Method for adjusting circumferential clearance of thrust pad bearing of marine gearbox

Abstract

The invention discloses a method for adjusting the circumferential clearance of a thrust pad bearing of a marine gearbox, which comprises the following steps of: firstly, installing other parts of a thrust pad bearing device except a partition plate, and determining the position of the center line of an output shaft after installation by utilizing a reference transfer method; the position relation between the center line of the output shaft and the center line of the bearing hole of the bearing box is established through the radial clearance and the offset angle alpha of the supporting bearing; the distance from the reference surface to the arcs of the thrust pads is measured, the positions of the circle centers of the two corresponding thrust pads are solved according to the three-point circle drawing principle on the arcs, the symmetrical positions of the two thrust pads during final assembly are determined according to the perpendicular line of the connecting line of the circle centers, and then machining diagrams of the arcs on the two sides of the partition plate are determined. And after machining, the total clearance of the thrust pad bearing in the circumferential direction is determined according to a size detection report and the radius value of the thrust pad.

Description

Technical Field

[0001] The invention relates to the technical field of thrust pad bearing assembly, and in particular to a method for adjusting the circumferential clearance of a thrust pad bearing of a marine gear box. Background Art

[0002] Thrust pad bearing is a very important mechanical component with strong axial load-bearing capacity and self-lubricating performance, simple structure, low maintenance and replacement cost, strong adaptability, and is widely used in industrial production and machinery manufacturing. It is one of the indispensable key components. Especially in the main propulsion transmission system of large ships, the marine gearbox is an important equipment of the ship propulsion system. The thrust pad bearing is set on both sides of the thrust flange of the output shaft of the high-power marine gearbox to withstand the forward thrust and reverse thrust generated by the propeller during the voyage of the ship. The forward and reverse thrust pad bearing of the marine gearbox is generally composed of a plurality of thrust pads, and is symmetrically arranged in the circumferential direction on both sides of the thrust flange of the output shaft system. In order to ensure that the forward or reverse thrust pad bearing can work reliably and stably in the circumferential direction, and to avoid the possibility of large-scale rotation or swing of each thrust pad in the circumferential direction and collision of adjacent thrust pads, it must be limited to a certain circumferential range by a partition.

[0003] The thrust pad bearing device includes a gear box body and an output shaft passing through the gear box body. The output shaft is located in the inner cavity of the gear box body and is provided with a thrust flange coaxial with the output shaft. A support bearing is installed between the output shaft and the bearing hole of the gear box body. Multiple thrust pads and a ring sleeve assembly for supporting the multiple thrust pads on the same side are respectively provided on both sides of the thrust flange. The multiple thrust pads on the same side are arranged around the center line direction of the bearing hole of the gear box body. The multiple thrust pads on the same side are abutted against each other so that a total measured clearance of all thrust pads in the circumferential direction is formed between two adjacent thrust pads located above on the same side. An observation hole connected to the inner cavity of the gear box body is opened at a position corresponding to the circumferential clearance on the top of the gear box body, and a hole cover mounting plane is provided on the top surface of the gear box body corresponding to the position of the observation hole. A hole cover is provided at the observation hole. The hole cover is used to be installed on the hole cover mounting plane and shield the observation hole, and the inner side surface of the hole cover is used to be fixedly connected with the upper end of the partition. However, during the assembly, adjustment and implementation process, on the one hand, the partition needs to use the "trial processing method" to determine the processing amount of the partition arc surface many times, install and disassemble the partition many times, and detect the total clearance in the circumferential direction, which has low adjustment efficiency; on the other hand, due to the limitation of the gear box structure, the total clearance in the circumferential direction of the thrust bearing can only be determined by visual inspection, and the circumferential clearance cannot be quantitatively judged, resulting in different judgment results for the inspection personnel, and it is difficult to ensure the assembly accuracy of the important dimensions of the thrust bearing. Therefore, how to solve the problem of the processing amount of the partition at one time, improve the assembly efficiency of the thrust bearing in the circumferential direction, and quantitatively determine the assembly dimension accuracy of the thrust bearing in the circumferential direction are important problems that technical personnel in the field need to solve urgently. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is: how to provide a method for adjusting the circumferential clearance of the thrust pad bearing of a marine gearbox, which can improve the adjustment efficiency of the partition, reduce the influence of human factors, and ensure the installation dimensional accuracy and assembly performance of the thrust pad bearing.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A method for adjusting the circumferential clearance of a thrust bearing of a marine gearbox, taking the mounting surface of a partition as a measuring reference surface, and taking the extension line of the shortest distance between the outer circle of a thrust flange on the output shaft and the measuring reference surface as a marking line HH on a projection surface along the center line of an output shaft; according to the formula ΔL=Sinα×δ / 2, where δ is the radial clearance between the output shaft and the support bearing in a stationary state, and α is the angle between the measuring reference surface and the horizontal plane, obtaining a marking line JJ after the marking line HH is offset by a distance ΔL; taking a projection line G of the measuring reference surface on the projection surface along the center line of the output shaft as the projection line G; G and marking line JJ establish a central coordinate system, and determine the positions of the centers of the two thrust pads in the central coordinate system by measuring the positional relationship of the outer circles of the two adjacent thrust pads on both sides of the total circumferential gap in the central coordinate system. The median perpendicular line connecting the centers of the two thrust pads is used as the center line of the projection of the partition along the center line of the output shaft, and the projection line GG is used as the installation reference line of the partition. The positional relationship between the partition and the two adjacent thrust pads on both sides of the total circumferential gap is established, and the machining radius dimensions of the arcs on both sides of the partition are obtained. According to the actual radius dimensions of the outer circles of the two thrust pads, the value of the total circumferential gap can be obtained.

[0007] As an optimization, when determining the positions of the centers of the two thrust pads in the central coordinate system, on the projection surface along the center line of the output shaft, at least three different positions on the outer circles of the two thrust pads are taken as measuring points, and the distance L between the measuring points and the marking line JJ and the distance H between the measuring points and the projection line GG are measured respectively to obtain the positions of the measuring points based on the central coordinate system. According to the principle of the three-point method for determining the center of a circle, the positions of the centers of the two thrust pads in the central coordinate system are further determined.

[0008] As an optimization, after determining the perpendicular bisector of the line connecting the centers of the two thrust pads, adjust the positions of the two adjacent thrust pads located on both sides of the total circumferential gap so that the perpendicular bisector of the line connecting the centers of the two thrust pads coincides with the marking line JJ, that is, the center line of the partition projected along the center line of the output shaft coincides with the perpendicular bisector of the line connecting the centers of the two thrust pads.

[0009] As an optimization, the machining radius dimension of the arc on the partition is R=R′+(K±T) / 2, wherein the nominal dimension of the total side clearance in the circumferential direction K=(the maximum value+minimum value required for the total circumferential clearance) / 2, the tolerance T=(the maximum value-minimum value required for the total circumferential clearance) / 2, and R′ is the actual radius dimension of the outer circle of the thrust pad, ensuring the consistency of the ± signs in the calculation formula for the machining radius dimensions of the arcs on both sides of the partition.

[0010] As an optimization, a reference transfer method is adopted to fix a reference measuring block on the gear box body corresponding to the positions of the thrust flange and the thrust pad on the output shaft, and transfer the measurement reference surface to a measurement surface on the reference measuring block that is parallel to it.

[0011] Compared with the prior art, the present invention uses the reference transfer method to establish a unified reference plane for measuring the outer circle distance between the thrust pad and the thrust flange on the output shaft with the measurement surface of the reference measuring block, thereby reducing the measurement error caused by inconsistent references and facilitating the operator to perform measurements.

[0012] Using the shortest distance from a straight line to a plane, measure the shortest distance from the reference surface to the outer circle of the thrust flange, and determine that the position of the center line of the output shaft after the thrust bearing is installed must be on the marked line HH. At the same time, the position relationship between the center line of the output shaft and the center line of the bearing hole of the housing is established through the radial clearance δ and the offset angle α of the support bearing, and then determine that the center line position of the bearing hole on the gear housing must be on the marked line JJ, and use it as the measurement reference;

[0013] After measuring the distance from the reference plane to the arc of the thrust pad, the position of the center of the thrust pad is solved by using the principle of drawing a circle with three points on the arc, and the position of the center point of the bearing hole of the box body is determined by using the vertical line connecting the center points of the circles;

[0014] The symmetrical position of the thrust pad during final assembly is determined based on the angle between the vertical line (symmetry line) connecting the center of the thrust pad and the measurement reference line. When the angle is zero, it indicates that the thrust pad is assembled in a symmetrical position; when the angle is not zero, it indicates that the thrust pad is in an asymmetrical position after assembly and installation. The thrust pad needs to be rotated by a corresponding angle relative to the center point of the bearing hole of the housing so that it coincides with the measurement reference line to determine the installation position and distance of the thrust pad.

[0015] Considering the actual assembly state and the final processing positioning reference of the partition, the position relationship diagram of the partition and the thrust pad is established, the processing diagram of the arcs on both sides of the partition and the alignment reference during processing are determined, and the processing size of the partition is solved at one time, which improves the adjustment efficiency and reduces the processing cost;

[0016] According to the inspection report of the partition size and the radius value of the thrust pad, the total clearance in the circumferential direction of the side thrust pad bearing can be quantitatively determined, which reduces the problem of different evaluation results caused by different inspectors and ensures the assembly accuracy of key dimensions of the thrust pad bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a flow chart of the present invention;

[0018] Figure 2 It is an axial cross-sectional view of the thrust pad bearing structure of the present invention;

[0019] Figure 3 A radial cross-sectional view of the thrust pad bearing structure of the present invention;

[0020] Figure 4 It is a schematic diagram of the actual installation of the thrust pad bearing and the arrangement of each measuring point in the present invention;

[0021] Figure 5 for Figure 4 Rotate the view in A direction;

[0022] Figure 6 It is a diagram for confirming the center of the thrust pad and the installation position in the present invention;

[0023] Figure 7 It is a diagram showing the position change process of the thrust pad and the installation distance confirmation in the present invention;

[0024] Figure 8 This is a dimension diagram of the arc processing of the partition in the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0026] It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In the description of the present invention, it should be noted that the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the invention product is usually placed when used, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In addition, the terms "horizontal", "vertical", etc. do not mean that the components are absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] like Figures 1 to 8As shown, in this specific embodiment, a method for adjusting the circumferential clearance of a thrust pad bearing of a marine gearbox is used. The mounting surface of the partition 1 is used as the measuring reference surface. The thrust flange on the output shaft 2 is axially pushed to fix the thrust pad 4 on the measuring side. On the projection surface along the center line of the output shaft 2, the extension line of the shortest distance between the outer circle of the thrust flange on the output shaft 2 and the measuring reference surface is used as the marking line HH; according to the formula ΔL=Sinα×δ / 2, where δ is the radial clearance between the output shaft 2 and the support bearing 3 in a stationary state, and α is the angle between the measuring reference surface and the horizontal plane, the marking line HH is obtained based on the marking line JJ after the offset distance ΔL; the measuring reference surface is used as the extension line of the shortest distance between the outer circle of the thrust flange on the output shaft 2 and the measuring reference surface. A central coordinate system is established by using the projection line GG and the marking line JJ on the projection surface along the center line direction of the output shaft 2. The positions of the centers of the two thrust pads 4 in the central coordinate system are determined by measuring the positional relationship between the outer circles of the two adjacent thrust pads 4 on both sides of the total circumferential gap in the central coordinate system. The perpendicular bisector connecting the centers of the two thrust pads 4 is used as the center line of the projection of the partition 1 along the center line direction of the output shaft 2. The projection line GG is used as the installation reference line of the partition 1. The positional relationship between the partition 1 and the two adjacent thrust pads 4 on both sides of the total circumferential gap is established, and the machining radius dimensions of the arcs on both sides of the partition 1 are obtained. According to the actual radius dimensions of the outer circles of the two thrust pads 4, the value of the total circumferential gap can be calculated.

[0028] Measure multiple distances h, h1, h2, h3, h4, ... from the measuring reference plane to the outer circle of the thrust flange on the output shaft 2, and determine the position of the marking line HH based on the minimum measured value, that is, the projection point O1 of the center line of the output shaft 2 must be on the marking line HH; the center line of the output shaft 2 and the center line of the bearing hole are not in the same position in the static state after assembly, and the center line of the output shaft 2 in the static state is lower than the center line of the bearing hole by δ / 2, and then the marking line JJ based on the offset distance ΔL of the marking line HH can be obtained according to the formula, that is, the projection point O of the center line of the bearing hole of the gear box body 5 on the projection plane must be on the marking line JJ; in addition, when 0<α<90°, the marking line JJ is on the right side of the marking line HH; when -90°<α<0°, the marking line JJ is on the left side of the marking line HH; when α=0°, the marking line JJ coincides with the marking line HH, that is, there is no offset;

[0029] In this specific embodiment, when determining the positions of the centers of the two thrust pads 4 in the central coordinate system, at least three different positions on the outer circles of the two thrust pads 4 are taken as measuring points on the projection surface along the center line of the output shaft 2, and the distance L between the two thrust pads 4 and the marking line JJ and the distance H between the two thrust pads 4 and the projection line GG are measured respectively, that is, the marking line JJ is used for positioning, and the first measuring position AA (distance L1), the second measuring position BB (distance L2), the third measuring position CC (distance L3), the fourth measuring position DD (distance L4), the fifth measuring position EE (distance L5), and the sixth measuring position FF (distance L6) are determined, and the distances AA1, BB1, CC1, DD1, EE1, and FF1 from the measuring reference plane to the corresponding positions of the outer circle of the thrust pad 5 are measured by using a depth gauge, which are recorded as H3, H2, H1, H6, H5, and H4 respectively; the positions of the measuring points based on the central coordinate system are obtained, and according to the principle of the three-point method for determining the center of a circle, the positions of the centers of the two thrust pads 4 in the central coordinate system are further determined. That is, after connecting A1B1, B1C1, D1E1, and E1F1, use the center point to draw perpendicular lines of each line segment, and then we can obtain the intersection M of the perpendicular lines of A1B1 and B1C1, and the intersection N of the perpendicular lines of D1E1 and E1F1. That is, the center of one thrust pad 4 after actual installation is M, and the center of the other thrust pad 4 after actual installation is N.

[0030] In this specific implementation manner, after determining the perpendicular bisector OO2 connecting the centers of the two thrust pads 4, according to the perpendicular bisector

[0031] The angle β between OO2 and the marking line JJ is used to adjust the positions of the two adjacent thrust pads 4 located on both sides of the total circumferential gap so that the perpendicular bisector OO2 of the line connecting the centers of the two thrust pads 4 coincides with the marking line JJ, that is, the center line of the partition 1 projected along the center line direction of the output shaft 2 coincides with the perpendicular bisector OO2 of the line connecting the centers of the two thrust pads 4.

[0032] In this specific embodiment, the machining radius dimension R of the arc on the partition 1 is R=R′+(K±T) / 2, wherein the nominal dimension of the total side clearance in the circumferential direction K=(the maximum value+minimum value required for the total circumferential clearance) / 2, the tolerance T=(the maximum value-minimum value required for the total circumferential clearance) / 2, and R′ is the actual radius dimension of the outer circle of the thrust pad 4, ensuring the consistency of the ± signs in the calculation formula for the machining radius dimensions of the arcs on both sides of the partition 1.

[0033] In this specific implementation, a reference transfer method is adopted, and a reference measuring block 6 is fixed on the gear housing 5 at the position corresponding to the thrust flange on the output shaft 2 and the thrust pad 4, and the measurement reference surface is transferred to the measurement surface parallel to the reference measuring block 6. The bottom surface of the reference measuring block 6 is parallel to the top surface, and the bottom surface of the reference measuring block 6 is fixed on the measurement reference surface, and it is required that a feeler gauge of 0.02mm cannot pass. After passing the test, the reference measuring block 6 is fixed to avoid movement or shaking during subsequent measurements.

[0034] The present invention can solve the problem of the processing amount of the partition at one time, improve the adjustment efficiency of the partition, and avoid the influence of human factors (visual inspection). It can quantitatively judge the total clearance in the circumferential direction of the thrust pad bearing and ensure the dimensional accuracy and assembly performance of the thrust pad bearing in the circumferential direction. The invention has the advantages of simple operation, high efficiency, low cost, high dimensional and assembly accuracy, and a wide range of applications.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described with reference to the preferred embodiments of the present invention, it should be understood by those skilled in the art that various changes may be made in form and details without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. A method for adjusting the circumferential clearance of a thrust bearing of a marine gearbox, characterized in that: Take the installation surface of the partition as the measurement reference surface, and on the projection surface along the center line of the output shaft, take the extension line of the shortest distance between the outer circle of the thrust flange on the output shaft and the measurement reference surface as the marking line HH; according to the formula ΔL=Sinα×δ / 2, where δ is the radial clearance between the output shaft and the support bearing in a static state, and α is the angle between the measurement reference surface and the horizontal plane, obtain the marking line HH based on the marking line JJ after the offset distance ΔL; establish the center coordinate by taking the projection line GG of the measurement reference surface on the projection surface along the center line of the output shaft and the marking line JJ. The center of the two thrust pads is connected at the perpendicular bisector line as the center line of the partition along the center line of the output shaft. The projection line GG is used as the installation reference line of the partition. The positional relationship between the partition and the two adjacent thrust pads on both sides of the total circumferential gap is established, and the machining radius size of the arc on both sides of the partition is obtained. According to the actual radius size of the outer circle of the two thrust pads, the value of the total circumferential gap can be obtained.

2. The method for adjusting the circumferential clearance of a thrust pad bearing of a marine gearbox according to claim 1, characterized in that: When determining the positions of the centers of the two thrust pads in the central coordinate system, at least three different positions on the outer circles of the two thrust pads are taken as measuring points on the projection surface along the center line of the output shaft, and the distance L between the measuring points and the marking line JJ and the distance H between the measuring points and the projection line GG are measured respectively to obtain the positions of the measuring points based on the central coordinate system. According to the principle of the three-point method for determining the center of a circle, the positions of the centers of the two thrust pads in the central coordinate system are further determined.

3. The method for adjusting the circumferential clearance of a thrust pad bearing of a marine gearbox according to claim 1, characterized in that: After determining the perpendicular bisector of the line connecting the centers of the two thrust pads, adjust the positions of the two adjacent thrust pads located on both sides of the total circumferential gap so that the perpendicular bisector of the line connecting the centers of the two thrust pads coincides with the marking line JJ, that is, the center line of the partition projected along the center line of the output shaft coincides with the perpendicular bisector of the line connecting the centers of the two thrust pads.

4. The method for adjusting the circumferential clearance of a thrust pad bearing of a marine gearbox according to claim 1, characterized in that: The machining radius dimension of the arc on the partition is R=R′+(K±T) / 2, wherein the nominal dimension of the total side clearance in the circumferential direction is K=(the maximum value+minimum value required for the total circumferential clearance) / 2, and the tolerance T=(the maximum value-minimum value required for the total circumferential clearance) / 2. R′ is the actual radius dimension of the outer circle of the thrust pad, ensuring the consistency of the ± signs in the calculation formula for the machining radius dimensions of the arcs on both sides of the partition.

5. The method for adjusting the circumferential clearance of a thrust pad bearing of a marine gearbox according to claim 1, characterized in that: By adopting the reference transfer method, a reference measuring block is fixed on the gear box body corresponding to the position of the thrust flange and the thrust pad on the output shaft, and the measurement reference surface is transferred to the measurement surface on the reference measuring block that is parallel to it.

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