A split-type steel Yanke cylinder structure

Abstract

This utility model relates to a split-type steel Yankee cylinder structure, belonging to the field of papermaking machinery technology. It includes a drying cylinder shell, an operating side end cover, a transmission side end cover, an operating side shaft head, and a transmission side shaft head. It also includes a central connecting pipe with flanges at both ends. The operating side shaft head and the transmission side shaft head are respectively installed at both ends of the central connecting pipe, and each end face of the operating side shaft head and the transmission side shaft head that contacts the central connecting pipe has a positioning stop. The operating side shaft head and the transmission side shaft head are connected to the central connecting pipe by multiple fastening bolts. This utility model, through the cooperation of the flanges at both ends of the central connecting pipe with the positioning stops of the operating side shaft head and the transmission side shaft head, and the connection by fastening bolts, forms a continuously supported "simply supported beam" structure. This significantly reduces the bending moment at the shaft head root and the additional stress borne by the main bolts, effectively preventing bolt fatigue fracture and significantly improving structural rigidity and stability.

Description

Technical Field

[0001] This utility model relates to the field of papermaking machinery technology, and in particular to a split-type steel Yankee cylinder structure. Background Technology

[0002] Steel Yankee cylinders are core drying components in high-speed tissue paper machines. They operate under harsh conditions including high temperature, high-pressure steam, high speed, high linear pressure, and complex temperature fields, demanding extremely high structural strength, rigidity, coaxiality, and service life. Existing steel Yankee cylinders are mainly divided into two categories: integrated mandrel structures and split mandrel structures. Integrated mandrel structures offer advantages such as high integrity, high rigidity, and stable operation, but they are also more expensive to manufacture and more difficult to process, especially in large drying cylinders. Split mandrel structures, on the other hand, use independent shaft heads that are positioned separately to the operating side end cover and the drive side end cover via locating joints and secured with main bolts. They are simpler in structure and lower in cost, and are widely used in low- to mid-range equipment or in situations where investment control is strict.

[0003] However, the split structure has inherent drawbacks: its shaft head is a cantilever support, which, under long-term operation, is susceptible to steam cavitation, thermal cycling, and vibration. This causes fretting wear on the mating surface between the shaft head and the end cover, creating gaps. These gaps result in the main bolts being subjected to additional alternating shear and tensile stresses, easily leading to bolt fatigue fracture and ultimately shaft head detachment, causing a major safety accident. This risk of failure increases significantly, especially under high-load continuous operation. Once a failure occurs, replacing the entire cylinder is not only costly but also requires prolonged downtime, severely impacting production efficiency and economic benefits. Utility Model Content

[0004] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a split steel Yanke cylinder structure, which aims to solve the problems in the background art.

[0005] To achieve the above-mentioned utility model objectives, the first aspect of this utility model proposes a split-type steel Yankee cylinder structure, including a drying cylinder shell, an operating side end cover, a transmission side end cover, an operating side shaft head, and a transmission side shaft head, and also includes a central connecting pipe. Flanges are provided at both ends of the central connecting pipe. The operating side shaft head and the transmission side shaft head are respectively installed at both ends of the central connecting pipe, and positioning stops are provided on the end faces of the operating side shaft head and the transmission side shaft head that contact the central connecting pipe. The operating side shaft head and the transmission side shaft head are connected to the central connecting pipe by multiple fastening bolts, thus forming an integrated spindle structure.

[0006] Optionally, the operating side end cover is fixedly installed to the operating side shaft head by a main bolt, and the transmission side end cover is fixedly installed to the transmission side shaft head by a main bolt.

[0007] Optionally, the central connecting pipe has several steam distribution holes and process installation holes on its pipe wall.

[0008] Optionally, the fastening bolts include a first set of bolts connecting the operating side shaft head to the central connecting pipe and a second set of bolts connecting the transmission side shaft head to the central connecting pipe.

[0009] Optionally, multiple circumferentially distributed bolt holes are arranged on the connection surfaces of the flanges at both ends of the central connecting pipe with the operating side shaft head and the transmission side shaft head.

[0010] Optionally, the central connecting pipe is bolted into the flange and connected to the bolt holes on the operating side shaft head and the transmission side shaft head.

[0011] The beneficial effects of this utility model are: 1. The present invention relates to a split steel Yanke cylinder structure, which uses flanges at both ends of the central connecting pipe to locating stops on the operating side shaft head and the transmission side shaft head, and is connected by fastening bolts to form a continuously supported "simply supported beam" structure, replacing the original "cantilever beam" form. This significantly reduces the bending moment at the shaft head root and the additional stress borne by the main bolts, effectively preventing bolt fatigue fracture and significantly improving structural rigidity and stability.

[0012] 2. The present invention provides a split-type steel Yankee cylinder structure, which ensures high-precision alignment between the operating side shaft head and the operating side end cover, the transmission side shaft head and the transmission side end cover, and the two side shaft heads and the central connecting pipe by setting multiple positioning stops between each component. This significantly improves the overall coaxiality, reduces operating vibration, and ensures stable and efficient operation of the drying cylinder. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a split-type steel Yanke cylinder structure, provided as an exemplary embodiment of the present invention. Figure 2 This invention provides an exemplary embodiment of a split-type steel Yankee cylinder structure. Figure 1 Enlarged diagram of point A in the middle.

[0014] Explanation of reference numerals in the attached figures: 1. Drying cylinder shell; 2. Operating side end cover; 3. Transmission side end cover; 4. Operating side shaft head; 5. Transmission side shaft head; 6. Central connecting pipe; 61. Steam distribution hole; 62. Process mounting hole; 7. Fastening bolt; 8. Main bolt.

[0015] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0016] It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0017] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0018] Reference Figures 1-2 This utility model provides an embodiment of a split steel Yankee cylinder structure, including a drying cylinder shell 1, an operating side end cover 2, a transmission side end cover 3, an operating side shaft head 4, and a transmission side shaft head 5, and also includes a central connecting pipe 6, with flanges provided at both ends of the central connecting pipe 6. The operating side shaft head 4 and the transmission side shaft head 5 are respectively installed at both ends of the central connecting pipe 6, and positioning stops are provided on the end faces of the operating side shaft head 4 and the transmission side shaft head 5 that contact the central connecting pipe 6. The operating side shaft head 4 and the transmission side shaft head 5 are connected to the central connecting pipe 6 by multiple fastening bolts 7, thus forming an integrated spindle structure.

[0019] The central connecting pipe 6 has several steam distribution holes 61 and process installation holes 62 on its pipe wall.

[0020] In some embodiments, the flanges at both ends of the central connecting pipe 6 are provided with a plurality of circumferentially distributed bolt holes on the connection surfaces of the operating side shaft head 4 and the transmission side shaft head 5. The central connecting pipe 6 is bolted into the flanges and connected to the bolt holes on the operating side shaft head 4 and the transmission side shaft head 5.

[0021] It should be noted that the central connecting pipe 6 is a hollow circular tube structure made of high-strength seamless steel pipe, with outwardly extending flanges at both ends. The flange end faces are machined with positioning stops that mate with the operating side shaft head 4 and the transmission side shaft head 5. This positioning stop adopts a stepped cylindrical surface structure to ensure radially precise positioning of the shaft head and the central connecting pipe 6 during assembly, preventing eccentricity or misalignment and improving overall coaxiality.

[0022] Multiple steam-generating holes 61 are evenly opened along the axial direction on the wall of the central connecting pipe 6 to introduce steam from the center into the internal cavity of the drying cylinder for uniform heating. At the same time, several process installation holes 62 are reserved at specific positions on the pipe wall for subsequent installation of auxiliary equipment such as condensate drain devices, temperature sensors, and pressure detection interfaces to meet the process requirements during production.

[0023] Multiple bolt holes are evenly distributed around the circumference on the flanges at both ends of the central connecting pipe 6. These bolt holes precisely match the corresponding threaded holes on the operating side shaft head 4 and the transmission side shaft head 5. The fastening bolts 7 pass through the through holes on the flanges and are screwed into the threaded holes at the ends of the shaft heads, thereby firmly connecting the shaft heads to the central connecting pipe 6.

[0024] Through the above structural design, the central connecting pipe 6 not only serves as a steam channel and process interface carrier, but more importantly, it acts as the core component connecting the two shaft heads, forming an assembled integrated mandrel structure. This fundamentally changes the cantilevered stress state of the traditional split Yankee cylinder. By setting flanges with positioning stops at both ends of the central connecting pipe 6 and connecting them with the shaft heads, high-precision assembly is achieved, significantly improving the overall coaxiality and geometric stability of the mandrel. The steam distribution hole 61 ensures uniform steam distribution within the drying cylinder, improving drying efficiency. The process mounting hole 62 facilitates the later integration of various functional modules, enhancing the maintainability and intelligence level of the equipment. Multiple circumferentially distributed bolt holes, combined with high-strength fastening bolts 7, form a rigid connection between the central connecting pipe 6 and the two shaft heads, effectively transmitting bending moment and torque, and avoiding local stress concentration. The overall structure forms a continuous and integrated mandrel structure, which greatly enhances the deformation resistance and structural rigidity of the Yanke cylinder under complex loads and solves the problem of fatigue fracture of the main bolt 8 caused by the gap of the stop in the traditional split structure.

[0025] In some embodiments, the operating side end cover 2 is fixedly installed to the operating side shaft head 4 by the main bolt 8, and the transmission side end cover 3 is fixedly installed to the transmission side shaft head 5 by the main bolt 8.

[0026] It should be noted that the operating side end cover 2 is fixedly connected to the operating side shaft head 4 by multiple main bolts 8; similarly, the transmission side end cover 3 is also fixedly connected to the transmission side shaft head 5 by main bolts 8. The main bolts 8 are evenly distributed along the circumference of the end cover, applying sufficient preload to ensure that the end cover and the shaft head stop are completely fitted together, ensuring a reliable seal. The stop mating surfaces between the end cover and the shaft head are precision ground to ensure a tight fit and effectively resist fretting wear caused by steam cavitation. In addition, high-temperature resistant sealant can be applied to the stop mating surfaces or a metal sealing ring can be installed to further improve the sealing performance.

[0027] In some embodiments, the fastening bolts 7 include a first set of bolts connecting the operating side shaft head 4 and the central connecting pipe 6, and a second set of bolts connecting the transmission side shaft head 5 and the central connecting pipe 6.

[0028] It should be noted that the operating side shaft head 4 and the transmission side shaft head 5 are independently forged high-strength alloy steel parts, located on the operating side and transmission side of the drying cylinder, respectively. One end of each shaft head has an external stop that mates with the end cover, used for radial positioning with the operating side end cover 2 or the transmission side end cover 3; the other end has an internal positioning stop that mates with the flange of the central connecting pipe 6, used for precise positioning and assembly with the central connecting pipe 6. The operating side shaft head 4 is connected to the central connecting pipe 6 by a first set of fastening bolts 7, and the transmission side shaft head 5 is connected to the central connecting pipe 6 by a second set of fastening bolts 7. The two sets of bolts are arranged and tightened independently, without affecting each other, facilitating step-by-step assembly and maintenance on site.

[0029] The shaft end is also machined with an internal threaded hole that matches the fastening bolt 7. The bolt is inserted from the side of the central connecting tube 6 and screwed into the threaded hole of the shaft end to form a reliable preload connection. All bolts are tightened in stages using a torque wrench according to the design preload requirements to ensure that the connection surfaces are fully fitted and to eliminate fretting gaps.

[0030] In practical application, firstly, the newly manufactured operating side shaft head 4 and the central connecting pipe 6 are pre-connected using the first set of fastening bolts 7. The shaft head is inserted from one side of the drying cylinder, and the stop of the shaft head is aligned and fitted with the stop of the operating side end cover 2. Then, the transmission side shaft head 5 is installed from the other side, so that it is simultaneously fitted with the flange stops at both ends of the transmission side end cover 3 and the central connecting pipe 6. The fastening bolts 7 connecting the operating side shaft head 4 and the central connecting pipe 6, and the transmission side shaft head 5 and the central connecting pipe 6 are tightened sequentially using a torque wrench. Then, the main bolts 8 between the operating side end cover 2 and the operating side shaft head 4, and between the transmission side end cover 3 and the transmission side shaft head 5 are tightened to ensure that each connection surface is evenly stressed. Finally, the bearing housing, frame and other components are reinstalled, the support fixtures are removed, and the internal siphon pipe and other components of the drying cylinder are installed. After inspection and confirmation, steam is introduced through the steam distribution hole 61 on the central connecting pipe 6 into the drying cylinder for heating, thereby achieving stable and efficient operation of the Yankee cylinder.

[0031] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural or procedural transformations made based on the content of the present utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present utility model.

Claims

1. A split-type steel Yankee cylinder structure, comprising a drying cylinder shell (1), an operating side end cover (2), a transmission side end cover (3), an operating side shaft head (4), and a transmission side shaft head (5), characterized in that: It also includes a central connecting pipe (6), which has flanges at both ends. The operating side shaft head (4) and the transmission side shaft head (5) are respectively installed at both ends of the central connecting pipe (6), and the end faces of the operating side shaft head (4) and the transmission side shaft head (5) that contact the central connecting pipe (6) are respectively provided with positioning stops. The operating side shaft head (4) and the transmission side shaft head (5) are connected to the central connecting pipe (6) by multiple fastening bolts (7), thus forming an integrated spindle structure.

2. The split-type steel Yankee cylinder structure according to claim 1, characterized in that, The operating side end cover (2) is fixedly installed to the operating side shaft head (4) by the main bolt (8), and the transmission side end cover (3) is fixedly installed to the transmission side shaft head (5) by the main bolt (8).

3. The split-type steel Yankee cylinder structure according to claim 1, characterized in that, The central connecting pipe (6) has several steam distribution holes (61) and process installation holes (62) on its pipe wall.

4. The split-type steel Yankee cylinder structure according to claim 1, characterized in that, The fastening bolts (7) include a first set of bolts connecting the operating side shaft head (4) and the central connecting pipe (6), and a second set of bolts connecting the transmission side shaft head (5) and the central connecting pipe (6).

5. The split-type steel Yankee cylinder structure according to claim 1, characterized in that, Multiple circumferentially distributed bolt holes are arranged on the connecting surfaces of the flanges at both ends of the central connecting pipe (6) and the operating side shaft head (4) and the transmission side shaft head (5).

6. The split-type steel Yankee cylinder structure according to claim 1, characterized in that, The central connecting pipe (6) is bolted into the flange and connected to the bolt holes on the operating side shaft head (4) and the transmission side shaft head (5).

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