CUTTING ROLLER

Abstract

1. Cutting roller.

Description

The invention relates to a cutting roller having an axle, on which a cutting ring is rotatably guided by means of a bearing device, which is sealed against the environment by means of a sealing device.

Cutting rollers of this type, that are used for mining of rock, are state of the art, see DE10 2012 220 434 A1. In particular, such cutting rollers are used as cutting tools at the front end of the drill head of tunnel boring machines. During operation, the assigned sealing device protects the bearing device of the respective cutting rings against harmful environmental influences such as the ingress of dirt and the like. However, the deep drilling depths frequently occurring in tunnel bores cause problems, if the drilling is performed under water or if water ingress occurs. Because of the water pressure, corresponding to the respective drilling depths, there is a water ingress despite the presence of the sealing device and in that way the bearing device is destroyed.

In view of this issue, the invention addresses the problem of providing a cutting roller of the genus mentioned above, which can be reliably used for mining of rock even if there is prevailing water pressure.

According to the invention, this problem is achieved by a cutting roller having the features of claim 1 in its entirety.

According to the characterizing part of claim 1, an essential feature of the invention is that by a compensating device any differential pressures between the bearing device and the environment is compensable. Even when operating underwater, the sealing device protects the bearing device reliably against water penetration based on the pressure compensation provided by the compensating device. The reliable operation is fail-safe in that way, even for deeper drilling sections where water pressure of up to 7 bar and more is to be expected.

In advantageous exemplary embodiments the compensating device has an elastically flexible separator element, the inner side of which is permanently pressurized at the environment pressure and the outer side of which is connected to the bearing device in a pressurized manner and in that way establishes environment pressure in the bearing device.

The arrangement can be particularly advantageous if the separator element is accommodated in a cavity of the axle, wherein said cavity is connected to at least parts of the bearing device via a pressurized connection. In this way the compensating device is completely integrated into the axle of the cutting roller, such that the cutting roller according to the invention can be built having a compact construction and without an increase in size compared to the known cutting rollers.

The separator element can advantageously have an accumulator bladder made of elastomeric material, wherein said accumulator bladder is held on the fixed axle by means of a holding device, which has a connection channel that establishes a media connection between the interior of the separator element and the environment.

In advantageous exemplary embodiments, the holding device has an end cap, into which the connection channel opens out centrally, to which supplying channels are connected, which are inserted into the top of the cover in the form of grooves. The supplying channels ensure that the environment pressure is not only transmitted to the connection channel and thus to the bladder from a singular point in the environment, but also from a larger environment area covered by the supplying channels.

The bearing device may advantageously have at least two rolling bearings, in particular taper roller bearings interacting in pairs, whose gap and/or seat geometries are at least partially connected to the pressurized connection.

The arrangement can be advantageously such that the pressurized connection consists of at least one cross channel, wherein one end of each cross channel opens out into the cavity of the axle and the other end of each cross channel opens out of this axle in the direction of a spacer sleeve, which is adjoined by the inner ring of the respective rolling bearing on both sides.

The outer rings of the rolling bearing pair can be connected to the cutting ring, rotatable on the axle, and can be axially spaced apart from each other, parallel to the axis of rotation of the cutting ring, at a distance equal to or preferably greater than the length of the spacer sleeve.

With regard to the formation of the sealing device, the arrangement can advantageously be such that the sealing device consists of two pairs, each having two sealing rings, one pair of which faces the bearing device and the other pair of which faces an end part, which is fixed on the axle, and which seal the bearing device at least against the environment.

According to patent claim 10, subject matter of the invention is also a tunnel boring machine having a drilling head, on which at least one cutting roller according to any one of the patent claims 1 to 9 is arranged.

The invention is explained in detail below with reference to an exemplary embodiment shown in the drawing. In the Figures:

FIG. 1 shows a schematically simplified longitudinal section of the exemplary embodiment of the cutting roller according to the invention;

FIG. 2 shows a partial section, magnified in relation to FIG. 1, of the area designated by II in FIG. 1;

FIG. 3 shows a longitudinal section of the bladder, forming a resilient separator element of the compensating device of the exemplary embodiment, together with an assigned holding device;

FIG. 4 shows a perspective oblique view of the accumulator bladder together with the holding device;

FIG. 5 shows a longitudinal section of the separately shown accumulator bladder;

FIG. 6 shows an enlarged partial cutout of the area, designated by VI in

FIG. 5, of the accumulator bladder; and

FIG. 7 shows the partial cutout of FIG. 6 having an end part that has a modified outer shape.

The exemplary embodiment, shown in FIG. 1, has a fixed axle 2, which defines the axis of rotation 6 for a cutting ring 4. The cutting ring 4 has a centrally located, radially protruding ring bulge 8, at the radially outer, tapered end of which cutting inserts are provided in the manner usual for cutting rollers of this type, wherein said cutting inserts are omitted in the schematically simplified illustration of FIG. 1. The bearing device, forming the rotary bearing for the cutting ring 4, is formed by a pair of rolling bearings comprising a first taper roller bearing 10 and a second taper roller bearing 12, the respective inner ring 14 and/or 16 of which surrounds the axle 2, axially separated from each other held by a spacer sleeve 18. Bearing covers 20 and 22, seated on the axle 2, hold the inner rings 14 and 16 in contact with the spacer sleeve 18. A shoulder 24 of the bearing cover 20, located on the left in FIG. 1, is fixed to a radially projecting collar 26 of the axle 2. The opposite bearing cover 22, as a screw ring seated on the axle 2, forms the axial fixing of the bearing device in the opposite direction. The outer rings 15 and 17, supporting the cutting ring 4, of the taper roller bearings 10 and/or 12 are held at an axial distance from each other by an inner collar 19 of the cutting ring 4, wherein said distance is slightly larger than the axial length of the spacer sleeve 18. Two pairs of sealing rings 28 and 30 are provided for sealing the bearing device, wherein the respective axially outer sealing ring 28 forms the sealing towards the fixed bearing cover 20 and/or 22 and the respective axially inner sealing ring 30 forms the sealing towards the surrounding cutting ring 4.

The axle 2 has an internal cavity 32, coaxial with the axis of rotation 6 and closed at the end 34 on the left in FIG. 1 and open at the opposite end 36. Central within the length range, cross holes 38 open the cavity 32 of the axle 2 to the outer circumference. In this way, a media connection from the cavity 32 of the axle 2 to the inside of the bearing device is established via gaps located on the outer circumference of the axle in the area of the inner rings 14, 16 and the spacer sleeve 18. The cutting roller, according to the invention, has a compensating device, which provides a pressure compensation between the environment and the cavity 32 and thus the bearing device. The compensating device has a movable separator element in the form of an elastically yielding accumulator bladder 40, which is shown separately in FIG. 5 and is made of an elastomer. As FIGS. 1 and 2 show most clearly, the accumulator bladder 40 is installed in the cavity from the open end 36 of the cavity 32 such that the outside of the accumulator bladder 40 is connected to the bearing device via the cross bores 38 in a pressurized manner, whereas the inside of the accumulator bladder 40 is connected to the environment. To form this connection and as a support for the accumulator bladder 40, as FIG. 2 shows most clearly, as a supporting device an end cap 42 is provided, which can be screwed into the open end 36 of the cavity 32 and which has a coaxial connection channel 44, which provides the connection between the environment and the inside of the accumulator bladder 40. As FIG. 4 shows most clearly, in the outside of the end cap 42 intersecting supplying channels 46 in the form of recessed grooves are formed, such that the connection to the environment is formed across a larger area. A sealing ring 48 is used to seal the end cap 42 against the inner wall of the cavity 32.

The mechanical connection between the end cap 42, which forms the holding device, and the accumulator bladder 40 can be seen most clearly in FIGS. 3 and 5 to 7. As shown, the accumulator bladder 40 has at the open end an edge bulge 52, surrounding its opening 50. As shown in FIG. 3, the end cap 42 has at the inner end of the connection channel 44 an extension 54, which has an annular groove, an undercut wall part 56 of which engages behind an annular part 58, which extends at the edge bulge 52 in the direction to the inside of the accumulator bladder 40. FIG. 7 shows a variant for the shape of the edge bulge 52a, which can be fixed in a correspondingly modified form of the annular groove (not shown) to the extension 54 of the end cap 42.

Because of the flexibility of the accumulator bladder 40, the spaces adjacent to the inside of the accumulator bladder 40 and those adjacent to the outside of the accumulator bladder 40 each have the same pressure level. If there is a water pressure, predominant in the environment and effective in the inside of the accumulator bladder 40 via the channels 44 and 46, the accumulator bladder 40 expands until the pressure between the inside of the bladder and the outside of the bladder, i.e. cavity 32, is balanced. This also results in a pressure compensation in the bearing unit via the cross bores 38, i.e. the internal bearing pressure is adjusted to the environment pressure. This pressure compensation ensures that the sealing device in the form of the sealing ring pairs 28, 30 provides reliable protection of the taper roller bearings 10, 12 against environmental influences, such that the cutting roller according to the invention can be safely operated even if an external water pressure occurs. The function of the accumulator bladder 40 described above can be further supported by a foam filling due to the permanent insertion of an elastically yielding foam material into the accumulator bladder 40.

Claims

1. A cutting roller having an axle (2), on which a cutting ring (4) is rotatably guided by means of a bearing device (10, 12), which is sealed against the environment by means of a sealing device (28, 30), characterized in that by a compensating device (40) any differential pressure between the bearing device (10, 12) and the environment is compensable.

2. The cutting roller according to claim 1, characterized in that the compensating device comprises an elastically flexible separator element (40), the inner side of which is permanently pressurized at the environment pressure and the outer side of which is connected to the bearing device (10, 12) in a pressurized manner.

3. The cutting roller according to claim 1, characterized in that the separator element (40) is accommodated in a cavity (32) of the axle (2), wherein said cavity (32) is connected to at least parts of the bearing device (10, 12) via a pressurized connection (38).

4. The cutting roller according to claim 1, characterized in that the separator element has an accumulator bladder (40) made of elastomeric material, wherein said accumulator bladder (40) is held on the fixed axle (2) by means of a holding device (42), which has a connection channel (44) that establishes a media connection between the interior of the separator element (40) and the environment.

5. The cutting roller according to claim 1, characterized in that the holding device has an end cap (42), into which the connection channel (44) opens out centrally, to which supplying channels (46) are connected, which are inserted into the top of the cover in the form of grooves.

6. The cutting roller according to claim 1, characterized in that the bearing device has at least two rolling bearings, in particular taper roller bearings (10, 12) interacting in pairs, whose gap and/or seat geometries are at least partially connected to the pressurized connection (38).

7. The cutting roller according to any one of the preceding claims claim 1, characterized in that the pressurized connection consists of at least one cross channel (38), wherein one end of each cross channel (38) opens out into the cavity (32) of the axle (2) and the other end of each cross channel (38) opens out of this axle (2) in the direction of a spacer sleeve (18), which is adjoined by the inner ring (14, 16) of the respective rolling bearing (10, 12) on both sides.

8. The cutting roller according to claim 1, characterized in that the outer rings (15, 17) of the rolling bearing pair (10, 12) are connected to the cutting ring (4), rotatable on the axle (2), and are axially spaced apart from each other, parallel to the axis of rotation (6) of the cutting ring (4), at a distance equal to or preferably greater than the length of the spacer sleeve (18).

9. The cutting roller according to claim 1, characterized in that the sealing device consists of two pairs, each having two sealing rings (28, 30), one pair of which faces the bearing device (10, 12) and the other pair of which faces an end part (20, 22), which is fixed on the axle (2), and which seal the bearing device at least against the environment.

10. A tunnel boring machine having a drilling head, characterized in that at least one cutting roller (2, 4) according to claim 1 is arranged on the drilling head.