CN-115087841-B - Mounting ceramic rolls in a roll hearth furnace

Abstract

Sleeve (3) for mounting a ceramic roll (2) in a roll hearth furnace (1), the sleeve (3) having a container (4) accommodating an end (5) of the ceramic roll (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) located therein in an axial direction, wherein a wall thickness (d) of the side wall (6) at the waist portion (7) is smaller than a wall thickness in the vicinity of the waist portion (7), and wherein a cross-sectional area of the container (4) at the clamping portion (8) is smaller than a cross-sectional area in the vicinity of the clamping portion (8). The ceramic roller (2) can be mounted particularly firmly in the roller hearth furnace (1) by means of the sleeve (3) even at high temperatures. For this purpose, the sleeve (3) has a reduced cross-sectional area at the clamping portion (8) during production. When the sleeve (3) is pressed axially against the end (5) of the ceramic roller (2), the reduced cross-sectional area at the clamping portion (8) generates an elastic force by which the sleeve (3) is fixed to the ceramic roller (2).

Inventors

• C. Nader
• A. Renats

Assignees

• 施瓦兹有限责任公司

Dates

Publication Date

20260505

Application Date

20210309

Priority Date

20200313

Claims (10)

1. 1. Sleeve (3) for mounting a ceramic roll (2) in a roll hearth furnace (1), characterized in that the sleeve (3) has a container (4) accommodating one end (5) of the ceramic roll (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 an 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 the waist portion (7), wherein a wall thickness (d) of the side wall (6) at the waist portion (7) is smaller than a wall thickness adjacent to the waist portion (7), and wherein a cross-sectional area of the container (4) at the clamping portion (8) is smaller than a cross-sectional area adjacent to the clamping portion (8).
2. 2. Sleeve (3) according to claim 1, characterized in that the wall thickness (d) of the side wall (6) at the waist portion (7) is 20% to 60% of the wall thickness (d) of the side wall (6) adjacent to the waist portion (7).
3. 3. 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 adjacent to the clamping portion (8).
4. 4. Sleeve (3) according to claim 1, characterized in that the axial extension (l K ) of the gripping portion (8) is at least 70% of the axial extension (l T ) of the waist portion (7).
5. 5. Sleeve (3) according to claim 1, characterized in that the axial extension (l T ) of the waist portion (7) is 40% to 80% of the axial extension (l A ) of the container (4).
6. 6. Device consisting of 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) accommodating an 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 an 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 coincide with the waist portion (7), wherein a wall thickness (d) of the side wall (6) at the waist portion (7) is smaller than a wall thickness adjacent to the waist portion (7), and wherein a cross-sectional area of the container (4) is smaller than a cross-sectional area of the end (5) of the ceramic roller (2) only at the clamping portion (8).
7. 7. Method of mounting a sleeve (3) on a ceramic roll (2) of a roll-hearth furnace (1), characterized in that the sleeve (3) is formed for mounting the ceramic roll (2) in the roll-hearth furnace (1), wherein the sleeve (3) has a container (4) accommodating an end (5) of the ceramic roll (2), wherein the container (4) is surrounded by a side wall (6), wherein the side wall (6) has a waist portion (7) in an axial direction, wherein a wall thickness (d) of the side wall (6) at the waist portion (7) is smaller than a wall thickness adjacent to the waist portion (7), and wherein the method comprises: a) -radially pressing the sleeve (3) at a clamping portion (8) located in the waist portion (7), wherein the side wall (6) is in each case subjected to a force directed radially inwards at least in three positions of the side wall (6); b) The sleeve (3) is pressed axially against the end (5) of the ceramic roller (2).
8. 8. A method according to claim 7, characterized in that after step a) the sleeve (3) is a sleeve (3) according to any one of claims 1 to 5.
9. 9. A 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. 10. 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 pressing jaws (9), each extending circumferentially over an angular region of 10 ° to 60 ° of the side wall (6) and/or each extending in axial direction over at least 80% of the waist portion (7) of the side wall (6).

Description

Mounting ceramic rolls in a roll hearth furnace Technical Field The present invention relates to a sleeve for mounting a ceramic roll in a roll hearth furnace, an apparatus comprising a ceramic roll for a roll hearth furnace and the sleeve, and a method for mounting the sleeve on a ceramic roll. Background Heating elements, in particular steel elements, in roller hearth furnaces are known. For this purpose, the component can be moved in a roller hearth furnace by a large number of rollers. The rolls are typically made of ceramic in order to be able to withstand the high temperatures in the roll hearth furnace. Various possibilities for mounting rolls of a roll bottom furnace are known. The connection between the roller made of ceramic and the mounting element made of steel is often problematic. Since steel has a much higher coefficient of thermal expansion than ceramic, at the high operating temperatures of such roller hearth furnace systems, the interference fit of the non-rigid connection (non-positive connection) is reduced if the metal sleeve is externally mounted on the ceramic. Thus, the preload is reduced and the ability to transmit drive torque is reduced. Based on the prior art described, it is an object of the present invention to provide a sleeve by means of which ceramic rolls in a roll hearth furnace can be mounted with a sufficiently non-rigid fit even at high temperatures. Further, an apparatus consisting of the sleeve and a ceramic roller, and a method for mounting the sleeve on a ceramic roller are provided. These objects are achieved by the subject matter of the independent claims. Further preferred embodiments are specified in the dependent claims. The features presented in the claims and in the description may be combined with each other in any technically significant manner. Disclosure of Invention According to the present invention, a sleeve for mounting ceramic rolls in a roll hearth furnace is provided. The sleeve has a receptacle accommodating an end of the ceramic roller, wherein the receptacle is surrounded by a side wall, wherein the side wall has a waist portion and a grip portion located therein in an axial direction, wherein a wall thickness of the side wall of the waist portion is smaller than a wall thickness in the vicinity of the waist portion, and wherein a cross-sectional area of the receptacle at the grip portion is smaller than a cross-sectional area in the vicinity of the grip portion. The sleeve is designed and configured to mount the ceramic roll in a roll hearth furnace. Preferably, the ceramic roll is one of a plurality of ceramic rolls mounted in the roll hearth furnace for transporting components through the roll hearth furnace. With the roller hearth furnace, the components, in particular those made of steel, can be heat treated, for example press hardened. Preferably, the roller hearth furnace is designed for the heat treatment of components, in particular for motor vehicles. The ceramic rolls may be mounted on two sleeves in a roll hearth furnace. Preferably, the ceramic roller is mounted at both ends thereof by respective sleeves. Preferably, the two sleeves have the same design. To install the ceramic roller, the ends of the ceramic roller are inserted into the corresponding receptacles of the sleeve. During operation, the sleeve is flexibly connected to the ceramic roller. Preferably, the sleeve is rigidly connected to the drive mounting means, for example by a hex fit. The part of the drive mounting means connected to said sleeve is rotatably fixed in the rest of the drive mounting means, which rest is fixed. In this respect, the sleeve represents an adapter between the drive mounting on one side and the ceramic roller on the other side. Thus, the ceramic roller receives a connection through the sleeve, through which the ceramic roller can be connected with the drive mounting device. To describe the sleeve, two axial portions of the sidewall, the waist portion and the clamping portion, are defined. 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. In addition to the waist portion and the clamping portion, preferably the side wall has a further axial portion. More preferably, the waist portion is spaced from the end face of the container. The waist portion and the clamping portion are defined by the conditions described below. In addition, the waist portion and the grip portion need not be identified as a waist portion and a grip portion. In particular, the different portions may be identified as waist portions and/or the different portions may be identified as grip portions. It is sufficient that one part can be identified as waist part and one part can be identified as clamping part, and that other possible allocations of parts are irrelevant. The waist portion is defined in that the wall thickness of