary axis.
• the rotation of the carrier device as a sun element around the sun's axis is driven by an electric drive motor, for example with a main drive belt.
• the rotation of the grinding bowl holder around the planetary axis is driven as a synchronous drive by a toothed belt relative to the carrier device in order to ensure a constructively defined speed ratio between the sun rotation and the planetary rotation.
• the main drive belt for the carrier device does not necessarily have to be a synchronous belt; a V-belt or a V-ribbed belt or another sheath drive can be used for this purpose, since a V-belt or V-ribbed belt drive is inexpensive and slippage can be acceptable at this point.
• a toothed belt or a completely different drive for the main drive belt should not be ruled out either.
• the planetary mill has non-parallel axes of rotation and an inclined grinding jar, i.e. the grinding jar receptacle and the grinding jar clamped or locked thereon, as well as the planetary axis, are inclined at an oblique angle to the sun axis, preferably viewed from the bottom up or from the grinding jar bottom to the Seen from the grinding jar opening, inclined inwards so that the opening of the grinding jar is closer to the sun's axis than the bottom of the grinding jar.
• the planetary axis and the sun's axis do not run parallel, in particular at an angle to one another in three-dimensional space.
• “Oblique” is understood here to mean that the axes are not parallel and not perpendicular to one another. "Oblique" in three-dimensional space includes on the one hand oblique in a common plane or on the other hand crooked, but not perpendicular, i.e. not parallel, not perpendicular and in three-dimensional space not cutting.
• the toothed belt drive In order to drive the obliquely inclined planetary axis, the toothed belt drive has input and output axes that are not parallel to one another or toothed drive and output pulleys that are not parallel to one another.
• the toothed belt drive drives the grinding cup holder directly so that no further gearing is required between the output toothed disk and the grinding cup holder in order to bring about the axis inclination in the planetary drive.
• the toothed belt transmits the rotational movement from the sun axis directly to the inclined planetary axis, with the driven toothed disc being arranged coaxially with the planetary axis or the grinding bowl holder and being firmly connected to the grinding bowl holder.
• the toothed belt thus brings about the drive of the grinding bowl holder and at the same time the deflection of the rotary drive for the grinding bowl holder by the angle of inclination of the grinding bowl holder.
• the toothed belt runs with a set, in particular with multiple sets, between the sun axis and the inclined planetary axis.
• the central sun axis is preferably designed as a central main axis, also called the center axis, which is firmly connected to the housing and on which the carrier device is rotatably mounted as a sun element, for example by means of ball bearings.
• the toothed drive pulley for the toothed belt drive is preferably connected coaxially to the central axis and is therefore stationary in relation to the device housing.
• a main driven pulley is fixed coaxially connected to the carriage and driven by the main drive belt so that the carriage rotates about the fixed center axis with the drive pulley.
• the carrier device entrains the grinding station or grinding cup holder, which is mounted in the carrier device at a distance from the center axis, about the fixed center axis, so that it rotates about the sun axis.
• the toothed belt for driving the rotation of the grinding station or grinding bowl holder is thus driven by the relative rotation of the carrier device to the drive toothed disc fixed to the device housing and in turn drives the driven toothed disc attached to the grinding bowl holder and inclined with the grinding bowl holder with a defined speed ratio.
• the rotation of the grinding bowl holder is therefore carried out with a synchronous drive by means of a toothed belt relative to the rotation of the carrier device, preferably in the opposite direction.
• a cost-effective, commercially available toothed belt can be used to drive the grinding bowl receptacle relative to the carrier device.
• the toothed belt forms a slip-free synchronous drive for the planetary rotation of the grinding jar receptacle relative to the sun rotation of the carrier device and at the same time adapts the inclination of the planetary axis or grinding jar receptacle relative to the central axis.
• a high grinding capacity and a narrow distribution range can be achieved. For example, mean particle sizes of up to ⁇ 0.1 pim can be achieved.
• a toothed belt (sometimes also called synchronous belt or timing belt in motor technology) is a toothed drive belt that runs in toothed pulleys with a positive fit. Toothed belts combine the properties of a chain and a flat belt. Teeth are formed on the inside of the toothed belt, which engage in a special toothed disc.
• An elastomer such as rubber, chloroprene rubber, hydrogenated acrylonitrile butadiene rubber (HNBR[1]) or polyurethane can be considered as the material for the teeth.
• a toothed belt has advantages over a V-belt and a flat belt, which only work with traction, since high forces can be transmitted with less pretension and no slippage occurs.
• a toothed belt is understood here to mean, in particular, a commercially available toothed belt with a plurality of tension cords arranged flat next to one another and with an overall flat cross-section, which is toothed transversely on one or both flat sides (single toothed belt or double toothed belt).
• the teeth engage in corresponding transverse grooves of toothed disks as drive toothed disks and driven toothed disks in a form-fitting manner and form a form-fitting synchronous drive.
• the tension cords are typically formed from a plurality of tension cords, eg steel cords, arranged flat next to one another and embedded in a base material, eg an elastomer or polyurethane, thereby forming a carrier strip with a flat cross section.
• the teeth running transversely to the tension cords have, for example, a trapezoidal or semi-circular cross-section.
• the toothed belt drive used here for the grinding station or grinding bowl holder is a so-called three-dimensional or offset toothed belt drive. With a set toothed belt drive, the flat toothed belt runs in the strands between the toothed pulleys and, if necessary, other rollers.
• the toothed belt does not have a rotationally symmetrical cross-section and, among other things, runs in a set manner in order to compensate for the axis inclination and, if applicable, a transmission ratio in the drive.
• Such commercial (standardized) toothed belts are commercially available from many suppliers, e.g. from Walther Elender (www.walther-flender.de), Opibelt (www.optibelt.com) or H. Fröhlich AG (www.hfag.ch) and can are subject to certain standards, e.g. ISO 13050, DIN 7721 or ISO 5296.
• a toothed belt T or HDT e.g. HTD5
• the use of commercially available toothed belts compared to special belts has particular advantages in terms of costs, availability of spare parts and reliability.
• the toothed belt drive is therefore designed in particular as a set toothed belt drive.
• the drive sprocket is preferably arranged coaxially to the sun axis and the driven sprocket is preferably arranged coaxially to the inclined planetary axis under the grinding bowl holder and is firmly connected to the grinding bowl holder, with the toothed belt running between the drive toothed disc and the drive toothed disc with at least one, preferably even multiple set, so that the drive toothed disc and the driven pulley are obliquely inclined to each other.
• the planetary axis or the output toothed disk are preferably offset by an angle ⁇ between 5°, if necessary 10° and 75°, preferably between 25° and 60°, particularly preferably by 37.5°+/-10° or 37.5°+ /-5° inclined to the drive sprocket or to the center axis.
• the set toothed belt drive with non-parallel axes has a translation and the driven pulley, which is inclined at an angle relative to the drive pulley, has a smaller diameter with fewer teeth than the drive pulley, corresponding to the translation ratio.
• the amount of the relative speed ratio between the rotation of the carrier device and the grinding bowl receptacle is particularly preferably in the range of 1:1.5 and 1:5. A high grinding capacity of the planetary mill can be achieved in this way in an advantageous manner.
• the rotation of the carrier device and the grinding bowl holder is in opposite directions and the relative speed ratio between the rotation of the carrier device and the grinding bowl holder is in particular between 1: ⁇ 1.5 and 1: ⁇ 5.
• both the translation and the counter-rotation are generated directly with the toothed belt drive with non-parallel axes, i.e. with one and the same toothed belt, i.e. the mutually inclined drive pulley and driven pulley of the toothed belt drive for driving the inclined grinding bowl holder with a translation, in particular with rotate in opposite directions at a speed ratio of 1:-1.5 to 1:-5.
• the planetary mill can be embodied as a monomill with only one grinding cup holder inclined inwardly when viewed from the bottom up and a counterweight, which can be adjusted in particular.
• This has the advantage that the grinding bowl can be arranged so far inside that the grinding bowl, if necessary with a grinding bowl extension, intersects the sun axis due to the combination of a small distance between the planetary axis and the sun axis and the inclination of the grinding bowl at the upper end of the grinding bowl or the grinding bowl extension .
• the bottom of the grinding jar is still so far away from the axis of the sun that the bottom of the grinding jar does not intersect the axis of the sun.
• the planetary mill can also be designed as a duo planetary mill with two opposite grinding stations or have additional grinding stations, e.g. as a quatro mill, with some or all of the planetary axes running at an angle relative to the sun axis.
• the toothed belt drive for the grinding bowl holder includes a first and/or second deflection roller with a first or second deflection roller axis.
• the first and second deflection or tensioning rollers are preferably arranged on opposite sides of the toothed belt drive, ie the first deflection roller (toothed or toothless) is arranged on the slack side and the second deflection roller on the tight side or vice versa.
• the toothed belt can be deflected in a suitable way in order to compensate for the inclination of the drive and driven pulleys and the twist of the toothed belt on both sides of the deflection rollers split up.
• the drive toothed disc is arranged coaxially to the sun axis and the driven toothed disc is arranged coaxially to the inclined planetary axis and is firmly connected to the grinding bowl receptacle.
• the toothing of the toothed belt which runs on the drive toothed disc and the driven toothed disc, engages positively in the toothing of the drive toothed disc and the driven toothed disc and, as already explained above, the toothed belt has several adjacent tension cords with an overall flat cross-section with a toothed flat side (inside) and an untoothed or possibly also toothed back (outside).
• the tangent run-out of the toothed belt on the drive sprocket in particular does not run parallel to the tangent run-in of the toothed belt on the driven sprocket, and the toothed belt runs with a set between them. Furthermore, the tangent run-out of the toothed belt on the driven sprocket does not run parallel to the tangent run-in of the toothed belt on the drive sprocket, and the toothed belt also runs with a set between them.
• first and second deflection roller axes are not coaxial, preferably at an angle to one another and/or at least one or both of them are skewed and at an angle to the sun's axis and/or at least one of them or both are skewed and at an angle to the inclined planetary axis.
• oblique to each other axes is understood herein that the axes are neither parallel nor perpendicular to each other, but obliquely, i.e. at an oblique angle to each other.
• the axes can be oblique in a common plane at an oblique angle to each other and in the common Intersect plane or run obliquely and skewed in three-dimensional space
• the angle or angle of inclination between the axes can be determined in a projection plane that runs perpendicular to the shortest connecting line between the skew axes.
• the angle of inclination of the first and/or second deflection roller axis to the sun axis and/or to the planetary axis or the angle of inclination between the center plane of the first and/or second deflection roller to the center plane of the drive pulley and/or to the driven pulley is between 1° and 89 ° or between 91° and 179°.
• the slack side and the tight side are each divided into two side sections with the first and second deflection roller.
• the setting of the toothed belt in the free strands can be acceptable limits and smooth running of the toothed belt drive can be achieved without the risk of the toothed belt "running off" the toothed discs or the deflection rollers.
• the toothed belt runs between the drive sprocket and the first deflection pulley, between the first deflection pulley and the driven sprocket, between the driven sprocket and the second deflection pulley, and/or between the second deflection pulley and the drive sprocket, with the set preferably being less than 90° in each case , in particular less than 60° in each case, in particular less than 45° in each case, in particular less than 30° in each case.
• the first deflection roller adapts the angular deviation from the parallelism or coaxiality of the tangent outlet on the drive pulley and the tangent inlet on the driven pulley by the first deflection roller shifting the line of action of the toothed belt in three-dimensional space from the direction of the tangent outlet on the drive pulley in the direction of the tangent inlet at the driven sprocket and thereby divides the pitch of the toothed belt between the drive sprocket and the driven sprocket, and/or the second deflection roller adapts the angular deviation from the parallelism or coaxiality of the tangent run-out on the driven sprocket and the tangent entry at the drive sprocket, in that the second deflection roller The line of action of the toothed belt in three-dimensional space deflects from the direction of the tangent outlet on the driven pulley to the direction of the tangent inlet on the drive pulley, thereby changing
• the tangent exit and tangent entry of the toothed belt at the drive pulley the tangent exit and tangent entry of the toothed belt at the driven pulley, the tangent exit and tangent entry of the toothed belt at the first deflection roller, the tangent exit and the tangent inlet of the toothed belt at the second deflection roller, each run at an oblique angle to one another, i.e. at an angle of unequal 90° and unequal to 180° and unequal to other multiples of 90°, whereby the angle is preferably smaller than 180°.
• the tangent run-out of the toothed belt on the drive sprocket and the tangent run-in of the toothed belt on the driven sprocket and/or the tangent run-out of the toothed belt on the driven sprocket and the tangent run-in of the toothed belt on the drive sprocket run at an oblique angle to one another, i.e. at an angle not equal to 90° and not equal to 180° and not equal to other multiples of 90°, but preferably the angle is less than 180°.
• the tangent run-out of the toothed belt on the drive pulley runs coaxially with the tangent run-in of the toothed belt on the first deflection pulley and the toothed belt between the drive pulley and the first deflection pulley is set
• the tangent run-out of the toothed belt on the first deflection pulley runs coaxial with the tangent run-in of the toothed belt on the driven pulley and the toothed belt between the first pulley and the driven pulley
• the tangent outlet of the toothed belt on the driven pulley runs coaxially to the tangent inlet of the toothed belt on the second pulley and the toothed belt between the driven pulley and the second pulley is set
• the tangent outlet of the toothed belt on the second pulley runs coaxially to the tangential entry of the toothed belt on the drive
• the first and/or second deflection roller axis run skewed and in particular not perpendicular to the axis of the drive sprocket and/or to the axis of the driven sprocket.
• the drive sprocket axis and the driven sprocket axis run obliquely to one another in a common plane and intersect in the common plane and the axes of the first and/or second deflection roller do not run parallel, in particular obliquely, to the common plane of the drive sprocket axis and the driven sprocket axis and in particular intersect them Level.
• geometrically desirable structural conditions for a planetary mill with an obliquely inclined planetary axis can be realized in an advantageous manner.
• At least one of the deflection rollers i.e. the first and/or the second deflection roller, is arranged on the toothed side inside the toothed belt and deflects the toothed belt outwards from the connecting line of the drive pulley and the driven pulley or from the common plane of the drive pulley axis and the Driven pulley axis away and/or deflects the toothed belt obliquely downwards based on an imaginary connecting line between the centers of the drive pulley and drive pulley.
• the toothed belt drive comprises a holding cross with crossed arms, the driving toothed disc, the driven toothed disc and the first and second deflection rollers being rotatably mounted on opposite ends of the crossed arms of the holding cross.
• a stable holding structure for the set toothed belt drive can thus be provided in an advantageous manner.
• the spatial arrangement of the drive sprocket and the driven sprocket and the first and second deflection roller has the shape of a convex, rounded quadrilateral that is bent at an oblique angle around the line connecting the first and second deflection roller.
• the spatial arrangement of the drive pulley and the driven pulley and the first and second deflection roller is mirror-symmetrical to the common plane of the drive pulley axis and the driven pulley axis.
• the arrangement particularly preferably has the shape of a rounded kite quadrilateral bent at an oblique angle around the connecting line of the first and second deflection rollers.
• a "square toothed belt drive kinked in space" is also spoken of here.
• One aspect of the disclosure also relates to a laboratory device with non-parallel axes of rotation, comprising: a carrier device which can be rotated about a sun axis, at least one beaker holder for inserting a beaker, the beaker holder being arranged on the carrier device in an axially offset manner with respect to the sun axis and relative to a planetary axis can be rotated in relation to the carrier device, a drive for driving the rotation of the carrier device and the cup holder, with the rotation of the cup holder relative to the rotation of the carrier device being driven synchronously by means of a toothed belt drive, and possibly further features of the planetary mill described herein, with the planetary axis not parallel to the axis of the sun, and wherein the toothed belt drive has non-parallel input and output axes.
• the set toothed belt drive disclosed here was specially developed as a synchronous drive for the grinding bowl holder in a planetary mill with an inclined planetary axis, it has been shown that such a set toothed belt drive with possibly very special skewed arrangements of the toothed discs or the axes can also be used in other areas of drive technology can be applied. Therefore, one aspect of the present disclosure relates to a set toothed belt drive as such, regardless of its particularly advantageous use in the planetary mill with an inclined planetary axis.
• a special toothed belt drive with non-parallel axes and a twist in the toothed belt is proposed.
• a toothed belt is understood to mean a toothed belt with several tension cords lying next to one another and embedded in plastic with an overall flat cross-section, which is toothed on one or both flat sides transversely to the circumference in order to positively engage in corresponding grooves of a toothed disk, such as this has already been explained above.
• a twist of the toothed belt means that all of the tension cords of the toothed belt are twisted in a spiral shape along its running direction.
• the set toothed belt drive comprises: a first sprocket as a drive sprocket with a first sprocket center plane and a first sprocket axis running perpendicular to the first sprocket center plane, and a second sprocket as a driven sprocket with a second sprocket center plane and a second sprocket axis running perpendicular to the second sprocket center plane, or vice versa.
• the first and second deflection roller can each be toothed or toothless and are arranged on opposite sides of the toothed belt drive, ie the first deflection roller on the slack side and the second deflection roller on the tight side of the tooth belt drive, with the first and second toothed pulley axes not running parallel to one another and preferably enclosing an angle of > 5°, in particular > 10°, in particular > 20°, with the tangent outlet of the toothed belt on the first toothed pulley not being parallel to the tangent inlet of the toothed belt of the second toothed pulley and the tangent outlet of the toothed belt
• the first deflection roller axis (144) runs at an angle to the second toothed disc center plane (42a), ill) the second deflection roller axis (146) runs at an angle to the first toothed disc center plane (36a), iv) the second deflection roller axis (146) runs at an angle to the second toothed disc center plane (42a), v) the first and second deflection roller axes (144, 146) do not run coaxially with one another.
• at least one, several or all of the above criteria i) to iv) and criterion v) are met.
• at least two of the above criteria i) to iv) and criterion v) are met.
• Oblique is understood here to mean an oblique angle, i.e. an angle that is neither parallel nor perpendicular, i.e. an angle not equal to 0°, not equal to 90° and not equal to 180° and not equal to any other multiple of 90°, the deviation being greater than usual tolerances .
• the deviation of an oblique angle from 0° or a multiple of 90° can be, for example, greater than or equal to 1°, preferably greater than or equal to 2°, preferably greater than or equal to 3°, i.e.
• the oblique angle can be, for example, between 1° and 89° or be between 91° and 179°, preferably between 2° and 88° or between 92° and 178°, preferably between 3° and 87° or between 93° and 177°.
• the first and second deflection rollers are both arranged on the toothed side inside the toothed belt and deflect the toothed belt outwards away from an imaginary connecting line between the centers of the first and second toothed disc or away from the other deflection roller, in particular a kite -Square is formed.
• the first deflection roller is arranged on the toothed side inside the toothed belt and deflects the toothed belt outwards, i.e. away from the connecting line of the first and second toothed disc or from the second deflection roller, and the second deflection roller is on the back of the toothed belt outside of the toothed belt and the toothed belt inwards, i.e. towards the first deflection roller, or vice versa.
• Such an arrangement can also be referred to as a knee-in-knee arrangement.
• the length of the strands can be increased in order to limit the transverse forces and keep the twist of the toothed belt within the permissible limit values.
• a minimum ratio between the center distance C and the toothed belt width b of at least 5:1 based on a twist of 90° can be maintained even with unusual drives, whereby the minimum ratio can also be reduced accordingly with a twist of less than 90°.
• the transverse forces can advantageously be kept within permissible limits.
• first and second toothed disk axes run obliquely, that is to say at an oblique angle to one another.
• the first and second toothed wheel axes preferably run as follows: i) the first and second pulley axes are non-parallel in a common plane and intersect in the common plane and the first and second pulleys are of different sizes so that a gear ratio is created or ii) the first and second pulley axes run obliquely to one another in a common plane and intersect in the common plane at an oblique angle or ill) the first and second pulley axes run skewed and not perpendicular to one another.
• the angle between the first and second toothed wheel axis or between the first and second toothed wheel center plane is between 5° and 85° or between 175° and 95°, in particular between 10° and 80° or between 170° and 100°, in particular between 25° and 75° or between 155° and 105°, in particular between 25° and 50° or between 155° and 130°.
• the angle between the axes can be determined, for example, between their projections in a projection plane that is perpendicular to the shortest line connecting the two skew axes.
• the first deflection roller axis runs crooked and not perpendicular to the first toothed disk axis
• the first deflection roller axis runs crooked and not perpendicular to the first toothed disk axis
• the second deflection roller axis runs crooked and not perpendicular to the first pulley axis
• the second deflection roller axis is skewed and not perpendicular to the first pulley axis.
• Skewed and not perpendicular are two axes that are skew to one another in three-dimensional space and whose projections are not perpendicular to one another or run at an oblique angle to one another in a projection plane that runs perpendicular to the shortest connection between the skew axes.
• the toothed belt drive can additionally or alternatively be implemented with a transmission or reduction, i.e. a transmission/reduction ratio not equal to 1:1, with the first toothed disc as the drive toothed disc having a larger or smaller diameter than the second toothed disc as the output toothed disc, or vice versa.
• a transmission or reduction i.e. a transmission/reduction ratio not equal to 1:1
• the tangent outlet of the toothed belt on the first toothed disc runs obliquely, in particular in a common plane, to the tangent inlet of the toothed belt on the second toothed disc and/or the Tangent entry of the toothed belt on the first toothed pulley runs obliquely, in particular in a common plane, to the tangent exit of the toothed belt on the second toothed pulley.
• the twist in the divided strands can be reduced, which enables a synergistic combination of deflection and adaptation of the oblique angles on the one hand and a compact construction on the other.
• the twist of the toothed belt in the following strands between the first pulley and the first pulley, between the first pulley and the second pulley, between the second pulley and the second pulley and/or between the second pulley and the first pulley is less than 90°, in particular less than 45° in each case.
• the first deflection roller adapts the angular deviation from the parallelism or coaxiality of the tangent outlet and the tangent inlet on the first or second toothed pulley, in that the first deflection roller moves the line of action of the toothed belt in three-dimensional space from the direction of the tangent outlet on the first toothed pulley in the direction of the tangent inlet at the second sprocket, thereby dividing the twist of the toothed belt between the tangent outlet of the first sprocket and the tangent entry of the second sprocket and/or the second deflection roller adapts the angular deviation from the parallelism or coaxiality of the tangent run-out and the tangent entry on the second or first toothed pulley, in that the second deflection roller deflects the line of action of the toothed belt in three-dimensional space from the direction of the tangent exit on the second toothed pulley in the direction of the tangent entry
• the tangent exit and tangent entry of the toothed belt at the first pulley, the tangent exit and tangent entry of the toothed belt at the second toothed pulley, the tangent exit and tangent entry of the toothed belt at the first deflection roller, the tangent outlet and the tangent inlet of the toothed belt on the second deflection roller each run at an oblique angle to one another, i.e. at an angle unequal to 90°, unequal to 180° and unequal to another multiple of 90°, but the angle is preferably smaller than 180° in each case amounts to.
• the tangent exit of the toothed belt on the first toothed disc and the tangent entry of the toothed belt on the second toothed wheel and/or the tangent exit of the toothed belt on the second toothed wheel and the tangent entry of the toothed belt on the first toothed wheel each run under at an oblique angle to one another, ie an angle not equal to 90°, not equal to 180° and not equal to another multiple of 90°, but the angle is preferably less than 180° in each case.
• the tangent outlet of the toothed belt on the first toothed pulley runs coaxially to the tangent inlet of the toothed belt on the first deflection roller and the toothed belt between the first toothed disc and the first deflection roller is set
• the tangent outlet of the toothed belt on the first pulley runs coaxially to the tangent inlet of the toothed belt on the second pulley and the toothed belt between the first pulley and the second pulley
• the tangent outlet of the toothed belt on the second pulley runs coaxially to the tangent inlet of the toothed belt on the second pulley and the toothed belt between the second pulley and the second pulley is set
• the tangent outlet of the toothed belt on the second pulley runs coaxially to the tangent inlet of the toothed belt on the first pulley and the toothed belt between the
• the first deflection roller axis preferably does not run coaxially, in particular at an angle to the second deflection roller axis.
• the first deflection roller axis and the second deflection roller axis run at an angle to one another in a common plane and intersect in the common plane.
• first and second toothed disc axes not only run at an angle to one another in a common plane and intersect in the common plane, but the spatial arrangement of the first and second toothed discs and the first and second deflection rollers is also mirror-symmetrical to this common plane of the first and second toothed disk axis, so that the arrangement in particular has the shape of a rounded kite quadrilateral kinked in space.
• a third and fourth deflection roller are arranged on one side of the belt drive, with the first or second deflection roller and the third and fourth deflection roller being arranged next to one another and having parallel axes and/or lying in a common plane, and with the toothed belt between these lying in a common plane deflection rollers is not set.
• the middle one of the three deflection rollers lying in a common plane for example the third or fourth deflection roller, can be linearly displaceable as a tension roller in the common plane.
• the planetary mill comprises: a carrier device as a sun element, which is rotatable about a sun axis, at least one grinding station with a grinding bowl holder for inserting a grinding bowl, the grinding bowl holder being arranged on the carrier device axially offset to the sun axis and relative to a planetary axis can be rotated in relation to the carrier device, a drive motor for driving the rotation of the carrier device and the grinding bowl holder, so that the grinding bowl holder and a grinding bowl that can be inserted into the grinding bowl holder run through a combined circulation and rotation trajectory during operation, and a cooling device with a cooling medium line and a cooling medium metering opening for metering cooling medium into the grinding jar receptacle and/or into a grinding jar inserted into the grinding jar receptacle.
• the material to be ground can be cooled actively and in a controlled manner during the rotation, and in particular cryogenic grinding can be made possible.
• Cryogenic grinding is suitable, for example, for grinding foodstuffs, powder coating, additives in viscosity control, polymers, especially thermoplastics, or in tire recycling.
• thermoplastic resins too high a processing temperature in a planetary ball mill can lead to out-of-spec particle size problems.
• recycling processes recycle unspecified and post-industrial waste thermoplastics and add other compounds as fillers to increase the toughness and strength properties of the resin matrix.
• This process requires uniform fine particles. Therefore, fluctuations in particle size can affect the efficiency of the processes.
• Production rates can also drop if the processing temperature increases undesirably. If the temperature gets too high, the resin can even partially melt and clog the mill.
• the cooling medium is metered into the grinding jar receptacle and/or into the grinding jar inserted into the grinding jar receptacle from above during the rotation of the carrier device and the grinding jar receptacle, so that gravity can be used when metering in.
• the cooling medium metering opening is preferably arranged above the carrier device, and the cooling medium is conducted through the cooling medium line to the cooling medium metering opening above the carrier device, and emerges from the cooling medium Dosing opening into the air space above the rotating carrier device and then enters the rotating grinding bowl holder and/or the rotating grinding bowl from above.
• the cooling medium does not need to be routed from below through the carrier device via complex rotary feedthroughs, ring distributors or the like, but can be metered directly from above into the grinding bowl holder and/or the grinding bowl despite circulation and rotation.
• cooling medium line and the cooling medium dosing opening can be arranged stationary to the device housing of the planetary mill and do not rotate with the carrier device or the grinding bowl receptacle, which considerably simplifies the supply of the cooling medium.
• a grinding jar with a grinding jar interior is inserted into the grinding jar receptacle, in which during operation, i.e. during rotation of the carrier device and the grinding jar receptacle, the material to be ground is preferably comminuted with the aid of grinding bodies, e.g. grinding balls, grinding puck or grinding ring. It is therefore a device for grinding, i.e. for finely comminuting the material to be ground, and not just a mixing or degassing device or similar.
• the cooling medium is discharged from the cooling medium metering opening from above metered into the interior of the grinding bowl and/or into a gap between the grinding bowl receptacle and a wall of the grinding bowl.
• direct cooling of the grinding sample and the grinding media can be achieved during the grinding process.
• This direct cooling is particularly effective because the grinding media, e.g. grinding balls, can reach very high temperature peaks, possibly up to 600°C, on impact (throw regime) and can also be cooled directly.
• the instillation of the cooling medium from above into a gap between the grinding bowl and the grinding bowl holder is particularly advantageous if the cooling medium must not come into contact with the material to be ground, e.g. to avoid contamination of the material to be ground. Nevertheless, effective external cooling of the grinding bowl can still be achieved in this way.
• the grinding jar receptacle and/or the grinding jar that can be inserted into the grinding jar receptacle have a metering opening at their respective upper axial end and the cooling medium metering opening is located at least temporarily directly vertically above the metering opening during the rotation of the carrier device and the grinding jar receptacle, so that the cooling medium flows out of the cooling medium metering opening, in particular independently with the help of gravity, can get down into the metering opening, in particular falls, drips, flows and/or sprays.
• the cooling medium is caused by a planetary axis that is inclined in relation to the planetary axis
• the axially acting component of the centrifugal force from the rotation of the carrier device is accelerated considerably more than by gravity towards the bottom of the grinding bowl receptacle or the grinding bowl.
• the planetary mill is preferably designed as a cryo-planetary mill and the cooling medium metering opening is designed as a nozzle and the cooling medium is a liquid cryogen.
• the liquid cryogen can flow, drip and/or spray out of the nozzle into the grinding jar receptacle and/or into a grinding jar that can be inserted into the grinding jar receptacle, which also enables precise dosing.
• the liquid cryogen has a boiling point well below room temperature and, during the rotation of the carrier device and the grinding jar receptacle, preferably reaches the grinding jar receptacle and/or the grinding jar that can be inserted into the grinding jar receptacle in the liquid cryogenic state. There it can evaporate and the resulting gas can escape into the ambient air through openings in the grinding bowl holder and/or the grinding bowl. As a result, a large amount of heat, possibly including the energy of the phase transition, can be withdrawn from the grinding station in a controlled manner, i.e. the cooling has a high and controllable cooling capacity.
• the liquid cryogen is preferably metered into the interior of the grinding bowl in a liquid state and remains there at least temporarily in the liquid aggregate state, so that wet grinding with the liquid cryogen, ie cryogenic wet grinding, takes place at least temporarily.
• the liquid cryogen particularly preferably contains liquid nitrogen or consists essentially exclusively of liquid nitrogen.
• liquid nitrogen has a boiling temperature of 77 K and is particularly suitable for grinding materials that are otherwise difficult to grind, such as some thermoplastics, polyolefins and some biological samples or spices, etc.
• Nitrogen does not support combustion, it can help make grinding safer. Nitrogen is inert and under normal conditions hardly or not reacts with other materials. Undesirable reactions with the material to be ground, the grinding bodies and/or the materials of the grinding bowl holder or the grinding bowl can thus be avoided in particular with liquid nitrogen.
• liquid nitrogen does not form any carbonic acid when it comes into contact with water, so that the pH value of the ground material is not changed in an undesired manner even in the event of direct contact.
• cryogenic milling particularly using liquid nitrogen to dissipate the heat generated during the milling process, can result in a finer, more uniform particle size distribution and higher throughputs for many products compared to conventional milling methods. This may apply, for example, to adhesives, waxes, carpets, color concentrates, pigments, composites, granules, pharmaceuticals, plastics, powder coatings, metal, composite materials, rubber, spices and herbs.
• a temperature sensor for measuring the temperature of the grinding bowl holder, the grinding bowl and/or directly the material to be ground and/or the grinding bodies can be included.
• the temperature sensor can be arranged, for example, on the grinding bowl holder and/or on a grinding bowl that can be inserted into the grinding bowl holder, or it can be designed as a non-contact temperature sensor, e.g. as an infrared sensor, which is directed into the grinding bowl holder or into the grinding bowl.
• the temperature can be monitored directly in the area of the grinding bowl and/or on the grinding bowl holder.
• the transmission of the measured values from the rotating planetary system can be accomplished, for example, with a radio link.
• the planetary mill includes an electronic control device with a user interface.
• the user can use the user interface, e.g. a touch screen display, to set the usual operating parameters of the planetary mill, such as speed and/or milling time.
• the user can now advantageously control the cooling via the user interface, e.g. by means of the coolant flow. For example, with a simple control, intervals for the opening times of the cooling medium valve can be set. With an active temperature control, a target value for the desired grinding temperature, in particular in a cryogenic range, can be set.
• Certain ground goods e.g. spices
• the heat generated during grinding can cause spices to lose their essential oils, distort their aroma and flavor, and change color, which can affect the quality of the spices. If the spices are not processed at a sufficiently low temperature, the oils and fats in the spices can cause agglomeration and possibly even clog the grinder. Cooling and controlling the operating temperature, e.g., by controlling the flow rate of liquid cryogen, can help avoid these problems.
• the control device preferably includes a control loop, the temperature measured by the temperature sensor being fed back as an actual value and compared with the setpoint value, and the control loop actively controlling the temperature on the grinding bowl holder and/or the grinding bowl, in that the control device changes the amount of liquid cryogen, which is fed to the cooling medium metering opening via the cooling medium line, used as a variable.
• a control loop the temperature measured by the temperature sensor being fed back as an actual value and compared with the setpoint value
• the control loop actively controlling the temperature on the grinding bowl holder and/or the grinding bowl, in that the control device changes the amount of liquid cryogen, which is fed to the cooling medium metering opening via the cooling medium line, used as a variable.
• the grinding jar receptacle and/or the grinding jar inserted into the grinding jar receptacle preferably has a metering opening at the upper axial end and the cooling medium metering opening is arranged in the area of the sun axis centrally above the carrier device.
• the grinding jar receptacle and/or the grinding jar inserted into the grinding jar receptacle intersects the sun's axis, so that the metering opening is located vertically below the cooling medium metering opening in any rotary position of the carrier device and the grinding jar receptacle.
• the cooling medium can be metered out of the cooling medium metering opening by gravity, in particular vertically from above through the axial metering opening into the grinding jar receptacle and/or into the grinding jar; in particular, the cooling medium can be flow, drip or spray through the axial metering opening at the top.
• the planetary mill comprises a first and second grinding jar variant as follows: i) The first grinding jar variant intersects the sun's axis when it is inserted into the grinding jar receptacle and has an upper axial metering opening, the metering opening being in any rotary position of the carrier device and the grinding jar holder, in particular vertically, below the cooling medium metering opening, and the cooling medium is fed through the metering opening into the interior of the grinding jar, so that at any time during the rotation of the carrier device and the grinding jar holder, the cooling medium from the cooling medium metering opening through the axial Metering opening can be metered into the interior of the grinding bowl.
• the second grinding jar variant does not itself intersect the sun's axis when inserted into the grinding jar receptacle, only the grinding jar receptacle intersects the sun's axis. At least in this second grinding jar variant, there is also a gap between a radial peripheral wall of the grinding jar and the grinding jar receptacle, and the grinding jar receptacle has an axial metering opening, the metering opening being located below the coolant Dosing opening is located, and the cooling medium is fed through the dosing opening into the gap, so that at any time during the rotation of the carrier device and the grinding bowl holder, the cooling medium can be dosed from the cooling medium dosing opening through the axial dosing opening into the gap.
• the user can choose between the first and second grinding jar variant and depending on which of the two grinding jar variants is used in the grinding jar receptacle, the cooling medium can either get into the interior of the grinding jar (first grinding jar variant) or onto the outer wall of the grinding jar, or into the gap between the grinding bowl and the grinding bowl holder (second grinding bowl variant), depending on whether the material to be ground should come into direct contact with the cooling medium or not.
• the planetary mill therefore includes a grinding jar set, which includes both, namely the first and the second grinding jar variant, and the first and second grinding jar variant can be optionally inserted into the grinding jar receptacle in order to direct the cooling medium, depending on the grinding jar variant used, either into the interior of the grinding jar or into the gap between the grinding bowl and the grinding bowl holder.
• the planetary mill can initially only be supplied with one of the grinding jar variants and the customer can buy the other grinding jar variant as an accessory if required.
• the grinding bowl receptacle and the planetary axis are inclined at an oblique angle relative to the sun axis, namely inclined obliquely inwardly towards the sun axis when viewed from the bottom up.
• the upper end of the grinding cup holder can be brought closer to the sun axis than the bottom of the grinding cup holder.
• the planetary axis is inclined at an angle to the sun axis, it is particularly advantageous to drive the rotation of the grinding bowl receptacle relative to the rotation of the carrier device synchronously by means of a crossed toothed belt drive, with the toothed belt drive not having parallel drive and output axes, which in particular are coaxial to the Sun axis or run to the planetary axis.
• the cooling described here in particular the dosing of (cryogenic) cooling medium, e.g. directly into the interior of the grinding bowl, can also be suitable for use in other laboratory mills, e.g. in vibratory mills or other mills.
• the laboratory mill comprises: at least one grinding jar holder for inserting a grinding jar, a drive for driving a movement of the grinding jar, e.g.
• a planetary movement or an oscillating movement in order to grind the material to be ground that has been filled into the grinding jar using grinding bodies, and a cooling device with a cooling medium metering opening for metering in Cooling medium into the grinding jar receptacle and/or directly into the interior of the grinding jar inserted into the grinding jar receptacle during the movement of the grinding jar, ie during operation of the laboratory mill, and possibly other features of the planetary mill described herein.
• the planetary mill comprises: a carrier device as a sun element, which is rotatable about a sun axis, at least one grinding station with a grinding bowl holder for inserting a grinding bowl, the grinding bowl holder being arranged on the carrier device axially offset to the sun axis and relative to a planetary axis can be rotated in relation to the carrier device, a drive motor for driving the rotation of the carrier device and the grinding bowl holder, so that the grinding bowl holder and a grinding bowl that can be inserted into the grinding bowl holder revolve during operation on a circular path around the sun's axis and simultaneously rotate around the planetary axis, i.e.
• the grinding jar receptacle and the planetary axis are inclined at an oblique angle to the sun axis, the grinding jar receptacle having an upper end on which the grinding jar is inserted and an upper end
• the end of the axially opposite lower end, seen from the bottom up, has the planetary axis inclined obliquely inwards in the direction of the sun axis, with the grinding bowl holder and/or the grinding bowl inserted in the grinding bowl holder remaining open at the top during the rotation of the carrier device and the grinding bowl holder.
• the effect can be used in many ways. Among other things, the effect can be used so that, e.g. during operation, a cooling medium can be dripped in from above into the inside of the grinding bowl or into the grinding bowl holder. The effect can also be used to monitor the grinding process from above, e.g. with a camera.
• the grinding jar inserted into the grinding jar receptacle preferably has an axial upper end and at its upper end an axial opening which remains open during the rotation of the carrier device and the grinding jar receptacle, with the axial opening of the grinding jar intersecting the sun axis, so that in any rotational position of the carrier device and the grinding jar receptacle from above, through the axial opening of the grinding jar, it is possible to view and/or add medium to the interior of the grinding jar and/or the grinding jar receptacle has an axial opening at its upper end, which opens during the rotation of the carrier device and the grinding jar receptacle remains, with the axial opening of the grinding cup holder intersects the axis of the sun, so that in any rotational position of the carrier device and the grinding jar receptacle, a view from above through the axial opening of the grinding jar receptacle and/or the addition of medium into the interior of the grinding jar receptacle, in particular
• a cooling medium can be injected vertically from above into the interior of the grinding jar or into the
• the grinding bowl holder can be dripped onto the outside of the grinding bowl wall and/or it can be filmed with a camera inside the grinding bowl and/or in the grinding bowl holder.
• the grinding jar is preferably fixed in the grinding jar receptacle so that it cannot rotate, e.g. latched or braced, so that effective power input for grinding the material to be ground in the grinding jar is possible.
• the grinding capacity of the planetary mill is sufficiently high to grind the material to be ground in the grinding bowl with grinding bodies, e.g.
• the drive motor preferably has a motor power of at least 300 W, preferably at least 500 W, preferably at least 1 kW, in particular in the range from 300 W to 3 kW, preferably in the range from 500 W to 2.5 kW, preferably in the range of 1 kW to 2 kW.
• the maximum speed of rotation of the carrier device is preferably at least 700 rpm , preferably at least 800 rpm , preferably at least 900 rpm , preferably at least 1000 rpm , preferably at least 1100 rpm and/or at most 1800 rpm , preferably at most 1400 min 1 , preferably at most 1200 min 1 .
• the amount of the relative speed ratio between the rotation of the carrier device and the grinding bowl receptacle is preferably between 1:1.2 and 1:5, preferably between 1:1.5 and 1:3, preferably in the range of 1:2+/-0. 5.
• the carrier device and the grinding bowl holder rotate in opposite directions and the relative speed ratio between the rotation of the carrier device and the grinding bowl holder is between 1: ⁇ 1.2 and 1: ⁇ 5, preferably between 1: ⁇ 1.5 and 1: ⁇ 3 in the range of 1:-2+/-0.5.
• effective grinding can be achieved with the planetary mill, especially when working in the throw regime and nevertheless grinding can be carried out with a grinding bowl that is open at the top.
• the relative inclination of the planetary axis to the sun axis is preferably in the range of 15° to 70°, preferably in the range of 25° to 60°, preferably in the range of 37.5° +/-10 ° , in particular in the range of 37.5 ° +/-5°.
• the spatial arrangement can be implemented in an advantageous manner with a mono mill, i.e. with a planetary mill with only one grinding bowl receptacle and a counterweight, which can be adjusted in particular, to compensate for the imbalance of the carrier device.
• the grinding jar receptacle has a base and the base of the grinding jar receptacle in particular does not intersect the sun's axis.
• the grinding jar base of the grinding jar inserted into the grinding jar receptacle preferably does not intersect the sun's axis. In this way, constructive advantages as well as advantages with regard to the grinding performance can be achieved.
• the drive for the grinding bowl holder in particular a toothed belt drive, is preferably arranged below the grinding bowl holder.
• the grinding jar receptacle has a base and a shaft extension extends obliquely downwards coaxially to the planetary axis from the base of the grinding jar receptacle.
• the shaft extension is rotatably mounted on the carrier device below the bottom of the grinding jar receiver, e.g. with a ball bearing, and below the bottom of the grinding jar receiver an output gear of the planetary drive is attached to the shaft extension to drive the grinding jar receiver to rotate about the inclined planetary axis when the carrier device rotates .
• the rotation of the grinding bowl receptacle relative to the rotation of the carrier device is preferably driven synchronously and directly by means of a set toothed belt drive, and the toothed belt drive preferably has non-parallel drive and output axes that run obliquely to one another.
• a camera and/or a non-contact temperature sensor e.g. an infrared sensor
• a non-contact temperature sensor e.g. an infrared sensor
• a camera and/or a non-contact temperature sensor can be included, which are arranged above the grinding jar receptacle and, if necessary, are directed vertically or obliquely from above into the grinding jar receptacle and/or into the interior of the grinding jar inserted into the grinding jar receptacle to permanently during the rotation of the carrier device and the grinding cup holder the interior of the grinding cup holder and / or the interior of the used in the grinding cup holder
• an optical monitoring of the grinding process for example, special insights into the grinding parameters or properties of the grinding can be determined.
• the temperature of the material to be ground can be measured directly with a temperature sensor.
• a cooling device for metering cooling medium into the grinding bowl holder and/or into the interior of the grinding bowl can in turn be advantageous for grinding certain samples.
• the cooling device can comprise a cooling medium line and a cooling medium dosing opening centrally in the area of the sun axis, and the cooling medium is conducted through the cooling medium line into the central area on the sun axis above the grinding bowl holder or above the grinding bowl and can during the Rotation of the carrier device and the grinding jar receptacle cooling medium from the coolant metering opening through the upper opening of the grinding jar receptacle or the grinding jar from above into the grinding jar receptacle and / or into the interior of the grinding jar.
• the cooling medium metering opening can be designed as a nozzle and the cooling medium can be a liquid cryogen, e.g. liquid nitrogen.
• the liquid cryogen preferably drips or sprays from above out of the nozzle into the grinding jar receptacle and/or into the grinding jar and evaporates in the grinding jar receptacle or the grinding jar.
• the resulting gas can escape into the ambient air through openings in the grinding bowl holder and/or the grinding bowl.
• One aspect of the disclosure also relates to a laboratory device, comprising: a carrier device which can be rotated about a sun axis, at least one beaker holder for inserting a beaker, the beaker holder being arranged on the carrier device in an axially offset manner with respect to the sun axis and being rotatable about a planetary axis relative to the carrier device is, a drive for driving the rotation of the carrier device and the cup holder, so that the cup holder and a cup that can be inserted into the cup holder run through a combined circulation and rotation trajectory during operation, and possibly further features of the planetary mill described herein, in particular the cup holder and the planetary axis is inclined at an oblique angle ( ⁇ ) to the sun's axis, the cup receptacle has an upper end and a lower end opposite the upper end, and the planetary axis is inclined inwardly toward the sun's axis when viewed from the bottom up is, and/or the cup holder and
• FIG. 3 shows a front view of the rotating parts and the drive of the planetary ball mill from FIG. 2,
• FIG. 4 shows a partially sectioned front view of the planetary ball mill with an embodiment of the grinding bowl holder and the grinding bowl,
• FIG. 7 like FIG. 6, but with a modified embodiment of the grinding bowl holder or the grinding bowl,
• FIG. 9 shows a front view of the toothed belt drive from FIG. 8,
• FIG. 11 is a view from below of the toothed belt drive from FIG. 10,
• 16 shows an exemplary schematic structural representation of the spatial arrangement of the center planes of a drive pulley and a driven pulley
• Fig. 17 shows a schematic construction illustration like Fig. 16 with construction points A and B for the deflection rollers
• Fig. 18 shows a schematic design representation as in Fig. 17 with a fillet for the deflection roller at design point B,
• Fig. 19 shows a schematic design representation as in Fig. 17 with an additionally designed deflection roller
• Fig. 20 is a schematic construction representation as in Fig. 19 but for a knee-in-knee arrangement.
• Fig. 21 shows a side view of the carrier device of a further embodiment of the planetary ball mill in
• FIG. 22 shows a front view of the rotating parts and the drive of the planetary ball mill from FIG. 21,
• FIG. 23 shows a top view of the rotating parts and the drive of the planetary ball mill from FIG. 21,
• Fig. 24 a complex set toothed belt drive with transmission ratio and linear tensioner
• 26 shows a measured grain size distribution of a PP sample, ground with an embodiment of the cryo planetary ball mill
• the planetary mill or planetary ball mill 1 on a laboratory scale has a device housing 12 with a user interface 14 with a display, eg a touchscreen display. Inside the device housing 12 are the rotating parts of the planetary ball mill 1, such as the carrier device 28 with one or more rotating grinding stations 2 or planets, the motor drive and an electronic control device for controlling the function of the planetary ball mill 1.
• the device housing 12 is with a housing cover 13 can be opened and closed, on the one hand to ensure access to the grinding stations 2 arranged in the housing interior 15 when the carrier device 28 is stationary and, on the other hand, to the housing interior 15 during operation of the planetary mill 1, in which the carrier device 28 rotates and the one or more grinding stations 2 rotate and rotate to lock securely.
• the planetary ball mill 1 is dimensioned as a laboratory device and can be set up with feet 16, for example, on a laboratory bench. Such laboratory planetary ball mills 1 are used in particular for the fine comminution of particularly brittle samples in process analysis.
• the volume of the grinding bowls 64 of the laboratory planetary mill 1 is between 50 ml and 1000 ml, preferably between 80 ml and 500 ml.
• the planetary ball mill 1 has a base plate 18 on which the rotating parts and the drive are mounted and supported.
• a drive motor 22 is mounted on the base plate 18 and drives a main pulley 26 in rotation via a main drive belt 24 .
• the main drive belt 24 can be a V-belt or a V-ribbed belt. Slippage is of secondary importance at the location of the main drive belt 24, so the use of a synchronous belt is not absolutely necessary here, but should not be ruled out either. It is therefore also conceivable that the main drive belt 24 is designed as a toothed belt.
• the main drive pulley 26 is rigidly connected to the support device 28 which carries out the sun's rotation about the sun's axis S .
• the carrier device 28 and the main pulley 26 are mounted in central ball bearings 32 on the central axis 34 .
• the central axis 34 is in turn rigidly connected to the base plate 18 or the device housing 12 .
• the drive motor 22 drives the rotation of the carrier device 28 as a sun element about the fixed central axis 34 via the belt drive 24, 26.
• the drive sprocket 36 is coaxially and rigidly connected to the center axle 34 .
• the toothed belt 38 is driven by the stationary drive sprocket 36 and in turn drives the driven sprocket 42 on the milling station 2.
• the grinding station 2 is entrained by the carrier device 28 to revolve around the central axis 34 or sun axis S and at the same time also rotates around its own axis, the planetary axis P.
• the planetary mill 1 is designed as a planetary mill 1 with non-parallel axes of rotation S and P.
• the output toothed pulley 42 is inclined at an angle to the input toothed pulley 36 or to the center axis 34 and arranged coaxially to the planetary axis P, so that a direct set toothed belt drive 50 with non-parallel input and output axes is formed.
• the output toothed disc 42 which is inclined obliquely to the drive toothed disc 36, has a smaller diameter than the driving toothed disc 36, so that a direct set toothed belt drive 50 with non-parallel input and output axes and an integrated transmission ratio is formed in one and the same direct toothed belt drive 50.
• the toothed belt 38 is also deflected by two toothed deflection rollers 44, 46 and tensioned outwards in order to adapt the obliquity of the toothed belt drive 50 between the drive and driven toothed pulleys 36, 42 arranged obliquely to one another.
• the axes of the deflection rollers 44, 46 run obliquely, more precisely even skewed, both to the drive axis (sun axis S) and to the output axis (planetary axis P), in order to smoothly convert the tangent inlets and tangent outlets of the toothed belt 38 into one another.
• the toothed belt 38 runs crossed in all four runs 52a-d.
• a simple, reliable, inexpensive, smooth-running and low-maintenance drive for a planetary ball mill with a tilted planetary axis can be created with the direct spatial toothed belt drive created in this way for the tilted grinding station 2 or tilted grinding bowl receptacle 62 .
• the embodiment shown in Fig. 2 and 3 is a so-called mono-mill with only a single grinding station 2 or grinding cup holder 62 and a counterweight 63 arranged on the opposite side of the sun axis S.
• the counterweight 63 fixed, but it is expedient to use a counterweight 63 that can be adjusted radially and, if necessary, also axially, in order to increase smooth running.
• the planetary mill 1 is designed as a cryo planetary (ball) mill.
• the cryo-planetary mill 1 has a cooling device 110 with which a cryogenic cooling medium 6, for example liquid nitrogen (LN2), can be dripped directly into the grinding bowl 64 and/or into the grinding bowl receptacle 62.
• the cooling device 110 has a cooling medium reservoir 112, in which a supply quantity of the cryogenic cooling medium 6, for example liquid nitrogen (LN2), can be filled and stored over a certain period of time.
• the cooling medium reservoir 112 may comprise a dewar or other thermally insulating vessel, for example.
• a coolant line 114 leads from the coolant reservoir 112 to a coolant metering opening in the form of a coolant nozzle 116 , from which the cryogenic coolant 6 , in particular liquid nitrogen, is dripped out and into the grinding station 2 .
• the amount of cooling medium 6 can be controlled, for example, with a solenoid valve 118, e.g. controlled or regulated by the control device 4 of the cryogenic planetary mill 1.
• the grinding bowl 64 or the grinding bowl receptacle 62 can have a temperature sensor 122 which transmits the measured temperature data to a radio interface 124 of the control device 4 via a radio link, for example. In this way, an active feedback control loop can be formed for temperature control.
• the user can use the user interface 14 to set a desired cryogenic target temperature, which is actively regulated by the control loop by regulating the amount of liquid nitrogen that has dripped in as a manipulated variable via the solenoid valve 118 .
• the cooling medium outlet or the cooling medium nozzle 116 can, as shown here, be arranged coaxially to the sun's axis, so that the liquid cooling medium 6 drips down coaxially along the sun's axis S due to gravity. Due to the inclination of the planetary axis P relative to the sun axis S, the upper end 62a of the grinding jar receptacle 62 or the upper end 64a of the grinding jar 64 is closer to the sun axis S than the bottom 62b of the grinding jar receptacle or the grinding jar bottom 64b. In the example of FIG.
• the grinding jar 64 has a tubular extension 66 such that the upper end 64a of the grinding jar in the form of the extension 66 intersects the sun's axis S .
• the grinding bowl 64 or the grinding bowl extension 66 has an opening 64c at its upper free end 64a, which also intersects the sun axis S, so that the cooling medium can drip directly vertically through the opening 64c and thus reach the interior 64d of the grinding bowl.
• the grinding bowl 64 has a grinding bowl cover 68 with a central opening 68c, which is in communication with the extension 66 and the upper grinding bowl opening 64c, so that the cooling medium that has dripped into the upper grinding bowl opening 64c reaches the interior 64d of the grinding bowl 64 .
• cryogenic cooling medium which is gaseous or vaporizes at room temperature and normal pressure, and the resulting gas can escape from the grinding bowl 64, depending on the application, other cryogenic cooling media, such as dry ice, are also possible, provided that this is compatible with the materials of the grinding jar, the grinding media (see FIG. 25) and the material to be ground (not shown).
• the embodiment shown there has a closed grinding bowl cover 68 and the communication connection for the supply of the cooling medium leads from the upper opening of the extension tube 66 into a gap 72 between the circumferential radial outer wall 64e of the grinding bowl 64 and the circumferential radial outer wall 62e the grinding cup receptacle 62.
• the gap 72 can also extend into an intermediate space 74 between the grinding cup base 64b and the grinding cup receptacle base 62b.
• the axial opening at the upper end of grinding station 2 or the planet, through which the cooling medium enters grinding station 2 is therefore an axial opening 62c of the grinding bowl receptacle, with opening 62c also intersecting the sun axis S here so that the cooling medium can be dosed or dripped into the grinding bowl receptacle 62 coaxially to the sun axis S perpendicularly.
• the coolant nozzle 116 eccentrically and to spray it obliquely into the opening 62c or 64c with a certain coolant pressure.
• the planetary ball mill 1 can have a camera 76 and/or an infrared sensor 77, which are fastened to the carrier device 28 with a holding device 78 and rotate with the carrier device 28 or the sun disk.
• the camera 76 or the infrared sensor 77 can "look inside" coaxially to the planetary axis P through the upper opening 62c or 64c directly into the grinding bowl 64 or into the grinding bowl receptacle 62, namely continuously during the operation of the planetary mill, i.e. during the rotation of the carrier device 28 and the grinding bowl holder 62.
• the grinding bowl 64 is configured so long axially that it intersects the sun axis S even without an extension 66 in order to be able to drop the cooling medium 6 directly into the interior 64d of the grinding bowl 64 .
• the extension 66 can therefore be dispensed with.
• the grinding bowl 64, with or without the extension 66 has an upper axial opening 64c which intersects the sun axis S and through which the cooling medium can be introduced.
• the grinding jar receptacle 62 can also be made so long that it, or its upper opening 62c, intersects the sun axis S even without an extension 66, in order to direct the cooling medium into the gap 72 between the grinding jar receptacle 62 and the grinding jar 64 carry.
• the grinding bowl cover 68 can either be closed (FIG. 5) or open (FIG. 7).
• a further advantage of the grinding bowl 64 inclined obliquely inwards towards the sun axis S is that it is possible to work with an open grinding bowl 64 at all. Due to the axial tilt of the planet, in which the upper edge 64a of the grinding bowl 64 is closer to the sun axis S than the grinding bowl bottom 64b, the material to be ground and the grinding media cannot leave the grinding bowl 64, as would be the case with an axis-parallel arrangement.
• the grinding sample can be embrittled either in direct contact with the liquid nitrogen (FIGS. 4 and 6) or indirectly via the grinding bowl wall 64e (FIGS. 5 and 7).
• the sample With the grinding jar 64 open and introducing the LN2 directly into the interior 64d of the grinding jar 64, the sample can be cooled down faster and with less use of LN2.
• it can happen that above a certain particle size (the smaller the stronger), the sample particles can be entrained to the outside with the escaping nitrogen. For this reason, too, indirect cooling via the grinding bowl wall 64e (FIGS. 5 and 7) can be advantageous, or if the sample is not to come into direct contact with the liquid nitrogen.
• neither the grinding bowl holder 62 nor the grinding vessel need to be changed to convert from direct to indirect cooling, but a different grinding bowl cover 68 and/or a different extension 66 may be sufficient to cool the grinding bowl from the outside (e.g. Fig. 4 -> 5 ).
• the set toothed belt drive 50 is located below the carrier device 28 and below the grinding bowl holder 62.
• the driven toothed pulley 42 is attached to a lower end 82a of a shaft extension 82, which opens into an upper base plate 84 on the grinding bowl holder side and on which the Grinding bowl receptacle 62 is attached, for example screwed on.
• the entire grinding station 2 or planetary arrangement 90 is rotatably mounted with ball bearings 92 coaxially to the inclined planetary axis P on the carrier device 28. The rotates upwards Grinding bowl holder 62 free.
• the grinding cup holder 62 is only supported at the lower end here.
• exemplary embodiments for the set toothed belt drive with non-parallel input and output axes are shown.
• the drive toothed disc 36, the driven toothed disc 42 and the first and second deflection rollers 44, 46 are each arranged at the free ends 154 of two crossed holding arms 152 of a holding cross 150 and are ball-bearing mounted there.
• the retaining cross 150 is produced by means of a 3D printing process.
• the crossed arms 152 are partially angled to achieve the desired tilt between the sun's S axis and the planetary P axis. In the embodiment illustrated in FIGS.
• the first and second idler pulleys 44, 46 are toothed idler pulleys and tension the toothed belt 38 outwardly. This has the advantage that the strands 52a-d of the toothed belt 38 can be lengthened, so that the twisting of the toothed belt 38 can be reduced. Nevertheless, with reference to FIGS. 10-11, the deflection can also take place with non-toothed deflection rollers 44, 46 on the rear side 38b of the toothed belt 38.
• the inside 38a or inner flat side of the toothed belt 38 is, as usual, toothed transversely with teeth 39, in the present case a commercially available HTD5 toothed belt with standardized non-circular teeth 39 either only on the inner flat side 38a (single toothed belt) or on the inner and outer flat side 38a, 38b (double toothed belt) is used.
• the various toothed belt pulleys or deflection pulleys can be designed with or without flanged pulleys 162 .
• the arrangement and inclination of the first and second deflection rollers 44, 46 is selected in both examples in FIGS. 8-11 in such a way that the tangent inlets and tangent outlets are converted coaxially into one another, as will be explained in more detail below.
• the input axis 136 and the output axis 142 are inclined toward each other at an oblique angle.
• the angle of inclination or inclination o is approximately 35° (cf. also FIG. 3).
• the drive axis 136 corresponds to the sun axis S and the output axis 142 to the planetary axis P. It has been found, however, that such a set spatial toothed belt drive 50 with non-parallel axes 136, 142 and, if necessary, a transmission or reduction +1 is of fundamental importance are and can also be used in other areas of drive technology or generally as a toothed belt drive 50, and not just for a planetary mill 1.
• the drive axis 136 of the drive pulley 36 is perpendicular to the center plane 36a of the drive pulley and the output axis 142 is perpendicular to the center plane 42a of the driven pulley 42.
• the drive axis 136 and the output axis 142 are obliquely below arranged at an oblique angle a + 0 to one another, but lie in a common plane, which is the plane of the paper in the illustration at the top left in FIG. Consequently, in this example, the drive axis 136 and output axis 142 are inclined in space to one another and intersect in a common plane, so they are not skewed to one another.
• the drive axis 136 and the output axis 142 can also be skewed (and not perpendicular), i.e. inclined and skewed to one another in three-dimensional space, i.e. the drive axis 136 and the output axis 142 are not parallel (rather than perpendicular) to each other and do not intersect in three-dimensional space.
• FIG. 15 shows another example in which the drive axis 136 and the output axis 142 run obliquely to one another in a common plane and intersect in the common plane.
• the deflection roller axes 144, 146 are also inclined at an angle to one another.
• the deflection roller axes 144, 146 are not skewed to one another, but also intersect in a common plane, which in the example in FIG.
• the deflection roller axes 144, 146 can also be skewed to one another.
• the deflection roller axes 144, 146 both run skewed and not perpendicular to both the drive axis 136 and the driven axis 142.
• the toothed belt is moved in the four strands 52a , 52b, 52c, 52d is deflected and set in such a way that the tangent outlets and the tangent inlets on the toothed disks or rollers 36, 42, 44, 46 are converted coaxially into one another.
• the tangent outlet 36b on the toothed drive pulley 36 is transferred coaxially into the tangent inlet 44c on the first deflection roller 44 .
• the tangent outlet 44b on the first deflection roller 44 is transferred coaxially into the tangent inlet 42c on the output toothed disc 42 .
• the tangent runout 42b on the output pulley 42 is coaxially transitioned into the tangent inlet 46c on the second idler pulley 46 and the tangent runout 46c on the second idler pulley is coaxially translated into the tangent inlet 36c on the drive pulley 36.
• FIG. 13-15 show further exemplary embodiments of an oblique set spatial toothed belt drive 50 in different arrangements.
• the drive sprocket 36 and the driven sprocket 42 are first placed freely in space at an angle to one another, corresponding to the arrangement of the drive axle 136 and the driven axle 142 desired on the drive side
• the axes 136 and 142 may be skewed in a common plane or skewed and skewed to each other, depending on the application.
• An auxiliary level is then constructed for each deflection of the toothed belt 38 to be created. Referring to FIG. 18, this will be described using point B as an example.
• a surface 174 is spanned by the two "toothed belt beams", which meet at point B.
• the plane constructed in this way then becomes the central plane 46a for the deflection roller 46 to be constructed "Rays" are made, which meet at point B.
• This rounding is to be assumed with the effective circle diameter of the deflection roller 46 to be designed. For this purpose, the diameter of the deflection roller 46 plus twice the distance of the toothed belt back 38b to the toothed belt effective line (neutral fiber) is used.
• This Fillet now represents an axis point of the deflection roller 46 to be designed.
• the center plane 46a on which the axis 146 is perpendicular by definition, and this axis point, the axis position of the deflection roller 46 to be designed is now clearly given.
• the deflection roller 46 can therefore be used accordingly.
• the toothed belt 38 now has optimal tangent inlets 36c, 42c, 44c, 46c and tangent outlets 36b, 42b, 44b, 46b on all toothed discs or deflection rollers 36, 42, 44, 46. It is advantageous that with the deflection rollers 44, 46 the toothed belt twisting in the strands 52a-d can be influenced, in particular reduced.
• the deflection roller 46 moves to the right in the upper right illustration, the two strands 52c, 52d become longer upstream and downward of the deflection roller 46 and in addition, the set in the strands 52c, 52d decreases, both of which are advantageous for the life of the toothed belt 38.
• the offset of each individual strand 52a-d can be kept relatively small and, as described above, can be structurally influenced by the designer within certain limits.
• the designer can construct the skewed set spatial toothed belt drive 50 relatively freely according to the desired geometric drive and output ratios.
• a construction can always be found for the oblique, offset spatial toothed belt drive 50 in which the toothed belt 38 deflects correctly and does not push in one direction at any point, but instead the toothed belt 38 always tends to move in the center planes 36a, 42a, 44a, 46a of the toothed discs or deflection rollers 36, 42, 44, 46 to remain. As a result, it may even be possible to dispense with flanged wheels 162.
• Figs. 15 and 20 It is also possible, as shown in Figs. 15 and 20, for example, to move one of the deflection rollers, in the example the first deflection roller 44, to the toothed belt back 38b and to tension the toothed belt 38 there not outwards but inwards Fig. 20: Construction point A), so that a "knee-in-knee arrangement" is created.
• the deflection rollers 44, 46 can also be used to retension the toothed belt 38, but this is not necessary depending on the application. If this should be desired, one or both deflection rollers 44, 46 can be fastened so that they can be moved and the toothed belt 38 can be tightened by shifting one or both deflection rollers 44, 46. Accordingly, at least one, if necessary both, deflection rollers 44, 46 can each form an adjustable tensioning roller.
• a third and a fourth, ie two further deflection rollers 202, 204 can be inserted in one of the strands.
• the third and fourth idler pulleys 202 , 204 are interposed between the second idler pulley 46 and the drive pulley 36 .
• the second deflection roller 46 and the two additional deflection rollers 202, 204 are arranged with parallel axes and in a common plane. This has the advantage that if a tensioning roller is desired, here e.g. the third deflection roller 202 as a tensioning roller for tensioning in this common plane can be pushed outwards in a straight line without having to change the inclination.
• a planetary ball mill with more than one grinding station 2, ie more than one planet, can also be built with the oblique set spatial toothed belt drive 50.
• the example shown in Figs. 21-23 shows a duo planetary mill 1, in which two grinding stations 2, each with a grinding bowl receptacle 62 with planetary axes P inclined to each other and inclined to the sun axis S are arranged.
• two drive pulleys 36 are fastened to the central sun axis 34, which, as described above, drive the rotation of the grinding stations 2 or grinding bowl receptacles 62 via two independent, oblique, offset spatial toothed belt drives.
• FIG. 25 it can be seen how the camera 76 can be photographed (or filmed) directly into the open grinding bowl 64, for example in the embodiment shown in Fig. 6, during the rotation of the carrier device 28 and the grinding station 2.
• the photo clearly shows how the grinding balls 70 (here in a test run without material to be ground) fly through the grinding bowl 64 with counter-rotating rotation and in the throw regime.
• Such investigations have shown, for example, that comminution with a grinding puck can be particularly effective if the puck rolls on the grinding bowl wall and the sample rotates around it.
• Such photo or film recordings allow unimagined monitoring and investigation possibilities and a profound understanding of the grinding process in a planetary mill 1.
• the curve 192 shows the particle size distribution of a sample of polypropylene pellets (PP) measured with an Analyzette® 22, which was cryogenically ground with a first functional model of the cryo-planetary ball mill 1.
• 27 and 28 show particle size distributions 194, 196 after similar milling, however, with a magnetically driven cryogenic mill or a cryogenic vibratory mill. It is easy to see that with the presently disclosed planetary mill 1 a higher degree of fineness or a significantly better grinding result can be achieved.
• grinding can advantageously be carried out with an open grinding bowl and/or a cryogen can be metered as required, if desired even metered directly into the interior of the grinding bowl.
• a cryogen can be metered as required, if desired even metered directly into the interior of the grinding bowl.
• non-metallic grinding bodies e.g. ceramic grinding balls or agate grinding balls, which can be advantageous for certain samples and is not possible with a magnetically driven mill, for example. If the liquid nitrogen flows around the material to be ground, it can even lead to cryogenic wet grinding - at least temporarily. As a result, the mixing of the ground material can be improved. Furthermore, the formation of agglomerates and/or the adhesion of the material to be ground to the grinding bowl wall can be reduced.
• the grinding volume of the present grinding bowl 64 is greater than or equal to 50 ml, greater than or equal to 100 ml, greater than or equal to 250 ml, greater than or equal to 500 ml, possibly even up to 1000 ml or more.
• a planetary mill 1 or a toothed belt drive 50 is hereby provided which has a number of advantageous technical aspects which can be implemented jointly or independently of one another.
• the toothed belt drive 50 can also be used for other purposes than for a planetary mill 1, for example.
• the planetary mill 1 can be provided with cryogenic cooling, which is able to introduce cooling medium directly into the grinding bowl receptacle 62 or the grinding bowl 64 .
• the grinding bowl 64 can optionally remain open at the top during the grinding process and a cryogen can be metered into the grinding bowl 64 and/or the grinding bowl receptacle 62 and/or the grinding process can be video-monitored during the rotation.
• material to be ground can even be filled or refilled into the grinding bowl 64 while the carrier device 28 and the grinding bowl 64 are rotating.
• the application discloses several aspects of the invention such as e.g during the grinding process in a planetary mill. It can be seen that these aspects of the invention in particular can be implemented both together and separately from one another and entail corresponding advantages.

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• Engineering & Computer Science (AREA)
• Food Science & Technology (AREA)
• Crushing And Grinding (AREA)
• Grinding Of Cylindrical And Plane Surfaces (AREA)
• Transmission Devices (AREA)

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• 2021
  • 2021-10-11 CN CN202180070795.1A patent/CN116438008A/zh active Pending
  • 2021-10-11 WO PCT/EP2021/078048 patent/WO2022078957A2/de unknown
  • 2021-10-11 EP EP21794109.5A patent/EP4228820A2/de active Pending

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