Mounting ceramic rolls in roller hearth furnaces

Abstract

A sleeve (3) for mounting a ceramic roller (2) in a roller hearth furnace (1) has a container (4) for accommodating the end (5) of the ceramic roller (2), wherein the container (4) is surrounded by a side wall (6), wherein the side wall (6) has a waist portion (7) and a clamping portion (8) therein in the axial direction, wherein the wall thickness (d) of the side wall (6) at the waist portion (7) is less than the wall thickness near the waist portion (7), and wherein the cross-sectional area of ​​the container (4) at the clamping portion (8) is less than the cross-sectional area near the clamping portion (8). Even at high temperatures, the ceramic roller (2) can be mounted particularly securely in the roller hearth furnace (1) by means of the sleeve (3). For this purpose, during production, the sleeve (3) has a reduced cross-sectional area at the clamping portion (8). When the sleeve (3) is axially pressed onto the end (5) of the ceramic roller (2), the reduced cross-sectional area at the clamping part (8) generates an elastic force, and the sleeve (3) is fixed onto the ceramic roller (2) by the elastic force.

Description

Technical Field

[0001] The present invention relates to a sleeve for mounting a ceramic roller in a roller hearth furnace; an apparatus comprising a ceramic roller for a roller hearth furnace and the sleeve; and a method for mounting the sleeve onto the ceramic roller. Background Technology

[0002] Heating components (especially steel components) in a roller hearth furnace is known. For this purpose, the components can be moved within the furnace by a large number of rollers. The rollers are typically made of ceramic to withstand the high temperatures within the roller hearth furnace.

[0003] Various possibilities for mounting rollers in a roller hearth furnace are known. The connection between a roller made of ceramic and a mounting element made of steel is often problematic. Because steel has a much higher coefficient of thermal expansion than ceramic, the interference fit of a non-rigid connection is reduced if the metal sleeve is externally mounted to the ceramic at the high operating temperatures of such a roller hearth furnace system. Consequently, preload is reduced, and the ability to transmit drive torque is also decreased.

[0004] Based on the aforementioned prior art, the object of the present invention is to provide a sleeve through which ceramic rollers in a roller hearth furnace can be installed with a sufficiently non-rigid fit, even at high temperatures. Furthermore, an apparatus consisting of the sleeve and the ceramic roller is provided, along with a method for mounting the sleeve onto the ceramic roller.

[0005] These objectives are achieved through the subject matter of the independent claims. Other preferred embodiments are specified in the dependent claims. The features presented in the claims and description can be combined with each other in any technically meaningful manner. Summary of the Invention

[0006] According to the present invention, a sleeve for mounting a ceramic roller in a roller hearth furnace is provided. The sleeve has a container for receiving the end of the ceramic roller, wherein the container is surrounded by a side wall, wherein the side wall has a waist portion and a clamping portion therein in an axial direction, wherein the wall thickness of the side wall at the waist portion is less than the wall thickness near the waist portion, and wherein the cross-sectional area of ​​the container at the clamping portion is less than the cross-sectional area near the clamping portion.

[0007] The sleeve is designed and configured to mount a ceramic roller in a roller hearth furnace. Preferably, the ceramic roller is one of a plurality of ceramic rollers mounted in the roller hearth furnace for conveying components through the furnace. Using the roller hearth furnace, components (particularly those made of steel) can be heat-treated, for example, by press hardening. Preferably, the roller hearth furnace is designed for the heat treatment of components, particularly for the heat treatment of motor vehicles.

[0008] The ceramic roller can be mounted on two sleeves in a roller hearth furnace. Preferably, the ceramic roller is mounted at both ends via corresponding sleeves. Preferably, the two sleeves have the same design. To mount the ceramic roller, the end of the ceramic roller is inserted into the corresponding container of the sleeve. During operation, the sleeve is flexibly connected to the ceramic roller. Preferably, the sleeve is rigidly connected to the drive mounting device, for example, via a hexagonal fit. The portion of the drive mounting device connected to the sleeve is rotatably fixed within the remaining portion of the drive mounting device, which is fixed. In this respect, the sleeve represents an adapter between the drive mounting device on one side and the ceramic roller on the other side. Thus, the ceramic roller receives the connection via the sleeve, and the ceramic roller can be connected to the drive mounting device via this connection.

[0009] To describe the sleeve, two axial portions of the sidewall are defined: the waist portion and the clamping portion. The clamping portion is located inside the waist portion. This means that the clamping portion does not protrude beyond the waist portion on one or both sides, and does not coincide with the waist portion. Preferably, in addition to the waist portion and the clamping portion, the sidewall has another axial portion. More preferably, the waist portion is spaced apart from the end face of the container. The waist portion and the clamping portion are defined by the conditions described below. Furthermore, the waist portion and the clamping portion need not be identified as waist portion and clamping portion. In particular, different portions may be identified as waist portion and / or different portions may be identified as clamping portion. It is sufficient for one portion to be identified as waist portion and one portion to be identified as clamping portion; other possible assignments of these portions are irrelevant.

[0010] The waist portion is defined in that the wall thickness of the sidewall is smaller than the wall thickness in the vicinity of the waist portion. This means that the wall thickness of the sidewall decreases at the waist portion. While this is preferred, the wall thickness of the sidewall does not necessarily have to be constant at the waist portion. Preferably, the wall thickness of the sidewall is constant outside the waist portion, but this is not mandatory. In both statements, the term "constant" refers to the fact that the wall thickness remains unchanged when viewed in the axial direction.

[0011] Since the waist portion is axially defined, "near the waist portion" should be understood to refer to those portions of the sidewalls that are axially adjacent to the waist portion. The wall thickness of the sidewalls in these portions does not necessarily need to be constant. The wall thickness of the sidewalls at the edges of the waist portion is as crucial as the wall thickness of the sidewalls "near the waist portion." These edges are not considered part of the waist portion.

[0012] When viewed along the circumferential direction, the wall thickness is preferably constant, especially for the entire sidewall. If the wall thickness is to vary in the circumferential direction, then any axial portion of the sidewall can be considered a waist portion, for which the condition that the wall thickness of the sidewall in that portion is less than the wall thickness in the vicinity of that portion is satisfied at least on a portion of the circumference of the sidewall. Preferably, the condition that the wall thickness of the sidewall at the waist portion is less than the wall thickness in the vicinity of that waist portion is satisfied at the waist portion of the entire circumference of the sidewall. Since the axial portion is taken into account, "vicinity of that portion" is also limited to the axial direction. Therefore, the vicinity of the portion at the corresponding position in the circumferential direction is decisive only.

[0013] At the waist portion, the wall thickness of the sidewall is preferably in the range of 0.5 to 1.0 mm. Near the waist portion, the wall thickness of the sidewall is preferably in the range of 1 to 2 mm.

[0014] The clamping portion is defined such that the cross-sectional area within the container is smaller than the cross-sectional area near the clamping portion. The cross-sectional area of ​​the container represents the area of ​​the container's two-dimensional extension when viewed perpendicular to the container's axis. The container is the space surrounded by the sidewalls. Therefore, when viewed perpendicular to the axis of the sidewalls, the cross-sectional area of ​​the container is the region defined by the inner side of the sidewalls. The fact that the cross-sectional area of ​​the container at the clamping portion is smaller than the cross-sectional area near the clamping portion means that the cross-sectional area of ​​the container at the clamping portion is reduced. While this is preferred, the cross-sectional area of ​​the container at the clamping portion does not necessarily have to be constant. Similarly, outside the clamping portion, preferably, the cross-sectional area of ​​the container is constant, but this is not required. In both statements, the term "constant" refers to the fact that the cross-sectional area remains unchanged when viewed along the axial direction.

[0015] Since the clamping portion is axially defined, "near the clamping portion" should be understood to refer to those portions of the sidewall that are axially adjacent to the clamping portion. The cross-sectional area of ​​the container in these portions does not necessarily need to be constant. The cross-sectional area of ​​the container at the edges of the clamping portion is as significant as the cross-sectional area of ​​the support in "near the clamping portion." These edges are not considered part of the clamping portion.

[0016] If the container is cylindrical, then the diameter of the container at the clamping portion is smaller than the diameter near the clamping portion. However, the container does not have to be perfectly cylindrical. Even more preferably, the container is deformed relative to a cylinder, at least at the clamping portion. To emphasize this possibility, the term "diameter" (which, by mathematical definition, refers to a circular cross-section) is not used for containers with such deformation. Instead, the distance between the interior of the sidewall and the axis of the sidewall should be considered. In the case of a cylindrical container, this distance corresponds to its radius. The fact that the cross-sectional area of ​​the container at the clamping portion is smaller than the cross-sectional area near the clamping portion can be particularly demonstrated by the fact that the distance between the interior of the sidewall and the axis of the sidewall of the clamping portion is smaller than the distance near the clamping portion.

[0017] When viewed circumferentially, the distance between the inner side of the sidewall and its axis does not need to be constant. In this respect, the sidewall can deviate from a rotationally symmetric shape. If the distance between the inner side of the sidewall and its axis varies circumferentially, then any axial portion of the sidewall near which the distance between the inner side of the sidewall and its axis is less than that portion can be considered a clamping portion. "Middle" refers to a plane perpendicular to the axis of the sidewall. Preferably, at the clamping portion along the entire circumference of the sidewall, the condition that the distance between the inner side of the sidewall and its axis is less than the distance near the clamping portion is satisfied. Since axial portions are considered, "near the portion" is also limited to the axial direction. Therefore, the proximity of the portion at the corresponding position in the circumferential direction is decisive only.

[0018] Near the clamping portion, preferably, the distance between the inner side of the sidewall and the axis of the sidewall is in the range of 24 to 100 mm. Preferably, the distance between the inner side of the sidewall and the axis of the sidewall at the clamping portion is 0.15 to 1.00 mm smaller than the distance near the clamping portion. Therefore, relatively small deformation of the sidewall is sufficient.

[0019] Even at high temperatures, the ceramic roller can be securely mounted in the roller hearth furnace using the sleeve. During the manufacturing process of the sleeve, plastic deformation of the clamping portion results in a reduction in its cross-sectional area. During the assembly of the sleeve, this cross-sectional area is elastically widened such that the minimum distance between the inner side of the sidewall at the clamping portion and the axis of the sidewall corresponds to the final cross-sectional area of ​​the ceramic roller. The radial force generated between the ceramic roller and the sleeve is very large, allowing the drive torque to be transmitted to the ceramic roller in a non-rigid manner through the sleeve. Preferably, the radial force is not higher than the value borne by the ceramic roller. It has been found that even at high temperatures, although excess is reduced due to the difference in thermal expansion coefficients between the sleeve and the ceramic roller, the radial force generated by the design of the sleeve is sufficiently high for the non-rigid connection between the sleeve and the ceramic roller. Preferably, the elasticity of the clamping portion is designed such that there is no permanent (i.e., plastic) deformation of the clamping portion under any operating condition.

[0020] Preferably, the sidewall is closed in the circumferential direction. This applies at least to the axial portion, particularly to the waist portion and / or clamping portion. More preferably, the sidewall is completely closed. Openings on the end face are not openings on the sidewall. In particular, the sidewall has no axial groove. Such a configuration can be provided to compensate for the different ductility of the ceramic roller and the sleeve through the spring effect thus achievable. However, since the stiffness of the sleeve is very limited in this design, the required preload can only be kept within a very limited range. Due to the configuration, particularly the waist portion and the clamping portion, such grooves are not required. Therefore, grooves can be omitted, thereby improving the stability of the sleeve and strengthening the connection with the ceramic roller. In addition, since no production groove is required, production is simplified, and production steps are eliminated in this respect.

[0021] In a preferred embodiment of the sleeve, the wall thickness of the sidewall at the waist portion is 20% to 60% of the wall thickness of the sidewall near the waist portion.

[0022] It has been found that the advantages of reducing the wall thickness can be achieved, and the sidewall is also sufficiently stable at the waist portion.

[0023] In another preferred embodiment of the sleeve, the cross-sectional area of ​​the container at the clamping portion is 0.03% to 0.3% smaller than the cross-sectional area near the clamping portion.

[0024] It has been found that the aforementioned advantage of reducing the cross-sectional area can be achieved, and the sleeve can be pressed onto the ceramic roller without damaging it.

[0025] In another preferred embodiment of the sleeve, the axial extension of the clamping portion is at least 70% of the axial extension of the waist portion.

[0026] More preferably, the axial extension of the clamping portion is between 70% and 90% of the axial extension of the waist portion.

[0027] In another preferred embodiment of the sleeve, the waist portion extends axially for 40% to 80% of the axial extension of the container.

[0028] It has been found that the aforementioned advantages of reducing wall thickness can be achieved, and the sidewalls are sufficiently stable.

[0029] As another aspect of the invention, an apparatus is proposed comprising a ceramic roller for a roller hearth furnace and a sleeve for mounting the ceramic roller in the roller hearth furnace. The sleeve has a container for receiving an end of the ceramic roller, wherein the container is surrounded by a sidewall having a waist portion in an axial direction and a clamping portion therein, wherein the wall thickness of the sidewall in the waist portion is less than the wall thickness near the waist portion, and the cross-sectional area of ​​the container is less than the cross-sectional area of ​​the end of the ceramic roller only at the clamping portion.

[0030] The specific advantages and design features of the described sleeve can be applied and transferred to the device, and vice versa. Preferably, the sleeve of the device is designed similarly to the sleeve described above. The sleeve is not pressed against the ceramic roller in the device. However, the sleeve is designed and positioned to press against the ceramic roller. Preferably, the device comprises two sleeves. In this case, one of the sleeves can press against each end of the ceramic roller.

[0031] In this respect, the cross-sectional area of ​​the container at the clamping portion is smaller than the cross-sectional area near the clamping portion because the cross-sectional area of ​​the container is smaller than the cross-sectional area of ​​the end of the ceramic roller only at the clamping portion. When viewed perpendicularly to the axis of the ceramic roller at the end of the ceramic roller, the cross-sectional area of ​​the end of the ceramic roller is the area covering the outside of the ceramic roller. The end of the ceramic roller is the portion of the ceramic roller that is housed by the sleeve. If the cross-sectional area of ​​the ceramic roller is not constant at the end, then the average value is decisive. Therefore, outside the clamping portion, the cross-sectional area of ​​the container is equal to or greater than the cross-sectional area of ​​the end of the ceramic roller. If the sleeve is pressed onto the ceramic roller, the sleeve is secured to the ceramic roller, particularly by the clamping portion. This is a clamping connection, which explains the term clamping portion.

[0032] As another aspect of the invention, a method for mounting a sleeve on a ceramic roller of a roller hearth furnace is provided. The sleeve is designed for mounting the ceramic roller in the roller hearth furnace, wherein the sleeve has a container for receiving an end of the ceramic roller, wherein the container is surrounded by sidewalls, wherein the sidewalls have a waist portion in the axial direction, wherein the wall thickness of the sidewall at the waist portion is less than the wall thickness near the waist portion, and wherein the method comprises:

[0033] a) The sleeve is radially compressed at the clamping portion at the waist portion, wherein in each case, the sidewall is subjected to a force that points radially inward at at least three locations on the sidewall.

[0034] b) Press the sleeve axially against the end of the ceramic roller.

[0035] The special advantages and design features of the sleeve and device can be applied to and transferred to the method, and vice versa. The sleeve, particularly the sleeve of the device, is preferably obtained by step a) of the method. After step a), the sleeve is preferably designed to resemble the sleeve, particularly the sleeve of the device. Step b) of the method can be performed accordingly with the sleeve, particularly with the device. Step b) is preferably performed by a device for axially pressing the sleeve onto the end of the ceramic roller. Preferably, the device has a hydraulic drive to apply the force required for axial pressing. Preferably, the method is performed twice for each ceramic roller by pressing the corresponding sleeve onto each end of the ceramic roller.

[0036] In a preferred embodiment of the method, by step b), the cross-sectional area of ​​the container at the clamping portion becomes smaller than the cross-sectional area of ​​the end of the ceramic roller.

[0037] Therefore, the initial cross-sectional area of ​​the container is greater than or equal to the cross-sectional area of ​​the end of the ceramic roller. Preferably, the cross-sectional area of ​​the container is constant over the entire container. In particular, the cross-section of the container is preferably circular over the entire container. This also applies to the end of the roller. Due to the radial compression in step a), the cross-sectional area of ​​the container at the clamping portion decreases, and is therefore smaller than the cross-sectional area of ​​the end of the ceramic roller. However, outside the clamping portion, the cross-sectional area of ​​the container is still greater than or equal to the cross-sectional area of ​​the end of the ceramic roller.

[0038] In another preferred embodiment of the method, in step b), the sleeve is pressed with at least three pressure claws, wherein each pressure claw extends circumferentially over an angular region of 10° to 60° on the sidewall, and / or each pressure claw extends axially to at least 80% of the waist portion of the sidewall.

[0039] Preferably, three pressure claws are used. Each pressure claw can apply a radially inward force on the sidewall. Preferably, the shape of the pressure claws matches the sidewall. The sidewall begins to deform (e.g., starting from a cylindrical shape) by the pressure claws, which are preferably evenly distributed around the circumference of the sidewall.

[0040] Preferably, in step b), the sleeve is pressed using at least three pressure claws, each pressure claw extending circumferentially over an angular region of 10° to 60° on the sidewall, and each pressure claw extending axially to at least 80% of the waist portion of the sidewall. Attached Figure Description

[0041] The invention will now be explained in more detail with reference to the accompanying drawings. The drawings illustrate particularly preferred embodiments; however, the invention is not limited thereto. In the drawings:

[0042] Figure 1 : is a schematic cross-sectional view of a roller hearth furnace having ceramic rollers mounted on two sleeves according to the present invention.

[0043] Figure 2 :yes Figure 1 A schematic enlarged view of a portion.

[0044] Figure 3 :yes Figure 2 A sectional view of the middle sleeve.

[0045] Figure 4 :yes Figure 2 and Figure 3 Side view of the middle sleeve.

[0046] Figure 5 :yes Figures 2 to 4 A sectional view of the middle sleeve.

[0047] Figure 6 : A cross-sectional view of a portion of the sleeve before radial compression by the pressure claws. Detailed Implementation

[0048] Figure 1 A roller hearth furnace 1 with a large number of ceramic rollers 2 is shown, with one of the ceramic rollers visible. The ceramic roller 2 is connected at its two ends 5 to corresponding (only shown) drive mounting devices 10 via corresponding sleeves 3 according to the invention, and in this respect, it is mounted via the sleeves 3. Figure 2 In the middle, shown in magnification Figure 1 The part is drawn with a dashed line.

[0049] exist Figure 2As can be seen, the end of the ceramic roller 2 is housed within the container 4 of the sleeve 3. The container 4 is surrounded by a sidewall 6. In this case, this is simplified to have constant inner and outer radii. A gap is formed between the ceramic roller 2 and the sleeve 3. This is for illustrative purposes only. The ceramic roller is actually in circumferential contact with at least a portion of the sidewall 6. Figure 2 The drive mounting device 10 is also shown.

[0050] Figure 3 yes Figure 1 and 2 Detailed and scaled cross-sectional view of sleeve 3 before it is assembled onto ceramic roller 2. Figure 3 As can be seen, container 4 is surrounded by sidewall 6, which has a waist portion 7 in the axial direction and a clamping portion 8 located therein. The wall thickness d of the sidewall 6 in the waist portion 7 is smaller than the wall thickness d near the waist portion 7. The cross-sectional area of ​​container 4 in the clamping portion 8 is smaller than the cross-sectional area near the clamping portion 8. However, this deviation is too small to be significant. Figure 3 Identified in the view. A reduced cross-sectional area is achieved by step a) of the method according to the invention, after which the sleeve 3 is radially pressed into the clamping portion 8, wherein in each case, the sidewall 6 is subjected to radially inward force at at least three locations on the sidewall 6.

[0051] In step b) of the method according to the invention, the sleeve 3 can be mounted on the ceramic roller 2 so as to... Figure 1 and Figure 2 It is used in the roller hearth furnace 1. For this purpose, the sleeve 3 is axially pressed against the end 5 of the ceramic roller 2, and in this respect the sleeve 3 is connected to the ceramic roller 2 in a non-rigid manner.

[0052] The axial extension l of the waist portion 7 is also shown. T and the axial extension l of the clamping part 8 K Additionally, the axial extension l of container 4 is also shown. A .

[0053] In addition, a hexagonal screw 11 can be seen, through which the sleeve 3 is securely connected to the drive mounting device 10.

[0054] Figure 4 yes Figure 2 and Figure 3 The side view of sleeve 3 shown. Figure 5 This is a cross-sectional view of sleeve 3.

[0055] Figure 6 This is a cross-sectional view of a portion of sleeve 3 prior to radial extrusion according to step b). From the sleeve 3 shown, radial extrusion can be achieved... Figures 2 to 5Sleeve 3 in the middle. Before radial extrusion, sidewall 6 is cylindrical. Sidewall 6 is slightly deformed by radial extrusion. R i,1 and R i,2 This indicates the inner side of side wall 6 and the axis of side wall 6 (located in...). Figure 6 The two distances between the outer side of sidewall 6 and the axis of sidewall 6 (located outside the details). Furthermore, Ra represents the distance between the outer side of sidewall 6 and the axis of sidewall 6 (located in...). Figure 6 The distance between (excluding details in the text). In the case shown before radial extrusion, the following conditions apply: R i,1 = R i,2 Radial compression can be achieved by pressure claws 9 or other means. Preferably, compression is performed by at least three pressure claws, which are designed similarly to pressure claw 9 shown and are evenly distributed around the circumference of the sleeve 3. Due to radial compression, R i,2 Because the arrangement of the pressure claw 9 is greater than R i,1 It is more significantly affected. The wall thickness remains constant during radial extrusion.

[0056] Even at high temperatures, the ceramic roller 2 can be securely mounted in the roller hearth furnace 1 using the sleeve 3. To achieve this, the sleeve 3 has a reduced cross-sectional area in the clamping portion 8 during production. When the sleeve 3 is axially pressed against the end 5 of the ceramic roller 2, the reduced cross-sectional area in the clamping portion 8 generates an elastic force, which secures the sleeve 3 to the ceramic roller 2.

[0057] Reference Symbol List

[0058] 1. Roller hearth furnace

[0059] 2 Ceramic Rollers

[0060] 3 sleeves

[0061] 4 containers

[0062] 5 ends

[0063] 6. Sidewalls

[0064] 7. Waist area

[0065] 8 Clamping Part

[0066] 9 pressure claws

[0067] 10. Drive mounting device

[0068] 11 Hex screws

[0069] d Wall thickness

[0070] l T Axial extension of the waist section

[0071] l KAxial extension of the clamping portion

[0072] l A Axial extension of the container

[0073] R i,1 Internal distance before radial compression

[0074] R i,2 Internal distance before radial compression

[0075] Ra external distance before radial compression

Claims

1. A sleeve (3) for mounting a ceramic roller (2) in a roller hearth furnace (1), characterized in that, The sleeve (3) has a container (4) for receiving one end (5) of the ceramic roller (2), wherein the container (4) is surrounded by a side wall (6), wherein the side wall (6) has a waist portion (7) and a clamping portion (8) in the axial direction, the clamping portion (8) being located inside the waist portion (7) such that the clamping portion (8) does not protrude beyond the waist portion (7) or overlap with the waist portion (7), wherein the wall thickness (d) of the side wall (6) at the waist portion (7) is less than the wall thickness of the adjacent waist portion (7), and wherein the cross-sectional area of ​​the container (4) at the clamping portion (8) is less than the cross-sectional area of ​​the adjacent clamping portion (8).

2. The sleeve (3) according to claim 1, characterized in that, The wall thickness (d) of the sidewall (6) at the waist portion (7) is 20% to 60% of the wall thickness (d) of the sidewall (6) adjacent to the waist portion (7).

3. The sleeve (3) according to claim 1, characterized in that, The cross-sectional area of ​​the container (4) at the clamping portion (8) is 0.03% to 0.3% smaller than the cross-sectional area of ​​the adjacent clamping portion (8).

4. The sleeve (3) according to claim 1, characterized in that, The axial extension (l) of the clamping portion (8) K ) at least the axial extension (l) of the waist portion (7) T 70% of ).

5. The sleeve (3) according to claim 1, characterized in that, The axial extension (l) of the waist portion (7) T ) is the axial extension (l) of the container (4). A 40% to 80% of ).

6. An apparatus comprising a sleeve and a ceramic roller, comprising a ceramic roller (2) for a roller hearth furnace (1) and a sleeve (3) for mounting the ceramic roller (2) in the roller hearth furnace (1), characterized in that, The sleeve (3) has a container (4) for accommodating the end (5) of the ceramic roller (2), wherein the container (4) is surrounded by a side wall (6), wherein the side wall (6) has a waist portion (7) and a clamping portion (8) in the axial direction, the clamping portion (8) being located inside the waist portion (7) such that the clamping portion (8) does not protrude beyond the waist portion (7) or overlap with the waist portion (7), wherein the wall thickness (d) of the side wall (6) at the waist portion (7) is less than the wall thickness of the adjacent waist portion (7), and wherein the cross-sectional area of ​​the container (4) is less than the cross-sectional area of ​​the end (5) of the ceramic roller (2) only at the clamping portion (8).

7. A method for installing a sleeve (3) on a ceramic roller (2) of a roller hearth furnace (1), characterized in that, Forming a sleeve (3) for mounting the ceramic roller (2) in the roller hearth furnace (1), wherein the sleeve (3) has a container (4) for receiving the end (5) of the ceramic roller (2), wherein the container (4) is surrounded by a side wall (6), wherein the side wall (6) has a waist portion (7) in the axial direction, wherein the wall thickness (d) of the side wall (6) at the waist portion (7) is less than the wall thickness of the adjacent waist portion (7), and wherein the method comprises: a) The sleeve (3) is radially compressed at the clamping portion (8) located in the waist portion (7), wherein in each case, the sidewall (6) is subjected to a force that points radially inward at at least three locations on the sidewall (6); b) Press the sleeve (3) axially onto the end (5) of the ceramic roller (2).

8. The method according to claim 7, characterized in that, After step a), the sleeve (3) is the sleeve (3) according to any one of claims 1 to 5.

9. The method according to claim 7, characterized in that, By step b), the cross-sectional area of ​​the container (4) at the clamping portion (8) becomes smaller than the cross-sectional area of ​​the end (5) of the ceramic roller (2).

10. The method according to any one of claims 7 to 9, characterized in that, In step b), the sleeve (3) is pressed with at least three pressure claws (9), each pressure claw extending circumferentially over an angular region of 10° to 60° on the sidewall (6), and / or each pressure claw extending axially beyond at least 80% of the waist portion (7) of the sidewall (6).

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