EP3575001B3 - Roller packages for milling devices, milling devices and method - Google Patents

Description

The present invention relates to roll packs for grinding devices, to grinding devices and to methods for determining the radial force acting between the rolls of a roll pack.

Various types of grinding devices are used for a large number of industrial applications, with which particulate material to be ground is ground. These include, for example, milling roller mills, grist malt mills, feed mills and coffee mills. Such grinding devices contain one or more roller packs, each with at least two rollers. The rollers can be held by a respective bearing body. A grinding gap is formed between the rollers, which can be adjusted in many roller stacks, for example by the bearing bodies being adjustable relative to one another.

The known roller packs are essentially constructed according to the same principle: the width of the grinding gap is reduced by moving the movably mounted roller to an operating gap by a mechanical, pneumatic or electromechanical drive, i. H. "indented". The operating gap can then be adjusted further during operation, for example manually or by motor.

In the documents DE 595 934 and DE 597 775 devices for controlling the contact pressure of grinding rollers are disclosed. These devices contain adjustable springs that allow the grinding rollers to deflect when hard foreign bodies pass through. US5018960A , DE 10125378 A1 and DE 524005 C disclose devices for adjusting the grinding gap.

Roll packs have a certain rigidity, which is determined by the dependency of the radial force acting between the rolls and the width of the grinding gap can be characterized. This rigidity is made up of the rigidities of the rolls, the roller bearings and the remaining components of the roll pack. In the engaged state, the positions of the rollers are therefore dependent on the forces prevailing in the grinding gap. Mainly the radial forces lead to a widening of the grinding gap. As long as the forces are constant, this can be corrected during operation and then has no negative impact.

However, the forces in the grinding gap are very variable for regrind, which is difficult to draw in between the rollers. When the material to be ground passes through the grinding gap, the rollers are pushed apart. If no material to be ground is drawn in for a short time, the rollers touch. In such a situation, the gap stiffness has a major impact on the behavior and properties of the regrind.

A first object of the invention is to eliminate the disadvantages of the known roll packs. In particular, roller packs are to be provided in which the width of the grinding gap remains as constant as possible in order to be able to produce ground material with properties that are as homogeneous as possible.

These and other objects are achieved in a first aspect of the invention by a roller pack for a grinding device according to claim 1, which has a first roller, which is held by at least one first bearing body, and a second roller, which is held by at least one second bearing body. contains. The first bearing body and the second bearing body can be adjusted relative to one another in such a way that a grinding gap formed between the first roller and the second roller can be adjusted. For example, the second bearing body can be pivotally supported on the first bearing body. The first bearing body and the second bearing body can be pretensioned against one another by means of a tensioning device in such a way that that the first roller and the second roller are pressed towards each other.

According to the invention, it is provided that the first bearing body has at least one first stop body with a first stop surface and the second bearing body has at least one second stop body with a second stop surface, the stop surfaces being designed and arranged or can be arranged on the bearing bodies in such a way that contact of the stop surfaces counteracts contact between the rollers. Here and in the following, counteracting is not necessarily understood to mean that contact between the rollers is completely prevented; such contact is also permitted within the scope of the present invention if the grinding gap widths are very small.

Furthermore, the first stop body can be rotated about a first axis of rotation. The first abutment surface is formed by a peripheral surface of the first abutment body that is eccentric with respect to the first axis of rotation, in such a way that the rotational position of the first abutment body determines the minimum width of the milling gap. The peripheral surface of the first stop body is referred to here and below as eccentric if it is not rotationally symmetrical with respect to the first axis of rotation, i.e. if it is caused by a rotation of the first stop body about the first axis of rotation by at least an angle that is greater than 0° and less than 360° is not converted into itself.

If the force prevailing in the refining gap varies in a roller stack according to the invention, only the prestressing force between the bearing bodies changes, but not their relative position. Thus, the only compliance with respect to the refining gap comes from the rollers and bearings. By rotating the first stop body, the properties of the ground material can be set precisely, such as starch damage, water absorption and above all the particle size distribution of flour (especially if the gap occupancy and thus the gap force varies due to a fluctuation in the mass flow fed to the grinding device).

In order to prevent the stop bodies from getting out of contact and the width of the grinding gap becoming too large, the pretensioning force exerted by the clamping device between the stop bodies should be greater than the maximum expected force between the stop bodies, which is due to the forces prevailing in the grinding gap.

The clamping device can be part of the roller pack. However, it is preferred if the clamping device is part of a machine stand of the grinding device and the roller assembly has a coupling device for detachable coupling to the clamping device. This facilitates the assembly and disassembly of the roller pack. Through this coupling, the tensioning device of the machine stand can cause the pretensioning of the bearing bodies of the roll pack. The coupling device can be arranged on one of the bearing bodies.

The peripheral surface of the first stop body can be cylindrical with respect to the first axis of rotation. In the circumferential direction with respect to the first axis of rotation, the circumferential surface can have the shape of a spiral, at least in sections. A spiral means that the distance between the peripheral surface and the first axis of rotation increases or decreases as a function of the angle. The spiral is preferably an Archimedean spiral in which the distance depends linearly on the angle.

Furthermore, according to the invention, the second stop body can be rotated about a second axis of rotation parallel to the first axis of rotation, and the second stop surface can be rotated by a relative to the second Axis of rotation formed rotationally symmetrical peripheral surface of the second stop body. Because when the first stop body is rotated in order to adjust the width of the grinding gap, the peripheral surfaces of the two stop bodies can roll against one another, as a result of which there is significantly less friction and consequently the adjustment is facilitated. This is important in the context of the present invention, since the stop bodies are preferably pressed against one another with a high degree of prestress.

Furthermore, it is expedient if the first axis of rotation of the first stop body and/or the second axis of rotation of the second stop body is arranged to be displaceable, in particular in a direction perpendicular to the first axis of rotation. While turning the first stop body causes a fine adjustment of the milling gap, a coarse adjustment of the milling gap can be achieved by moving at least one of the stop bodies.

The fine adjustment is made even easier if the roller assembly has a handwheel that can be rotated about a handwheel axis of rotation and is coupled to the first stop body via a handwheel gear such that turning the handwheel causes the first stop body to rotate. In a way that is known per se, a gear can be selected in such a way that a comparatively small torque on the hand wheel is translated into a large torque on the first stop body. The handwheel gear should preferably have the highest possible efficiency. A small gear play is also advantageous in order to enable the most precise possible position display on the hand wheel and the most precise possible position of the first stop body. All of this is important within the scope of the present invention, since the stop bodies are preferably pressed against one another with a high degree of pretension. In addition, it is preferred if the hand wheel gear has a plurality of gear inputs, in particular a first gear input for the Hand wheel and a second gear input for motorized adjustability.

The invention also includes a method for operating a roll pack as described above. The method includes a step in which the first bearing body and the second bearing body are pretensioned against one another by means of the tensioning device in such a way that the first roller and the second roller are pressed towards one another.

In order to set the minimum width of the grinding gap, the method can include a further step in which the first stop body is rotated about a first axis of rotation in order to set the minimum width of the grinding gap.

Furthermore, it makes sense if the roll pack has a force measuring device that contains a first sensor for determining a first force with which the first bearing body and the second bearing body are prestressed against one another, and a second sensor for determining a second force between the first stop body and the second stop body acts. One or both sensors can be force sensors for directly determining the forces. Alternatively, however, at least one of the two sensors can also be designed for indirectly determining the forces, for example as a pressure sensor with which a pressure prevailing in a cylinder (in particular in a bellows cylinder explained below) can be determined, from which the associated force can then be determined can. The force acting between the rollers can be calculated from the two forces determined directly or indirectly by the sensors.

The first sensor can be integrated in the clamping device, for example. The second sensor can be arranged, for example, on the second stop body.

The invention also includes a method for determining the radial force acting between the rolls of such a roll stack. The method includes a step in which the force acting between the rolls is calculated from the forces determined by the sensors.

Position displays are used in the prior art in order to display the position of a handwheel as mentioned above in the simplest possible way (without electronic elements such as gap sensors or encoders). When the operating gap is set as desired, the position of the hand wheel is referenced by turning the position indicator. This means that the basic state can easily be found again if the grinding gap needs to be adjusted. The position indicator is accommodated in the hand wheel and, in the prior art, is clamped by a radial adjusting screw and is thus secured against twisting or slipping out. Another variant is axial clamping to the rear. However, the vibrations that occur during grinding operation can significantly affect the position display.

Oil-filled position indicators are more robust in this regard; However, the clamping of the position indicator is even more critical: if the position indicator is not tightly clamped, it will come loose; if it is too tight, it can break. Attempts have already been made to eliminate this problem with special screws. However, such a special screw can get lost. If it is replaced with an ordinary screw, leakage may occur. Another disadvantage is that a tool is required for referencing and that the screws are small and often difficult to access.

In order to solve this problem, according to a preferred embodiment of the invention, a roller pack for a grinding device is proposed which has a first roller and a second roller and a Contains handwheel, by means of which a grinding gap formed between the first roller and the second roller can be adjusted, which is a roller stack as described above. According to this preferred embodiment, it is provided that the roller assembly has a position indicator for indicating a position of the handwheel and the position indicator contains a position indicator housing and an indicator element that can be moved along the axis of rotation of the handwheel relative to the position indicator housing and is prestressed by means of a position indicator spring in the direction of the axis of rotation of the handwheel against the position indicator housing or can be preloaded so that it is secured in a holding position by contact with the position indicator housing against rotation about the handwheel axis of rotation and can only be rotated about the handwheel axis of rotation when the pretension caused by the position indicator spring is overcome.

In order to be able to rotate the display element when referencing, it simply has to be pressed by hand against the preload and can then be rotated. This eliminates the need for the screws and tools mentioned above. In addition, the disturbing influences of vibrations during the grinding operation can be effectively prevented.

In one possible embodiment, the indicator element and the position indicator housing have contact surfaces that allow a form fit in the holding position. As a result, the disturbing influences of vibrations during grinding operation can be suppressed particularly effectively. As an alternative or in addition to the form fit, however, there can also be a force fit in the holding position.

For example, for inspection purposes, it is occasionally necessary to exchange one or more rollers of a grinding device. For this purpose, the set of rollers can have an integrated roller device with at least one roller, which is arranged or can be arranged on the roller pack in such a way that the roller pack with the at least one roller can be placed on a horizontal base and moved thereon.

The storage of the rolls in roller bearings of the bearing body requires the use of lubricants, the uncontrolled escape of which should be prevented from the bearings. There are sealing systems that are robust against overlubrication or against harsh assembly conditions, but which cannot completely prevent the lubricant from escaping.

In order to allow the lubricants to escape in a controlled manner, a bearing cap of the roller bearing supporting the roller stub can have on its inside a guide channel for lubricant which runs around the roller stub and is connected to an outlet opening through which lubricant can escape from the guide channel. A collecting device for collecting the lubricant, for example a collecting container, can be arranged below the outlet opening. The targeted collection of the escaped lubricant allows a robust seal design that is inexpensive and easy to install, does not pose a risk of over-lubrication and at the same time allows hygienic operation of the grinding device.

In order to achieve homogeneous grinding over the entire length of the rollers, the rollers are often cambered. However, if uniform grinding work cannot be achieved over the entire length of the roller, the crowning can be adjusted. By setting the rollers, i.e. tilting the roller axes, a manipulated variable results in addition to the gap adjustment in order to influence the grinding over the roller length and to achieve more uniform grinding. For this purpose it can be provided that the first roller is held by two first bearing bodies, the second roller is held by two second bearing bodies and the first bearing bodies independently of one another are adjustable and / or the second bearing body are independently adjustable.

In one possible embodiment, this can be achieved in that the second bearing body is pivotably supported on the first bearing body via a pivot pin and the pivot pin is adjustable relative to the first bearing body, for example in the vertical direction. This can be achieved, for example, by the first bearing body having a wedge which is designed and arranged in such a way that a displacement of the wedge in a first direction relative to the first bearing body causes a displacement of the pivot pin in a second direction, which is different from the first direction, relative to the causes first bearing body. As an alternative to this, the second bearing body can also be adjustable relative to the first bearing body with the aid of an eccentric.

The roll packs according to the invention are particularly advantageous in connection with a device as described in the international patent application PCT/EP2018/061793 disclosed gear.

In particular, the present invention therefore includes that the roll pack also contains a gear which includes a bearing housing in which an input shaft, a first output shaft and a second output shaft are accommodated, the input shaft and the first output shaft perpendicular to one another and the first output shaft and the second output shaft are arranged parallel to one another, the input shaft and the first output shaft are operatively connected to one another via a pair of bevel gears, the first output shaft and the second output shaft are operatively connected to one another via a torque transmission arrangement, the first output shaft is coupled to the first roller and the second output shaft is coupled to it the second roller is coupled.

A further aspect of the invention is a grinding device, for example a milling roller mill, a grist malt mill, a feed grinder or a coffee grinder. The grinding device contains a machine stand and at least one set of rollers as described above, which is designed according to one of the preceding claims and is used or can be used in the machine stand. This results in the advantages already explained above for the roller stack for the grinding device.

As already explained above, it is expedient if the machine stand has a clamping device and the roll assembly has a coupling device for detachable coupling to the clamping device. This facilitates namely the assembly and disassembly of the roll pack.

To generate the pretension, the tensioning device can have a cylinder, which is preferably designed as a bellows cylinder. It is particularly preferred if the bellows cylinder is coupled to a vent valve. In this way, in the event of an overload (e.g. when a foreign body enters the grinding gap), relief can be achieved by the pressure in the bellows cylinder being released by opening the vent valve. The vent valve should be dimensioned accordingly for rapid relief.

In order to increase the expansion of the grinding gap in the event of an overload, the tensioning device can also have at least one spring which is pretensioned and in particular is connected in series with the cylinder. The preloaded spring can be a known disc spring assembly.

The tensioning device can contain a tie rod, a tie bushing pivotably mounted at a first end of the tie rod, a tie rod partially accommodated in the tie bushing and pretensioned by a spring, and the cylinder which is coupled to a second end of the tie rod. The tie rod can be coupled to a coupling device of the roller pack arranged on the second bearing body. The tie rod can are supported in the mounted state of the roll pack in a support point located between its ends on the bearing body. By activating the cylinder, the second end of the tie rod can be pressed against the first bearing body and supported thereon, as a result of which the overall torque acting on the roll pack can be reduced. The tie rod can be swiveled around the support point and thus pull on the tie bush and the tie rod. In this way, the first bearing body and the second bearing body can be prestressed against one another in such a way that the first roller and the second roller are pressed towards one another.

It has already been mentioned that, for example, one or more rollers of a grinding device have to be exchanged for inspection purposes. The rolls can be removed one at a time, or the entire pack can be removed. The rollers can be mounted on the grinding surfaces, on the bearing bodies or on the roller stubs. In the first variant, lifting takes place using hydraulic lifting tables and then rolling out. When recording on the bearing bodies, rollers are first mounted, and then the roller pack is raised by lowering the rollers and then rolled out on the rollers. For hanging up on the roller stubs, these can be lifted with chain hoists and the chain hoists can then be moved in rails. A horizontal recording on the roll stubs is also possible by attaching rollers to them and moving them in rails. The document EP 1 201 308 A1 also discloses a roller pack with integrated rollers, which can be placed down by means of an eccentric in order to be able to raise the roller pack.

However, all of these methods have disadvantages. For example, the rollers must first be installed or at least adjusted in a preparatory step for unrolling.

In addition, the raising of the roller pack is in accordance with EP 1 201 308 A1 quite difficult.

According to a further preferred embodiment of the invention, these disadvantages are eliminated by a grinding device, in particular a milling roller mill, which contains a machine frame and at least one roller pack with a first roller and a second roller, which is used or can be used in the machine frame, the roller pack being is as described above. The set of rollers has an integrated rolling device with at least one roller, which is arranged or can be arranged on the set of rollers in such a way that the set of rollers with the at least one roller can be placed on a horizontal base and moved thereon. Furthermore, the machine stand has at least one rail on which the at least one roller of the roller pack can be moved during assembly and/or disassembly of the roller pack. Furthermore, the set of rollers has at least one contact surface, and the machine stand has at least one counter-contact surface. The contact surface and the counter-contact surface are matched to one another and to the at least one rail in such a way that the at least one roller of the roller stack does not rest on the rail when the roller stack is in a mounting position due to a positive fit between the contact surface and the counter-contact surface.

Due to this inventive design, the package is not raised during disassembly, but lowered onto the rollers. In addition, the rollers of the roller pack do not lie on the rail in the assembly position, which protects the rollers.

Figur 1:

ein erfindungsgemässes Walzenpaket in einer ausgerückten Stellung mit einem Teil einer Spanneinrichtung;

Figur 2:

das erfindungsgemässe Walzenpaket in einer eingerückten Stellung mit dem Teil der Spanneinrichtung;

Figur 3a:

einen erfindungsgemässen Müllereiwalzenstuhl mit zwei erfindungsgemässen Walzenpaketen in einer perspektivischen Ansicht;

Figur 3b:

den erfindungsgemässen Müllereiwalzenstuhl in einer Seitenansicht;

Figur 3c:

den erfindungsgemässen Müllereiwalzenstuhl in einer Draufsicht;

Figur 4:

einen erfindungsgemässen Müllereiwalzenstuhl mit einem erfindungsgemässen Walzenpaket in einer Seitenansicht;

Figur 5:

eine Detailansicht eines Handrads und eines Handradgetriebes zur Feineinstellung der Spaltbreite;

Figur 6:

eine Detailansicht einer Positionsanzeige zum Anzeigen einer Position des Handrads;

Figur 7:

eine Detailansicht zweier Kraftsensoren zur Bestimmung der zwischen den Walzen wirkenden Kraft;

Figur 8:

eine Detailansicht des Walzenpakets zur Verstellung der Lagerkörper;

Figur 9:

eine Schnittansicht durch ein Wälzlager des Walzenpakets;

Figur 10:

eine perspektivische Ansicht des Walzenpakets mit einer Auffangwanne für Schmiermittel;

Figur 11:

eine Detailansicht einer Rolleinrichtung des Walzenpakets mit Rollen und Kontaktflächen;

Figur 12:

eine Detailansicht des Maschinenständers mit Schienen und Gegenkontaktflächen.

The invention is explained below using an exemplary embodiment and several drawings. show it

Figure 1:

a roller pack according to the invention in a disengaged position with part of a tensioning device;

Figure 2:

the roll pack according to the invention in an engaged position with the part of the clamping device;

Figure 3a:

a milling roller mill according to the invention with two roller packs according to the invention in a perspective view;

Figure 3b:

the milling roller mill according to the invention in a side view;

Figure 3c:

the milling roller mill according to the invention in a plan view;

Figure 4:

a milling roller mill according to the invention with a roller pack according to the invention in a side view;

Figure 5:

a detailed view of a hand wheel and a hand wheel gear for fine adjustment of the gap width;

Figure 6:

a detailed view of a position display for displaying a position of the handwheel;

Figure 7:

a detailed view of two force sensors for determining the force acting between the rollers;

Figure 8:

a detailed view of the roll pack for adjusting the bearing body;

Figure 9:

a sectional view through a roller bearing of the roll pack;

Figure 10:

a perspective view of the roll pack with a drip pan for lubricant;

Figure 11:

a detailed view of a rolling device of the roller pack with rollers and contact surfaces;

Figure 12:

a detailed view of the machine stand with rails and mating contact surfaces.

the figures 1 and 2 show a roller pack 10 for a milling roller mill in a side view. The roller pack 10 contains a first roller 11 which is held by two first bearing bodies 13 and a second roller 12 which is held by two second bearing bodies 14 . The second bearing bodies 14 are pivotably supported on the first bearing bodies 13 via pivot bolts 57 .

The in the Figures 3a to 3c The milling roller mill 70 shown has a machine stand 71 and two roller packs 10 arranged one above the other to save space. Each roller pack 10 can be driven by means of a gearbox 43, which includes a bearing housing 44, in which an input shaft (not visible here), a first output shaft 46 and a second Output shaft 47 are added. The input shaft and the first output shaft 46 are perpendicular to each other, and the first output shaft 46 and the second output shaft 47 are parallel to each other. The input shaft and the first output shaft 46 are operatively connected to one another via a pair of bevel gears (not shown here), and the first output shaft 46 and the second output shaft 47 are operatively connected to one another via a torque transmission arrangement, also not shown. The first output shaft is coupled to the first roll 11, and the second output shaft 47 to the second roll 12. For a detailed description of the transmission 43, reference is made to the international patent application already mentioned PCT/EP2018/061793 referred. The gear 43 allows the second roller 12 to be movably mounted.

The first bearing body 13 also has a first stop body 17, which can be rotated about a first axis of rotation A1, and has a first stop surface 18. This is formed by a circumferential surface 18 of the first stop body 17 that is eccentric with respect to the first axis of rotation A1. The second bearing body 14 has a second stop body 19, which can be rotated about a second axis of rotation A2 parallel to the first axis of rotation A1, and has a second stop surface 20. This is formed by a peripheral surface 20 of the second stop body 19 that is rotationally symmetrical with respect to the second axis of rotation A2. The two stop surfaces 18, 20 are designed and arranged on the bearing bodies 13, 14 in such a way that contact between the stop surfaces 18, 20 counteracts contact between the rollers 11, 12, as will be explained below.

In figure 1 a disengaged position of the roller pack 10 is shown, in which the stop surfaces 18, 20 are not in contact with each other. The first bearing body 13 and the second bearing body 14 can be adjusted relative to one another by means of a clamping device 16, which is part of the machine stand 71 and is only partially shown here, such that a grinding gap formed between the first roller 11 and the second roller 12 can be adjusted. The tensioning device 16 contains a tie rod 51, a tie rod 55 which is pivotably mounted at an upper end 67 of the tie rod 51 via a joint 54, a tie rod 52 which is partially accommodated in the tie rod 55 and is pretensioned by means of a set of disk springs 41, and a bellows cylinder 40 which is connected to a lower End 68 of the tie rod 51 is coupled and only in figure 4 is shown. The pull rod 52 is coupled to the second bearing body 14 with a coupling direction 66 arranged on the second bearing body 14 . The tie rod 51 is supported in a support point 75 on the first bearing body 13, as long as the roller assembly 10 is installed.

figure 4 shows a side view of a milling roller mill 70 with the roller pack 10. By activating the bellows cylinder 40, the lower end 68 of the tie rod 51 is pressed against the first bearing body 13 and supported thereon, whereby the overall torque acting on the roller pack 10 is reduced. The tie rod 51 is pivoted about the support point 75 and thus pulls on the tie bushing 55 and on the tie rod 52 and thus via the coupling device 66 on the second bearing body 14. In this way, the first bearing body 13 and the second bearing body 14 are prestressed against one another in such a way that that the first roller 11 and the second roller 12 are pressed towards each other.

The storage via the bellows cylinder 40 causes an overload protection. In order to enable immediate relief in the event of an overload (e.g. when a foreign body enters the grinding gap), the bellows cylinder is coupled with a sufficiently dimensioned vent valve so that the pressure in the bellows cylinder can be quickly reduced by opening the vent valve. Without opening the vent valve, there would also be an increase in force, but this would be significantly smaller than if only one spring assembly were present.

In the figure 2 shown engaged position of the roll pack 10 is reached when the stop surfaces 18, 20 come into contact with each other. If the force prevailing in the grinding gap varies, only the prestressing force between the bearing bodies 13, 14 changes, but not their relative position. The rotational position of the first stop body 17 determines the minimum width of the milling gap.

In order to be able to roughly set the width of the milling gap, the first axis of rotation A1 of the first stop body 17 and the second axis of rotation A2 of the second stop body 19 can be displaced arranged in a direction perpendicular to the rotation axes A1, A2.

The roller stack 10 also has a handwheel 21 that can be rotated about a handwheel axis of rotation H for fine adjustment of the width of the grinding gap. The handwheel 21 is an in figure 5 illustrated hand wheel gear 22 is coupled to the first stop body 17 . It is designed in such a way that turning the hand wheel 21 causes the first stop body 17 to turn. As a result, a comparatively small torque on the hand wheel 21 can be translated into a large torque on the first stop body 17 . The hand wheel gear 22 has a high degree of efficiency and a small gear backlash for the purposes mentioned above.

The roller pack 10 also has a detailed in figure 6 Position indicator 26 shown for indicating a position of the handwheel 21. The position indicator 26 contains a position indicator housing 27 and an indicator element 28 that can be moved along the handwheel axis of rotation H relative to the position indicator housing 27. The indicator element 28 is by means of at least one position indicator spring 29 in the direction of the handwheel axis of rotation H against the position indicator housing 27 is pretensioned or can be pretensioned in such a way that it can be rotated about the handwheel axis of rotation H only when the pretension caused by the position indicator spring 29 is overcome. This is done by form-fitting elements 53 on the display element 28 and on the position indicator housing 27.

In order to determine the radial forces prevailing between the rollers 11 , 12 , the roller assembly 10 includes a force measuring device which contains a first force sensor 24 and a second force sensor 25 . The first force sensor 24 is integrated in the tensioning device 16, namely in the area of the joint 54 formed between the tie rod 51 and the tie rod 52; the second force sensor 25 is on the second Stop body 19 (see figure 7 ). As a result, a first force can be determined with the first sensor 24, with which the first bearing body 13 and the second bearing body 14 are prestressed against one another, and with the second sensor 25, a second force can be determined, which acts between the first stop body 17 and the second Stop body 19 acts. The force acting between the rollers 11, 12 can be calculated from these forces.

In figure 8 shows in detail how the second bearing bodies 14 are pivotably supported on the first bearing bodies 13 via pivot bolts 57 . The first bearing body 13 each contain a wedge 39 through which an adjusting screw 56 is guided. Turning the adjusting screw 56 causes a displacement of the wedge 39 in a horizontal first direction R1 and thus a displacement of the pivot pin 57 and the second bearing body 14 in a second direction R2 vertical to the first direction R1. In this way, the second bearing bodies 14 can be adjusted individually relative to the first bearing bodies 13, which allows the roller axes to tilt.

the figures 9 and 10 show in detail a roller bearing 58 and its seal. A roll stub 33 of the second roll 12 is supported by an inner ring 59 , a plurality of rolling elements 60 and an outer ring 61 . In the axial direction of this are an inner bearing cap 62 and an outer bearing cap 63, which have on their inner sides 34 the roll stub 33 circumferential grooves 64 for seals and guide grooves 35 for lubricant (not shown here). Paragraphs 65 are also present, which support the slinging away of the lubricant. The guide channel 35 of the outer bearing cap 63 is connected to an outlet opening 36 through which lubricant can escape from the guide channel 35 of the outer bearing cap 63 . Below the outlet opening 36 there is a collecting device 37 for collecting the Lubricant, which is in the form of a trough 37. There is a connecting bore, not shown, between the inner space and the guide channel 35 in order to prevent over-greasing and to allow excess grease to escape through this connecting bore. As a result, the milling roller mill 70 can be operated hygienically.

As figure 11 shows, the roller pack 10 has an integrated rolling device 30 with rollers 31 . The rollers 31 are arranged on the roller pack 10 in such a way that the roller pack 10 with the rollers 31 can be placed on a horizontal base (not shown here) and can be moved thereon. The machine stand 71 of the milling roller mill 70 has according to figure 12 Rails 72 on which the rollers 31 of the roll pack 10 can be moved during assembly and/or dismantling of the roll pack 10. The roll pack 10 also has front contact surfaces 76 (see FIG figure 8 ) and rear contact surfaces 42, and the machine stand 71 has corresponding mating contact surfaces 73. The contact surfaces 42, 76 and the mating contact surface 73 are matched to one another and to the rails 72 in such a way that the rollers 31 in a mounting position of the roller stack 10 due to a form fit between the contact surface 42, 76 and the counter-contact surface 73 do not rest on the rail 72.

Claims (16)

1. Roll assembly (10) for a milling apparatus (70), comprising a first roll (11), which is held by at least one first bearing body (13), and a second roll (12), which is held by at least one second bearing body (14),

   wherein the first bearing body (13) and the second bearing body (14) are adjustable relative to one another in such a way that a milling gap formed between the first roll (11) and the second roll (12) is adjustable,

   wherein the first bearing body (13) and the second bearing body (14) can be pretensioned with respect to one another by means of a tensioning device (16) in such a way that the first roll (11) and the second roll (12) are pressed towards one another, characterized in that

   - the first bearing body (13) has at least one first abutment body (17) with a first abutment surface (18), and the second bearing body (14) has at least one second abutment body (19) with a second abutment surface (20),

   - the abutment surfaces (18, 20) are formed and are or can be arranged on the bearing bodies (13, 14) in such a way that a contact of the abutment surfaces (18, 20) counteracts a contact of the rolls (11, 12),

   - the first abutment body (17) is rotatable about a first axis of rotation (A1), and the first abutment surface (18) is formed by a circumferential surface (18) of the first abutment body (17) that is eccentric with respect to the first axis of rotation (A1), with the result that the rotational position of the first abutment body (17) determines the minimum width of the milling gap, and wherein the second abutment body (19) is rotatable about a second axis of rotation (A2) which is parallel to the first axis of rotation (A1), and the second abutment surface (20) is formed by a circumferential surface (20) of the second abutment body (19) that is rotationally symmetrical with respect to the second axis of rotation (A2).
2. Roll assembly (10) according to claim 1,
   wherein the first axis of rotation (A1) of the first abutment body (17) and/or the second axis of rotation (A2) of the second abutment body (19) are/is arranged displaceably, in particular in a direction perpendicular to the first axis of rotation (A1).
3. Roll assembly (10) according to one of the preceding claims,
   wherein the roll assembly (10) has a handwheel (21) which can be rotated about a handwheel axis of rotation (H) and which is coupled via a handwheel gear mechanism (22) to the first abutment body (17) in such a way that a rotation of the handwheel (21) causes a rotation of the first abutment body (17).
4. Roll assembly (10) according to one of the preceding claims,
   wherein the roll assembly (10) has a force-measuring device which comprises:

   - a first sensor (24) for directly or indirectly determining a first force with which the first bearing body (13) and the second bearing body (14) are pretensioned with respect to one another;

   - a second sensor (25) for directly or indirectly determining a second force with acts between the first abutment body (17) and the second abutment body (19).
5. Roll assembly (10) according to Claim 3,
   characterized in that
   the roll assembly (10) has a position indicator (26) for indicating a position of the handwheel (21), and the position indicator (26) comprises a position indicator housing (27) and an indicator element (28) which is movable along the handwheel axis of rotation (H) relative to the position indicator housing (27) and which is or can be pretensioned by means of a position indicator spring (29) in the direction of the handwheel axis of rotation (H) with respect to the position indicator housing (27) in such a way that it can be rotated about the handwheel axis of rotation (H) only upon overcoming the pretensioning brought about by the position indicator spring (29).
6. Roll assembly (10) according to one of the preceding claims,
   wherein the roll assembly (10) has an integrated rolling device (30) having at least one roller (31) which is or can be arranged on the roll assembly (10) in such a way that the roll assembly (10) can be placed onto a horizontal base and moved thereon by means of the at least one roller (31) .
7. Roll assembly (10) according to one of the preceding claims,
   wherein at least one of the bearing bodies (13, 14) has a rolling bearing (58) which supports a roll stub (33) of one of the rolls (11, 12), wherein a bearing cover (63) of the rolling bearing (58) has on its inner side (34) a guide channel (35) for lubricant that extends around the roll stub (33) and is connected to an outlet opening (36) through which lubricant can exit the guide channel (35).
8. Roll assembly (10) according to one of the preceding claims
   wherein the first roll (11) is held by two first bearing bodies (13), the second roll (12) is held by two second bearing bodies (14), and the first bearing bodies (13) are adjustable independently of one another and/or the second bearing bodies (14) are adjustable independently of one another.
9. Milling apparatus (70), in particular a mill roll frame (70) comprising a machine stand (71) and at least one roll assembly (10) according to one of the preceding claims that is or can be inserted in the machine stand (71).
10. Milling apparatus (70) according to Claim 9,
    wherein the machine stand (71) has a tensioning device (16), and the roll assembly (10) has a coupling device (66) which is arranged in particular on the second bearing body (14) and intended for releasably coupling the roll assembly (10) to the tensioning device (16).
11. Milling apparatus (70) according to either of Claims 9 and 10,
    wherein the tensioning device (16) has a cylinder (40), in particular a bellows cylinder (40).
12. Milling apparatus (70) according to one of Claims 9 to 11,
    wherein the tensioning device (16) has at least one pretensioned spring (41) which is in particular connected in series with the cylinder (40) .
13. Milling apparatus (70) according to one of Claims 9 to 12,

    wherein the roll assembly has an integrated rolling device (30) having at least one roller (31) which is or can be arranged on the roll assembly (10) in such a way that the roll assembly can be placed onto a horizontal base and moved thereon by means of the at least one roller (31),
    and

    the machine stand (71) has at least one rail (72) on which the at least one roller (31) of the roll assembly (10) is movable during mounting and/or demounting of the roll assembly (10), the roll assembly (10) has at least one contact surface (42, 76) and the machine stand (71) has at least one counter-contact surface (73), and the contact surface (42, 76) and the counter-contact surface (73) are tailored to one another and to the at least one rail (72) in such a way that, in a mounted position of the roll assembly (10), by virtue of at least one form-fitting engagement between the at least one contact surface (42, 76) and the at least one counter-contact surface (73), the at least one roller (31) of the roll assembly (10) does not lie on the rail (72).
14. Method for determining the radial force acting between the rolls (11, 12) of a roll assembly (10) according to Claim 4, comprising a step in which the force acting between the rolls (11, 12) is calculated from the forces determined by means of the sensors (24, 25).
15. Method for operating a roll assembly (10) according to one of Claims 1 to 8, comprising a step in which the first bearing body (13) and the second bearing body (14) are pretensioned with respect to one another by means of the tensioning device (16) in such a way that the first roll (11) and the second roll (12) are pressed towards one another.
16. Method according to Claim 15,
    wherein the method comprises a further step in which the first abutment body (17) is rotated about a first axis of rotation (A1) in order to set the minimum width of the milling gap.

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