EP3575001B1 - Roller packages for milling devices, milling devices and method - Google Patents

Description

The present invention is concerned with roller assemblies for grinding devices, with grinding devices and with methods for determining the radial force acting between the rollers of a roller assembly.

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

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

In the documents DE 595 934 and DE 597 775 Devices for regulating the contact pressure of grinding rollers are disclosed. These devices contain adjustable springs that allow the grinding rollers to evade when hard foreign bodies pass through them. US 5018960 A , DE 10125378 A1 and DE 524055 C disclose devices for adjusting the grinding gap.

Roll stacks have a certain rigidity, which can be characterized by the dependence of the radial force acting between the rolls and the width of the grinding gap.

This rigidity is made up of the rigidity of the rollers, the roller bearings and the remaining components of the roller set. 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 influence.

In the case of grinding stock that is difficult to pull in between the rollers, the forces in the grinding gap are very variable. If the grist passes the grinding gap, the rollers are pushed apart. If no regrind is drawn in for a short time, the rollers touch. In such a situation, the stiffness of the gap has a major influence on the behavior and properties of the regrind.

It is a first object of the invention to overcome the disadvantages of the known roll packs. In particular, roll 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 the most homogeneous properties possible.

These and other objects are achieved in a first aspect of the invention by a roller set 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 are adjustable 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 pivotably supported on the first bearing body. The first bearing body and the second bearing body can be prestressed against one another by means of a clamping device in such a way 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, wherein the stop surfaces are designed and arranged or can be arranged on the bearing bodies such that contact of the stop surfaces counteracts contact of the rollers. Here and in the following, counteraction does not necessarily mean that contact between the rollers is completely prevented; Such contact is also permitted within the scope of the present invention for very small predetermined grinding gap widths.

Furthermore, the first stop body can be rotated about a first axis of rotation. The first stop surface is formed by a circumferential surface of the first stop body which is eccentric with respect to the first axis of rotation, specifically in such a way that the rotational position of the first stop body determines the minimum width of the grinding gap. The circumferential surface of the first stop body is referred to as eccentric here and below 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 greater than 0 ° and less than 360 ° is not converted into itself.

If the force prevailing in the grinding gap varies in a roller set according to the invention, only the pretensioning force between the bearing bodies changes, but not their relative position. The only flexibility with regard to the grinding gap therefore results from the rollers and bearings. By rotating the first stop body, the properties of the ground material can be set precisely, for example the starch damage, the water absorption and, above all, the particle size distribution of flour (especially if the gap occupancy and thus the splitting force varies due to a fluctuation in the mass flow supplied to the grinding device).

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

The tensioning device can be part of the roll assembly. However, it is preferred if the tensioning device is part of a machine stand of the grinding device and the roller set has a coupling device for releasable coupling with the tensioning device. This facilitates the assembly and disassembly of the roller pack. This coupling enables the clamping device of the machine stand to preload the bearing bodies of the roll assembly. The coupling device can be arranged on one of the bearing bodies.

The circumferential 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 for example have the shape of a spiral, at least in sections. A spiral is understood to mean that the distance between the circumferential 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.

It is advantageous if 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 by one relative to the second Axis of rotation rotationally symmetrical circumferential surface of the second stop body is formed. 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, which results in significantly less friction and consequently the adjustment is made easier. This is important in the context of the present invention, since the stop bodies are preferably pressed against one another with a high preload.

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 rotating the first stop body causes a fine adjustment of the grinding gap, a rough adjustment of the grinding gap can be achieved by moving at least one of the stop bodies.

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

The invention also comprises a method for operating a set of rolls as described above. The method includes a step in which the first bearing body and the second bearing body are preloaded against one another by means of the clamping 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 roller set has a force measuring device which contains a first sensor for determining a first force with which the first bearing body and the second bearing body are preloaded against one another, as well as 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 the direct determination of the forces. Alternatively, at least one of the two sensors can also be designed for indirect determination of 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 for example be integrated in the clamping device. The second sensor can for example be arranged on the second stop body.

The invention also comprises a method for determining the radial force acting between the rollers of such a roller set. The method includes a step in which the force acting between the rollers is calculated from the forces determined by means of the sensors.

In order to display the position of a handwheel as already mentioned above in the simplest possible way (without electronic elements such as gap sensors or encoders), position indicators are used in the prior art. If the operating gap is set as required, the position of the handwheel is referenced by turning the position indicator. In this way, if the grinding gap is to be adjusted, the basic state can be found again in a simple manner. The position indicator is received in the handwheel and, in the prior art, clamped by a radial adjusting screw and thus secured against twisting or slipping out. Another variant is axial clamping to the rear. However, the vibrations that occur during milling operations can significantly impair the position indicator.

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 too weakly tensioned, it loosens, and if it is too tensioned it can break. Attempts have already been made to overcome this problem with special screws. However, such a special screw can get lost. If it is replaced with an ordinary screw, leakage can occur. Another disadvantage is that a tool is required for referencing and that the screws are small and often difficult to access.

To solve this problem, according to a preferred embodiment of the invention, a roller set for a grinding device is proposed, which has a first roller and a second roller as well as a rotary shaft rotatable about a handwheel Contains hand wheel, by means of which a grinding gap formed between the first roller and the second roller can be adjusted, this being a roller set as described above. According to this preferred embodiment it is provided that the roller package has a position indicator for displaying a position of the handwheel and the position indicator contains a position indicator housing and a display element which is movable along the handwheel axis of rotation relative to the position indicator housing and which is pretensioned or biased against the position indicator housing by means of a position indicator spring in the direction of the handwheel axis of rotation It can be pre-tensioned 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 bias caused by the position indicator spring is overcome.

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

In one possible embodiment, the display element and the position display housing have contact surfaces which allow a form fit in the holding position. In this way, the disruptive influences of vibrations can be particularly effectively suppressed during the grinding operation. As an alternative or in addition to the form fit, however, a force fit can also be present in the holding position.

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

The storage of the rollers in roller bearings of the bearing bodies requires the use of lubricants whose uncontrolled escape from the bearings should be prevented. There are sealing systems that are robust against over-lubrication or against harsh installation conditions, but which cannot completely prevent the lubricants from escaping.

In order to enable a controlled discharge of the lubricants, a bearing cover of the roller bearing supporting the roller stub can have on its inside a guide channel for lubricant that runs around the roller stub and is connected to an outlet opening through which lubricant can exit 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 leaked lubricant allows a robust seal structure that is inexpensive and easy to assemble, poses no risk of over-lubrication and at the same time enables 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, in addition to adjusting the gap, there is a manipulated variable to influence the grinding over the length of the roller and to achieve a more even 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 are independent of one another are adjustable and / or the second bearing bodies are adjustable independently of one another.

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 bolt and the pivot bolt is adjustable relative to the first bearing body, for example in the vertical direction. This can be achieved, for example, in that the first bearing body has 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 different from the first direction relative to the first bearing body causes. Alternatively, 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 one as in the international patent application PCT / EP2018 / 061793 disclosed gearbox. In particular, the present invention also includes the fact that the roller set furthermore contains a transmission which comprises a bearing housing in which an input shaft, a first output shaft and a second output shaft are received, 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 each other, the input shaft and the first output shaft are in operative connection with each other via a bevel gear pair, the first output shaft and the second output shaft are in operative connection with each other via a torque transmission arrangement, the first output shaft is coupled to the first roller and the second output shaft with the second roller is coupled.

Another aspect of the invention is a grinding device, for example a milling roller mill, a malt grist mill, a feed mill 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 which is inserted or can be used in the machine stand. This results in the advantages already explained above for the roller set for the grinding device.

As has already been explained above, it is expedient if the machine frame has a clamping device and the roll set has a coupling device for releasable coupling with the clamping device. This is because this facilitates the assembly and disassembly of the roller set.

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 (for example when a foreign body penetrates the grinding gap), relief can be achieved by reducing the pressure in the bellows cylinder by opening the vent valve. The vent valve should be dimensioned accordingly for quick relief.

To enlarge the grinding gap enlargement in the event of an overload, the tensioning device can furthermore have at least one pretensioned spring, in particular connected in series with the cylinder. The pretensioned spring can be a well-known disk spring package.

The tensioning device can contain a tie rod, a tie rod pivotably mounted at a first end of the tie rod, a tie rod partially received in the tie sleeve and pretensioned by means of a spring, and the cylinder which is coupled to a second end of the tie rod. The pull rod can be coupled to a coupling device of the roller set arranged on the second bearing body. In the assembled state of the roller set, the tie rod can be supported 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, whereby the total torque acting on the roller set can be reduced. The tie rod can be swiveled around the support point and thus pull on the tension bushing and on the tie rod. In this way, the first bearing body and the second bearing body can be preloaded 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 one or more rollers of a grinding device have to be replaced, for example for inspection purposes. The rollers can be removed one after the other, or the entire package can be removed. The rollers can be accommodated on the grinding surfaces, on the bearing bodies or on the roller stubs. In the first variant, it is raised by hydraulic lifting tables and then rolled out. When receiving on the bearing bodies, rollers are first mounted, and then the roller set is raised by lowering the rollers and then rolled out on the rollers. Chain hoists can be used to lift them for hanging on the roller stubs and the chain hoists can then be moved in rails. A horizontal mounting on the roller stubs is also possible by attaching rollers to them and moving them in rails. The document EP 1 201 308 A1 further discloses a roller set with integrated rollers which can be set down by means of an eccentric so that the roller set can be raised.

However, all of these methods have disadvantages. For example, in a preparatory step for rolling out the rollers are mounted or at least adjusted. In addition, the lifting of the roller pack is in accordance with EP 1 201 308 A1 quite laborious.

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

With this design according to the invention, the package is not raised during dismantling, but rather is lowered onto the rollers. In addition, the rollers of the roller pack do not rest 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 roll package according to the invention in a disengaged position with part of a tensioning device;

Figure 2:

the roll package according to the invention in an engaged position with the part of the tensioning 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 handwheel and a handwheel gear for fine adjustment of the gap width;

Figure 6:

a detailed view of a position indicator 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 roller set for adjusting the bearing body;

Figure 9:

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

Figure 10:

a perspective view of the roller set with a collecting tray 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 roll pack 10 for a milling roll mill in a side view. The roll package 10 contains a first roll 11, which is held by two first bearing bodies 13, and a second roll 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 pins 57.

The one in the Figures 3a to 3c Milling roller chair 70 shown has a machine stand 71 and two roller packs 10 arranged one above the other and thus in a space-saving manner. Each roller pack 10 can be driven by means of a gear 43 which comprises a bearing housing 44 in which an input shaft (not shown 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 one another, and the first output shaft 46 and the second output shaft 47 are arranged parallel to one another. The input shaft and the first output shaft 46 are operatively connected to one another via a pair of bevel gears, which cannot be seen here, and the first output shaft 46 and the second output shaft 47 are operatively connected to one another via a torque transmission arrangement, which is likewise not shown. The first output shaft is coupled to the first roller 11, and the second output shaft 47 to the second roller 12. For a detailed description of the transmission 43, reference is made to the aforementioned international patent application PCT / EP2018 / 061793 referenced. The gear 43 allows the second roller 12 to be movably supported.

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

In Figure 1 shows a disengaged position of the roller set 10, in which the stop surfaces 18, 20 are not in contact with one another. By means of a clamping device 16, which is part of the machine frame 71 and is only partially shown here, the first bearing body 13 and the second bearing body 14 can be adjusted relative to one another in such a way 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 52 pivotally mounted on an upper end 67 of the tie rod 51 via a joint 54, a tie rod 52 partially received in the tie bush 55 and pretensioned by means of a plate spring assembly 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 tie rod 52 is coupled to the second bearing body 14 by 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 set 10 is installed.

Figure 4 shows a side view of a milling roller frame 70 with the roller set 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 total torque acting on the roller set 10 is reduced. The tie rod 51 is pivoted about the support point 75 and thus pulls on the tension 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 preloaded against each other in such a way that that the first roller 11 and the second roller 12 are pressed towards one another.

The storage via the bellows cylinder 40 causes overload protection. In order to enable immediate relief in the event of an overload (e.g. when a foreign body penetrates the grinding gap), the bellows cylinder is coupled to 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, which, however, would be much smaller than if only one set of springs were present.

In the Figure 2 The illustrated engaged position of the roller set 10 is reached when the stop surfaces 18, 20 come into contact with one another. If the force prevailing in the grinding gap varies, only the pretensioning 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 grinding gap.

In order to be able to roughly set the width of the grinding 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 are displaceable arranged in a direction perpendicular to the axes of rotation A1, A2.

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

The roller set 10 also has a in detail in Figure 6 Position indicator 26 shown for displaying a position of the handwheel 21. The position indicator 26 contains a position indicator housing 27 and a display element 28 which is movable along the handwheel axis of rotation H relative to the position indicator housing 27 27 is preloaded or preloaded so that it can only be rotated about the handwheel axis of rotation H when the preload caused by the position indicator spring 29 is overcome. This is done by positive locking elements 53 on display element 28 and on position display housing 27.

To determine the radial forces prevailing between the rollers 11, 12, the roller set 10 comprises 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 clamping 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 located 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 preloaded against each other, and with the second sensor 25 a second force can be determined, which 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 it is shown in detail how the second bearing bodies 14 are pivotably supported on the first bearing bodies 13 via pivot pins 57. The first bearing bodies 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 individually adjusted relative to the first bearing bodies 13, which enables the roller axes to be tilted.

The Figures 9 and 10 show in detail a roller bearing 58 and its seal. A roller stub 33 of the second roller 12 is supported by an inner ring 59, a plurality of roller bodies 60 and an outer ring 61. In the axial direction thereof there is an inner bearing cover 62 and an outer bearing cover 63, which have grooves 64 running around the roller stub 33 on their inner sides 34 for seals (not shown here) and guide channels 35 for lubricants. Furthermore, there are paragraphs 65 that help the lubricant to be thrown away. The guide channel 35 of the outer bearing cover 63 is connected to an outlet opening 36 through which lubricant can exit from the guide channel 35 of the outer bearing cover 63. Below the outlet opening 36 there is a collecting device 37 for collecting the Lubricant, which is designed in the form of a trough 37. There is a connecting bore, not shown, between the interior space and the guide channel 35 in order to prevent over-greasing and thus excess grease can escape through this connecting bore. As a result, the milling roller chair 70 can be operated hygienically.

How Figure 11 shows, the roll package 10 has an integrated rolling device 30 with rollers 31. The rollers 31 are arranged on the roller set 10 in such a way that the roller set 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 frame 70 according to FIG Figure 12 Rails 72 on which the rollers 31 of the roller set 10 can be moved during the assembly and / or disassembly of the roller set 10. The roll package 10 also has front contact surfaces 76 (see Figure 8 ) and rear contact surfaces 42, and the machine frame 71 has corresponding counter-contact surfaces 73. The contact surfaces 42, 76 and the counter-contact surface 73 are coordinated with one another and with the rails 72 in such a way that the rollers 31 in a mounting position of the roller set 10 due to a form fit between of the contact surface 42, 76 and the mating contact surface 73 do not rest on the rail 72.

Claims (17)

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.
2. Roll assembly (10) according to Claim 1,
   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).
3. Roll assembly (10) according to one of the preceding claims,
   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).
4. 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).
5. 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).
6. Roll assembly (10) according to Claim 4,
   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).
7. 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) .
8. 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).
9. 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.
10. 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).
11. Milling apparatus (70) according to Claim 10,
    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).
12. Milling apparatus (70) according to either of Claims 10 and 11,
    wherein the tensioning device (16) has a cylinder (40), in particular a bellows cylinder (40).
13. Milling apparatus (70) according to one of Claims 10 to 12,
    wherein the tensioning device (16) has at least one pretensioned spring (41) which is in particular connected in series with the cylinder (40) .
14. Milling apparatus (70) according to one of Claims 10 to 13,
    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).
15. Method for determining the radial force acting between the rolls (11, 12) of a roll assembly (10) according to Claim 5, 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).
16. Method for operating a roll assembly (10) according to one of Claims 1 to 9, 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.
17. Method according to Claim 16,
    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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