A moving blade adjusting traveling device with an external speed reducer

Abstract

The present invention discloses a moving blade adjustment and advancing device of an external reduction box, comprising a rotary oil seal connecting flange, a connecting shaft, an adjusting connecting rod, an advancing shaft, a reduction box output gear, a reduction gear set and a reduction box input shaft; the rotary oil seal connecting flange is sleeved on one end of the connecting shaft, the other end of the connecting shaft is connected to one end of the adjusting connecting rod, the other end of the adjusting connecting rod is connected to one end of the advancing shaft, the reduction gear set and the reduction box output gear are respectively sleeved on the reduction box input shaft, and the other end of the advancing shaft is meshed with the reduction box output gear. The present invention can effectively reduce the transmission ratio of the actuator's own reduction box, reduce the dead zone of the actuator, and through the meshing between the output gear of the external reduction box and the flat gear shaft, make the horizontal vector control smoother, and reduce the inflexible control caused by factors such as friction between mechanical transmissions. It can effectively increase the linear characteristics of the dynamic adjustment fan.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal-fired thermal power generation, and particularly relates to a moving blade adjusting traveling device with an external speed reducer. Background Art

[0002] The swing arm type moving blade adjusting axial flow induced draft fan equipped in the flue gas and air system of a coal-fired thermal power plant generally has advantages such as good adjustment performance and sensitive response to changes in the flue gas and air system. Its moving blade adjusting mechanism generally consists of components such as an electric actuator, a connecting rod, a rotary oil seal, and a hydraulic cylinder. There are problems such as unstable transmission and a large dead zone of the electric actuator in this set of mechanisms, resulting in uneven movement, sometimes fast and sometimes slow, of the fan during adjustment, and even seriously affecting the stability of the furnace negative pressure, with relatively high potential safety hazards. Summary of the Invention

[0003] The purpose of the present invention is to provide a moving blade adjusting traveling device with an external speed reducer for the problems of unstable transmission and a large dead zone of the electric actuator existing in the prior art.

[0004] The present invention is realized by adopting the following technical solutions:

[0005] A moving blade adjusting traveling device with an external speed reducer includes a rotary oil seal connecting flange, a connecting shaft, an adjusting connecting rod, a traveling shaft, a speed reducer output gear, a speed reduction gear set, and a speed reducer input shaft;

[0006] The rotary oil seal connecting flange is sleeved on one end of the connecting shaft, the other end of the connecting shaft is connected to one end of the adjusting connecting rod, the other end of the adjusting connecting rod is connected to one end of the traveling shaft, the speed reduction gear set and the speed reducer output gear are respectively sleeved on the speed reducer input shaft, and the other end of the traveling shaft meshes with the speed reducer output gear.

[0007] A further improvement of the present invention is that the connecting shaft and the adjusting connecting rod, and the adjusting connecting rod and the traveling shaft are respectively connected together by a fixing nut.

[0008] A further improvement of the present invention is that the length of the adjusting connecting rod can be locked through the fixing nut.

[0009] A further improvement of the present invention is that a fixing pin is also provided at the end of the other end of the traveling shaft.

[0010] A further improvement of the present invention is that the rotary oil seal connecting flange is used for connecting with the rotary oil seal of the hydraulic cylinder.

[0011] A further improvement of the present invention is that one end of the traveling shaft is a cylindrical rod with flat tooth threads and the other end has internal threads, and it is connected to the adjusting connecting rod through the internal threads and meshes with the speed reducer output gear through the flat tooth threads.

[0012] A further improvement of the present invention lies in that the output gear of the speed reducer is the output gear of the planetary speed reducer, which is used to mesh with the traveling shaft to convert the angular displacement of the gear into the linear displacement of the traveling shaft.

[0013] A further improvement of the present invention lies in that the gear set of the speed reducer further reduces the angular velocity input from the actuator and is provided with physical limits.

[0014] The present invention has at least the following beneficial technical effects:

[0015] A moving blade adjusting traveling device with an external speed reducer provided by the present invention can change the layout of the control mechanism from the output end of the actuator to the rotary oil seal of the original moving blade adjustable fan, and add a uniform speed reduction traveling adjusting device, so as to first reduce the rotational vector (0 - 720°, ω≈0 - 24° / s) output from the actuator (0 - 60°, ω≈0 - 2° / s), and then convert it into a horizontal vector and use it to adjust the extension and retraction of the fan hydraulic cylinder (the output gear runs from angle θ1 to angle θ2, the angular stroke θ3 = 60°, the traveling shaft runs from position A to position B, and the traveling distance δ L = L2 - L1 = the stroke of the hydraulic cylinder). Through the device of the present invention, the transmission ratio of the built-in speed reducer of the actuator can be effectively reduced, the dead zone situation of the actuator can be reduced, and the control of the horizontal vector is smoother through the meshing between the output gear of the external speed reducer and the flat tooth shaft, reducing the situation of inflexible control caused by factors such as friction between mechanical transmissions. It can effectively increase the linear characteristics of the moving blade adjustable fan.

[0016] Furthermore:

[0017] The present invention can select meshing gears and traveling shafts with different ratios according to fans for different purposes and different adjustment requirements of users for the flue gas and air system.

[0018] For fans for different purposes and their application environments:

[0019] If the applicable object is a primary air fan, considering the characteristics of the primary air fan and the response to extreme operating conditions of the unit, the present device can increase the angular velocity ω to 3.5 - 4° / s, and make the blade control of the primary air fan smooth by adjusting the meshing ratio of the output gear and the traveling shaft.

[0020] If the applicable objects are forced draft fans and induced draft fans, considering the matching relationship between the forced draft fans and induced draft fans and the flue gas and air system, the present device can adjust the output angular velocity ω to 2.0 - 3.0° / s, and make the linear effect of the blades of the forced draft fans and induced draft fans reach the optimal state by adjusting the meshing ratio of the output gear and the traveling shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the gear meshing of the speed reducer, where Figure 1(a) Schematic diagram of the drive shaft, Figure 1 (b) Schematic diagram of the driven shaft.

[0022] Figure 2 It is a gear power model diagram of the planetary reduction gearbox.

[0023] Figure 3 It is a schematic diagram of the overall structure of the traveling device of the present invention (viewpoint 1).

[0024] Figure 4 It is a schematic diagram of the overall structure of the traveling device of the present invention (viewpoint 2).

[0025] Figure 5 It is a schematic diagram of the traveling of the device of the present invention.

[0026] Figure 6 It is a linear comparison diagram of the actuator commands and feedback before modification, where Figure 6 (a) is a linear comparison diagram of the command and feedback of the angle, Figure 6 (b) is a linear diagram of the response time of the opening degree.

[0027] Figure 7 It is a linear comparison diagram of the actuator commands and feedback after modification, where Figure 7 (a) is a linear comparison diagram of the command and feedback of the angle, Figure 7 (b) is a linear diagram of the response time of the opening degree. Detailed implementation manners

[0028] Hereinafter, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be completely conveyed to those skilled in the art. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. Hereinafter, the present invention will be described in detail with reference to the drawings and in conjunction with the embodiments.

[0029] A moving blade adjusting traveling device with an external reduction gearbox provided by the present invention adjusts the original reduction ratio of the actuator reduction gearbox (the original reduction ratio i = 21:1, adjusted to i' = 3:1), adjusts the original actuator speed (19.8 r / min) to 6.6 r / min, and adds a single-stage planetary reduction gearbox (reduction ratio I" = 7:1) between it and the rotary oil seal, and the final speed output is 0.94 r / min.

[0030] Among them, the schematic diagram of the gear meshing of the planetary reduction gearbox is as Figure 1 shown

[0031] In the formula, θ qis the driving shaft rotation angle, θ c is the driven gear rotation angle, k is the gear meshing stiffness coefficient, c is the meshing damping coefficient, T is the gear transmission torque, and 2α is the size of the backlash.

[0032] The nonlinear description of the backlash can be described by the dead zone model.

[0033]

[0034] where Δθ(t) = θ q (t) - 1 / i·θ c (t)

[0035] The gear dynamic model diagram of the planetary reduction gearbox is as Figure 2 shown

[0036] where J 1s is the rotational inertia of the input shaft; b1 is the viscous friction coefficient of the input shaft; j c2 s is the rotational inertia of the output gear; b c2 is the viscous friction coefficient of the output gear, c e is the internal shaft transmission damping;

[0037] After being connected through the secondary planetary reduction gearbox and the traveling connecting rod, the response speed of the moving blade and the uniformity of the movement can be increased, and the present invention can be optimized and configured in combination with the selection of the fan head, so that the fan can achieve a better linear effect without affecting its adjustment ability.

[0038] As Figures 3 to 5 shown, a moving blade adjusting traveling connecting device with an external reduction gearbox provided by the present invention is composed of nine parts: a rotary oil seal connecting flange 1, a connecting shaft 2, a fixing nut 3, an adjusting connecting rod 4, a traveling shaft 5, a reduction gearbox output gear 6, a fixing pin 7, a reduction gear set 8, and a reduction gearbox input shaft 9, and the specific description is as follows:

[0039] 1) The rotary oil seal connecting flange 1 is mainly used for connecting with the rotary oil seal of the hydraulic cylinder.

[0040] 2) The connecting shaft 2 is mainly used for connecting and fixing the rotary oil seal flange and the adjusting connecting rod.

[0041] 3) The fixing nut 3 is used to lock the adjusting connecting rod 4, and the length of the adjusting connecting rod can be locked through the fixing nut.

[0042] 4) The adjusting connecting rod 4 is a connecting rod with threaded ends at both ends. It can achieve the telescopic adjustment function through the internal thread cooperation with the connecting shaft 2 and the traveling shaft 5, and is locked and fixed through the fixing nut 3. It mainly plays the function of adjusting the length of the overall connecting rod, so that the whole structure can be applicable to different fan forms.

[0043] 5) Traveling shaft 5, a cylindrical rod with flat teeth at one end and internal threads at the other end, is connected to the adjusting link 4 through the internal threads and meshes with the output gear 6 of the reduction gearbox through the flat teeth to perform the functions of forward and backward movement.

[0044] 6) Reduction gearbox output gear 6, the output gear of the planetary reduction gearbox, whose main function is to mesh with the traveling shaft and convert the angular displacement of the gear into the linear displacement of the traveling shaft.

[0045] 7) Fixed pin 7, whose main function is to prevent tooth disengagement during the movement of the traveling shaft, is composed of a clamp and fixing bolts. It needs to be manually fixed after determining the stroke of the hydraulic cylinder during actual installation.

[0046] 8) Reduction gearbox gear set 8, whose main function is to further reduce the angular velocity input from the actuator and is provided with appropriate physical limits, which can be limited to 270°.

[0047] 9) Reduction gearbox input shaft 9, connecting the output of the actuator and the input end of the reduction gearbox. According to the type of output of the actuator, a toothed shaft, a key pin structure or a flange connection can be selected.

[0048] 10) The overall installation method is as follows: The output end of the actuator is connected to the reduction gearbox gear set 8 through the input shaft 9. After being decelerated by the reduction gearbox, it meshes with the traveling shaft 5 through the reduction gearbox output gear 6, and drives the rotary oil seal to push the hydraulic cylinder through the forward and backward movement of the traveling shaft, so that the blade has a better uniform adjustment function.

[0049] Implementation case

[0050] The adjustable vane axial flow fan of a domestic 300MW unit has always had problems such as slow opening of the fan adjustable vane and sudden increase and decrease of the blades at the initial stage of operation. The detailed linear situation of the blade command is as Figure 6 shown. After inspection, it was found that the dead zone of the reduction gearbox equipped with the adjustable vane actuator was relatively large, and the bolt clearance of the adjustable vane transmission components was relatively large. After replacing the relevant components, the problem was still not effectively solved. Finally, the bolt connectors of the transmission part had to be processed by welding technology, which caused great inconvenience to the subsequent maintenance work.

[0051] Regarding the problems in adjustable vane adjustment, an adjustable vane traveling device with an external reduction gearbox can be proposed. By reducing the reduction ratio of the original adjustable vane actuator reduction gearbox, its output dead zone is reduced. The original reduction ratio of 21:1 is reduced to 11:1. An external two-stage reduction gearbox with a reduction ratio of 8:1 is added between the output shaft of the actuator and the small chamber of the fan hydraulic cylinder, and a traveling shaft is used to replace its crank arm link to push the hydraulic cylinder.

[0052] Implementation effect of the present invention:

[0053] After the installation of the moving blade adjusting and traveling device with an external speed reducer is completed, since the actuator has replaced the speed reducer with a lower reduction ratio, the dead zone problem of the actuator itself has been greatly alleviated. Moreover, the transmission structure inside for meshing the traveling shaft of the external speed reducer also greatly improves the linearity of the blade movement. After the transformation, the linearity of the actuator command and feedback is as Figure 7 shown. The phenomena of slow opening, sudden increase and sudden decrease of the fan blades are basically eliminated, the regulation is flexible and reliable, and the control accuracy is further improved.

[0054] Although the present invention has been described in detail with general descriptions and specific implementation manners in the above text, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. An adjustable moving blade traveling device with an external speed reducer, characterized in that It includes a rotary oil seal connecting flange (1), a connecting shaft (2), an adjusting link (4), a traveling shaft (5), a speed reducer output gear (6), a speed reduction gear set (8), and a speed reducer input shaft (9); The rotary oil seal connecting flange (1) is sleeved on one end of the connecting shaft (2). The other end of the connecting shaft (2) is connected to one end of the adjusting link (4). The other end of the adjusting link (4) is connected to one end of the traveling shaft (5). The speed reduction gear set (8) and the speed reducer output gear (6) are respectively sleeved on the speed reducer input shaft (9). The other end of the traveling shaft (5) meshes with the speed reducer output gear (6); Between the connecting shaft (2) and the adjusting link (4), and between the adjusting link (4) and the traveling shaft (5), they are respectively connected together by a fixing nut (3); One end of the traveling shaft (5) is a cylindrical rod with flat tooth threads and the other end has internal threads, which is connected with the adjusting link (4) through the internal threads and meshes with the speed reducer output gear (6) through the flat tooth threads.

2. The moving blade adjusting traveling device of an external speed reducer according to claim 1, characterized in that Through the fixing nut (3), the length of the adjusting link (4) can be locked.

3. The moving blade adjusting traveling device of an external speed reducer according to claim 1, characterized in that, A fixing pin (7) is also arranged at the other end of the traveling shaft (5).

4. The moving blade adjusting traveling device of an external speed reducer according to claim 1, characterized in that, The rotary oil seal connecting flange (1) is used for connecting with the rotary oil seal of the hydraulic cylinder.

5. The moving blade adjusting traveling device of an external speed reducer according to claim 1, characterized in that, The speed reducer output gear (6) is the output gear of the planetary speed reducer, which is used for meshing with the traveling shaft to convert the gear angular displacement into the linear displacement of the traveling shaft.

6. The moving blade adjusting traveling device of an external speed reducer according to claim 1, characterized in that, The speed reducer gear set (8) is to further reduce the angular velocity input from the actuator and is provided with physical limits.

Images