Assembly method of herringbone planetary gear train components

Abstract

The present invention discloses an assembly method for a herringbone gear planetary gear train assembly. During the installation of the herringbone gear planetary gear, a centering tooling is used to quickly center and position the shaft hole of the planetary gear and the mounting hole of the planet carrier, reducing the collision between the planetary gear shaft and the planetary gear; during the installation of the gear ring and the fixed sleeve, after the lower gear ring meshes with the lower tooth part of the planetary gear, the lower gear ring is jacked up by a supporting tooling, avoiding the weight of the gear ring and the fixed sleeve being concentrated on the meshing teeth of the planetary gear and the gear ring, resulting in damage to the meshing teeth.

Description

Technical Field

[0001] The present invention relates to the field of nuclear power speed reducers, and particularly to an assembly method for a herringbone gear planetary gear train assembly. Background Art

[0002] The technology of star gear speed reduction drive is applied in many fields such as aviation and nuclear power, and is often used as a power split gear drive. Its transmission route is input from the sun gear, through the planetary gears to the internal gear ring output, and it relies on multiple planetary gears to achieve the power split drive of the gear train. The star gear drive uses multiple planetary gears to share the load in terms of structure, forming power split, and has the characteristics of small volume, light weight, strong load-bearing capacity, and high reliability. Compared with the planetary gear drive, since it all adopts a fixed-axis gear train, the strength, stiffness and working reliability of the system are relatively high, and this transmission form is widely used in the speed reducers in the aero-engine body.

[0003] The patent document with the publication number of CN104141745A discloses a star herringbone gear speed reducer, which includes a planetary carrier, a fixed ring, a sun gear, and a star gear pair composed of planetary gears and an internal gear ring. The teeth of the sun gear, planetary gears and internal gear ring in the star gear pair are all herringbone teeth; the sun gear is an integral type with involute splines inside, and the sun gear is connected to the input shaft through the splines; the internal gear ring is assembled by combining an upper gear ring and a lower gear ring; the fixed ring is assembled with the internal gear ring to achieve torque output.

[0004] In the prior art, although the herringbone gear planetary gear train has advantages such as small volume, light weight, and strong load-bearing capacity, the installation process of the herringbone gear planetary gear train assembly is also particularly important. During the installation process of the herringbone planetary gear train, due to the relative positions of the mounting holes of the planetary carrier and the shaft holes of the planetary gears, there will be collisions between the planetary gear shafts, the planetary carrier and the planetary gears during the installation process of the planetary gear shafts, resulting in damage to the planetary gear shafts; during the installation process of the herringbone gear ring, the weights of the gear ring and the fixed sleeve are both concentrated on the meshing teeth of the planetary gear and the gear ring, resulting in damage to the meshing teeth of the planetary gear and the gear ring. Summary of the Invention

[0005] In order to solve the problems of slow assembly efficiency and component damage caused by inaccurate positioning of each component during the installation process of the herringbone planetary gear train in the prior art, the purpose of the present invention is to provide an assembly method for a herringbone gear planetary gear train assembly, which realizes the rapid centering and positioning of the shaft holes of the planetary gears and the mounting holes of the planetary carrier through a centering tooling, reducing the collision between the planetary gear shafts and the planetary gears; and jacking up the lower gear ring through a supporting tooling to avoid the weights of the gear ring and the fixed sleeve being concentrated on the meshing teeth of the planetary gear and the gear ring.

[0006] To achieve the above object, the present invention adopts the following technical solutions: An assembling method for a herringbone gear planetary gear train assembly, the herringbone gear planetary gear train assembly comprising a planet carrier, a lower gear ring, an upper gear ring, a fixing sleeve, a sun gear, a plurality of planet gear shafts and a plurality of planet gears. The plurality of planet gears are arranged around the sun gear and mesh for transmission. The external teeth of the sun gear and the plurality of planet gears are all herringbone teeth. Both the upper gear ring and the lower gear ring have internal teeth and external teeth. The internal teeth of the upper gear ring and the internal teeth of the lower gear ring can be assembled into a complete herringbone tooth. There are corresponding positioning marks on both the upper gear ring and the lower gear ring. The positioning marks are respectively engraved on the upper gear ring and the lower gear ring after the external teeth of the upper gear ring and the lower gear ring are processed simultaneously while being installed on the tooth alignment tooling. The herringbone gear planetary gear train assembly is assembled by the following steps;

[0007] Step 1) Place the planet carrier on the first tooling table. After installing the sun gear on the planet carrier, install the plurality of planet gear shafts and the plurality of planet gears on the planet carrier one by one. Among them, when installing the planet gear, first insert a centering tooling made of nylon material into the second installation hole of the planet carrier and the shaft hole of the planet gear, so that the annular first centering part on the centering tooling is in tight fit with the shaft hole, and the annular second centering part on the centering tooling is in tight fit with the second installation hole. Remove the centering tooling and insert the planet gear shaft into the second installation hole and the shaft hole, and then fix the planet gear shaft and the planet carrier. Among them, the first centering part and the second centering part are coaxially arranged, and the material of the centering tooling is nylon;

[0008] Step 2) Lift and sleeve the lower gear ring on the second tooling table, then lift the planet carrier with the installed planet gears and move it to the second tooling table. The planet carrier is located at the center of the lower gear ring, the axis of the sun gear is vertically upward, and the outer circular surface of the planet carrier extends out from the second tooling table;

[0009] Step 3) Lift the lower gear ring from bottom to top so that the internal teeth of the lower gear ring mesh with the lower half of the tooth profiles of the plurality of planet gears. Then install two jacking toolings on the side of the planet carrier. The two jacking toolings are arranged oppositely. The mounting seat of the jacking tooling is fixed on the planet carrier, and the screw rod threadedly connected to the mounting seat supports the lower gear ring. Then horizontally lift the upper gear ring, rotate the upper gear ring according to the position of the positioning mark on the lower gear ring, and sleeved the upper gear ring from top to bottom outside the plurality of planet gears so that the internal teeth of the upper gear ring mesh with the upper half of the tooth profiles of the plurality of planet gears. Then rotate the screw rods of the two jacking toolings respectively to adjust the relative positions of the upper gear ring and the lower gear ring so that the positioning internal marks located on the upper gear ring and the lower gear ring correspond to each other. Then lift and sleeve the fixing sleeve on the upper gear ring and the lower gear ring so that the external teeth of the upper gear ring and the external teeth of the lower gear ring are both meshed with the internal teeth of the fixing sleeve, and use a snap ring to axially position the upper gear ring, the lower gear ring and the fixing sleeve.

[0010] Preferably, in the step 1), after the static balance test of the planet carrier, the sun gear is installed on the planet carrier. Among them, the unbalance amount on the outer circular surface of the planet carrier ≯ 50g.

[0011] Preferably, the interior of the planet carrier is a cavity and the side surface of the planet carrier has a plurality of openings communicating with its interior. The plurality of second mounting holes all penetrate through the cavity. An annular first positioning groove is provided on the planet wheel shaft, and a plurality of second positioning holes are formed in the side surface of the planet carrier. The plurality of second positioning holes are respectively communicated with the plurality of second mounting holes located at the lower side. In step 1) above, after the planet wheel shaft is inserted into the second mounting hole and the shaft hole, the top of the planet wheel shaft is in tight fit with the second mounting hole located at the upper side. The first positioning hole is reamed at the joint of the planet wheel shaft and the second mounting hole located at the upper side, and then the first positioning pin is driven into the first positioning hole to radially fix the planet wheel shaft. The bottom of the planet wheel shaft is in tight fit with the second mounting hole located at the lower side. The first positioning groove is in the second mounting hole located at the lower side, and the second positioning pin is driven into the second positioning hole so that one end of the second positioning pin is inserted into the first positioning groove to complete the axial fixation of the planet wheel shaft.

[0012] Preferably, the planet wheel is pre-cooled to -50 °C before installation.

[0013] Preferably, after the installation of the planet wheel shaft is completed, the circular runout error of the planet wheel shaft and the planet wheel does not exceed 0.03.

[0014] Preferably, the mounting seat is fixed to the side surface of the planet carrier by two bolts, and the two bolts are respectively arranged on both sides of the screw rod. In step 1) above, when installing the jacking tooling, the lengths of the two bolts in contact with the planet carrier are respectively rotated to adjust the inclination angle of the mounting seat, and then the position where the screw rod contacts the lower ring gear is finely adjusted, and the relative positions of the screw rods on the two jacking toolings are precisely adjusted.

[0015] Preferably, in step 1) above, the screw rod of the jacking tooling abuts against the bottom of the lower ring gear through a gasket.

[0016] Preferably, after the installation of the upper ring gear is completed, by adjusting the screw rods of the two jacking toolings, the circular runout error between the upper ring gear and the lower ring gear does not exceed 0.03.

[0017] Preferably, in step 1) above, before removing the centering tooling, a fixing tooling is installed on the side surface of the planet carrier so that the planet wheel is clamped between the sun gear and the fixing tooling to radially fix the planet wheel. Since the external teeth of the sun gear and the external teeth of the planet wheel are both herringbone teeth, the planet wheel is axially fixed; after the planet wheel shaft is fixed on the planet carrier, the fixing tooling is removed.

[0018] Preferably, the fixing tooling includes a connecting portion capable of being fixed to the planet carrier, and a blocking portion for abutting against the planet wheel protrudes from the top of the connecting portion.

[0019] The beneficial effects of the technical solution of the present invention are as follows: 1) The second mounting hole of the planet carrier and the shaft hole of the planet gear are quickly aligned through the centering tooling, facilitating the installation of the planet gear shaft; 2) After the lower ring gear is installed, the lower ring gear is jacked up and supported at the current position by the supporting tooling, avoiding the weight of the upper ring gear and the fixing sleeve being concentrated on the meshing teeth of the planet gear and the ring gear during subsequent installation, better protecting the tooth profile of the gear, and at the same time being able to accurately adjust the relative position of the upper ring gear and the lower ring gear, making the operation of the planetary gear train assembly more stable and the assembly of the planetary gear train assembly easier; 3) Through the design of the tooth alignment tooling and the positioning marks, the positioning accuracy of the upper ring gear and the lower ring gear is improved, and the assembly difficulty of the planetary gear train assembly is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of a herringbone gear planetary gear train assembly;

[0021] Figure 2 is Figure 1 an enlarged view at A in

[0022] Figure 3 is a schematic diagram of completing the positioning of the planet gear through the centering tooling and the fixing tooling;

[0023] Figure 4 is a schematic structural diagram of the completed planet gear set;

[0024] Figure 5 is a schematic structural diagram of the centering tooling;

[0025] Figure 6 is a schematic structural diagram of the fixing tooling;

[0026] Figure 7 is a schematic structural diagram of the jacking tooling;

[0027] Figure 8 is a schematic structural diagram of the planet gear shaft.

[0028] Reference numerals: 19, central oil pipe; 20, sun gear; 201, intermediate through hole; 21, planet gear shaft; 211, positioning groove; 212, notch; 22, planet gear; 221, shaft hole; 23, oil injection pipe; 25, jacking tooling; 251, mounting seat; 252, screw 27, centering tooling; 271, first centering part; 272, second centering part; 273, lifting hole; 28, fixing tooling; 281, connecting part; 282, blocking part; 8, planet carrier; 81, cavity; 811, first mounting hole; 812, second mounting hole; 813, third mounting hole; 814, second positioning hole; 815, first positioning hole; 82, opening; 9, lower ring gear; 10, upper ring gear; 11, fixing sleeve; 110, upper snap ring; 111, lower snap ring. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

[0030] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

[0031] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more, unless otherwise clearly defined.

[0032] In the present invention, unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] In the present invention, unless otherwise clearly specified and defined, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features between them. Moreover, the first feature being "above", "over" and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "under" and "beneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or simply means that the horizontal height of the first feature is lower than that of the second feature. Embodiment

[0034] Assembly method of herringbone gear planetary gear train assembly, as Figure 1-8 shown, the herringbone gear planetary gear train assembly includes a planetary carrier 8, a lower gear ring 9, an upper gear ring 10, a fixing sleeve 11, a sun gear 20, a plurality of planetary gear shafts 21 and a plurality of planetary gears 22. The plurality of planetary gears 22 are arranged around the sun gear 20 and mesh for transmission. The external teeth of the sun gear 20 and the plurality of planetary gears 22 are all herringbone teeth. Both the upper gear ring 10 and the lower gear ring 9 have internal teeth and external teeth. The internal teeth of the upper gear ring 10 and the internal teeth of the lower gear ring 9 can be combined into a complete herringbone tooth. It is characterized in that: there are corresponding positioning marks on both the upper gear ring 10 and the lower gear ring 9. The positioning marks are respectively engraved on the upper gear ring 10 and the lower gear ring 9 after the external teeth are processed simultaneously when the upper gear ring 10 and the lower gear ring 9 are installed on the tooth alignment tooling. The herringbone gear planetary gear train assembly is assembled by the following steps;

[0035] Step 1) Place the planetary carrier 8 on the first tooling table. After installing the sun gear 20 on the planetary carrier 8, install the plurality of planetary gear shafts 21 and the plurality of planetary gears 22 on the planetary carrier 8 one by one; among them, when installing the planetary gear 22, first insert the centering tooling 27 into the second installation hole 812 of the planetary carrier 8 and the shaft hole 221 of the planetary gear 22, so that the annular first centering part 271 on the centering tooling 27 is in tight fit with the shaft hole 221, and the annular second centering part 272 on the centering tooling 27 is in tight fit with the second installation hole 812. Take out the centering tooling 27 and insert the planetary gear shaft 21 into the second installation hole 812 and the shaft hole 221, and then fix the planetary gear shaft 21 and the planetary carrier 8; among them, the first centering part 271 and the second centering part 272 are coaxially arranged, and the material of the centering tooling 27 is nylon;

[0036] Step 2) Lift and sleeve the lower gear ring 9 on the second tooling table, then lift the planetary carrier 8 installed with the planetary gears 22 and move it to the second tooling table. The planetary carrier 8 is located at the center of the lower gear ring 9, the axis of the sun gear 20 is vertically upward, and the outer circular surface of the planetary carrier 8 extends out of the second tooling table;

[0037] Step 3) Lift the lower ring gear 9 from bottom to top. After the internal teeth of the lower ring gear 9 are engaged with the lower half tooth profiles of the multiple planet gears 22, install two jacking tools 25 on the side of the planet carrier 8. The two jacking tools 25 are arranged oppositely. The mounting base of the jacking tool 25 is fixed on the planet carrier, and the screw 252 threadedly connected to the mounting base 251 supports the lower ring gear 9. Then, horizontally lift the upper ring gear 10, rotate the upper ring gear 10 according to the position of the positioning mark on the lower ring gear 9, and sleuth the upper ring gear 10 from top to bottom outside the multiple planet gears 22 so that the internal teeth of the upper ring gear 10 are engaged with the upper half tooth profiles of the multiple planet gears 22. Then, rotate the screws 252 of the two jacking tools 25 respectively to adjust the relative positions of the upper ring gear 10 and the lower ring gear 9 so that the positioning inner marks on the upper ring gear 10 and the lower ring gear 9 correspond to each other. Then, lift and sleuth the fixing sleeve 11 on the upper ring gear 10 and the lower ring gear 9. After the external teeth of the upper ring gear 10 and the external teeth of the lower ring gear 9 are both engaged with the internal teeth of the fixing sleeve 11, use a circlip to axially position the upper ring gear 10, the lower ring gear 9 and the fixing sleeve 11.

[0038] With such a setting, the centering tool 27 facilitates the quick centering of the planet carrier and the planet gears and the installation of the planet gear shafts 21. After the lower ring gear 9 is installed, the lower ring gear 9 is jacked up and supported at the current position by the supporting tool, avoiding the weight of the upper ring gear 10 and the fixing sleeve 11 being concentrated on the meshing teeth of the planet gears 22 and the ring gear during the subsequent installation process, and better protecting the gear tooth profiles. By arranging the jacking tools 25 oppositely, the inclination angle between the ring gear and the planet gears 22 can be adjusted quickly and accurately, and the relative positions of the upper ring gear and the lower ring gear are adjusted to make the relative positions between the ring gear and the planet gears 22 more precise.

[0039] In this embodiment, two annular positioning grooves are formed inside the fixing sleeve 11. The two positioning grooves are arranged in the up-down direction and are formed on the internal tooth section of the fixing sleeve 11. In the above step 4), the axial fixing method of the upper ring gear 10, the lower ring gear 9 and the fixing sleeve 11 is as follows: Before hoisting the fixing sleeve 11, install the upper circlip 110 in the upper positioning groove. After the fixing sleeve 11 is hoisted, install the lower circlip 111 in the lower positioning groove. The external teeth of the upper ring gear 10 and the external teeth of the lower ring gear 9 are located between the upper circlip 110 and the lower circlip 111. With such a setting, the axial positions of the upper and lower ring gears are adjusted to make the herringbone teeth radially meshed and centered, and the external teeth are aligned, so that the fixing sleeve, the upper ring gear and the lower ring gear are connected into a whole.

[0040] In this embodiment, the interior of the planet carrier 8 is a cavity 81 and the side surface of the planet carrier 8 has a plurality of openings 82 communicating with its interior, and the second mounting hole 812 penetrates through the cavity 81; in step 3), after the planet gear 22 is pushed into the cavity 81 of the planet carrier 8 from the opening 82 on the side surface of the planet carrier 8, the centering tooling 27 is inserted into the second mounting hole 812 of the planet carrier 8 and the shaft hole 221 of the planet gear 22, one end of the planet gear shaft 21 is axially fixed to the planet carrier 8, and the other end of the planet gear shaft 21 is radially fixed to the planet carrier 8. With such a setting, one end of the planet gear shaft 21 is axially fixed to the planet carrier 8, and the other end of the planet gear shaft 21 is radially fixed to the planet carrier 8, avoiding a complex fixing structure and reducing the influence of the fixing structure on the overall assembly accuracy. Further, as Figure 1 , Figure 2 , Figure 3 and Figure 4 shown, since a plurality of second mounting holes 812 all penetrate through the cavity 81, a plurality of second mounting holes 812 are all divided into upper and lower sections; the fixing method of the planet gear shaft 21 is: the top of the planet gear shaft 21 is in a tight fit with the second mounting hole 812 located on the upper side, a first positioning hole 815 is reamed at the joint of the planet gear shaft 21 and the second mounting hole 812 located on the upper side, and a first positioning pin is driven into the first positioning hole 815 to prevent the planet gear shaft 21 from rotating axially; the bottom of the planet gear shaft 21 is located in the second mounting hole 812 on the lower side, the bottom of the planet gear shaft 21 is in a tight fit with the second mounting hole 812 on the lower side, a circular positioning groove 211 is formed at the bottom of the planet gear shaft 21, a second positioning hole 814 communicating with the second mounting hole 812 on the lower side is formed on the planet carrier 8, and a second positioning pin is driven into the second positioning hole 814, and one end of the second positioning pin passes through the second positioning hole 814 and is inserted into the positioning groove 211. With such a setting, the planet gear shaft is axially and radially fixed in two ways, and the two positioning methods do not affect each other, making the positioning of the planet gear shaft and the planet carrier more accurate. Further, a notch 212 is formed on the planet gear shaft 21; when the planet gear shaft 21 is installed, the notch of the planet gear shaft 21 should be parallel to the tangential direction of the rotation path of the planet carrier 8. Further, before hoisting the planet gear shaft 21, the planet gear shaft 21 is pre-frozen. With such a setting, based on the principle of thermal expansion and contraction, the planet gear shaft is pre-frozen to facilitate the installation of the planet gear shaft 21. When the planet gear shaft 21 returns to normal temperature, the planet gear shaft 21 abuts against the planet carrier 8. Further preferably, the planet gear shaft 21 is pre-frozen to -50 °C. Further, the outer surface of the planet gear shaft is coated with a babbit alloy coating, and white oil is applied to the outer periphery of the babbit alloy coating before hoisting the planet gear shaft 21. With such a setting, the friction coefficient between the planet gear 22 and the planet gear shaft 21 is reduced, making the installation process of the planet gear shaft 21 smoother.

[0041] In this embodiment, in step 1), as Figure 3As shown, before removing the centering tooling 27, a fixing tooling 28 that abuts against the planet gear 22 is installed on the side wall of the planet carrier 8, so that the planet gear 22 is positioned by the sun gear 20, the centering tooling 27 and the fixing tooling 28; after the fixing tooling 28 is installed, since the external teeth of both the planet gear 22 and the sun gear 20 are herringbone teeth, and the axial movement of the planet gear 22 is prevented by the meshing teeth of the planet gear 22 and the sun gear 20, the fixing of the centering position of the shaft hole 221 of the planet gear 22 and the second mounting hole 812 of the planet carrier 8 is completed; then the centering tooling 27 is removed, and the planet gear 22 is clamped by the fixing tooling 28 and the sun gear 20 to radially fix the planet gear 22; after the planet gear shaft 21 is fixed to the planet carrier 8, the fixing tooling 28 is removed. With such a setting, the planet gear 22 is positioned by the sun gear 20, the centering tooling 27 and the fixing tooling 28. Even after the centering tooling is removed, the planet gear 22 is still clamped and positioned by the sun gear 20 and the fixing tooling 28, preventing the planet gear from moving around and improving the installation accuracy and efficiency. Further, as Figure 6 shown, the fixing tooling 28 includes a connecting portion 281 that can be fixed to the planet carrier 8. A blocking portion 282 for abutting against the planet gear 22 protrudes from the top of the connecting portion 281. The connecting portion 281 can be fixed to the planet carrier 8 by bolts. With such a setting, on the premise of meeting the assembly requirements, the structure of the tooling is simplified, and the manufacturing difficulty and cost of the tooling are reduced.

[0042] In this embodiment, after the planet gear shaft 21 is installed, the circular runout error between the planet gear shaft 21 and the planet gear 22 does not exceed 0.03.

[0043] In this embodiment, as Figure 1 and Figure 7 shown, the mounting seat 251 of the jacking tooling 25 is fixed to the side of the planet carrier 8 by two bolts. The threaded section of the bolt passes through the mounting seat 251 and is threadedly connected to the planet carrier 8. The two bolts are arranged on both sides of the screw rod 252; when installing the jacking tooling 25, the lengths of the two bolts connected to the planet carrier 8 are adjusted by rotating the two bolts respectively, thereby adjusting the inclination angle of the mounting seat 251, and further finely adjusting the position where the screw rod 252 contacts the lower ring gear 9, and finely adjusting the relative position of the screw rods 252 on the two jacking toolings 25. With such a setting, it is convenient to adjust the accuracy of the relative position between the two screw rods, making the effect of the jacking tooling more obvious and facilitating the adjustment of the relative position between the upper ring gear and the lower ring gear. Further, the screw rod 252 of the jacking tooling 25 abuts against the bottom of the lower ring gear 9 through a gasket. With such a setting, the force-bearing area of the lower ring gear is increased, preventing damage to the lower ring gear 9.

[0044] In this embodiment, the material of the centering tool 27 is nylon. This arrangement enables the use of a softer material to prevent the centering tool 27 from damaging the surface of the shaft hole 221. Further, at least two lifting holes 273 for installing lifting rings are provided on the top of the first centering portion 271, and the axes of the lifting holes 273 are parallel to the central axis of the first centering portion 271. Further, a plurality of lifting holes 273 for installing lifting ears are provided on the top of the first centering portion 271. In the step 1), before moving the centering tool 27, the lifting ears are installed at the lifting holes 273, and the centering tool 27 is lifted horizontally by the lifting ears. This arrangement facilitates the lifting of the centering tool through the lifting holes, and the annular centering tool effectively reduces its own weight, facilitates the movement of the centering tool, and can reduce the conflict between the centering tool and the inner hole of the planetary gear during the centering process, thereby reducing the damage to the inner hole of the planetary gear.

[0045] In this embodiment, when the upper and lower gear rings are processed, after the upper and lower gear rings 10 and 9 are fixed on the gear tooling, the distance between the top of the upper gear ring 10 and the bottom of the lower gear ring 9 is greater than the height of the correction tire, and the lower clamping plate of the gear tooling is fixedly connected to the bottom of the correction tire and the bottom of the lower gear ring 9 by multiple bolts, and the upper clamping plate is fixedly connected to the top of the correction tire and the top of the upper gear ring 10 by multiple bolts; wherein the lower clamping plate and the upper clamping plate are both circular, the outer diameter of the lower clamping plate is smaller than the diameter of the root circle of the lower gear ring 9, and the outer diameter of the upper clamping plate is smaller than the diameter of the root circle of the upper gear ring 10. With such an arrangement, the outer teeth of the upper gear ring and the lower gear ring have a high degree of consistency through the above method, and after matching through the positioning mark, the tooth profile of the outer teeth of the upper gear ring is consistent with the tooth profile of the outer teeth of the lower gear ring, which reduces the error, improves the installation efficiency and installation accuracy, and makes the transmission process more stable. Furthermore, after the outer teeth of the upper gear ring 10 and the lower gear ring 9 are processed and the upper gear ring 10 and the lower gear ring 9 are assembled, the circular runout error between the upper gear ring 10 and the lower gear ring 9 does not exceed 0.03.

[0046] In this embodiment, Figure 1 , Figure 3 and Figure 4 As shown, the herringbone planetary gear train assembly also includes a plurality of fuel injection pipes 23, and a plurality of third mounting holes 813 are opened on the planet carrier 8, and the plurality of third mounting holes 813 correspond to the plurality of fuel injection pipes 23 one by one, and the plurality of third mounting holes 813 all pass through the cavity 81; in the step 1), before the sun gear 20 is installed, the plurality of fuel injection pipes 23 are respectively inserted into the plurality of third mounting holes 813, and the plurality of fuel injection pipes 23 are all fixed on the planet carrier 8. Furthermore, after the fuel injection pipe 23 is installed, the two ends of the fuel injection pipe 23 do not extend beyond the planet carrier 8. In this way, interference between the fuel injection pipe 23 and other components is avoided. Further, as Figure 1 and Figure 4As shown in the figure, the fixing method of the fuel injection pipe 23 is to expand both ends of the fuel injection pipe 23 and fix the fuel pipe on the planet carrier 8 through bolts and glue. With this setting, expanding both ends of the fuel injection pipe 23 can effectively prevent the axial movement of the fuel injection pipe 23 and improve the connection strength and stability of the components inside the planetary gear set. Further, after the fuel injection pipe is coated with glue, the planet carrier 8 is heated to 150 °C. With this setting, the solidification of the glue is accelerated and the assembly efficiency is improved. Further, a plurality of fuel injection holes are provided on the plurality of fuel injection pipes 23, and the fuel injection holes are oriented towards the meshing portion of the planetary gear 22 and the sun gear 20. With this setting, lubrication and cooling protection can be provided more directly for the internal transmission structure of the planetary gear set.

[0047] In this embodiment, as Figure 1 , Figure 3 and Figure 4 shown, the herringbone gear planetary gear train assembly further includes an intermediate oil pipe 19. A first mounting hole 811 is provided on the planet carrier 8, and a plurality of second mounting holes 812 and a plurality of third mounting holes 813 are all arranged around the first mounting hole 811, and the first mounting hole penetrates through the cavity 81; in the above step 1), after a plurality of planetary gears 22 are all mounted on the planet carrier 8, the planet carrier 8 is lifted, and the intermediate oil pipe 19 is inserted into the planet carrier 8 from the first mounting hole 811 located on the lower side. The intermediate oil pipe 19 is inserted into the intermediate through hole 201 of the sun gear 20, and then the intermediate oil pipe is fixedly connected to the bottom of the planet carrier 8, and the first mounting hole 811 located on the lower side is blocked. With this setting, after the planetary gear 22 is installed, the sun gear 20 will no longer move, so that the intermediate oil pipe 19 can be smoothly installed. Further, as Figure 1 and Figure 3 shown, the first mounting hole 811 located on the lower side is a countersunk hole, and a fixing mounting seat is fixedly installed on the bottom end of the intermediate oil pipe 19; the mounting seat is inserted into the countersunk hole and fixedly connected to the bottom of the planet carrier 8, and the intermediate oil pipe 19 blocks the bottom of the first mounting hole 811 through the mounting seat.

[0048] In this embodiment, after the lower ring gear 9 meshes with the planetary gear 22, a plurality of support tools are used to assist in supporting the lower ring gear. The support tool includes a jack and a wooden cushion block, and the jack jacks up the lower ring gear 10 through the wooden cushion block. With this setting, since the fixing sleeve 11 and the upper ring gear 10 still need to be hoisted later, the lower ring gear 9 needs to be in a stable and safe state at this time. The jack can provide sufficient supporting force for the lower ring gear, and the wooden cushion block can prevent damage to the lower ring gear 9.

[0049] In this embodiment, the planet carrier 8 needs to be subjected to a static balance test before assembly, and it is required that the unbalance amount on the outer cylindrical surface of the planet carrier 8 ≯ 50 g. With this setting, the stability and reliability of the planetary gear set during operation are ensured.

[0050] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0051] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention without departing from the principles and purposes of the present invention.

Claims

1. A method for assembling a herringbone gear planetary gear train assembly, the herringbone gear planetary gear train assembly comprising a planetary carrier (8), a lower gear ring (9), an upper gear ring (10), a fixing sleeve (11), a sun gear (20), a plurality of planetary gear shafts (21) and a plurality of planetary gears (22), the plurality of planetary gears (22) being arranged around the sun gear (20) and meshing for transmission, the external teeth of the sun gear (20) and the plurality of planetary gears (22) being herringbone teeth, both the upper gear ring (10) and the lower gear ring (9) having internal teeth and external teeth, and the internal teeth of the upper gear ring (10) and the internal teeth of the lower gear ring (9) being capable of being assembled into a complete herringbone tooth, characterized in that: Both the upper gear ring (10) and the lower gear ring (9) are provided with corresponding positioning marks. The positioning marks are respectively engraved on the upper gear ring (10) and the lower gear ring (9) after the outer teeth are processed simultaneously when the upper gear ring (10) and the lower gear ring (9) are installed on the tooth-aligning tooling. The herringbone gear planetary gear train assembly is assembled by the following steps; Step 1) Place the planetary carrier (8) on the first tooling table. After installing the sun gear (20) on the planetary carrier (8), install multiple planetary gear shafts (21) and multiple planetary gears (22) on the planetary carrier (8) one by one; among them, when installing the planetary gear (22), first insert the centering tooling (27) made of nylon into the second installation hole (812) of the planetary carrier (8) and the shaft hole (221) of the planetary gear (22), so that the annular first centering part (271) on the centering tooling (27) is in tight fit with the shaft hole (221), and the annular second centering part (272) on the centering tooling (27) is in tight fit with the second installation hole (812). Take out the centering tooling (27) and insert the planetary gear shaft (21) into the second installation hole (812) and the shaft hole (221), and then fix the planetary gear shaft (21) and the planetary carrier (8); among them, the first centering part (271) and the second centering part (272) are coaxially arranged, and the material of the centering tooling (27) is nylon; Step 2) After hoisting and sleeving the lower gear ring (9) on the second tooling table, hoist the planetary carrier (8) installed with the planetary gears (22) and move it to the second tooling table. The planetary carrier (8) is located at the center of the lower gear ring (9), the axis of the sun gear (20) is vertically upward, and the outer circular surface of the planetary carrier (8) extends out from the second tooling table; Step 3) Hoist the lower gear ring (9) from bottom to top, so that the internal teeth of the lower gear ring (9) are meshed with the lower half tooth profiles of multiple planetary gears (22). Then, install two jacking toolings (25) on the side of the planetary carrier (8). The two jacking toolings (25) are arranged oppositely. The mounting seat of the jacking tooling (25) is fixed on the planetary carrier, and the screw rod (252) threadedly connected with the mounting seat (251) supports the lower gear ring (9); then hoist the upper gear ring (10) horizontally, rotate the upper gear ring (10) according to the position where the positioning mark of the lower gear ring (9) is located, and sleev the upper gear ring (10) from top to bottom outside multiple planetary gears (22), so that the internal teeth of the upper gear ring (10) are meshed with the upper half tooth profiles of multiple planetary gears (22); then rotate the screw rods (252) of the two jacking toolings (25) respectively to adjust the relative positions of the upper gear ring (10) and the lower gear ring (9) so that the positioning internal marks located on the upper gear ring (10) and the lower gear ring (9) correspond to each other; then hoist the fixing sleeve (11) and sleev it on the upper gear ring (10) and the lower gear ring (9). After the external teeth of the upper gear ring (10) and the external teeth of the lower gear ring (9) are both meshed with the internal teeth of the fixing sleeve (11), use a circlip to axially position the upper gear ring (10), the lower gear ring (9) and the fixing sleeve (11).

2. The assembling method of a herringbone gear planetary gear train assembly according to claim 1, characterized in that: In step 1), after the static balance test of the planet carrier (8), the sun gear is installed on the planet carrier; wherein, the unbalance amount on the outer cylindrical surface of the planet carrier (8) is not more than 50 g.

3. The assembling method of a herringbone planetary gear train assembly according to claim 1, characterized in that: The interior of the planet carrier (8) is a cavity (81), and the side surface of the planet carrier (8) has a plurality of openings (82) communicating with its interior. A plurality of second mounting holes (812) all penetrate through the cavity (81). An annular first positioning groove (211) is provided on the planet gear shaft (21). A plurality of second positioning holes (814) are formed on the side surface of the planet carrier (8). The plurality of second positioning holes (814) are respectively communicated with a plurality of second mounting holes (812) located on the lower side. In the above step 1), after the planet gear shaft (21) is inserted into the second mounting hole (812) and the shaft hole (221), the top of the planet gear shaft (21) is in tight fit with the second mounting hole (812) located on the upper side. A first positioning hole (815) is reamed at the joint of the planet gear shaft (21) and the second mounting hole (812) located on the upper side. Then, a first positioning pin is driven into the first positioning hole (815) to radially fix the planet gear shaft (21). The bottom of the planet gear shaft (21) is in tight fit with the second mounting hole (812) located on the lower side. The first positioning groove (211) is inside the second mounting hole (812) located on the lower side. A second positioning pin is driven into the second positioning hole (814) so that one end of the second positioning pin is inserted into the first positioning groove (211) to complete the axial fixation of the planet gear shaft (21).

4. The assembling method of a herringbone gear planetary gear train assembly according to claim 1, characterized in that: The planet gear (22) is pre-cooled to -50 °C before installation.

5. The assembling method of a herringbone gear planetary gear train assembly according to claim 1, characterized in that: The mounting base (251) is fixed to the side surface of the planet carrier (8) by two bolts. The two bolts are respectively arranged on both sides of the screw rod (252). In the above step 1), when installing the jacking tooling (25), the lengths of the two bolts in contact with the planet carrier (8) are respectively rotated to adjust the inclination angle of the mounting base (251), and further finely adjust the position where the screw rod (252) contacts the lower ring gear (9), and finely adjust the relative positions of the screw rods (252) on the two jacking toolings (25).

6. The assembling method of a herringbone gear planetary gear train assembly according to claim 1, characterized in that: In the above step 1), the screw rod (252) of the jacking tooling (25) abuts against the bottom of the lower ring gear (9) through a gasket.

7. A method for assembling a herringbone gear planetary gear train assembly according to claim 1, characterized in that: In the above step 1), before removing the centering tooling (27), a fixing tooling (28) is installed on the side surface of the planet carrier (8) so that the planet gear (22) is clamped between the sun gear (20) and the fixing tooling (28) to radially fix the planet gear (22). Since the external teeth of the sun gear (20) and the external teeth of the planet gear (22) are both herringbone teeth, the planet gear (22) is axially fixed. After the planet gear shaft (21) is fixed on the planet carrier (8), the fixing tooling (28) is removed.

8. The assembling method of a herringbone gear planetary gear train assembly according to claim 7, characterized in that: The fixing tooling (28) includes a connecting portion (281) capable of being fixed to the planet carrier (8). A blocking portion (282) for abutting against the planet gear (22) protrudes from the top of the connecting portion (281).

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