A heat conducting oil internal circulation type film heating roller

Abstract

The present application relates to the field of film heating roller, and specifically discloses a heat-conducting oil inner circulation type film heating roller, which comprises a roller body and a supporting core shaft, the roller body is provided with an oil cavity, the supporting core shaft is rotatably and sealingly connected in the oil cavity, and the supporting core shaft is provided with an injection flow channel communicated with the oil cavity; the roller body is provided with a plurality of heat transfer holes extending in the axial direction, a heat transfer wall is formed between two adjacent heat transfer holes, an electric heating pipe is embedded in the heat transfer wall, a plurality of circulation holes communicated between each heat transfer hole and the oil cavity are arranged, and the supporting core shaft is provided with a spiral blade arranged in the oil cavity; the spiral blade drives the heat-conducting oil to circulate between the oil cavity, corresponding heat transfer holes and circulation holes through rotation in the oil cavity, so that the heating roller in the embodiment can effectively avoid the coking and fouling of high-temperature heat-conducting oil on the heat transfer wall or the surrounding area, and has high and uniform heat transfer efficiency.

Description

Technical Field

[0001] This invention relates to the field of film heating rollers, which include at least an electric heating tube embedded in the roller body and heat transfer oil for conducting heat, and particularly to a film heating roller with internal heat transfer oil circulation. Background Technology

[0002] In the calendering process of PVC film production, after the substrate film and the film to be laminated undergo plasticizing and cooling processes, they are continuously extruded and stretched using calendering rollers to produce sheets of specified dimensions. During this process, to ensure a stable bond between the substrate and the laminated film and to allow for some flowability along the stretched surface, the calendering rollers in the calendering roller set must be heated rollers capable of raising the film to its viscous flow temperature. Traditionally, heated rollers typically have a drilled heating structure inside, using heat transfer oil or other media for heating. Compared to heating with electric heating wires inside the roller, media heating allows for more uniform heating temperature along the axial direction of the roller. Among these, heat transfer oil heated rollers are the most commonly used type of media heated roller. Compared to steam heated rollers, they not only save on the equipment cost of steam boilers but also offer faster heat transfer and higher temperatures.

[0003] Existing heat transfer oil heating rollers generally have two structural forms: First, the roller consists of a roller body and a journal. An oil chamber is located within the roller body, and a flow channel is formed within the journal. This flow channel is connected to an external oil pipe via a rotary joint. The roller is heated by continuously filling the oil chamber with high-temperature oil. To achieve this structure, a heat transfer oil furnace is needed to continuously heat the heat transfer oil, and a circulating pump is used to pump the heated oil into the oil chamber, resulting in high equipment costs. Second, the roller consists of an inner cylinder and an outer cylinder, with a filling cavity between them. This cavity is filled with heat transfer oil, and an electric heating tube or wire is installed within it. The heat transfer oil is heated by the heating tube or wire, thus heating the roller. This type of heating roller requires less frequent replacement of the heat transfer oil and eliminates the need for an oil furnace and other external equipment, resulting in significantly lower costs. However, this type of heating roller also has potential drawbacks. The heat transfer oil near the heating element is prone to coking on the inner wall of the roller due to excessive temperature, forming carbon deposits and oil stains. Over time, this can lead to problems such as excessive expansion pressure inside the roller and uneven temperature conduction to the roller surface.

[0004] An applicant filed a Chinese patent with publication number CN103234273A and publication date of May 25, 2016, which specifically discloses a heat transfer oil internal circulation heating roller. The heating roller includes inner and outer cylinders arranged coaxially, forming a heat transfer oil cavity between the inner and outer cylinders, which is filled with heat transfer oil. A heat transfer oil injection hole is provided on one end plate of the cylinder, and a heating device is provided in the heat transfer oil cavity. The heating device is connected to a conductive slip ring on a support shaft via a wire, and an oil discharge pipe is connected to the other end plate of the cylinder, which is connected to a recovery oil tank. Although this solution can save on the equipment cost of the heat transfer oil furnace and can promptly discharge excessively pressurized oil through the oil discharge pipe, the heat transfer oil in the oil cavity has insufficient fluidity, causing it to stick to the cylinder wall, and thus the high-temperature oil near the heat source will still coke. Furthermore, in this design, the support shaft of the support roller must bear the weight of the oil, roller, and film material, as well as the tension and transmission pressure. Due to the large load, fatigue fracture is likely to occur at the connection between the roller body and the journal.

[0005] Therefore, it is urgent to improve the traditional heat transfer oil heating roller to overcome the coking problem of the high-temperature oil and the excessive load on the support bearing, so as to make the heating roller heat the film better and have a longer service life. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a heat transfer oil internal circulation thin film heating roller, which has the advantages of effectively avoiding the coking and fouling of high temperature heat transfer oil in the roller body and reducing the load on the support core bearing.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] This application first discloses a heat transfer oil internal circulation thin film heating roller, including a roller body and a supporting mandrel. The roller body has an oil cavity, and the supporting mandrel is rotatably and sealed to the oil cavity. The supporting mandrel has an injection channel communicating with the oil cavity. The roller body has a plurality of heat transfer holes extending axially, and a heat transfer wall is formed between two adjacent heat transfer holes. An electric heating tube is embedded in the heat transfer wall. A plurality of circulation holes communicating between each heat transfer hole and the oil cavity are provided. The supporting mandrel is provided with a helical blade, which is placed in the oil cavity. The rotation of the helical blade in the oil cavity drives the heat transfer oil to circulate between the oil cavity, the corresponding heat transfer hole, and the circulation holes.

[0009] To optimize the above technical solution, the following technical measures were also adopted:

[0010] Preferably, the system also includes a transmission mechanism and a pair of slewing bearings that rotatably support the roller body, the transmission mechanism being connected to at least one slewing bearing and transmitting power to the roller body through the slewing bearing.

[0011] Preferably, each of the pair of slewing bearings includes a slewing seat, an inner flange, and a rolling element movably embedded between the two, wherein the slewing seat is fixed on a mounting base, the inner flange is fixedly connected to the end face corresponding to the roller body, and the support spindle passes through the two inner flanges and is dynamically sealed to both of them.

[0012] Preferably, the transmission mechanism includes a motor, a drive gear is provided on the output shaft of the motor, and the at least one slewing bearing has an internal gear ring that meshes with the drive gear.

[0013] Preferably, the support mandrel has an extension that extends out of the inner flange, and a gear sleeve is fitted onto the extension, the gear sleeve being externally meshed with the drive gear.

[0014] Preferably, the transmission mechanism further includes an idler gear that meshes with the internal gear ring. The idler gear is connected to the mounting base via a rotating shaft, and the idler gear is positioned opposite the drive gear along the radial direction of the internal gear ring.

[0015] Preferably, the idler wheel and the gear sleeve are connected by external meshing.

[0016] Preferably, the support mandrel is also provided with a drain hole that communicates with the oil chamber. The drain hole includes a first channel extending upward along the axial direction and a second channel penetrating the shaft in the radial direction. A drain bolt is provided in the first channel.

[0017] Preferably, the support spindle is fixedly connected to the mounting base.

[0018] Preferably, the roller body includes a roller body portion suitable for supporting the film and roller shoulders formed on the left and right end faces of the roller body portion. Two roller shoulders extend from both ends of the support mandrel, and a positioning ring surface is formed on the side of each roller shoulder facing the oil cavity. The support mandrel has a sealing flange that abuts against the positioning ring surface, and the sealing flange is dynamically sealed to the oil cavity.

[0019] Compared with the prior art, the beneficial effects of the embodiments of this application are as follows:

[0020] In the above technical solution, the rotation of the support spindle relative to the roller body in the oil cavity drives the spiral blades to rotate in the oil cavity, thereby driving the heat transfer oil in the oil cavity to circulate in the flow path formed by the oil cavity, the corresponding heat transfer holes and the circulation holes. Compared with the traditional heat transfer oil heating roller, it can effectively avoid the high temperature heat transfer oil from coking and accumulating on the heat transfer wall and the surrounding area or from oil sticking.

[0021] In the above technical solution, the transmission mechanism is connected to a slewing bearing and transmits power to the roller body through the slewing bearing. Compared with the traditional solution where the transmission components are concentrated at the neck of the heating roller, in this solution the heating roller can bear part of the weight of the roller body and other components through the slewing bearing, and the transmission mechanism transmits power to the roller body through the slewing bearing without passing through the support spindle, thus effectively reducing the load and transmission pressure borne by the support spindle. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention.

[0023] Figure 1 This is a schematic diagram of the longitudinal cross-sectional structure of the heating roller in Embodiment 1;

[0024] Figure 2 This is a schematic diagram of the transverse cross-sectional structure of the heating roller in Embodiment 1;

[0025] Figure 3 This is a schematic diagram of the end face structure of the heating roller in Embodiment 1 (I);

[0026] Figure 4 This is a schematic diagram (II) of the end face structure of the heating roller in Embodiment 1;

[0027] Figure 5 This is a schematic diagram of the end face structure of the heating roller in Example 2.

[0028] Figure label:

[0029] Roller body 1; oil chamber 11; heat transfer hole 12; circulation hole 13; heat transfer wall 14; embedding hole 15; support mandrel 2; injection channel 21; spiral blade 22; drain hole 23; sealing flange 24; slewing bearing 3; inner flange 31; inner gear ring 311; slewing seat 32; rolling element 33; drain bolt 4; drive gear 5; motor 6; rotary joint 7; mounting base 8; electric heating tube 9; gear sleeve 10; fastening bolt 16; idler wheel 17; idler shaft 171. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0031] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0032] Unless otherwise defined, the technical or scientific terms used in this patent document shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this patent specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms "an," "a," or "the" do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" indicate that the element or object preceding "comprising" encompasses the element or object listed following "comprising" or its equivalents, and do not exclude other elements or objects. Terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" are used only to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly. These terms are only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention.

[0033] This application provides an internal circulation thermal oil thin-film heating roller, which solves the problem of high-temperature thermal oil easily coking and accumulating in existing thermal oil heating rollers. It achieves the effect of uniformly transferring the heat generated by the heating tubes inside the roller to the roller surface without frequent replacement of the thermal oil. Furthermore, it reduces the load on the supporting spindle and extends the service life of the heating roller.

[0034] To address the problem of high-temperature heat transfer oil easily coking and accumulating inside the roller, the general approach of the embodiments in this application is as follows:

[0035] The relative rotation of the support spindle 2 within the oil chamber 11 of the roller body 1 drives the spiral blades 22 to rotate within the oil chamber 11, thereby causing the heat transfer oil in the oil chamber to circulate within the flow path formed by the oil chamber 11, the corresponding heat transfer holes 12, and the circulation holes 13. This prevents the high-temperature heat transfer oil from coking and accumulating on the heat transfer wall and in the surrounding area, or from becoming viscous, thus improving the heat transfer efficiency and making the heating of the film more uniform.

[0036] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, features in the following embodiments can be combined with each other.

[0037] Example 1:

[0038] Please see Figures 1 to 2 This embodiment discloses a heat-conducting oil internal circulation type thin-film heating roller. The film can be PVC film or polypropylene calendered film. Taking the processing of PVC film as an example, the glass transition temperature of PVC film is generally 80-95℃, and the melting temperature is generally 105-125℃. Therefore, the temperature of the heating roller is set at 95-115℃. The roller surface is plated with hard chrome and mirror polished. Specifically, the heating roller includes a roller body 1 and a supporting mandrel 2. The roller body 1 has an oil cavity 11, and the supporting mandrel 2 is rotatably and sealed within the oil cavity 11 relative to the roller body 1. The roller body 1 includes a roller body portion suitable for supporting the film and roller shoulders formed on the left and right end faces of the roller body portion. Two roller shoulders extend from the two ends of the support spindle 2 respectively. Each roller shoulder has a positioning ring surface on the side facing the oil cavity. The support spindle 2 has a sealing flange 24 that abuts against the positioning ring surface. The sealing flange 24 and the oil cavity 11 can be connected by a dynamic sealing method, such as a labyrinth seal or a packing seal. These are all described in the prior art and will not be elaborated here.

[0039] In this embodiment, the roller body 1 has a plurality of heat transfer holes 12 extending axially, as shown in the reference. Figure 2As shown, multiple heat transfer holes 12 are evenly distributed at equal angles in the circumferential direction. In this embodiment, four heat transfer holes 12 are provided. A heat transfer wall 14 is formed between each pair of adjacent heat transfer holes 12. An electric heating tube 9 is embedded in the heat transfer wall 14. The electric heating tube 9 can be a bent tube or a straight tube. In this embodiment, a U-shaped electric heating tube 9 is used. Specifically, each heat transfer wall 14 is provided with an embedding hole 15. The electric heating tube 9 is embedded in the corresponding embedding hole 15 and is connected to the power supply through a conductive slip ring. Multiple circulation holes 13 are provided between each heat transfer hole 12 and the oil chamber 11 to connect the two. In this embodiment, each heat transfer hole 12 is provided with two circulation holes 13. The two circulation holes 13 correspond to the distance between the spiral blade 22 and the left and right sealing flanges, respectively. The support spindle 2 has an injection channel 21 that communicates with the oil chamber 11. The injection channel 21 is connected to the oil inlet pipe through a rotary joint 7 to inject heat transfer oil into the oil chamber 11. The support spindle 2 is provided with a spiral blade 22, which is placed in the oil chamber 11. The rotation of the spiral blade 22 in the oil chamber 11 drives the heat transfer oil to circulate between the oil chamber, the corresponding heat transfer hole and the circulation hole, thereby avoiding the high temperature heat transfer oil from coking and depositing on the heat transfer wall 14 and the surrounding area or from oil sticking.

[0040] To reduce the load on the supporting spindle 2, in this embodiment, the heating roller also includes a transmission mechanism and a pair of slewing bearings 3 that rotatably support the roller body 1. The transmission mechanism is connected to one of the slewing bearings 3 and transmits power to the roller body 1 through the slewing bearing 3. With this arrangement, the slewing bearing 3 can bear part of the weight of the roller body 1 and other components, and the transmission mechanism transmits power to the roller body 1 through the slewing bearing 3, thus effectively reducing the load and transmission pressure on the supporting spindle 2.

[0041] Specifically, each of the pair of slewing bearings 3 includes a slewing seat 32, an inner flange 31, and a rolling element 33 movably embedded between the two. The slewing seat 32 can be fixedly mounted on the mounting base 8. The inner flange 31 is fixedly connected to the end face of the roller body 1, i.e., the roller shoulder. In this embodiment, the inner flange 31 is connected to the roller shoulder of the roller body 1 by a plurality of fastening bolts 16. The support spindle 2 passes through the inner flange 31 and is dynamically sealed to the inner flange 31.

[0042] refer to Figure 3 and 4As shown, the transmission mechanism includes a motor 6. A drive gear 5 is mounted on the output shaft of the motor 6. One of the slewing bearings 3 has an inner flange 31 with a mounting groove. An annular flange is formed on the inner wall of the mounting groove, and an internal gear ring 311 meshing with the drive gear 5 is formed on the inner side of the annular flange. The motor 6 drives the drive gear 5 to rotate, which in turn drives the internal gear ring 311 to rotate, i.e., the inner flange 31 rotates, thereby driving the roller 1 to rotate. Preferably, another slewing bearing 3 also has an internal gear ring, and a balance gear meshing with the internal gear ring is connected to the mounting base 8 via a rotating shaft, so that the forces on the two roller shoulders are balanced, reducing the overturning moment on the roller 1.

[0043] refer to Figure 1 , 3 As shown in Figure 4, the support spindle 2 has an extension extending from the inner flange 31. The extension is rotatably connected to the mounting base 8 via a bearing. A gear sleeve 10 is fitted onto the extension. The gear sleeve 10 can be welded to the support spindle 2 or connected to the support spindle 2 via a fixing key. The gear sleeve 10 meshes with the drive gear 5. The rotation of the drive gear 5 drives the inner gear ring 311 to rotate, which in turn drives the gear sleeve 10 to rotate, i.e., the support spindle 2 to rotate. Since the drive gear 5 is externally meshed with the gear sleeve 10 and internally meshed with the inner gear ring 311, the rotation directions of the support spindle 2 and the roller body 1 are opposite. This increases the rotation speed of the spiral blades 22 in the oil chamber 11, thereby increasing the circulation speed of the heat transfer oil in the heat transfer holes 12, circulation holes 13, and oil chamber 11. As a result, the temperature distribution of the heat transfer oil in the roller body 1 is more uniform, and the heat transferred to the surface of the roller body 1 is more uniform.

[0044] refer to Figure 4 As shown, when the drive gear 5, internal gear ring 311, and gear sleeve 10 mesh with each other, since the power is transmitted from one side of the internal gear ring 311 to the inner flange 31, the inner flange 31 will be subjected to a thrust deviating from the tangential direction of the seat body when it rotates within the rotary seat 32. This thrust causes the inner flange 31 to generate radial vibration during rotation. To eliminate this vibration, the transmission mechanism also includes an idler wheel 17 that meshes with the internal gear ring 311. The idler wheel is connected to the mounting base 8 via an idler shaft 171, and the idler wheel 17 is opposite to the drive gear 5 along the radial direction of the internal gear ring 311. Preferably, the idler wheel 17 and the gear sleeve 10 are connected by external meshing.

[0045] refer to Figure 1As shown in this embodiment, the support mandrel 2 is also provided with a drain hole 23 communicating with the oil chamber 11. The drain hole 23 includes a first channel extending axially upward along the support mandrel 2 and a second channel penetrating the shaft body radially upward along the support mandrel 2. A drain bolt 4 is provided in the first channel. When the oil pressure in the oil chamber is too high, the drain bolt 4 can be unscrewed out of the first channel to open the drain hole 23, thereby draining some heat transfer oil to maintain the oil pressure in the oil chamber in a balanced state.

[0046] Example 2:

[0047] refer to Figure 5 As shown, the basic structure of this embodiment is the same as that of Embodiment 1. The difference is that the support spindle 2 is fixedly connected to the mounting base 8. Although the support spindle 2 is fixed to the mounting base 8, when the roller body 1 rotates, the spiral blades 22 also rotate, so there is a relative rotation between the roller body 1 and the spiral blades 22 (or the support spindle 2). This allows the spiral blades 22 to circulate the heat transfer oil in the oil chamber 11, the corresponding heat transfer holes 12, and the circulation holes 13, thereby preventing the viscous high-temperature heat transfer oil from coking and accumulating. In this case, the drive input component can also be made without the internal gear ring 311, drive gear 5, and motor 6 structure described in Embodiment 1. Instead, a standard rotary drive component with built-in transmission and motor components can be used, such as the rotary drive device of model SE7-73-H-16R, which can improve the efficiency of manufacturing and assembling the heating roller.

[0048] In summary, in the above embodiments, the relative rotation of the support spindle 2 within the oil cavity 11 of the roller body 1 drives the spiral blades 22 to rotate within the oil cavity 11. This causes the heat transfer oil within the oil cavity 11 to circulate within the flow path formed by the oil cavity 11, the corresponding heat transfer holes 12, and the circulation holes 13, thereby preventing the high-temperature heat transfer oil from coking and accumulating on the heat transfer wall and in the surrounding area, or from becoming viscous. Simultaneously, the roller body 1 is supported by the slewing bearing 3, and the transmission mechanism is connected to the slewing bearing 3 to transmit power to the roller body 1. Therefore, the load and transmission pressure borne by the support spindle 2 can be effectively reduced, effectively extending the service life of the heating roller.

[0049] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A heat-conducting oil internal circulation thin-film heating roller, comprising a roller body and a supporting mandrel, wherein the roller body has an oil cavity, and the supporting mandrel is rotatably and sealingly connected to the oil cavity relative to the roller body, and the supporting mandrel has an injection channel communicating with the oil cavity; characterized in that, The roller has multiple heat transfer holes extending axially, and a heat transfer wall is formed between two adjacent heat transfer holes. An electric heating tube is embedded in the heat transfer wall. Multiple circulation holes are provided between each heat transfer hole and the oil cavity. A spiral blade is provided on the support spindle. The spiral blade is placed in the oil cavity. The rotation of the spiral blade in the oil cavity drives the heat transfer oil to circulate between the oil cavity, the corresponding heat transfer hole and the circulation hole.

2. The heat-conducting oil internal circulation thin-film heating roller according to claim 1, characterized in that, It also includes a transmission mechanism and a pair of slewing bearings that rotatably support the roller body, the transmission mechanism being connected to at least one slewing bearing and transmitting power to the roller body through the slewing bearing.

3. The heat-conducting oil internal circulation thin-film heating roller according to claim 2, characterized in that, Each of the pair of slewing bearings includes a slewing seat, an inner flange, and a rolling element movably fitted between the two. The slewing seat is fixed to a mounting base, the inner flange is fixedly connected to the end face corresponding to the roller body, and the support spindle passes through both inner flanges and is dynamically sealed to both.

4. The heat-conducting oil internal circulation thin-film heating roller according to claim 2 or 3, characterized in that, The transmission mechanism includes a motor, a drive gear is provided on the output shaft of the motor, and the at least one slewing bearing has an internal gear ring that meshes with the drive gear.

5. The heat-conducting oil internal circulation thin-film heating roller according to claim 3, characterized in that, The support mandrel has an extension that extends out of the inner flange, and a gear sleeve is fitted onto the extension. The gear sleeve is externally meshed with the drive gear.

6. The heat-conducting oil internal circulation thin-film heating roller according to claim 4, characterized in that, The transmission mechanism further includes an idler gear that meshes with the internal gear ring. The idler gear is connected to the mounting base via a rotating shaft, and the idler gear is positioned opposite the drive gear along the radial direction of the internal gear ring.

7. The heat-conducting oil internal circulation thin-film heating roller according to claim 6, characterized in that, The idler wheel and the gear sleeve are connected by external meshing.

8. The heat-conducting oil internal circulation thin-film heating roller according to claim 2, characterized in that, The support spindle is fixedly connected to the mounting base.

9. The heat-conducting oil internal circulation thin-film heating roller according to claim 1, characterized in that, The support mandrel is also provided with a drain hole that communicates with the oil chamber. The drain hole includes a first channel extending upward along the axial direction and a second channel penetrating the shaft in the radial direction. A drain bolt is provided in the first channel.

10. The heat-conducting oil internal circulation thin-film heating roller according to claim 1, characterized in that, The roller body includes a roller body portion suitable for supporting a film and roller shoulders formed on the left and right end faces of the roller body portion. Two roller shoulders extend from the two ends of the support mandrel respectively. Each roller shoulder portion has a positioning ring surface on the side facing the oil cavity. The support mandrel has a sealing flange that abuts against the positioning ring surface. The sealing flange is dynamically sealed to the oil cavity.

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