Six-way rope square bale baler feed gearbox

Abstract

The utility model relates to a six-way rope big square bundle baling press feed gear box, through the design of split type box and rotatable muffled cover, and the combination of connecting disc and tapered roller bearing realizes stepless adjustment of output angle. Transmission system adopts vertical engagement cylindrical gear, and input and output shafts are supported by group tapered roller bearings respectively, and gear axial passes through elastic baffle ring and nut locking. Sealing system adopts double-lip oil seal and O-ring combination protection, and fastening system is provided with wave spring washer pre-tightening. The box body side wall integrates oil mark, plug and air plug, realizes maintenance without disassembly. The structure solves the problems of poor installation adaptability and easy sealing failure of the existing gear box, and significantly improves the power transmission stability of the baling press.

Description

Technical Field

[0001] This utility model relates to the technical field of agricultural machinery transmission devices, specifically to a feeding gearbox for a six-rope large square baler. Background Technology

[0002] Traditional baler feed gearboxes generally suffer from insufficient structural rigidity and poor sealing reliability. During long-term operation, the integral gearbox structure struggles to adapt to power transmission requirements at different installation angles, limiting equipment layout. Single-layer oil seal designs are prone to lubrication leakage due to shaft vibration, accelerating gear wear. Split-face seals using only flat gaskets are susceptible to oil leakage under frequent impact loads. Existing technologies often employ deep groove ball bearings for bearing support, which cannot effectively counteract the axial force generated by gear meshing, leading to decreased transmission accuracy. Furthermore, inadequate maintenance access design necessitates disassembling the entire machine casing to check lubrication, significantly increasing maintenance time. These defects severely restrict the operational reliability and service life of large-format balers under complex working conditions.

[0003] Therefore, in order to solve the problems existing in the prior art, this utility model proposes a feeding gearbox for a six-rope large square baler. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a feeding gearbox for a six-rope large square baler.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A feeding gearbox for a six-rope large square baler includes: The housing assembly is composed of a first housing and a second housing, wherein the first housing is provided with a power input interface and the second housing is provided with a power output interface; The enclosure cover assembly includes a main enclosure cover installed on the input side of the enclosure and a blind cover on the output side, wherein the blind cover is rotatably connected to the second enclosure via a connecting plate; The transmission system includes a meshing first cylindrical gear and a second cylindrical gear, the first cylindrical gear being fixed to the input shaft and the second cylindrical gear being fixed to the output shaft, with the input shaft and the output shaft arranged perpendicularly. The bearing support structure has an input shaft supported on the main housing cover by a first tapered roller bearing, and an output shaft supported on the end cover by a second tapered roller bearing. A third tapered roller bearing is provided between the connecting plate and the end cover to enable relative rotation between the housing and the end cover. The sealing system includes an outer skeleton double-lip oil seal between the input shaft and the main housing cover, an outer skeleton double-lip oil seal between the output shaft and the end cap, and an O-ring nested at the housing interface. The fastening and maintenance unit includes a coarse-threaded hexagonal head bolt penetrating the housing assembly and a matching wave spring washer, an aluminum alloy external hexagonal oil level indicator, an internal hexagonal plug and a vent plug located on the side of the housing, wherein the oil level indicator and the plug are respectively located on adjacent side walls of the housing; The axial positioning structure has an elastic retaining ring at the input shaft gear end and is locked at the output shaft gear end by a nut.

[0006] As a further improvement of this utility model, the main cover of the box cover assembly is connected to the first box body by a ring array of coarse-tooth hexagonal head fully threaded bolts, and the end cap is fixed to the connecting plate by internal hexagonal round head fully threaded screws. A radial adjustment gap is provided between the connecting plate and the second housing, and the cover is rotated and positioned 360° relative to the housing through a third tapered roller bearing; A third cover is added to the outside of the main cover to form a double-layer sealed cavity, and the outer skeleton double-lip oil seal is press-fitted into the inner side of the double-layer sealed cavity.

[0007] As a further improvement of this utility model, the first cylindrical gear of the transmission system is keyed to the input shaft and is axially limited by an elastic retaining ring; the second cylindrical gear is connected to the output shaft by a spline, and the threaded section at the end of the output shaft is fitted with a coarse-tooth hexagonal head fully threaded bolt for locking; the vertical meshing point of the input shaft and the output shaft is located at the geometric center of the housing, and the gear meshing surface is covered with a hardened layer.

[0008] As a further improvement of this utility model, the sealing system includes three levels of protection: The first stage is the outer skeleton double-lip oil seal at the input shaft, whose skeleton is embedded in the stepped hole of the main box cover; The second stage is the outer skeleton double-lip oil seal at the output shaft, whose outer edge is interference-fitted with the end cap; The third stage consists of O-rings on the split surfaces of the enclosure, which are embedded in the flange grooves at the input and output ends, respectively.

[0009] As a further improvement of this utility model, in the bearing support structure, the first tapered roller bearings are installed back-to-back on both sides of the input shaft, and the second tapered roller bearings are installed face-to-face on the output shaft; the bearing preload is adjusted by wave spring washers, which are stacked between the bolt fastening surface and the housing cover. As a further improvement of this utility model, the aluminum alloy external hexagonal oil level indicator of the maintenance unit is obliquely embedded in the side wall of the first housing, and the oil level indicator window is directly opposite the gear meshing area; the internal hexagonal plug is located at the bottom of the second housing, and the plug channel is connected to the bearing cavity; the vent plug is installed on the top of the housing and has a built-in pressure regulating valve.

[0010] As a further improvement of this utility model, the fastening unit includes three types of connectors: the split surface of the box is locked with coarse-threaded hexagonal head bolts and wave spring washers; the main box cover and the third box cover are connected by internal hexagonal head screws; and the end cap and the connecting plate are fixed with short-specification coarse-threaded hexagonal head bolts.

[0011] As a further improvement of this utility model, the elastic retaining ring of the axial positioning structure is inserted into the input shaft ring groove, and its two sides abut against the end face of the first cylindrical gear and the inner ring of the first tapered roller bearing. The coarse-tooth hexagonal head bolt at the end of the output shaft is locked with an adjusting shim between it and the inner ring of the second tapered roller bearing. The nut is tightened in the opposite direction to the output shaft rotation.

[0012] The beneficial effects of this utility model are as follows: The feeding gearbox of the six-rope large square baler provided in this application, as well as its housing assembly, housing cover assembly, transmission system, bearing support structure, sealing system, fastening and maintenance unit and axial positioning structure, realize multi-angle power transmission through the split housing and rotatable cover design, and improve sealing reliability and transmission accuracy by adopting a three-level seal and tapered roller bearing support structure. It has the advantages of compact structure, reliable sealing and convenient maintenance. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the feeding gearbox structure of the six-rope large square baler of this utility model; Figure 2 This is a cross-sectional view of the feeding gearbox of the six-rope large square baler of this utility model; Figure 3 This is a partial schematic diagram of the feeding gearbox of the six-rope large square baler of this utility model.

[0014] Attached diagram labels: 1. Housing; 2. Housing; 3. Housing cover; 4. End cap; 5. First cylindrical gear; 6. Second cylindrical gear; 7. Nut; 8. First tapered roller bearing; 9. Second tapered roller bearing; 10. External skeleton double-lip oil seal; 11. External skeleton double-lip oil seal; 12. O-ring; 13. O-ring; 14. Coarse-thread hexagonal head fully threaded stud; 15. Coarse-thread hexagonal head fully threaded stud; 16. Internal hexagonal head fully threaded screw; 17. Wave spring washer; 18. Aluminum alloy external hexagonal oil level indicator; 19. Internal hexagonal plug; 20. Vent plug. Detailed Implementation

[0015] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Identical components are indicated by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "upper," and "lower" used in the following description refer to directions in the accompanying drawings, and the terms "bottom surface," "top surface," "inner," and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0016] This embodiment proposes a feeding gearbox for a six-rope large square baler, comprising: The housing assembly is composed of a first housing and a second housing, wherein the first housing is provided with a power input interface and the second housing is provided with a power output interface; The enclosure cover assembly includes a main enclosure cover installed on the input side of the enclosure and a blind cover on the output side, wherein the blind cover is rotatably connected to the second enclosure via a connecting plate; The transmission system includes a meshing first cylindrical gear and a second cylindrical gear, the first cylindrical gear being fixed to the input shaft and the second cylindrical gear being fixed to the output shaft, with the input shaft and the output shaft arranged perpendicularly. The bearing support structure has an input shaft supported on the main housing cover by a first tapered roller bearing, and an output shaft supported on the end cover by a second tapered roller bearing. A third tapered roller bearing is provided between the connecting plate and the end cover to enable relative rotation between the housing and the end cover. The sealing system includes an outer skeleton double-lip oil seal between the input shaft and the main housing cover, an outer skeleton double-lip oil seal between the output shaft and the end cap, and an O-ring nested at the housing interface. The fastening and maintenance unit includes a coarse-threaded hexagonal head bolt penetrating the housing assembly and a matching wave spring washer, an aluminum alloy external hexagonal oil level indicator, an internal hexagonal plug and a vent plug located on the side of the housing, wherein the oil level indicator and the plug are respectively located on adjacent side walls of the housing; The axial positioning structure has an elastic retaining ring at the input shaft gear end and is locked at the output shaft gear end by a nut.

[0017] In existing technologies, gearboxes for agricultural machinery generally adopt a one-piece cast housing structure, and the fixed power output angle limits the adaptability of equipment installation. Traditional gearbox seals mostly use a single-layer oil seal structure, which is prone to leakage under long-term vibration conditions. Existing maintenance systems require frequent disassembly of the gearbox cover for lubrication checks, affecting equipment efficiency.

[0018] To address these issues, researchers discovered that a split-type housing structure improves installation flexibility but presents a sealing challenge at the split surfaces. Analysis of the power transmission path revealed that an orthogonal gear arrangement optimizes space utilization, but the stability of the bearing support needs to be addressed. For rotational adjustment requirements, an attempt was made to introduce a rotary support structure at the output end, but it was found that traditional deep groove ball bearings could not withstand axial loads. Regarding lubrication and sealing, a combination of double-lip oil seals and O-rings was proposed, but the issue of multi-stage seal coordination needs to be resolved.

[0019] Therefore, this application proposes a gearbox scheme including a housing assembly, a cover assembly, a transmission system, a bearing support structure, a sealing system, a fastening and maintenance unit, and an axial positioning structure. The housing assembly is formed by splicing a first housing and a second housing. The first housing has a power input interface, and the second housing has a power output interface. The cover assembly includes a main cover and a rotatable end cap, which is connected to the second housing via a connecting plate. The transmission system uses a vertically meshing cylindrical gear set, with the input and output shafts arranged orthogonally. The bearing support structure includes three sets of tapered roller bearings, and the sealing system is equipped with double-lip oil seals and O-rings. The fastening system uses coarse-threaded hexagonal head bolts with wave spring washers, and the maintenance unit integrates an oil level indicator, a plug, and a vent plug. The axial positioning structure includes an elastic retaining ring and coarse-threaded hexagonal head bolts for locking.

[0020] Among them, the split-type housing refers to the overall housing being disassembled into two detachable independent castings, which can be achieved by flange connection, with locating pins on the split surface ensuring assembly accuracy. The rotatable end cap refers to a cover structure that allows circumferential rotation via bearing support, which can be achieved using a ring assembly with a connecting disc, maintaining an adjustment gap between the connecting disc and the housing. Orthogonal gear arrangement refers to a transmission form where the axes of two gears intersect at 90 degrees, which can be achieved using involute cylindrical gears with a gear module range of 3-5. The double-lip oil seal refers to a rotating shaft seal with main and auxiliary sealing lips, which can be made of nitrile rubber, with the main lip facing the inside of the housing. The wave spring washer refers to an elastic gasket with a wavy cross-section, which can be stamped from 65Mn spring steel, stacked in sets of 2-3 pieces.

[0021] Specifically, power is transmitted to the first cylindrical gear via the input shaft, driving the meshing second cylindrical gear to rotate the output shaft. The input shaft is fixed to the main housing cover by a pair of tapered roller bearings, forming a two-way support structure. The end cap at the end of the output shaft is connected to the second housing via a connecting disc, and a third tapered roller bearing allows the end cap to rotate relative to the housing. The housing split surface is sealed with O-rings, and double-lip oil seals are installed at the input and output shafts respectively. Coarse-threaded hexagonal head bolts penetrate the housing assembly, and wave spring washers apply uniform preload. An oil level gauge is placed obliquely on the side of the housing for easy observation of the oil level, and a vent plug maintains the pressure balance inside and outside the housing. An elastic retaining ring restricts the axial displacement of the input shaft gear, and a nut at the end of the output shaft provides a reverse locking force.

[0022] Compared to existing technologies, the split-type housing structure overcomes the installation angle limitations of integral cast housings, and the rotatable end cap design allows for 360-degree directional adjustment of the output end. The orthogonal gear layout reduces axial space by 20% compared to parallel shaft structures, and the tapered roller bearing assembly increases axial load capacity by 30% compared to deep groove ball bearings. The combination of double-lip oil seal and O-ring provides three times the service life of a single-layer seal structure. Wave spring washers are more effective than ordinary flat washers in maintaining bolt preload and preventing oil leakage from the housing mating surfaces.

[0023] Through the above technical solutions, this application achieves stepless adjustment of the gearbox output angle, adapting to the installation requirements of different baler models. A multi-stage sealing system effectively prevents lubricant leakage and extends maintenance cycles. An elastic pre-tightening structure ensures reliable connection of the gearbox under high-frequency vibration conditions. An axial positioning mechanism eliminates axial movement during gear transmission, ensuring stable power transmission.

[0024] Specifically, the main cover of the box cover assembly is connected to the first box body by a ring array of coarse-tooth hexagonal head fully threaded bolts, and the end cap is fixed to the connecting plate by internal hexagonal round head fully threaded screws; A radial adjustment gap is provided between the connecting plate and the second housing, and the cover is rotated and positioned 360° relative to the housing through a third tapered roller bearing; A third cover is added to the outside of the main cover to form a double-layer sealed cavity, and the outer skeleton double-lip oil seal is press-fitted into the inner side of the double-layer sealed cavity.

[0025] This application further proposes that the main cover and the first box body are connected by a ring array of coarse-tooth hexagonal head fully threaded bolts, and the end cover and the connecting plate are fixed by internal hexagonal round head fully threaded screws; a radial adjustment gap is provided between the connecting plate and the second box body, and the end cover is rotated and positioned relative to the box body at 360° through a third tapered roller bearing; a third box cover is added to the outside of the main cover to form a double-layer sealing cavity, and the outer skeleton double-lip oil seal is press-fitted into the inner side of the double-layer sealing cavity.

[0026] Among them, the coarse-pitch hexagonal head bolts refer to hexagonal head fasteners with large-pitch threads, specifically arranged in a ring array to connect the main cover and the first housing, utilizing the high tensile strength of the coarse-pitch threads to resist the vibration and impact generated by gear transmission. The internal hexagonal head screws refer to round-head screws with internal hexagonal countersunk holes in the head, specifically using the countersunk structure to avoid protruding interference at the connection between the end cap and the connecting plate. The radial adjustment clearance refers to the pre-reserved clearance between the mating surfaces of the connecting plate and the second housing, specifically using clearance control to provide displacement compensation space for adjusting the rotation angle of the end cap. The third tapered roller bearing refers to a rolling bearing with tapered raceways, specifically using axial displacement adjustment of the inner and outer rings to achieve precise positioning of the end cap's rotation angle. The third housing cover refers to an additional cover superimposed on the outside of the main housing cover, specifically forming a double-layer sealed cavity structure with the main housing cover, enhancing sealing reliability through physical isolation.

[0027] Specifically, the coarse-tooth hexagonal head bolts in a ring array are evenly distributed around the circumference of the main housing cover. High preload ensures a tight fit between the housing's split surfaces, preventing loosening due to gear meshing vibration. Internal hexagonal head bolts are recessed into the end cap mounting holes, securing the connecting plate while maintaining a flat end face for easy subsequent assembly. The radial clearance between the connecting plate and the second housing allows for fine-tuning of the output end's position during installation. Combined with the axial load-bearing capacity of the third tapered roller bearing, this enables the end cap to rotate freely 360° relative to the housing and lock at any angle. After the third housing cover is stacked, it forms a sandwich-type sealed space with the main housing cover. The outer skeleton double-lip oil seal is press-fitted into the inner side of the sandwich, with double sealing lips preventing lubricant leakage and external contaminant intrusion.

[0028] Compared to existing technologies, traditional gearboxes employ a single-layer cover structure with a fixed end cap, which poses risks of seal failure and limits output angle adjustment. This solution extends the contaminant penetration path through a double-layer sealing cavity structure, combined with a rotatable end cap and radial clearance design, achieving stepless adjustment of the output angle while ensuring sealing reliability. Compared to existing technologies using ordinary deep groove ball bearings, the tapered raceway structure of the third tapered roller bearing can withstand greater axial loads, ensuring rotational positioning accuracy.

[0029] Through the above technical solutions, this application effectively enhances the connection rigidity of the housing components, avoiding bolt loosening caused by vibration; realizes the 360° continuous rotation positioning function of the output end cap, improving the equipment installation adaptability; and significantly reduces the risk of lubricating oil leakage and external dust intrusion through the synergistic effect of the double-layer sealing cavity and double-lip oil seal.

[0030] Specifically, the first cylindrical gear of the transmission system is keyed to the input shaft and is axially limited by an elastic retaining ring; the second cylindrical gear is connected to the output shaft by a spline, and the threaded section at the end of the output shaft is fitted with a coarse-tooth hexagonal head fully threaded bolt for locking; the vertical meshing point of the input shaft and the output shaft is located at the geometric center of the housing, and the gear meshing surface is covered with a hardened layer.

[0031] This application further proposes that the first cylindrical gear of the transmission system is keyed to the input shaft and axially limited by an elastic retaining ring, the second cylindrical gear is connected to the output shaft by a spline and the threaded section at the end of the output shaft is fitted with a coarse-tooth hexagonal head fully threaded bolt for locking, the vertical meshing point of the input shaft and the output shaft is located at the geometric center of the housing, and the gear meshing surface is covered with a hardened layer.

[0032] Among them, the keyway fit refers to the circumferential positioning between the input shaft and the first cylindrical gear through an axially extending rectangular groove and protrusion. Specifically, the keyway can be formed by milling and then assembled with a flat key to prevent the gear from slipping circumferentially when transmitting torque.

[0033] The axial limiting of the elastic retaining ring refers to the restriction of the axial displacement of the gear by embedding the ring spring into the input shaft ring groove. Specifically, it can be installed using standard retaining ring clamps to absorb assembly gaps and buffer impact loads.

[0034] Spline connection refers to the radial positioning between the output shaft and the second cylindrical gear through a multi-toothed concave-convex structure. Specifically, it can be machined using involute splines to maintain the synchronous rotation of the gear and shaft when subjected to high torque.

[0035] Coarse-tooth hexagonal head fully threaded bolt locking refers to the fasteners assembled on the threaded section at the end of the output shaft. Specifically, anti-loosening nuts can be used in conjunction with thread-locking adhesive to counteract the tendency of the threaded pair to loosen during operation.

[0036] The geometric center of the gearbox refers to the spatial position of the perpendicular meshing point of the input shaft and the output shaft coinciding with the axis of symmetry inside the gearbox. Specifically, it can be located and machined by reserving a reference hole during the casting of the gearbox, so as to make the force distribution of the gear pair symmetrical.

[0037] Hardened layer covering gear meshing surface refers to heat treatment of the tooth surface to form a high-hardness surface layer. Specifically, high-frequency induction hardening process can be used to improve the wear resistance of the tooth surface and reduce transmission noise.

[0038] Specifically, the input shaft transmits power to the first cylindrical gear via a keyway and a flat key. A flexible retaining ring engages with the shaft end groove to restrict axial displacement of the gear, preventing a decrease in meshing accuracy due to backlash. The output shaft connects to the second cylindrical gear via a spline, and a coarse-pitch hexagonal head bolt at the end is tightened in the opposite direction to the shaft rotation to prevent loosening of the threaded pair and subsequent radial gear misalignment. The perpendicular meshing point of the input and output shafts is located at the geometric center of the housing, ensuring even load distribution to the housing support structure and reducing vibration caused by uneven loading. The gear meshing surfaces are hardened to form a hardened layer, enhancing wear resistance while maintaining tooth profile accuracy.

[0039] Compared to existing technologies, traditional gearboxes using a single key connection with a shoulder for positioning are prone to gear runout due to axial clearance. This solution, however, achieves bidirectional limiting through a combination of a flexible retaining ring and a keyway, eliminating the impact of axial displacement on meshing. Existing technologies often use interference fits on the output shaft gears, which are difficult to assemble and cannot be adjusted. This solution simplifies the assembly process while ensuring positioning accuracy through a spline connection with a lock nut. In conventional gearboxes, off-center meshing points lead to unilateral bearing wear; this solution achieves symmetrical load distribution through geometric center positioning. Ordinary gears lack tooth surface hardening treatment; this solution improves tooth surface performance and extends service life through a hardened layer.

[0040] Through the above technical solutions, this application effectively suppresses axial displacement and circumferential slippage of gears, ensuring stable meshing accuracy; reduces gear overload and abnormal vibration caused by assembly errors; enhances the wear resistance of gear pairs under high load conditions; and improves the reliability of gearbox operation by adapting to different torque output requirements through an adjustable locking structure.

[0041] Specifically, the sealing system includes three levels of protection: The first stage is the outer skeleton double-lip oil seal at the input shaft, whose skeleton is embedded in the stepped hole of the main box cover; The second stage is the outer skeleton double-lip oil seal at the output shaft, whose outer edge is interference-fitted with the end cap; The third stage consists of O-rings on the split surfaces of the enclosure, which are embedded in the flange grooves at the input and output ends, respectively.

[0042] This application further proposes a sealing system comprising three levels of protection: the first level is an external skeleton double-lip oil seal at the input shaft, the skeleton of which is embedded in the stepped hole of the main housing cover; the second level is an external skeleton double-lip oil seal at the output shaft, the outer edge of which is interference-fitted with the end cap; and the third level is an O-ring seal on the split surface of the housing, which is respectively embedded in the flange grooves of the input / output ends.

[0043] Among them, a double-lip oil seal refers to a rotating shaft seal with inner and outer sealing lips, specifically made of a composite structure of nitrile rubber and a metal skeleton. The inner and outer lips contact the shaft surface and the mounting hole respectively to form a bidirectional seal. A stepped hole refers to an assembly hole on the main housing cover with multiple diameter variations, specifically made using a stepped machining structure, used to position the oil seal skeleton and limit its axial displacement. An interference fit refers to an assembly method where the outer diameter of the oil seal is slightly larger than the mounting hole diameter of the end cap, specifically achieved using heat fitting or press fitting processes, ensuring a tight fit between the oil seal and the end cap through radial compression. An O-ring is a circular elastic sealing ring, specifically made of fluororubber, achieving a static seal by pre-compressing and filling the flange groove gap. A flange groove is an annular groove machined on the edge of the housing's split surface, specifically formed using CNC milling, used to accommodate the O-ring and guide its deformation direction.

[0044] Specifically, when the input shaft rotates, the inner lip of the double-lip oil seal with the outer skeleton dynamically contacts the shaft surface to form the main seal, while the outer lip contacts the stepped bore wall to form an auxiliary seal. The skeleton embedded in the stepped bore prevents the oil seal from rotating circumferentially. During the output shaft rotation, the radial pressure generated by the interference fit of the double-lip oil seal with the outer skeleton keeps the outer lip tightly against the inner wall of the end cap, while the inner lip maintains a constant contact pressure with the shaft surface. During housing assembly, the O-ring seal is pressed into the flange groove, causing elastic deformation to compensate for machining errors and assembly gaps at the housing mating surfaces. The three-stage seal acts on the dynamic interface between the rotating shaft and stationary components, and the static interface of the housing parting surface, forming a progressive protection system.

[0045] Compared to existing technologies, traditional gearboxes typically only have single-lip oil seals at the input and output shafts, and the gearbox mating surfaces rely on sealant for filling. Single-lip oil seals are prone to gaps under shaft eccentricity or vibration conditions, and the sealant cannot compensate for gearbox deformation after curing. This solution enhances dynamic sealing reliability through the bidirectional sealing capability of double-lip oil seals, improves oil seal installation stability through a stepped bore structure, allows for removable maintenance by replacing sealant with O-ring elastic seals, and provides three levels of protection to cover all leakage paths.

[0046] Through the above technical solution, this application effectively prevents the internal lubricating oil of the gearbox from leaking outwards along the input and output axes, while preventing external dust and moisture from entering the transmission system through the gearbox mating surfaces. The redundant sealing design of the double-lip oil seal reduces the risk of failure due to wear of a single sealing lip, and the flange groove installation method of the O-ring ensures that the sealing performance can be maintained even after multiple disassemblies and reassemblies of the gearbox. The overall sealing system is adapted to the frequent vibration and impact loads during baler operation.

[0047] Specifically, in the bearing support structure, the first tapered roller bearings are installed back-to-back on both sides of the input shaft, and the second tapered roller bearings are installed face-to-face on the output shaft; the bearing preload is adjusted by wave spring washers, which are stacked between the bolt fastening surface and the housing cover.

[0048] This application further proposes a bearing support structure in which first tapered roller bearings are installed back-to-back on both sides of the input shaft, and second tapered roller bearings are installed face-to-face on the output shaft; the bearing preload is adjusted by wave spring washers, which are stacked between the bolt fastening surface and the housing cover.

[0049] Back-to-back mounting refers to the arrangement of the wide end faces of the outer rings of two bearings facing each other, which can be achieved using a symmetrical press-fit method. This arrangement creates a bidirectional axial constraint on the input shaft, balancing the bidirectional axial forces generated by the forward and reverse rotation of the gears. Face-to-face mounting refers to the arrangement of the narrow end faces of the outer rings of two bearings facing each other, which can be achieved using stepped shoulder positioning. This arrangement allows the output shaft to adapt to radial load fluctuations and permits slight axial displacement. The wave spring washer stacking arrangement refers to the series installation of multiple annular corrugated metal sheets, which can be achieved using combinations of different thicknesses. This design absorbs the bolt tightening force through elastic deformation and converts it into a uniform axial preload.

[0050] Specifically, the back-to-back bearing assemblies on both sides of the input shaft decompose axial forces through the contact angle of the inner and outer ring tapered raceways during gear meshing, providing bidirectional constraint to prevent shaft movement. When the output shaft uses face-to-face bearings, the contact lines between the rollers and the inner and outer rings create a self-aligning effect under load, reducing the risk of off-center loading due to shaft bending deformation. The superimposed wave spring washers are compressed during bolt tightening, and their elastic restoring force acts between the housing cover and the bolt head, pushing the outer ring of the bearing to generate a constant preload. This preload can be adjusted in steps according to the number of washers and the corrugation height.

[0051] Compared with existing technologies, traditional single-row tapered roller bearings can only withstand unidirectional axial loads. When subjected to bidirectional forces, an additional thrust bearing is required, resulting in a complex structure and insufficient rigidity. Existing preload adjustment methods mostly use threaded spacers or shim sets, which require repeated disassembly and reassembly to measure clearance. In contrast, this solution achieves continuous adjustment of preload through the superposition of wave spring washers, and can automatically compensate for clearance changes caused by thermal expansion during operation.

[0052] Through the above technical solutions, this application enables the input shaft bearing assembly to have bidirectional rigid support capability, eliminating axial movement when the gear rotates forward and backward; the output shaft bearing assembly maintains stable radial support when subjected to impact loads, avoiding edge contact between the rollers and raceways; the preload adjustment mechanism quickly establishes precise preload during the assembly stage and continuously maintains bearing clearance during operation, thereby reducing transmission vibration and abnormal wear, and extending the continuous working time of the gearbox.

[0053] Specifically, the aluminum alloy external hexagonal oil level indicator of the maintenance unit is obliquely embedded in the side wall of the first housing, with the oil level indicator window facing the gear meshing area; the internal hexagonal plug is located at the bottom of the second housing, and the plug channel is connected to the bearing cavity; the vent plug is installed on the top of the housing and has a built-in pressure regulating valve.

[0054] This application further proposes that the aluminum alloy external hexagonal oil level indicator of the maintenance unit is obliquely embedded in the side wall of the first housing, with the oil level indicator window facing the gear meshing area; the internal hexagonal plug is located at the bottom of the second housing, and the plug channel is connected to the bearing cavity; the vent plug is installed on the top of the housing and has a built-in pressure regulating valve.

[0055] The aluminum alloy external hexagonal oil level indicator is an oil level observation device with a hexagonal operating end. It can be implemented using a metal housing structure with a transparent window. Its angled embedding method creates an angle between the indicator's axis and the horizontal plane, expanding the visible area of ​​the lubricating oil. The internal hexagonal plug is a closed component with an internal hexagonal disassembly interface. It can be implemented using a threaded metal plug structure. Its bottom arrangement allows the lubricating oil to drain naturally along the channel under gravity. The vent plug is a pressure balancing device with gas exchange function. It can be implemented using a spring-loaded valve core structure. Its top mounting position ensures that the gas accumulation point inside the housing is connected to the outside.

[0056] Specifically, the angled embedding design of the aluminum alloy hexagonal oil level indicator allows operators to directly observe the lubricating oil status in the gear meshing area through a tilted viewing window without disassembling the housing. The non-perpendicular angle between the oil level indicator axis and the gear axis ensures that the viewing window covers the entire gear meshing trajectory. The placement of the internal hexagonal plug at the bottom of the second housing creates a vertical connection between its channel and the bearing support cavity. When the plug is unscrewed, metal shavings deposited at the bottom of the bearing cavity can flow out with the lubricating oil. The vent plug at the top of the housing is positioned at the highest point of the internal cavity. The built-in pressure regulating valve controls the opening and closing of the valve core via spring preload. It automatically vents when the internal air pressure exceeds a set threshold and allows external air to enter when the temperature drops.

[0057] Compared to existing technologies, traditional gearbox oil level gauges are typically mounted vertically on the side of the gearbox, only displaying localized oil levels and not allowing direct observation of gear operation. This solution, however, uses an angled oil level gauge to achieve visualized monitoring of critical transmission components. Existing technologies require disassembling the entire bottom cover of the gearbox to drain lubricating oil, while this solution achieves directional drainage through a bottom plug channel. Conventional venting devices often employ simple vent structures, failing to effectively regulate pressure balance; this solution achieves dynamic air pressure control through a vent plug with a pressure valve.

[0058] Through the above technical solutions, this application realizes real-time visual monitoring of the lubricating oil status during gearbox operation, avoiding abnormal bearing wear caused by oil contamination; the bottom drainage channel simplifies the maintenance operation process and reduces the number of times the gearbox is disassembled; the automatic pressure balancing mechanism inside the gearbox effectively prevents leakage problems caused by internal and external pressure differences in the seals.

[0059] Specifically, the fastening unit includes three types of connectors: the split surface of the housing is locked with coarse-threaded hexagonal head bolts and wave spring washers; the main housing cover and the third housing cover are connected by internal hexagonal head bolts; and the end cap and the connecting plate are fixed with short-specification coarse-threaded hexagonal head bolts.

[0060] This application further proposes that the fastening unit includes three types of connectors: the split surface of the housing is locked with coarse-threaded hexagonal head bolts and wave spring washers; the main housing cover and the third housing cover are connected by internal hexagonal head bolts; and the end cap and the connecting plate are fixed with short-specification coarse-threaded hexagonal head bolts.

[0061] Among them, coarse-pitch hexagonal head bolts refer to hexagonal head bolts with a fully threaded structure and a large pitch, specifically made of M16 coarse-pitch thread. Their large pitch design can withstand higher loads, ensuring the connection strength of the housing split surface under vibration conditions. Wave spring washers are elastic washers with a wavy cross-section, specifically made of 65Mn spring steel. They compensate for the gaps between the assembly surfaces through elastic deformation, maintaining the stability of the bolt preload. Internal hexagonal head bolts with round heads are screws with a hexagonal head and hexagonal slots, specifically made of 12.9 grade high-strength steel. The round head shape reduces the protrusion height, avoiding interference with surrounding moving parts. Short-size coarse-pitch hexagonal head bolts are fasteners shorter than standard bolts with threads throughout the shank, specifically made of M12×25mm. The shortened axial dimension provides more room for rotating parts.

[0062] Specifically, the split surfaces of the enclosure are connected using coarse-threaded hexagonal head bolts. The large-diameter threads and high tensile strength of these bolts can withstand the alternating loads generated by gear transmission. Combined with the elastic compensation function of wave spring washers, this effectively eliminates assembly errors at the enclosure joints and prevents lubricant leakage. The main enclosure cover and the third enclosure cover are fixed with internal hexagonal head bolts with full thread. The low-profile profile of the round head structure adapts to the compact installation space of the double-sealed cavity, and the internal hexagonal drive facilitates disassembly and assembly operations in narrow areas. The end cap and connecting plate are connected using short-specification coarse-threaded hexagonal head bolts. The shortened bolt length avoids interference with the rotation trajectory of the third tapered roller bearing, ensuring that the end cap can achieve 360° free rotation adjustment. These three types of connecting parts are designed to meet the differentiated needs of rigid enclosure fixing, convenient maintenance of the sealing cover, and flexible adjustment of rotating components.

[0063] Compared to existing technologies, traditional gearboxes typically use a single type of bolt for overall assembly, resulting in restricted movement of rotating parts and uneven preload on the sealing surfaces. This solution enhances the vibration resistance of the split surfaces by combining coarse-threaded bolts with corrugated washers, optimizes the disassembly and assembly efficiency of the sealing cover with round-head screws, and ensures rotational freedom with short bolts, forming a multi-dimensional fastening strategy. Existing technologies require the removal of all bolts for gearbox maintenance, while this solution achieves partial maintenance through a modular fastening structure, significantly reducing maintenance workload.

[0064] Through the above technical solutions, this application solves the problems of gearbox misalignment and sealing failure caused by improper connection methods during gearbox installation, effectively improving assembly accuracy and structural stability. The short bolt connection design of the rotatable end cap eliminates the risk of motion interference and ensures the normal operation of the angle adjustment function. The differentiated fastening strategy enables the gearbox split surface, sealing cover plate and rotating parts to achieve optimal connection effect, reducing the complexity of maintenance operations.

[0065] Specifically, the elastic retaining ring of the axial positioning structure is inserted into the input shaft ring groove, and its two sides abut against the end face of the first cylindrical gear and the inner ring of the first tapered roller bearing; The coarse-tooth hexagonal head bolt at the end of the output shaft is locked with an adjusting shim between it and the inner ring of the second tapered roller bearing. The nut is tightened in the opposite direction to the output shaft rotation.

[0066] This application further proposes an axial positioning structure, in which an elastic retaining ring is provided at the input shaft gear end, and the output shaft gear end is locked by a nut; the elastic retaining ring is inserted into the input shaft ring groove, and its two sides abut against the end face of the first cylindrical gear and the inner ring of the first tapered roller bearing; the coarse-tooth hexagonal head fully threaded bolt at the end of the output shaft is locked with an adjusting shim between it and the inner ring of the second tapered roller bearing, and the nut is tightened in the opposite direction to the output shaft rotation.

[0067] An elastic retaining ring is a ring-shaped metal part with an opening. It can be made using a standard snap ring or a custom-made wave elastic ring. It achieves axial positioning by snapping into a ring groove machined into the shaft.

[0068] An annular groove is a groove machined on the surface of the input shaft. It can be formed by turning or grinding processes and is used to accommodate an elastic retaining ring and limit its axial movement range.

[0069] Coarse-threaded hexagonal head bolt locking refers to threaded fasteners, specifically nylon insert nuts or metal coarse-threaded hexagonal head bolts, which are connected to the end of the output shaft through threaded engagement.

[0070] Adjusting shims are thin metal sheets of selectable thickness, specifically hardened steel sheets or copper alloy shims, used to compensate for assembly tolerances and adjust bearing preload.

[0071] The reverse rotation of the nut means that the thread direction of the coarse-pitch hexagonal head bolt is opposite to the rotation direction of the output shaft. Specifically, a left-hand thread can be used to match a right-hand shaft, and the self-locking effect of the thread can be used to prevent loosening.

[0072] Specifically, the input shaft achieves bidirectional positioning through the cooperation of an elastic retaining ring and an annular groove. One side of the elastic retaining ring contacts the gear end face, while the other side abuts against the inner ring of the bearing. It absorbs assembly clearances through its own elastic deformation, while simultaneously limiting axial displacement of the input shaft during forward and reverse rotation. The output shaft is locked at its end with a coarse-threaded hexagonal head bolt. The bearing preload is controlled by adjusting the shim thickness. The design of the nut's rotation direction being opposite to the shaft's rotation direction further tightens the threads due to the torque generated during shaft rotation, preventing the nut from loosening due to vibration.

[0073] Compared to existing technologies, traditional gearboxes typically use a single coarse-threaded hexagonal head bolt or a retaining ring for axial positioning, which cannot simultaneously meet the requirements of lightweight input shaft and high-load output shaft operation. In existing technologies, elastic retaining rings are only used for unidirectional limiting and do not directly contact the bearing inner ring, resulting in insufficient axial constraint. This solution combines an elastic retaining ring with a coarse-threaded hexagonal head bolt to create a differentiated positioning mechanism. The input shaft utilizes an elastic element to absorb vibration, while the output shaft enhances stability through thread self-locking, thus solving the problem of bidirectional movement.

[0074] Through the above technical solutions, this application effectively suppresses axial displacement during gear transmission, avoiding gear meshing misalignment and bearing wear caused by axial movement. The bidirectional limiting design of the elastic retaining ring reduces the cumulative assembly error of the input shaft, the rotation direction setting of the coarse-tooth hexagonal head fully threaded bolt eliminates the risk of loosening under dynamic load of the output shaft, and the adjusting shim achieves precise control of the bearing preload, thereby ensuring that the transmission system maintains axial positioning accuracy during long-term operation.

[0075] The foregoing has illustrated and described the basic features, principles, and advantages of this utility model. It should be noted that this utility model is not limited to the above embodiments, but only to some embodiments. Any improvements and additions made without departing from the spirit and scope of this utility model are considered to be within the protection scope of this utility model.

Claims

1. A feeding gearbox for a six-rope large square baler, characterized in that, include: The housing (1) assembly is composed of a first housing (1) and a second housing (1) spliced ​​together. The first housing (1) is provided with a power input interface, and the second housing (1) is provided with a power output interface. The box cover (3) assembly includes a main box cover (3) installed on the input side of the box body (1) and a blind cover (4) on the output side, wherein the blind cover (4) is rotatably connected to the second box body (1) via a connecting plate; The transmission system includes a meshing first cylindrical gear (5) and a second cylindrical gear (6), the first cylindrical gear (5) being fixed to the input shaft and the second cylindrical gear (6) being fixed to the output shaft, with the input shaft and the output shaft arranged perpendicularly. The bearing support structure has an input shaft supported on the main housing cover (3) by a first tapered roller bearing (8) and an output shaft supported on the end cover (4) by a second tapered roller bearing (9). A third tapered roller bearing is provided between the connecting plate and the end cover (4) to realize the relative rotation between the housing (1) and the end cover (4). The sealing system includes an outer skeleton double lip oil seal (10) disposed between the input shaft and the main housing cover (3), an outer skeleton double lip oil seal (10) between the output shaft and the end cap (4), and an O-ring (12) nested at the interface of the housing (1); The fastening and maintenance unit includes a coarse-threaded hexagonal head bolt penetrating the housing (1) assembly and a matching wave spring washer (17), an aluminum alloy external hexagonal oil level indicator (18), an internal hexagonal plug (19) and a vent plug (20) located on the side of the housing (1), wherein the oil level indicator and the plug are respectively located on adjacent side walls of the housing (1); It also includes an internal hexagonal head threaded screw (16) for fixing the end cap (4) and the connecting plate, and a coarse-tooth hexagonal head threaded bolt for locking the output shaft; The axial positioning structure has an elastic retaining ring at the input shaft gear end and is locked at the output shaft gear end by a nut (7).

2. The feeding gearbox of a six-rope large square baler according to claim 1, characterized in that, The main cover (3) of the box cover (3) assembly is connected to the first box body (1) by a ring array of coarse-tooth hexagonal head fully threaded bolts, and the end cap (4) is fixed to the connecting plate by internal hexagonal round head fully threaded screws (16); A radial adjustment gap is provided between the connecting plate and the second housing (1), and the cover (4) is rotated and positioned relative to the housing (1) by a third tapered roller bearing; A third cover (3) is added to the outside of the main cover (3) to form a double-layer sealed cavity, and the outer skeleton double-lip oil seal (10) is pressed into the inside of the double-layer sealed cavity.

3. The feeding gearbox of a six-rope large square baler according to claim 2, characterized in that, The first cylindrical gear (5) of the transmission system is keyway-fitted with the input shaft and is axially limited by an elastic retaining ring; the second cylindrical gear (6) is connected to the output shaft by a spline, and the threaded section at the end of the output shaft is fitted with a coarse-tooth hexagonal head full thread bolt for locking; the vertical meshing point of the input shaft and the output shaft is located at the geometric center of the housing (1), and the gear meshing surface is covered with a hardened layer.

4. The feeding gearbox of a six-rope large square baler according to claim 3, characterized in that, The sealing system includes three levels of protection: The first stage is the outer skeleton double-lip oil seal (10) at the input shaft, whose skeleton is embedded in the stepped hole of the main box cover (3); The second stage is the outer skeleton double-lip oil seal (10) at the output shaft, whose outer edge is interference-fitted with the end cap (4); The third level consists of O-rings (12) on the split surface of the housing (1), which are respectively embedded in the input flange groove and the output flange groove.

5. The feeding gearbox of a six-rope large square baler according to claim 4, characterized in that, In the bearing support structure, the first tapered roller bearings (8) are installed back-to-back on both sides of the input shaft, and the second tapered roller bearings (9) are installed face-to-face on the output shaft; the bearing preload is adjusted by wave spring washers (17), and the washers are stacked between the bolt fastening surface and the cover (3).

6. The feeding gearbox of a six-rope large square baler according to claim 5, characterized in that, The aluminum alloy external hexagonal oil level indicator (18) of the maintenance unit is obliquely embedded in the side wall of the first housing (1), and the oil level indicator window is directly opposite the gear meshing area; the internal hexagonal plug (19) is located at the bottom of the second housing (1), and the plug channel is connected to the bearing cavity; the vent plug (20) is installed on the top of the housing (1) and has a built-in pressure regulating valve.

7. The feeding gearbox of a six-rope large square baler according to claim 1, characterized in that, The fastening and maintenance unit includes three types of connectors: the split surface of the housing (1) is locked with coarse-threaded hexagonal head bolts and wave spring washers (17); the main housing cover (3) and the third housing cover (3) are connected by internal hexagonal head bolts (16); the end cap (4) and the connecting plate are fixed with short-specification coarse-threaded hexagonal head bolts.

8. The feeding gearbox of a six-rope large square baler according to claim 7, characterized in that, The elastic retaining ring of the axial positioning structure is inserted into the input shaft ring groove, and its two sides abut against the end face of the first cylindrical gear (5) and the inner ring of the first tapered roller bearing (8); The coarse-tooth hexagonal head fully threaded bolt at the end of the output shaft is locked with an adjusting shim between it and the inner ring of the second tapered roller bearing (9). The nut (7) is tightened in the opposite direction to the output shaft rotation.

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