EP4010121B1 - Roller mill with a synchronising device - Google Patents

Description

The invention relates to a roller mill for comminuting bulk material, the roller mill having two grinding rollers which are connected to a synchronization device.

Roller mills are usually used to crush grist, such as limestone, clinker, ore or similar rocks. A roller mill usually has two grinding rollers which are arranged parallel to one another and can be rotated in opposite directions, with a grinding gap being formed between the grinding rollers for comminuting the material. From the DE 39 30 773 A1 discloses a roller mill with a fixed and a loosely mounted grinding roller, with the loose bearings each being connected to hydraulic cylinders.

During operation of the roller mill, the grinding rollers are often loaded unevenly, which can be attributed, for example, to uneven wear on the surface of the grinding rollers or materials with different properties and grain sizes. Such uneven loading leads to misalignment of the grinding rollers, with the grinding rollers not being arranged parallel to one another. Increased misalignment results in uneven wear or damage to the grinding roller, with edge elements attached in particular to the roller ends being damaged or destroyed.

Proceeding from this, it is the object of the present invention to provide a roller mill which reliably prevents damage to the roller mill caused by misalignment of the grinding rollers.

According to the invention, this object is achieved by a grinding roller having the features of independent device claim 1 . Advantageous developments result from the dependent claims.

According to a first aspect, a roller mill for comminuting bulk material comprises a first grinding roller and a second grinding roller, which are arranged opposite one another and can be driven in opposite directions, with a grinding gap being formed between the grinding rollers. The roller mill also has a fixed bearing unit for accommodating the second grinding roller and a floating bearing unit for accommodating the first grinding roller, with a plurality of hydraulic actuators being attached to the floating bearing unit for moving the floating bearing unit and/or subjecting the floating bearing unit to a force, for example the grinding force. The roller mill also has a synchronization device that is hydraulically connected to the hydraulic actuators. The synchronizing device has a plurality of hydraulic cylinders, each with a piston, the pistons being connected to one another via a mechanical coupling, so that the movements of the pistons are coupled.

The synchronization device is designed in particular in such a way that it couples the movement of the hydraulic actuators. The movements of the pistons are preferably coupled by mechanical coupling in such a way that the pistons move at least partially or completely synchronously with one another. The mechanical coupling is in particular a rigid coupling to which all the hydraulic cylinders of the synchronization device are attached. The hydraulic cylinders are in particular arranged parallel to one another. Each hydraulic cylinder has at least one or a plurality of cylinder chambers. Each hydraulic cylinder preferably has a hydraulic chamber which is filled with an in particular incompressible hydraulic oil. The pistons preferably each define a hydraulic chamber and are mounted so that they can move in the axial direction within the cylinder. The hydraulic cylinders of the synchronizing device are connected, for example via hydraulic lines, to one or more of the hydraulic actuators, which are preferably attached in an articulated manner to the movable bearing unit. The synchronization device is preferably designed in such a way that it couples the movement of the hydraulic actuators attached to the floating bearing unit.

The floating bearing unit has, in particular, two bearings, each of which accommodates one end of the first grinding roller. Each grinding roller preferably has a roller base body and a roller shaft which is coaxial thereto and protrudes from the roller base body, in particular at the end faces thereof. In particular, the roller shaft is accommodated at each of its opposite ends in a bearing of the floating bearing unit. The bearings of the floating bearing unit are preferably movably accommodated on a machine frame of the roller mill, with the bearings of the fixed bearing unit being fixedly attached to the machine frame. Preferably, each bearing comprises a bearing jewel and a rolling bearing unit attached thereto with an outer and an inner bearing ring and rolling elements arranged therebetween. On. The outer race is preferably fixedly attached to the jewel. The floating bearing unit and the fixed bearing unit each have two bearing blocks, the bearing blocks of the floating bearing unit being movably received on the machine frame and the bearing blocks of the fixed bearing unit being fastened to the machine frame, so that the bearing block cannot be moved relative to the machine frame.

The hydraulic actuator is an actuator that applies a force to the floating bearing unit and moves it, for example. A hydraulic actuator is preferably attached to each bearing jewel of the floating bearing unit. The hydraulic actuator comprises, for example, a cylinder with a piston movably mounted therein, movement of the piston resulting in movement of the jewel or in a change in the force acting on the jewel.

A synchronization device with a plurality of hydraulic cylinders, each of which has a piston coupled via a mechanical coupling, ensures that the pistons in the respective hydraulic cylinders perform a coupled movement, in particular the same movement, although the hydraulic pressure applied to the pistons can be different. The hydraulic actuators connected to the synchronizing device, for example via hydraulic lines, preferably also perform an identical or coupled movement. This ensures that the hydraulic actuators and thus the bearings of the floating bearing unit each execute an identical or coupled movement and that the first grinding roller is limited or prevented from running out of alignment relative to the second grinding roller.

According to a first embodiment, the movable bearing unit has two bearings, each of which accommodates one end of the first grinding roller, at least one, preferably two, hydraulic actuators being attached to each bearing, and half of the hydraulic cylinders of the synchronization device being connected to the hydraulic actuators of one bearing. Preferably, one half of the hydraulic cylinders of the synchronization device is connected exclusively to the hydraulic actuators that are attached to a common bearing of the floating bearing unit, with the other half of the hydraulic cylinders of the synchronization device being connected exclusively to the hydraulic actuators of the other bearing of the floating bearing unit. The synchronizing device has, for example, four, six, eight, ten, twelve or more hydraulic cylinders. The synchronization device preferably has an even number of hydraulic cylinders. The hydraulic cylinders of the synchronization device are preferably connected to the hydraulic actuators attached to the floating bearing unit via hydraulic lines. In particular, each hydraulic cylinder of the synchronization device is connected to exactly one hydraulic actuator. Such a connection of the synchronizing device to the hydraulic actuators attached to the floating bearing unit ensures that the hydraulic actuators execute the same or preferably a coupled movement.

According to a further embodiment, the mechanical coupling is plate-shaped. Preferably, the mechanical coupling comprises a plate, for example circular, which is fixed, preferably articulated, to the pistons of the hydraulic cylinders. In particular, all the pistons of the synchronizing device are attached to a common mechanical coupling. The hydraulic cylinders of the synchronizing device are in particular aligned parallel to one another, the pistons which can be displaced axially therein being preferably fitted orthogonally to the plate-shaped mechanical coupling.

According to a further embodiment, each hydraulic cylinder comprises a piston rod which is attached at its one end to the mechanical coupling and at its other end to one of the pistons. Each of the hydraulic cylinders has in particular at least one hydraulic chamber with a filled with incompressible hydraulic oil. The piston is preferably movable within the cylinder and delimits the hydraulic chamber. The hydraulic cylinders are, for example, single-acting hydraulic cylinders, with only one of the piston surfaces coming into contact with the hydraulic fluid. It is also conceivable that the hydraulic cylinders are differential cylinders, synchronized cylinders or tandem cylinders.

According to a further embodiment, the piston rod is accommodated on the piston or the mechanical coupling in such a way that the piston rod and the piston or the mechanical coupling can be moved relative to one another. Preferably, the piston rod and the mechanical coupling or the piston are linearly movable relative to each other, the movement being in particular limited. For example, a relative movement is only possible in the axial direction of the hydraulic cylinder. For example, the piston rod is movable about 2 to 10 cm relative to the mechanical linkage or the piston. This allows limited misalignment of the grinding rollers.

According to a further embodiment, the piston or the mechanical coupling has an elongated hole in which the piston rod is accommodated. One end of the piston rod is preferably accommodated in the elongated hole, so that the piston rod can be moved in the direction of the extension of the elongated hole. The elongated hole extends, for example, in the axial direction of the hydraulic cylinder.

According to a further embodiment, each hydraulic cylinder has a gas chamber which is delimited by the piston. Preferably the gas chamber is filled with a compressible gas such as nitrogen. Each hydraulic cylinder has, for example, two chambers, one chamber being a gas chamber filled with a compressible gas and the other being a hydraulic chamber filled with an incompressible hydraulic oil. The piston preferably separates the gas chamber from the hydraulic chamber. In particular, the hydraulic chamber of each hydraulic cylinder is connected to at least one hydraulic actuator attached to the floating bearing unit. The gas chamber filled with the compressible gas acts like a spring on the piston works. The spring characteristic is set with the selection of the gas, volume and pressure.

According to a further embodiment, each hydraulic cylinder has a gas chamber and a hydraulic chamber, the gas chamber and the hydraulic chamber each being separated by a piston. According to a further embodiment, the piston rod extends through the hydraulic chamber or through the gas chamber. The hydraulic chamber is preferably arranged on the side of the hydraulic cylinder facing the mechanical coupling, with the piston rod extending through the hydraulic chamber to the mechanical coupling.

According to a further embodiment, at least one buffer unit is arranged between the synchronizing device and the hydraulic actuators, which buffer unit is preferably designed in such a way that it limits the difference in movement of the hydraulic actuators. At least two hydraulic lines are preferably arranged between the synchronizing device and the hydraulic actuators, with each of the hydraulic lines having a buffer unit which is preferably designed in such a way that it limits the difference in movement of the hydraulic actuators. The buffer unit is preferably designed in such a way that it limits the difference in movement of the hydraulic actuators relative to one another to a predetermined maximum value. The buffer unit includes, for example, a cylinder with a gas chamber and a hydraulic chamber connected to the hydraulic line. The gas chamber and the hydraulic chamber are separated by a piston movable within the cylinder. When the hydraulic pressure increases, the piston is moved towards the gas chamber and compresses the gas, such as nitrogen, contained therein. The gas chamber preferably acts on the piston like a gas spring, the movement of the piston being limited, for example, by a mechanical stop. Such a buffer unit allows the grinding rollers to run slightly skewed relative to one another.

According to a further embodiment, the buffer unit is connected in parallel to the synchronization device and the hydraulic actuators. For example, the roller mill has exactly one buffer unit. The buffer unit is preferably a double-acting hydraulic cylinder with two hydraulic chambers separated by a piston.

According to a further embodiment, the synchronizing device has a cylinder with a gas chamber which is preferably filled with a compressible gas such as nitrogen, and the mechanical coupling is designed as a piston and delimits the gas chamber of the synchronizing device. For example, the cylinder also has a hydraulic chamber and a further piston, the further piston separating the hydraulic chamber from the gas chamber. The gas chamber preferably serves as a gas spring, which applies a force to the mechanical coupling so that it is moved. The synchronizing device comprises, for example, a gas spring which is arranged in such a way that it applies a force to the mechanical coupling. The mechanical coupling is preferably designed as a piston, with one piston surface delimiting the gas chamber and the clamp rods of the hydraulic cylinders being attached to the other piston surface.

Description of the drawings

• Fig. 1 zeigt eine schematische Darstellung einer Walzenmühle mit einer Gleichlaufeinrichtung in einer Längsschnittansicht gemäß einem Ausführungsbeispiel.
• Fig. 2 zeigt eine schematische Darstellung einer Walzenmühle mit einer Gleichlaufeinrichtung in einer Schnittansicht gemäß einem weiteren Ausführungsbeispiel.
• Fig. 3 zeigt eine schematische Darstellung einer Walzenmühle mit einer Gleichlaufeinrichtung in einer Querschnittansicht gemäß dem Ausführungsbeispiel der Fig. 1.
• Fig. 4 zeigt eine schematische Darstellung einer Walzenmühle mit einer Gleichlaufeinrichtung in einer Schnittansicht gemäß einem weiteren Ausführungsbeispiel.
• Fig. 5 zeigt eine schematische Darstellung einer Walzenmühle mit einer Gleichlaufeinrichtung in einer Schnittansicht gemäß einem weiteren Ausführungsbeispiel.

The invention is explained in more detail below on the basis of several exemplary embodiments with reference to the attached figures.

• 1 shows a schematic representation of a roller mill with a synchronization device in a longitudinal sectional view according to an embodiment.
• 2 shows a schematic representation of a roller mill with a synchronization device in a sectional view according to a further embodiment.
• 3 shows a schematic representation of a roller mill with a synchronization device in a cross-sectional view according to the embodiment of FIG 1 .
• 4 shows a schematic representation of a roller mill with a synchronization device in a sectional view according to a further embodiment.
• figure 5 shows a schematic representation of a roller mill with a synchronization device in a sectional view according to a further embodiment.

1 shows a roller mill 10 with a first grinding roller 12 and a second grinding roller 14, the grinding rollers 12, 14 being arranged opposite one another and being rotatable in opposite directions. A grinding gap 16 is formed between the grinding rollers 12 , 14 . The grinding rollers 12, 14 each have a substantially cylindrical roller body 18, 20 and a drive shaft 22, 24 arranged coaxially thereto, the ends of which preferably extend beyond the respective roller body 18, 20 in the axial direction. Each of the grinding rollers 12, 14 is accommodated in a bearing unit, with the bearing units being located, for example, on an in 1 not fully supported machine frame 29 shown. The first grinding roller 12 is accommodated in a floating bearing unit 26 , the second grinding roller 14 being accommodated in a fixed bearing unit 28 . The fixed bearing unit 28 comprises two bearings 30, 32, which are each arranged at opposite ends of the roller and accommodate the drive shaft 24. The bearings 30, 32 are fixedly attached to the machine frame 29, so that they absorb forces in particular in the axial and radial direction of the grinding roller 14 and cannot be moved. The floating bearing unit 26 includes two bearings 34, 36, each receiving one end of the drive shaft 22 of the first grinding roller 12. The bearings 34, 36 of the floating bearing unit 26 are accommodated on the machine frame 29 in such a way that they are linear, preferably are slidably movable. In the axial direction of the first grinding roller 12, the bearings 34, 36 are preferably fixed. The bearings 34, 36 of the movable bearing unit 26 are each connected to one, preferably two, hydraulic actuators 38, 40. The hydraulic actuators 38, 40 each serve to apply a grinding force in the direction of the second grinding roller 14 to the first grinding roller 12, which is mounted in the floating bearing unit 26. The grinding force is preferably aligned in a direction orthogonal to the feeding of the material into the grinding gap 16, in particular the grinding force runs in a horizontal direction. The floating bearing unit 26 can be moved in particular in the direction of the grinding force applied by means of the hydraulic actuators 38 , 40 .

The hydraulic actuators 38, 40 are each supported with their one end on a bearing 34, 36 and with their opposite other end on the machine frame 29. A movement of the respective bearing 34, 36 of the floating bearing unit 26 results in a corresponding movement of the hydraulic actuator 38, 40 respectively attached thereto. Each hydraulic actuator preferably has a cylinder and a piston movably attached therein, with the movement of the hydraulic actuator causing, for example, a movement of the piston is to be understood inside the cylinder. The roller mill 10 also has a synchronization device 42 which is connected to the hydraulic actuators 38 , 40 via hydraulic lines 44 , 46 . The synchronizing device 42 serves to couple, in particular to synchronize, the movement of the hydraulic actuators 38, 40, so that the bearings 34, 36 move in a coupled manner or move in the same way and, in particular, a misalignment of the grinding roller 12, 14, in which they are not aligned parallel to one another, is avoided or preferably limited. In particular, the synchronization device is designed in such a way that a movement of one of the hydraulic actuators results in a corresponding movement of the other of the hydraulic actuators.

The synchronizing device 42 has a plurality of hydraulic cylinders 50, 52, 54, 56. 2 shows a cross-sectional view of the synchronization device 42 with four hydraulic cylinders 50, 52, 54, 56, for example, which are arranged in a housing 48, for example are. It is also conceivable to provide only two hydraulic cylinders, six, eight, or for example ten hydraulic cylinders. In each case half of the hydraulic cylinders 50 to 56 is preferably exclusively connected to one of the hydraulic actuators 38 , 40 . For example, one, two or more hydraulic actuators 38, 40 are attached to each bearing 34, 36 of the floating bearing unit 26, with half of the hydraulic cylinders 50 to 56 of the synchronization device 42 preferably being hydraulically operated exclusively with the hydraulic actuators 38, 40 of one bearing 34, 36 each are connected. For example, each hydraulic cylinder 50 to 56 of the synchronization device 42 is connected to exactly one hydraulic actuator 38, 40.

In each of the hydraulic cylinders 50 to 56, a piston 58, 60 is arranged to be linearly movable. The pistons 58, 60 are connected to one another via a mechanical coupling 62 in such a way that their movement is coupled, with the pistons 58, 60 preferably executing a synchronous movement. In particular, all the pistons 58, 60 of the synchronizing device 42 are firmly connected to one another via the mechanical coupling 62. The pistons 58 , 60 preferably each have one end protruding from the respective hydraulic cylinder 50 to 56 , the end of the piston 58 , 60 protruding from the hydraulic cylinder being fastened to the mechanical coupling 62 .

The mechanical coupling 62 is, for example, a plate to which the pistons 58, 60 are attached. The pistons 58, 60 are preferably aligned parallel to one another and orthogonal to the mechanical linkage 62, preferably the platen. The hydraulic cylinders 50 to 56 are connected to the hydraulic actuators 38, 40 via the hydraulic lines 44, 46. The roller mill 10 preferably has two hydraulic lines 44, 46, one hydraulic line 44 being connected to the hydraulic actuators 38 of a bearing 34 of the floating bearing unit 26 and the other hydraulic line 46 being connected to the hydraulic actuators 40 of the other bearing 36 of the floating bearing unit 26. Each of the hydraulic lines 44, 46 is preferably connected exclusively to one half of the hydraulic cylinders 50 to 56 of the synchronization device 42.

The mechanical coupling 62 in the embodiment of FIG 1 designed as a piston 62, the synchronizing device 42 having a cylinder 74 with a gas chamber 76, which is preferably filled with a compressible gas, such as nitrogen. The gas chamber 76 is limited, for example, by two pistons 62 , 78 , one of the pistons preferably being the mechanical coupling and the other piston 78 separating the gas chamber 76 from a hydraulic chamber 80 . The hydraulic chamber 80 is preferably filled with an incompressible hydraulic oil and in particular is connected to a hydraulic pump (not shown) via a hydraulic line.

In the embodiment of 1 a buffer unit 64, 66 is arranged between the synchronizing device 42 and each hydraulic actuator 38, 40. The buffer units 38, 40 are each connected to the synchronization device 42 and the hydraulic actuators 38, 40 via one of the hydraulic lines 44, 46. The buffer units 38, 40 are preferably of essentially identical design. Each buffer unit 64, 66 is designed in particular as a single-acting hydraulic cylinder and each has a cylinder with a piston 68 which separates a gas chamber 70 from a hydraulic chamber 72 and is movable within the cylinder. The gas chamber 70 is preferably filled with a compressible gas, such as nitrogen, with the hydraulic chamber being filled with an incompressible hydraulic oil and being connected to the respective hydraulic line 44, 46, so that hydraulic oil can flow from the respective hydraulic line 44, 46 into the hydraulic chamber 72 is. The buffer unit 64, 66 serves as a buffer between the synchronizing device 42 and the hydraulic actuators, so that the hydraulic actuators 38, 40 are decoupled from the synchronizing device 42 when the movement of the hydraulic actuators does not exceed a specific path limit value. The path limit value is preferably a deviation in the position of the hydraulic actuator relative to a zero position, which corresponds to the desired size of the grinding gap.

When the roller mill 10 is in operation, the hydraulic actuators 38, 40 are each initially subjected to the same hydraulic pressure. If the grinding rollers are misaligned 12, 14, which can be caused, for example, by uneven loading of the grinding rollers in the grinding process, one of the bearings 34, 36 of the floating bearing unit moves away from the grinding gap 16, so that the hydraulic cylinders 38 or 40 connected to the respective bearing 34 or 36 move with it the bearing 34, 36 are moved. Movement of at least one of the bearings 34, 36 results in an increase in hydraulic pressure in one of the hydraulic lines 44, 46, forcing the piston 68 towards the gas chamber 70 so that the gas contained therein is compressed. The movement of the piston is limited, for example, by a stop in the hydraulic chamber 72 or the compression limit of the gas, with the hydraulic actuators 38, 40 being coupled to the synchronization device 42 again when the movement limit of the piston 68 is reached. The compressibility of the gas contained in the gas chamber causes a moderate increase in pressure. The buffer unit 64, 66 allows a limited travel of the hydraulic actuators 38 or 40, so that a limited misalignment of the grinding rollers 12, 14, in which they are no longer parallel, is made possible. Such a limited misalignment prevents damage to the grinding roller, damage being prevented in particular at the edge elements attached to the ends of the roller. As soon as the uneven loading, for example due to fluctuations in the material composition, is over, the hydraulic pressure is automatically regulated back to the initial value by the buffer unit 64, 66.

It is also conceivable that the roller mill 10 of 1 without forming a buffer unit, so that a difference in movement of the bearings 34, 36, in particular a misalignment of the first grinding roller 12, is completely prevented.

2 shows a further exemplary embodiment of a roller mill 10 with a synchronization device 42, the same elements being provided with the same reference symbols. The roller mill 10 of 2 has in contrast to the roller mill of the embodiment of FIG 1 an alternative synchronization device 42. The hydraulic cylinders 50 to 56 of the synchronizing device 42 each have a gas chamber 82, 84 which is delimited by a piston 58, 60 in each case. The pistons 58, 60 of each hydraulic cylinder 50 to 56 separate a respective gas chamber 82, 84 by a hydraulic chamber 86, 88, the hydraulic chamber 86, 88 being filled with an incompressible hydraulic oil and the gas chamber being filled with a compressible gas such as nitrogen. The pistons 58, 60 each have a piston rod 90, 92 which extends through the respective hydraulic chamber 86, 88 and is attached to the mechanical linkage 62. The mechanical coupling 62 is, for example, a plate to which the piston rods 90, 92 are firmly attached. The piston rods 90, 92 are each fastened at one end to the mechanical coupling 62 and at their other, opposite end to the respective piston 58, 60. Each of the pistons 58, 60 preferably has an elongated hole 94, 96, in which the end of the respective piston rod 90, 92 is received in such a way that the piston 58, 60 and the piston rods 90, 92 can be moved relative to one another in the direction in which the piston rod 90, 92 extends are. It is also conceivable that the pistons 58, 60 are firmly connected to the respective piston rods 90, 92 and the mechanical coupling 62 has a plurality of elongated holes, in each of which a piston rod 90, 92 is movably accommodated.

In the embodiment of 2 the misalignment of the two grinding rollers 12, 14 is made possible by the movable accommodation of the piston rod 90, 92 in the piston 58, 60 or the mechanical coupling, the length of the elongated hole, the difference in movement of the bearings 36, 36, in particular limiting the maximum misalignment.

3 FIG. 12 shows a cross-sectional view of the roller mill 10 according to FIG 1 , wherein the same elements have the same reference numbers. 3 shows the arrangement of the hydraulic actuators 38a and 38b, with FIG 1 only one of the hydraulic actuators 38 is visible. By way of example, the hydraulic actuators 38a and 38b are arranged at an equal distance from the center line of the grinding roller 12 and are each fastened to the bearing 34 of the floating bearing unit 26 . Each hydraulic actuator 38a, 38b is preferably connected to exactly one hydraulic cylinder 50 to 56 of the synchronization device 42 via a hydraulic line 44a, b. Each of the hydraulic lines 44a,b has a respective buffer unit 64a,b.

4 shows a further exemplary embodiment of a roller mill 10 with a synchronization device 42, the same elements being provided with the same reference numbers. The roller mill 10 of 4 has in contrast to the roller mill of the embodiment of FIG 2 an alternative synchronization device 42. The piston rods 90, 92 are each movably attached at one end to the mechanical linkage 62 and attached at their other, opposite end to the respective piston 58, 60 or formed integrally therewith. The piston rods 90, 92 each extend, for example, through a bore in the mechanical coupling 62. Each piston rod 90, 92 has two stops for limiting the movement of the respective piston rod 90, 92, with the mechanical coupling 62 being arranged between the two stops of the piston rod 90, 92. The two stops are spaced apart from one another, so that movement of the piston rod 90, 92 relative to the mechanical coupling 62 is possible. Preferably, half of the plurality of piston rods 90, 92 of the synchronizer 42 are movably attached to the mechanical linkage 62 and the other half of the piston rods 90, 92 are fixedly connected to the mechanical linkage 62.

figure 5 shows a further exemplary embodiment of a roller mill 10 with a synchronization device 42, the same elements being provided with the same reference symbols. The roller mill 10 of figure 5 has in contrast to the roller mill 10 of the embodiment of FIG 1 an alternative buffer unit 94 on. For example, the roller mill 10 of figure 5 only one buffer unit 94, which is connected in parallel to the synchronization device 42 and the hydraulic actuators 38, 40. The buffer unit 94 is preferably designed as a double-acting cylinder, with a piston 96 separating two hydraulic chambers 98, 100 from one another. It is also conceivable to connect a plurality of buffer units 94 in parallel with one another.

Reference List

10

roller mill

12

first grinding roller

14

second grinding roller

16

milling gap

18

roller body

20

roller body

22

drive shaft

24

drive shaft

26

floating bearing unit

28

fixed bearing unit

29

machine frame

30

camp

32

camp

34

camp

36

camp

38,a,b

hydraulic actuator

40

hydraulic actuator

42

synchronization device

44,a,b

hydraulic line

46

hydraulic lines

48

Housing

50

hydraulic cylinder

52

hydraulic cylinder

54

hydraulic cylinder

56

hydraulic cylinder

58

Pistons

60

Pistons

62

mechanical coupling

64,a,b

buffer unit

66

buffer unit

68

Pistons

70

gas chamber

72

hydraulic chamber

74

cylinder

76

gas chamber

78

Pistons

80

hydraulic chamber

82

gas chamber

84

gas chamber

86

hydraulic chamber

88

hydraulic chamber

90

piston rod

92

piston rods

94

buffer unit

96

Pistons

98

hydraulic chamber

100

hydraulic chamber

Claims (12)

1. A roller mill (10) for the comminution of bulk material, having

   a first grinding roller (12) and a second grinding roller (14), which are arranged opposite one another and can be driven in opposite directions, wherein a grinding gap (16) is formed between the grinding rollers (12, 14), and

   a fixed bearing unit (28) for holding the second grinding roller (14) and a floating bearing unit (26) for holding the first grinding roller (12),

   wherein there is attached to the floating bearing unit (26) a plurality of hydraulic actuators (38, 40) for applying a force to the floating bearing unit, and

   wherein the hydraulic actuators (38, 40) are hydraulically connected to a synchronization device (42),

   characterized in that

   the synchronization device (42) has a plurality of hydraulic cylinders (50, 52, 54, 56) each having a piston (58, 60), and wherein the pistons (58, 60) are connected to one another via a mechanical coupling (62) so that the movements of the pistons (58, 60) are coupled.
2. The roller mill (10) as claimed in claim 1, wherein the floating bearing unit (26) has two bearings (34, 36) which each hold one end of the first grinding roller (12), wherein at least one hydraulic actuator (38, 40) is attached to each bearing (34, 36), and wherein half the hydraulic cylinders (50 - 56) of the synchronization device (42) is in each case connected to the hydraulic actuator (38, 40) of a bearing (34, 36).
3. The roller mill (10) as claimed in one of the preceding claims, wherein the mechanical coupling (62) is in plate form.
4. The roller mill (10) as claimed in one of the preceding claims, wherein each hydraulic cylinder (50 to 56) comprises a piston rod which is attached at one end to the mechanical coupling (62) and at its other end to one of the pistons (58, 60).
5. The roller mill (10) as claimed in claim 4, wherein the piston rod (90, 92) is held on the piston (58, 60) or the mechanical coupling (62) such that the piston rod (90, 92) and the piston (58, 60) or the mechanical coupling (62) are movable relative to one another.
6. The roller mill (10) as claimed in one of the preceding claims, wherein the piston (58, 60) or the mechanical coupling (62) has an elongated hole in which the piston rod (90, 92) is held.
7. The roller mill (10) as claimed in one of the preceding claims, wherein each hydraulic cylinder has a gas chamber (82, 84), which is delimited by the piston (58, 60).
8. The roller mill (10) as claimed in one of the preceding claims, wherein each hydraulic cylinder (50 to 56) has a gas chamber (82, 84) and a hydraulic chamber (86, 88), and wherein the gas chamber (82, 84) and the hydraulic chamber (86, 88) are separated by a piston (58, 60).
9. The roller mill (10) as claimed in one of claims 4 to 8, wherein the piston rod (90, 92) extends through the hydraulic chamber (86, 88) or through the gas chamber (82, 84).
10. The roller mill (10) as claimed in one of the preceding claims, wherein at least one buffer unit (64, 66; 94) is arranged between the synchronization device (42) and the hydraulic actuators (38, 40) and is configured such that it limits the movement difference of the hydraulic actuators (38, 40).
11. The roller mill (10) as claimed in claim 10, wherein the buffer unit (64, 66; 94) is connected parallel to the synchronization device (42) and the hydraulic actuators (38, 40).
12. The roller mill (10) as claimed in one of the preceding claims, wherein the synchronization device (42) has a cylinder (74) with a gas chamber (76), which is preferably filled with a compressible gas, such as, for example, nitrogen, and wherein the mechanical coupling (62) is in the form of a piston and delimits the gas chamber (76) of the synchronization device (42).

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