DEVICE FOR REFINING A FIBER PULP SUSPENSION

Abstract

DEVICE FOR REFINING A FIBER PULP SUSPENSION. The present invention relates to a refiner for refining pulps, comprising a shaft (1), a rotor disc (2) firmly fixed to the shaft (1) and a shaft bearing (3), the rotor disc (2) being disposed between two stator discs (4, 5) and forming a refining chamber (6) between the rotor disc (2) and the stator discs (4, 5), where the shaft (1) is movable in the axial direction (7). It is characterized in that the shaft bearing (3) is hydraulically connected to the refining chamber (6). The system ensures low wear on the rotor and stator discs and, in particular, on the refining plates of these discs - also in continuous operation.

Description

1 / 16 Descriptive Report of the Invention Patent for a DEVICE FOR REFINING A FIBER PULP SUSPENSION.

[0001] The invention relates to a refiner for refining pulps in a fiber pulp suspension, comprising a shaft, a rotor disc firmly fixed to the shaft, and a shaft bearing, the rotor disc being disposed between two stator discs and forming a refining chamber between the rotor disc and the stator discs, the shaft being movable in the axial direction, at least one stator disc being sliding in the axial direction, the size of the refining chamber being adjustable by means of the spacing between the stator discs and the rotor disc being movable between the stator discs, moving the shaft in the axial direction.

[0002] The refiners – or rather, the double-disc refiners described – are known with different designs. Typically, a rotor disc rotates between two stationary stator discs, the rotor disc and the stator discs being equipped with refining plates. The pulp in suspension is refined in the refining chamber between the rotor disc and the stator discs. Uniform distribution of the refining pressure in the refining chamber, and therefore in the area between the rotor disc and the first stator disc, as well as in the area between the rotor disc and the second stator disc, is essential. To this end, the rotor must be movable in the axial direction. Several solutions are known in the state of the art.

[0003] For example, DE 20 2006 002 999 U1 describes a disc refiner for refining a pulp material. The details of the rotor and stator are described, the rotor having a support disc that can be displaced on the rotor axis in the axial direction, for example, by means of an axial tooth. The support disc, and therefore the entire rotor, can be freely aligned in the axial direction. It is explained that it also Petition 870220061860, dated 07 / 13 / 2022, page 7 / 40 2 / 16 It can also be advantageous if the rotor itself can be moved in the axial direction.

[0004] The object of the invention is a refiner with reduced wear on the rotor and stator discs and, in particular, on the refiner plates of these discs.

[0005] According to the invention, this is achieved insofar as the shaft bearing is hydraulically connected to the refining chamber. In this case, hydraulically connected means that a fluid – preferably water – can be transferred between the shaft bearing and the refining chamber. As a result, continuous flow filaments of the fluid – hydraulically speaking – can be shown or are present between the shaft bearing and the refining chamber. Surprisingly, it appears that the shaft can be moved particularly smoothly in the axial direction if the shaft bearing is hydraulically connected to the refining chamber according to the invention. In particular, this smooth movement is also retained when the refiner is in operation.The smooth axial movement of the shaft, and therefore of the rotor disc firmly fixed to the shaft, is an essential prerequisite for the pulp present in a suspension to be uniformly refined in the refining chamber, i.e., in the area between the rotor disc and the first stator disc and in the area between the rotor disc and the second stator disc, as the refining pressure is uniformly distributed in the refining chamber. The uniform distribution of refining pressure results here from the autonomous and smooth positioning of the rotor disc between the stator discs. Any resistance to positioning, for example, by friction, is conducive to an uneven distribution of refining pressure, thus directly promoting uneven pulp refining and uneven wear of the rotor discs and stator discs; this wear affects the refining plates in the rotor disc and stator discs in particular. According to the invention, the firm connection... Petition 870220061860, dated 07 / 13 / 2022, page 8 / 40 A 3 / 16 distance between the rotor disc and the shaft means that there is no axial mobility between the shaft and the rotor disc and therefore no relative movement in the axial direction between the shaft and the rotor disc. However, the connection between the rotor disc and the shaft can, of course, be designed to be detachable, which may be important for service and installation purposes.

[0006] A favorable embodiment of the refiner is characterized by the fact that the rotor disc is firmly fixed to the shaft inside or outside the shaft bearing. Therefore, the shaft is supported on both sides of the rotor disc or has a swing arrangement. Supporting the refiner shaft on both sides of the rotor disc allows for a uniform and distributed bearing load, but it is not a very compact design, as the shaft is supported on both sides of the rotor disc. If you have a suspended arrangement, the rotor shaft is firmly fixed to the shaft at one end of the shaft and the rotor disc is outside the shaft bearing. At a second end of the shaft, the shaft is connected to a motor through a coupling, the coupling being outside the shaft bearing. Advantageously, the arrangement of the rotor disc together with the hydraulically connected shaft bearing according to the invention allows for a very compact design.

[0007] An advantageous embodiment of the refiner is characterized by the fact that the shaft is supported entirely on fluid-lubricated sliding bearings. This allows for particularly smooth movement of the shaft in the axial direction of the shaft. If the shaft is supported on both sides of the rotor disc, only fluid-lubricated sliding bearings are arranged on both sides of the rotor disc. If the shaft is supported in a swing arrangement, one end of the shaft is firmly fixed to the rotor disc and the shaft is supported entirely on fluid-lubricated plain bearings. Petition 870220061860, dated 07 / 13 / 2022, page 9 / 40 4 / 16 of the shaft bearing is arranged between the rotor disc and a second end of the shaft. Another favorable embodiment of the refiner is characterized by the fact that the shaft bearing is designed as a fluid-lubricated sliding bearing, where a fluid, preferably water, can be fed into the refining chamber through the shaft bearing. The design as a water-lubricated sliding bearing is particularly advantageous. According to the hydraulic connection between the shaft bearing and the refining chamber, as described in the invention, water can be fed into the refining chamber through the water-lubricated sliding bearing. Using water as a fluid means that it is possible to support the shaft without using oil, thus excluding the risk of the pulp suspension being contaminated with oil, or rather, with hydraulic oil.Forced orientation is particularly advantageous for ensuring that the direction of fluid flow – preferably water – passes through the water-lubricated plain bearing into the refining chamber. This type of forced orientation can be easily achieved if the fluid in the shaft bearing has a higher pressure than the fiber pulp suspension in the refining chamber in the area where the fluid enters the refining chamber. Due to the higher fluid pressure in the shaft bearing, the fluid flows in the direction of the refining chamber, which has the advantage of effectively preventing the shaft bearing, or rather the water-lubricated plain bearing, from being contaminated. Thus, the water-lubricated plain bearing is always washed in the direction of the refining chamber, and the shaft maintains its smooth mobility during operations.If the refiner shaft is supported on both sides of the rotor disc, the shaft bearing is designed as a sliding bearing lubricated with fluid on both sides of the rotor disc, where a fluid, preferably water, can be fed into the refining chamber through the shaft bearing. Petition 870220061860, dated 07 / 13 / 2022, p. 10 / 40 5 / 16

[0008] Another favorable embodiment of the refiner is characterized by the fact that a seal is disposed between the refining chamber and the shaft bearing. The shaft bearing is designed as a fluid-lubricated plain bearing, where a fluid, preferably water, can be fed through the shaft bearing via the seal to the refining chamber. An advantageous design of the seal comprises a rotary shaft seal or a throttle ring. For example, the seal is disposed between the shaft and the bearing housing, placed in a recess in the bearing housing and secured to the bearing housing by a retaining ring. The shaft passes through the seal, the seal contacts the shaft if it is a rotary shaft seal, and a gap is formed between the shaft and the seal if it is a throttle ring. It is advantageous if the seals have at least one sealing edge.

[0009] An advantageous embodiment of the refiner is characterized by the fact that the sealing effect of the seal depends on the direction of fluid flow. Rotary shaft seals or throttle rings are seals of this type. The flow direction-dependent sealing effect can be achieved if the fluid, or rather the fluid pressure, lifts the seal from the sealing surface and / or the seal provides a larger flow cross-section for the fluid when, for example, the fluid flows from the shaft seal to the refining chamber. When the seal lifts from the sealing surface and / or the fluid flow cross-section is increased, the sliding friction, in particular between the seal and the sealing surface, is prevented or reduced, increasing the smooth movement of the shaft in the axial direction of the shaft. The seal is advantageously designed with a sealing edge, the sealing edge having a truncated conical shape in order to create a sealing effect that depends on the flow direction.In order to create a seal towards the rotating axis, for example, between the rollers. Petition 870220061860, dated 07 / 13 / 2022, page 11 / 40 6 / 16 In the shaft and refining chamber, a seal with a truncated cone-shaped sealing edge can be arranged in such a way that the shaft moves within the seal, the axial direction of the shaft and the axis of the truncated cone-shaped sealing edge coincide with each other. In a first example, the seal would be mounted in the bearing housing and the truncated cone-shaped sealing edge would be pressed onto the shaft. Then, the fluid flowing from the base to the imaginary tip of the truncated cone-shaped sealing edge would cause the sealing edge to expand and the seal to lift off the shaft, or at least reduce the pressure force of the seal, which is important for sealing and sliding friction, against the sliding surface, or rather, against the shaft.If the flow direction in this first example is reversed—that is, the fluid flows from the imaginary tip of the cone to the base of the truncated cone-shaped sealing edge—the fluid would press the sealing edge against the shaft and increase the sealing edge's pressure force. In a second example, the sealing edge would be mounted on the shaft, for example, and the truncated cone-shaped sealing edge would be facing the bearing housing. If the fluid flows from the base to the imaginary tip of the truncated cone-shaped sealing edge, this would cause the base surface to expand, thus increasing the sealing edge's pressure force and increasing the sealing effect towards the bearing housing. Seals with a sealing effect that depends on the fluid flow direction are advantageous because the seal can achieve very little or no friction losses if the fluid flows in the desired flow direction.However, the best possible seal is obtained if the flow direction is reversed, and any fluid flow in the opposite direction to the desired one is reduced or avoided.

[0010] An equally favorable refiner design is characterized Petition 870220061860, dated 07 / 13 / 2022, page 12 / 40 7 / 16 of this is due to the fact that the seal has a smaller sealing effect if the fluid flows through the shaft seal into the refining chamber than if the fluid flows out of the refining chamber into the shaft seal. Seals with a sealing effect that depends on the direction of fluid flow are advantageous because they allow very little or no friction loss through the seal if the fluid flows in the desired flow direction out of the shaft seal and into the refining chamber. If the flow direction is reversed, this behavior is advantageous because the best possible seal is required if the fluid flows out of the refining chamber and into the shaft seal, particularly to prevent the fiber pulp suspension from flowing out of the refining chamber and into the shaft seal, thus contaminating the shaft seal with the pulp.

[0011] Another favorable embodiment of the refiner is characterized by the fact that a damping element is attached to the shaft bearing, the damping element being disposed between the rotor disc and a motor, preferably between the rotor disc and a coupling, the coupling being disposed between the rotor disc and the motor. The bearing according to the invention allows such smooth movement of the shaft in the axial direction that the abrupt and jerky movements of the shaft that may occur during operation are avoided. For example, when the feeding of the fiber pulp suspension to the refiner begins, there may be a resultant force acting on the rotor disc and therefore on the shaft that causes a jerky movement of the shaft. Similarly, there may also be a resultant force acting on the rotor disc or on the shaft during operation. The coupling may provide a slight damping effect, for example, by the action of friction in the coupling.However, this is not enough, therefore, it is advantageous to include a damping element to ensure uniform shaft movements in the axial direction. Petition 870220061860, dated 07 / 13 / 2022, page 13 / 40 8 / 16

[0012] An advantageous embodiment of the refiner is characterized by the fact that the damping elements are hydraulically connected to the shaft bearing. The damping element comprises a damping area, for example, and a throttling element. The throttling element may be a throttling ring, for example, disposed between the shaft and the bearing housing and extensively covering the space between the shaft and the bearing housing. The damping area is formed, for example, by an area between the shaft, the bearing housing and the throttling element, the damping area being disposed between the shaft bearing and the coupling.Here, the damping element is hydraulically connected to the shaft bearing; that is, the fluid – preferably water – that can be fed to the shaft bearing is also fed to the damping element, where continuous flow filaments of fluid can be introduced between the shaft bearing (i.e., the fluid feed to the shaft bearing) and the damping element. If the shaft moves in the axial direction, the volume of the damping area changes, with fluid flowing into the damping area through the accelerator element if the volume increases, and out of the damping area through the accelerator element if the volume decreases. This results in a damping effect according to the viscosity losses of the fluid as it passes through the damping element. It is advantageous to place the damping element between the bearing and the coupling because there is no hydraulic influence on the seal when the bearing is placed between the seal and the damping element.

[0013] An equally advantageous embodiment of the refiner is characterized by the fact that the fiber pulp suspension can be fed into the refining chamber through an inlet area or through the shaft. This advantageous bearing allows diameters of ei Petition 870220061860, dated 07 / 13 / 2022, p. 14 / 40 9 / 16 xo which can be used to feed the fiber pulp suspension through the shaft in the refining chamber, and larger shaft diameters can also be implemented in a technically feasible way, unlike when using conventional antifriction bearings.

[0014] Another advantageous embodiment of the refiner is characterized by the fact that the rotor disc contains openings; these openings provide a uniform distribution of the fiber pulp suspension in the refining chamber, which can be fed through the inlet area or the shaft. Advantageously, the fiber pulp suspension is fed to the refiner on one side of the rotor disc, with the fiber pulp suspension being guided directly to a first opening between a first stator disc and the rotor disc. The cellulose fiber pulp suspension can also be fed through the openings of the rotor disc to the second side of the rotor disc, where the fiber pulp suspension can be guided to a second opening between a second stator disc and the rotor disc.

[0015] An advantageous embodiment of the refiner is characterized by the fact that the shaft is connected via a coupling to a motor, where the movement of the shaft in the axial direction can be absorbed by the coupling. As the motor is rigidly arranged and the shaft is advantageously movable in the axial direction, any relative movement in the axial direction between the shaft and the motor can be absorbed through the coupling.

[0016] A particularly advantageous embodiment of the refiner is characterized by the fact that the coupling is designed as a curved tooth coupling and radial and / or axial movement of the shaft is possible in the curved tooth coupling. Here, the shaft is connected to the motor with external teeth in the coupling area and through an intermediate coupling piece with internal teeth. When maintenance is required, very good access is obtained. Petition 870220061860, dated 07 / 13 / 2022, page 15 / 40 10 / 16 to the refiner disassembling the intermediate piece. Curved tooth couplings allow the shaft to move in both the radial and axial directions. Furthermore, curved tooth couplings allow the outer tooth of the shaft and the inner tooth of the intermediate coupling piece to oscillate as the shaft rotates, with permanent sliding friction between the teeth. Thus, there is no initial static friction in the coupling if there is relative axial movement between the shaft and the motor during shaft rotation because there is always sliding friction in the coupling between the teeth. As a result, particularly smooth shaft movement in the axial direction is possible.

[0017] The invention will now be described using the examples in the drawings.

[0018] Figure 1 shows a refiner according to the state of the art.

[0019] Figure 2 shows a refiner according to the invention.

[0020] Figure 3 shows details of the shaft bearing according to the invention.

[0021] Figures 4a and 4b show advantageous seals.

[0022] Figure 1 shows a refiner according to the state of the art. Here, a rotor disc 2 is arranged on a shaft 1 in a housing 19, the rotor disc 2 being movable in the axial direction 7 relative to shaft 1. The fiber pulp suspension is fed to the refiner 17 through an inlet area 12 and is distributed in the refining chamber 6 through openings 13 (not shown) in the rotor disc 2. Here, the fiber pulp suspension is refined in a first refining space between the rotor disc 2 and the first stator disc 4, and in a second refining space between the rotor disc 2 and the second stator disc 5, and leaves the refiner 17 through the outlet area 18. Interchangeable refining plates are arranged in the rotor disc 2 and in the discs 19 and 19. Petition 870220061860, dated 07 / 13 / 2022, p. 16 / 40 11 / 16 stator discs 4, 5. The second stator disc 5 can be moved axially by means of an adjustment device 20, and the spacing between stator discs 4, 5 and between rotor disc 2 and stator discs 4, 5, respectively, can be adjusted. The axial movement of rotor disc 2 on the shaft allows autonomous centering of rotor disc 2 between the two stator discs 4, 5, where comparable refining gaps are formed. This refiner design 17 does not provide for any movement of shaft 1 in the axial direction 7, the shaft bearing 3 being designed as an antifriction bearing. The shaft bearing 3 and the refining chamber 6 are clearly separated. The antifriction bearings are oil lubricated. A seal 8 seals outside the refining chamber 6 and the inlet area 12 towards shaft 1.The design must prevent any oil from entering refining chamber 6, and no fiber pulp suspension must be able to enter the oil circulation system for the antifriction bearing.

[0023] Figure 2 shows a refiner in a radial load arrangement. Here, a rotor disc 2 is arranged on a shaft 1 in a housing 19, the rotor disc 2 being firmly fixed to the shaft 1 and the shaft 1 being movable in the axial direction 7. The fiber pulp suspension is fed to the refiner 17 through an inlet area 12 and is distributed into the refining chamber 6 through openings 13 (not shown) in the rotor disc 2. Here, the fiber pulp suspension is refined in a first refining space between the rotor disc 2 and the first stator disc 4 and in a second refining space between the rotor disc 2 and the second stator disc, 5 and leaves the refiner 17 through the outlet area 18. Interchangeable refining plates are arranged on the rotor disc 2 and the stator discs 4, 5.The second stator disc 5 can be moved in the axial direction by means of an adjustment device 20, and the spacing between the stator discs 4, 5 and between the rotor disc 2 and the stator discs 4, 5, respectively, can be. Petition 870220061860, dated 07 / 13 / 2022, page 17 / 40 12 / 16 adjusted. The axial movement of shaft 1 and therefore of rotor disc 2 firmly fixed to shaft 1 allows autonomous centering of rotor disc 2 between the two stator discs 4, 5, with the formation of comparable refining gaps. According to the movement of shaft 1 in the axial direction 7, shaft 1 is connected to a motor 10 (not shown) through a coupling 11, the coupling 11 being capable of absorbing the movement of shaft 1 in the axial direction 7. Shaft 1 is mounted in a swing arrangement by means of a shaft bearing 3, the rotor disc 2 being disposed outside the shaft bearing 3. According to the invention, the shaft bearing 3 is hydraulically connected to the refining chamber 6. Here, the shaft bearing 3 is designed as a fluid-lubricated bearing 23, where a fluid – preferably water – serves as a lubricant in the shaft bearing 3 and can be fed at least partially to the refining chamber 6 through the shaft bearing 3.The seal 8, located between the shaft bearing 3 and the refining chamber 6, limits the amount of fluid flowing according to the pressure conditions between the shaft bearing 3 and the refining chamber 6. Advantages: the fluid is systematically driven out of the shaft bearing 3 towards the refining chamber 6. This is achieved by the higher fluid pressure in the shaft bearing 3 compared to the pressure in the refining chamber 6. In this way, no fiber pulp suspension and no pulp from the refining chamber 6 can enter the shaft bearing 3. It is also appropriate to implement a seal 8 with a sealing effect that depends on the direction of fluid flow. A seal 8 that has a smaller sealing effect when the fluid flows through the shaft bearing 3 to the refining chamber 6 than when the fluid flows out of the refining chamber 6 into the shaft bearing 3 is particularly advantageous.Thus, if there is higher pressure in refining chamber 6 and lower pressure in shaft bearing 3, the fiber pulp suspension will flow. Petition 870220061860, dated 07 / 13 / 2022, page 18 / 40 13 / 16 of the refining chamber 6 for the shaft bearing 3 can be reduced to a minimum or completely avoided. Advantageously, the refiner 17 also comprises a damping element 9 for the shaft bearing 3. The damping element 9 is disposed between the rotor disc 2 and the motor 10 (not shown) and, preferably, between the rotor disc 2 and the coupling 11. The damping element 9 can be hydraulically connected to the shaft bearing 3; the damping element 9 comprises a damping area 15 and an accelerator element 16. The fluid supplied to the shaft bearing 3 flows through the shaft bearing 3 here, and also fills the damping area 15.The volume of the damping area 1 can be changed by moving the axis 1 in the axial direction 7, where the fluid flows into the damping element 9 when the volume of the damping area 15 increases and the fluid flows away from the damping element 9 when the volume of the damping area 15 decreases, the fluid flows into and away from the damping area 15 through the accelerator element 16 in each case.

[0024] Figure 3 shows details of a suspended shaft bearing 3 according to the invention. Fluid is introduced into the shaft bearing 3 through a fluid inlet 21 and flows through the fluid-lubricated bearing 23, filling the damping area 15. The seal 8 is disposed between the shaft bearing 3 and the refining chamber 6 and restricts the amount of fluid flowing according to the pressure conditions between the shaft bearing 3 and the refining chamber 6, with most of the fluid being discharged from the shaft bearing 3 through the fluid return line 22. Advantageously, the fluid is systematically directed towards the refining chamber 6 by the fluid that has a higher pressure in the shaft bearing 3 compared to the pressure in the refining chamber 6. The damping element 9 is hydraulically connected to the shaft bearing 3 and with Petition 870220061860, dated 07 / 13 / 2022, p. 19 / 40 14 / 16 encloses the damping area 15 and the accelerator element 16. The accelerator element 16 is connected to shaft 1 in Figure 3, with the damping area 15 delimited by shaft 1, the bearing housing 14, and the accelerator element 16. The volume of the damping area 15 can be changed by moving shaft 1 in the axial direction 7, where fluid flows towards the damping element 9 when the volume of the damping area 15 is increased and fluid flows away from the damping element 9 when the volume of the damping area 15 decreases, fluid flows towards and away from the damping area 15 through the accelerator element 16 in each case.

[0025] Figures 4a and 4b show an advantageous seal 8 for the shaft bearing 3 that allows a sealing effect dependent on the direction of fluid flow. The seal 8 is fixed to the bearing housing 14 by a fastening element 24, the sealing edges 25 facing the shaft 1. According to the truncated cone shape of the sealing edges 25, a smaller sealing effect is obtained when the fluid flows through the bearing of shaft 3 to the refining chamber 6 than when the fluid flows from the refining chamber 6 to the bearing of shaft 3. The fluid flowing from the base to the imaginary tip of the truncated cone-shaped sealing edge 25 – and thus from the bearing of shaft 3 towards the refining chamber 6 – causes the sealing edge 25 to expand and the sealing edge 25 to lift off shaft 1, or at least reduces the pressure force of the seal 8, which is important for sealing 8 and sliding friction, against the shaft.If the flow direction is reversed, i.e., the fluid flows from the imaginary tip of the cone to the base of the truncated cone-shaped sealing edge 25 – or from the refining chamber 6 towards the shaft bearing 3 – the fluid presses the sealing edge 25 against shaft 1 and causes the pressure force of the sealing edge 25 on shaft 1 to increase. Figure 4a. Petition 870220061860, dated 07 / 13 / 2022, page 20 / 40 Figure 15 / 16 shows a sealing edge 8 with two free sealing edges 25. Figure 4b shows a seal 8 with two sealing edges 25, one free sealing edge 25 being disposed closer to the shaft bearing 3 and the sealing edge 25 that is disposed closer to the refining chamber 6 not having a cavity 26 facing the refining chamber 6, which advantageously prevents the pulp from being deposited there and possibly hardening the pulp in the cavity 26 facing the refining chamber 6.

[0026] The present invention thus offers numerous advantages. The reduced wear on the rotor and stator discs – especially on the refining plates of these discs – achieved by the very smooth positioning of the rotor disc, which is also retained in continuous operation, is particularly advantageous. Here, the solution according to the invention avoids any pulp contamination in the seal and bearing area. Similarly, the bearing according to the invention avoids the risk of oil contamination of the fiber pulp suspension because the bearing can be operated without oil, in addition to eliminating or minimizing the risk of pulp contaminating the bearing. The bearing according to the invention also allows for a more compact refiner design and, above all, a shorter overall length. Reference numbers (1) Shaft (2) Rotor disc (3) Shaft bearing (4) First stator disc (5) Second stator disc (6) Refining chamber (7) Axial direction (8) Seal (9) Damping element Petition 870220061860, dated 07 / 13 / 2022, page 21 / 40 16 / 16 (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) Engine Coupling Entrance area Openings Bearing housing cushioning area Choking element Refiner Exit area Accommodation Adjustment device Fluid inlet Fluid return line Fluid-lubricated plain bearing Fastening element Sealing edge Cavity Petition 870220061860, dated 07 / 13 / 2022, page 22 / 40

Claims

1 / 3 CLAIMS 1. A refiner for refining fiber pulp suspension, comprising a shaft (1), a rotor disc (2) firmly fixed to the shaft (1), and a shaft bearing (3), the rotor disc (2) being disposed between two stator discs (4, 5) and forming a refining chamber (6) between the rotor disc (2) and the stator discs (4, 5), the shaft (1) being sliding in an axial direction (7), at least one stator disc (4, 5) being sliding in an axial direction (7), the size of the refining chamber (6) being adjustable by means of the spacing between the stator discs (4, 5) and the rotor disc (2) moving between the stator discs (4, 5) moving the shaft (1) in an axial direction (7), characterized in that the shaft bearing (3) is hydraulically connected to the refining chamber. (6).

2. Refiner, according to claim 1, characterized in that the rotor disc (2) is firmly fixed to the shaft (1) inside or outside the shaft bearing (3).

3. Refiner, according to claim 1 or 2, characterized in that the shaft bearing (3) is designed as a fluid-lubricated plain bearing (23), where a fluid, preferably water, can be fed into the refining chamber (6) through the shaft bearing (3).

4. Refiner, according to any one of claims 1 to 3, characterized in that a seal (8) is disposed between the refining chamber (6) and the shaft bearing (3).

5. Refiner, according to claim 4, characterized in that the sealing effect of the seal (8) depends on the direction of fluid flow.

6. Refiner, according to claim 5, characterized in that the seal (8) has a smaller sealing effect when the fluid flows through the shaft bearing (3) into the refining chamber (6) than when the fluid flows out of the refining chamber (6) into the shaft bearing (3).

7. Refiner, according to any one of claims 1 to 6, characterized in that a damping element (9) is attached to the shaft bearing (3), the damping element (9) being disposed between the rotor disc (2) and a motor (10), preferably between the rotor disc (2) and a coupling (11), the coupling (11) being disposed between the rotor disc (2) and the motor (10).

8. Refiner, according to claim 7, characterized in that the damping element (9) is hydraulically connected to the shaft bearing (3).

9. Refiner, according to claim 1, characterized in that the fiber pulp suspension can be fed into the refining chamber (6) through an inlet area (12) or through the shaft (1).

10. Refiner, according to claim 9, characterized in that the rotor disc (2) contains openings (13), these openings (13) provide a uniform distribution of the fiber pulp suspension in the refining chamber (6), which can be fed through the inlet area (12) or the shaft (1).

11. Refiner, according to claim 1, characterized in that the shaft (1) is connected via a coupling (11) to a motor (10), wherein the movement of the shaft (1) in the axial direction (7) can be absorbed by the coupling (11).

12. Refiner, according to claim 11, characterized in that the coupling (11) is designed as a curved tooth coupling and radial and / or axial movement of the shaft is possible in the curved tooth coupling.

13. Refiner, according to any of the claims 1 to 12, characterized in that the shaft (1) is supported entirely on fluid-lubricated sliding bearings (23).

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