Gearbox and gearbox housing

Abstract

The present disclosure relates to a gearbox housing, comprising an input-side housing, a side housing and an output-side housing, wherein the input-side housing and the output-side housing are connected to the side housing by means of a plurality of bolt holes arranged along the side housing; the input-side housing is provided with first and second bearing seats and a plurality of radial rib plates; the plurality of radial rib plates include first radial rib plates and second radial rib plates; each first radial rib plate extends radially outward from the center of the first bearing seat, and each second radial rib plate extends radially outward from the center of the second bearing seat; the radial rib plates are connected to the bolt holes; the direction connecting the center of the first bearing seat and the center of the second bearing seat is a first direction, and a second direction is perpendicular to the first direction; around the center of the first bearing seat, in the areas deviating ±30° of a pressure angle relative to the second direction, the first radial rib plates and the bolt holes are arranged more densely than in other areas, the pressure angle being the pressure angle of the pressure acting on the first bearing seat. The gearbox housing of the present disclosure can achieve beneficial effects such as inhibiting deformation, improving supporting stiffness and facilitating heat dissipation.

Description

Gearbox and gearbox housing

[0001] Citation of relevant applications

[0002] This application claims the benefit of Chinese Patent Application No. 202421187858.9, filed on May 28, 2024, with the State Intellectual Property Office of the People's Republic of China; Chinese Patent Application No. 202410671711.5, filed on May 28, 2024; Chinese Patent Application No. 202410674747.9, filed on May 28, 2024; and Chinese Patent Application No. 202421182665.4, filed on May 28, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to a gearbox in fracturing equipment and the gearbox housing, and more specifically, to a gearbox with an oil return port. Background Technology

[0004] The gearbox is the transmission system in fracturing equipment. It connects the crankcase and the engine's power input. Through the design of different speed variations of the gears inside the gearbox, the converted power is transmitted to the crankcase, thereby achieving the effect of deceleration and torque increase or speed increase and torque decrease, providing different transmission capabilities for fracturing equipment.

[0005] However, during operation, the gearbox may experience continuous and severe vibrations due to various factors such as gear meshing, shaft torsional vibration, and fracturing pump housing vibration. Therefore, the entire gearbox housing needs to have sufficient rigidity and shock absorption performance in terms of materials, structure, and construction to absorb and buffer internal vibrations to the maximum extent and prevent wear and damage to critical components such as gears, bearings, etc.

[0006] In existing gearboxes, steel plate welded housings are commonly used. However, since welding is a localized and rapid heating and cooling process, the molten metal in the welding zone is constrained by the surrounding body metal material and cannot freely expand or contract. Therefore, during the cooling and contraction process, it will be subjected to tensile stress from the body metal material. Furthermore, the unmelted metal material around the weld will produce an uneven distribution of microstructure under the action of welding thermal cycle.

[0007] Because the stress generated by the changes in the distribution of this tissue cannot be eliminated, it can easily become the fatigue crack source of the gearbox. Under the cyclic alternating stress and impact vibration of the gearbox during long-term high-load operation, it can extend into an extended crack, which will lead to a shorter service life of the gearbox.

[0008] In addition, the cast gearbox housing is usually thin-walled, and it is difficult to resist the meshing impact transmitted from the gear to the bearing housing and the housing by the connection between the housing and the bearing seat. Moreover, since the rigidity and strength of the cast flat plate structure are very low, it is prone to deformation when subjected to alternating loads for a long time, causing uneven wear of gears and bearings and transmission errors, which ultimately leads to damage to the internal transmission system and the external cast housing.

[0009] Moreover, conventional gearbox housings are very heavy, which not only increases casting costs but also makes installation, maintenance, and transportation extremely inconvenient.

[0010] In addition, when the transmission ratio of the parallel stage gearbox is large, the diameters of the input gear and the output gear also differ greatly. The shape of the housing surrounding the parallel stage gearbox is also inconsistent due to this large size difference, which will result in the overall shape of the gearbox being round and clumsy.

[0011] A gearbox is a transmission system in mechanical equipment such as fracturing equipment. Its function is to convert the power output from the engine through different gear ratios within the gearbox, thereby achieving the effects of speed reduction and torque increase, and speed increase and torque reduction, providing different transmission capabilities for such mechanical equipment. Gearbox designs are generally divided into planetary-stage plus parallel-stage gearboxes and single-parallel-stage gearboxes. Existing fracturing equipment using single-parallel-stage gearboxes employs a double-sided single-parallel-stage drive system to improve power. Its working principle is that the engine drives and connects to the gearbox on one side, which is then connected to the gearbox on the other side via a bottom drive shaft. Gearbox assemblies composed of parallel stages and planetary stages use standardized flanges and spline structures at the interfaces between the parallel stages and planetary stages, enabling rapid matching and switching between parallel stage gearboxes with different speed ratios for the same planetary stage structure, thus achieving different speed ratio switching.

[0012] The gearbox is equipped with a lubrication system that provides lubricating oil. During operation, the gearbox requires a large amount of lubricating oil to circulate to all key friction contact points, forming a lubricating oil film on the contact surfaces to prevent dry friction between rotating transmission components. This circulation process also carries away a significant amount of heat, thus facilitating system heat dissipation.

[0013] Common lubrication methods include splash (oil immersion) lubrication and forced lubrication. For splash (oil immersion) lubrication, the rotating gears are submerged or partially submerged in the lubricating oil in the housing, and the oil is splashed onto other gears and bearings for lubrication. Therefore, it has a simple structure, low cost, and is easy to maintain. The disadvantage is that for high-speed gearboxes, this method cannot provide timely and sufficient cooling. If the oil level is increased to achieve a cooling effect, the excessively high oil level increases the viscous resistance of the gears against the lubricating oil, and also increases the power loss caused by the pumping action of the gear meshing on the lubricating oil.

[0014] For high-speed gearboxes, forced lubrication is often used. An oil pump establishes a certain oil pressure, drawing oil to the friction surfaces. The amount of oil can be determined by the amount of heat to be removed. This method avoids oil churning losses and allows for oil filtration, cooling, and monitoring during circulation. However, the disadvantages are the need for oil channels to guide the oil, resulting in a relatively complex lubrication system and more difficult maintenance.

[0015] Depending on its design and positioning, the gearbox can also integrate the advantages of the two lubrication methods mentioned above. While meeting lubrication requirements, it can choose splash (oil immersion) lubrication and / or forced lubrication. For lightweight positioning gearboxes, forced lubrication is chosen. Due to their relatively simple structure and fewer lubrication points, lightweight positioning gearboxes are best suited for forced lubrication. Their oil passage design is simple, maintenance is convenient, and oil volume requirements are low. They can share a filter-equipped oil pump with the main equipment (such as a fracturing pump) and do not need a separate pump. For medium- and high-speed gearboxes, splash (oil immersion) lubrication combined with forced lubrication is chosen. A certain level of oil is stored at the bottom of the gearbox housing. This oil is splashed as the gears / bearings rotate, carrying away some heat and compensating for insufficient forced lubrication. Furthermore, since splash (oil immersion) lubrication is auxiliary here, the oil level will not be too high.

[0016] Since the lubricating oil supplied by the gearbox lubrication system is usually provided with an oil return port on the gearbox housing, a reasonable design and layout of the oil return port on the gearbox housing can realize the smooth circulation of lubricating oil and prevent oil accumulation in the gearbox due to poor oil return and heat generated by gear oil churning.

[0017] Whether it's a two-stage reduction gear with a planetary stage or a single parallel stage reduction gear, the lubricating oil return port is located at the bottom of the parallel stage housing. Existing return port designs suffer from insufficient oil return flow. Summary of the Invention

[0018] Technical problems to be solved

[0019] To address the aforementioned problems with welded gearbox housings, this invention provides a gearbox housing that offers advantages such as suppressing housing deformation, improving housing support rigidity, and aiding in gearbox heat dissipation.

[0020] In addition, the present invention provides a gearbox housing that can reduce the weight of the gearbox and improve the housing shape.

[0021] In addition, the purpose of this application is to provide a gearbox with a novel oil return port structure, which can improve the discharge of lubricating oil through the oil return port, making the oil return smooth, thereby preventing oil accumulation in the gearbox and heat generation caused by gear oil churning due to poor oil return.

[0022] Technical solutions to solve technical problems

[0023] A first aspect of the invention provides a gearbox housing, comprising an input-side housing, a side housing, and an output-side housing, wherein the input-side housing and the output-side housing are connected to the side housing by a plurality of bolt positions arranged along the side housing, wherein the input-side housing is provided with a first bearing seat, a second bearing seat, and a plurality of radial stiffeners, wherein the plurality of radial stiffeners include a plurality of first radial stiffeners and a plurality of second radial stiffeners, each first radial stiffener extending radially outward from the center of the first bearing seat, and each second radial stiffener extending radially outward from the center of the second bearing seat, wherein the radial stiffeners are connected to the bolt positions, wherein the direction connecting the center of the first bearing seat and the center of the second bearing seat is a first direction, and a second direction is perpendicular to the first direction, wherein, with the center of the first bearing seat as the center, in a region deviating from the second direction by a pressure angle ±30°, the first radial stiffeners and the bolt positions are arranged more densely than in other regions, wherein the pressure angle is the pressure angle of the pressure exerted on the first bearing seat.

[0024] In another aspect of the invention, in the region, the included angle between the first radial stiffeners is 15°-25°.

[0025] In another aspect of the invention, an internal oil passage integrally formed with the housing is provided in the radial stiffeners at an angle of 0-30° to the second direction.

[0026] In another aspect of the invention, the two sides of the radial stiffeners perpendicular to the surface of the input side housing are arranged in parallel or the distance between them gradually decreases in the direction toward the side housing.

[0027] In another aspect of the invention, the connection point between the first radial stiffener and the first bearing seat is a first connection point, the height of the first connection point from the surface of the housing is a first height, the connection point between the first radial stiffener and the bolt position is a second connection point, and the height of the second connection point from the surface of the housing is a second height. Then, the third height of the first radial stiffener from the surface of the housing is set as follows:

[0028] i. When the difference between the first height and the second height is less than or equal to 5mm, the third height is the smaller value between the first height and the second height;

[0029] ii. When the difference between the first height and the second height is greater than 5mm and less than or equal to 20mm, the third height is the first height between the first connection point and the turning point. Between the turning point and the second connection point, the top surface of the first radial stiffener is inclined relative to the input-side housing, so that the third height linearly decreases from the first height to the second height.

[0030] The turning point is located between the first connection point and the connection point;

[0031] iii. When the difference between the first height and the second height is greater than 20mm, the top surface of the first radial stiffener is inclined relative to the input side box, so that the third height decreases linearly from the first height to the second height.

[0032] In another aspect of the invention, the distance between the turning point and the second connection point is 1 / 5 to 1 / 3 of the length of the first radial stiffener.

[0033] In another aspect of the invention, when the difference between the first height and the second height is greater than 5 mm and less than or equal to 20 mm, the angle at which the first radial stiffener is tilted relative to the input side housing is in the range of 2°-10°, and wherein, when the difference between the first height and the second height is greater than 20 mm, the angle at which the first radial stiffener is tilted relative to the input side housing is in the range of 2°-15°.

[0034] In another aspect of the invention, the gearbox housing further includes: a plurality of circumferential stiffeners, the plurality of circumferential stiffeners intersecting with the radial stiffeners to connect the plurality of radial stiffeners to each other, wherein the circumferential stiffeners are configured to intersect the radial stiffeners perpendicularly, or the circumferential stiffeners are configured to surround the center of the first bearing seat and the center of the second bearing seat in a direction along the side housing.

[0035] In another aspect of the invention, a first opening is provided in the region surrounded by the circumferential stiffener and the radial stiffener.

[0036] In another aspect of the invention, a rib skirt is provided along the portion of the circumferential rib and the radial rib along the first opening, the width of the rib skirt being 1-5 times the thickness of the input-side housing or the output-side housing.

[0037] In another aspect of the invention, the gearbox housing further includes: a horizontal stiffener, the horizontal stiffener being disposed in the region between two tangents of the first bearing seat and the second bearing seat, wherein the horizontal stiffener includes a first horizontal stiffener and a second horizontal stiffener, the first horizontal stiffener being located on the line connecting the center of the first bearing seat and the center of the second bearing seat, and the second horizontal stiffener being symmetrically disposed with respect to the first horizontal stiffener.

[0038] In another aspect of the invention, the included angle between the first horizontal stiffener and the second horizontal stiffener is 0°-10°, and a weight-reducing groove is provided between the first horizontal stiffener and the second horizontal stiffener.

[0039] In another aspect of the invention, the thickness of the horizontal stiffener is 1.5 to 3 times the thickness of the input-side housing or the output-side housing.

[0040] In another aspect of the invention, the gearbox housing further includes: a plurality of vertical stiffeners, the vertical stiffeners being disposed in the second direction and connected to the bolt position.

[0041] In another aspect of the invention, the radial stiffener is connected to the vertical stiffener, thereby forming a triangular structure with the horizontal stiffener.

[0042] In another aspect of the invention, the gearbox housing further includes: a plurality of axial stiffeners disposed inside the side housing and perpendicular to the input side housing and the output side housing, wherein one end of the axial stiffener is connected to the bolt position, and the other end is connected to the radial stiffener through a turning stiffener located at the connection between the side housing and the output side housing.

[0043] In another aspect of the invention, a sealing structure is included in the mating surface between the input-side housing and / or the output-side housing and the side housing, the sealing structure including at least a seal.

[0044] In another aspect of the invention, the radial stiffener has a rectangular cross-sectional shape.

[0045] In another aspect of the invention, the thickness of the second radial stiffener is 2-5 times the thickness of the output end housing.

[0046] In another aspect of the invention, with the center of the second bearing housing as the center, in a region that deviates from the pressure angle by ±30° relative to the second direction, the second radial stiffener and the bolt positions are arranged more densely than in other regions.

[0047] In a first aspect of the invention, a gearbox housing is provided, comprising an input-side housing, a side housing, and an output-side housing, wherein the input-side housing and the output-side housing are connected together with the side housing, wherein the input-side housing is provided with a first bearing seat, a second bearing seat, and a plurality of circumferential stiffeners, and in a direction from the center of the first bearing seat toward the outer periphery of the side housing, the input-side housing is formed as a stepped structure having a plurality of stepped portions, wherein the circumferential stiffeners are at least partially formed on the stepped portions and are configured to (i) surround the center of the first bearing seat or the center of the second bearing seat, or (ii) surround the center of the first bearing seat and the center of the second bearing seat in a direction along the side housing (3).

[0048] In another aspect of the invention, the height of the step portion is 0.5-2 times the thickness of the input-side housing.

[0049] In another aspect of the invention, the spacing between the stepped portions may be equal to or different from each other.

[0050] In another aspect of the invention, the gearbox housing further includes: a plurality of radial stiffeners, the radial stiffeners extending radially outward from the center of the first bearing seat and intersecting with the circumferential stiffeners, wherein the radial stiffeners are composed of alternating horizontal and inclined surfaces, the horizontal surfaces being parallel to the extension plane of the output side housing, and the inclined surfaces being formed on the plane of the stepped portion that intersects with the extension plane.

[0051] In another aspect of the invention, the angle between the inclined surface and the horizontal surface is less than 45°.

[0052] In another aspect of the invention, an opening is provided in the region surrounded by the circumferential stiffener and the radial stiffener.

[0053] In another aspect of the invention, the gearbox housing further includes: a plurality of bolt positions arranged along the side housing to connect the input side housing and the output side housing to the side housing, wherein the radial stiffener is connected to the bolt positions.

[0054] In another aspect of the invention, the gearbox housing further includes: a horizontal stiffener, the horizontal stiffener being disposed in the region between two tangents of the first bearing seat and the second bearing seat, wherein the horizontal stiffener includes a first horizontal stiffener and a second horizontal stiffener, the first horizontal stiffener being located on the line connecting the center of the first bearing seat and the center of the second bearing seat, and the second horizontal stiffener being symmetrically disposed with respect to the first horizontal stiffener.

[0055] In another aspect of the invention, the gearbox housing further includes: a plurality of vertical stiffeners, the vertical stiffeners being disposed in a direction perpendicular to the horizontal stiffeners and connected to the bolt positions, wherein the radial stiffeners are connected to the vertical stiffeners, thereby forming a triangular structure with the horizontal stiffeners.

[0056] In another aspect of the invention, a gearbox housing is provided, comprising an input-side housing, a side housing, and an output-side housing, wherein the input-side housing and the output-side housing are connected together with the side housing, wherein the input-side housing is provided with a first bearing seat, a second bearing seat, and a plurality of vertical stiffeners, and in the direction from the center of the first bearing seat to the center of the second bearing seat, the input-side housing is formed as a stepped structure having a plurality of first stepped portions, wherein the vertical stiffeners are formed on a line perpendicular to the line connecting the centers of the first bearing seat and the second bearing seat, and are at least partially formed on the first stepped portions.

[0057] In another aspect of the invention, the gearbox housing further includes: a plurality of bolt positions arranged along the side housing to connect the input side housing and the output side housing to the side housing, wherein the vertical stiffener is connected to the bolt positions.

[0058] In another aspect of the invention, the stepped structure gradually decreases in height in the direction from the center of the first bearing housing toward the center of the second bearing housing.

[0059] In another aspect of the invention, the output side housing is provided with a third bearing seat, a fourth bearing seat, and a plurality of circumferential stiffeners, the third bearing seat being opposite to the first bearing seat and the fourth bearing seat being opposite to the second bearing seat, wherein, in the direction from the center of the fourth bearing seat toward the center of the third bearing seat, the output side housing is formed as a stepped structure having a plurality of second steps, wherein the circumferential stiffeners are at least partially formed on the second steps, and wherein the circumferential stiffeners are configured to (i) surround the center of the third bearing seat (20) or the center of the fourth bearing seat, or (ii) surround the center of the third bearing seat and the center of the fourth bearing seat in the direction along the side housing (3).

[0060] In another aspect of the invention, the stepped structure on the output side housing gradually increases in height in the direction from the center of the fourth bearing housing toward the center of the third bearing housing.

[0061] In another aspect of the invention, the gearbox housing further includes: a plurality of radial stiffeners, the radial stiffeners extending radially outward from the center of the first bearing seat and the center of the second bearing seat, and connected to the bolt position.

[0062] In another aspect of the invention, the gearbox housing further includes: a horizontal stiffener, the horizontal stiffener being disposed in the region between two tangents of the first bearing seat and the second bearing seat, wherein the horizontal stiffener includes a first horizontal stiffener and a second horizontal stiffener, the first horizontal stiffener being located on the line connecting the center of the first bearing seat and the center of the second bearing seat, and the second horizontal stiffener being symmetrical with respect to the first horizontal stiffener.

[0063] In another aspect of the invention, the radial stiffener is connected to the vertical stiffener, thereby forming a triangular structure with the horizontal stiffener.

[0064] In another aspect of the invention, the radial stiffeners gradually decrease in width in a direction outward from the center of the first bearing seat and the center of the second bearing seat.

[0065] In another aspect of the invention, the thickness of the housing is greater in the region between the two tangents of the first bearing housing and the second bearing housing than in other regions.

[0066] In another aspect of the invention, with the center of the first bearing seat and the center of the second bearing seat respectively as centers, in a region where the direction of the vertical stiffener deviates from the pressure angle by ±30°, the width of the radial stiffener is set to 1.1-2 times the width of the radial stiffener in other regions, and the pressure angle is the pressure angle of the pressure on the first bearing seat.

[0067] A first aspect of the present invention provides a gearbox housing, comprising an input-side housing, a side housing, and an output-side housing, characterized in that the input-side housing and the output-side housing are connected together with the side housing, the input-side housing is provided with a first bearing seat and a second bearing seat, the side housing is composed of a first arc portion, a second arc portion, and two straight portions, the two straight portions being tangent to the first arc portion and the second arc portion, and the center of the first arc portion coinciding with the center of the first bearing seat.

[0068] In another aspect of the invention, a gearbox housing is provided, comprising an input-side housing, a side housing, and an output-side housing, characterized in that the input-side housing and the output-side housing are connected together with the side housing, the input-side housing is provided with a first bearing seat and a second bearing seat, the side housing is composed of a first arc portion, a second arc portion, and two straight portions, the two straight portions being tangent to the first arc portion and the second arc portion, and the first center of the first arc portion being located on the line connecting the second center of the first bearing seat and the third center of the second bearing seat.

[0069] In another aspect of the invention, the radius of the first arc portion is 1.2 to 1.8 times the radius of the gear supported by the first bearing seat.

[0070] In another aspect of the invention, the distance between the first center and the second center is between 50 and 150 mm.

[0071] In another aspect of the invention, a gearbox housing is provided, comprising an input-side housing, a side housing, and an output-side housing, characterized in that the input-side housing and the output-side housing are connected together with the side housing, the input-side housing is provided with a first bearing seat and a second bearing seat, and in a front view, in the horizontal direction of the line connecting the first center of the first bearing seat and the second center of the second bearing seat, the side housing has a first straight segment in a vertical direction perpendicular to the horizontal direction.

[0072] In another aspect of the invention, in the front view, the side box has a second straight segment parallel to the horizontal direction, the second straight segment overlapping the second center in the vertical direction.

[0073] To achieve the above objectives, according to one aspect of the present invention, the inventors have developed a gearbox comprising: a housing; and an oil return port, the oil return port being disposed on the wall at the bottom of the housing and used to discharge lubricating oil from inside the housing, characterized in that the oil return port has an oil baffle plate, an oil return through hole, and a curved transition portion, the oil baffle plate and the curved transition portion being disposed on opposite sides of the oil return through hole, and the oil baffle plate protruding from the wall at the bottom of the housing toward the interior of the housing.

[0074] Furthermore, the gearbox also includes one or more auxiliary oil return ports, which are located on the gearbox body at different positions from the main oil return port.

[0075] Furthermore, the oil return port is lowered relative to the housing.

[0076] Furthermore, the oil return port is lowered as a whole along with the wall at the bottom of the tank.

[0077] Furthermore, the oil return port is locally sunken within a range of 1 to 3 times the wall thickness of the box body, centered on the center of the oil return through hole.

[0078] Furthermore, the height of the depression is 1 to 5 times the wall thickness of the box.

[0079] Furthermore, the oil return port has a transition portion that smoothly transitions with the housing of the housing when it sinks relative to the housing, along the direction in which the lubricating oil is thrown out.

[0080] Furthermore, the gearbox also includes a gear assembly disposed inside the gearbox body, wherein the angle between the transition portion and the tangential direction of the addendum circle of the gear assembly is 0 to 20°.

[0081] Furthermore, the gearbox also includes a gear assembly disposed inside the gearbox body, and the height of the oil baffle is set to be as high as possible without interfering with the gear assembly.

[0082] Furthermore, the shape of the oil return through hole is circular, polygonal, or elliptical.

[0083] Furthermore, the oil baffle is integrally formed with the housing. Beneficial effects

[0084] According to one aspect of this disclosure, a gearbox housing is provided, which has beneficial effects such as suppressing housing deformation, improving housing support stiffness and facilitating gearbox heat dissipation, and can also reduce the weight of the gearbox and improve the housing shape.

[0085] In addition, according to the present invention, the distance between the oil return port and the tooth tip circle of the gear device is increased, which is conducive to the settling and discharge of lubricating oil, so that the lubricating oil can be discharged smoothly, preventing the accumulation of oil in the gearbox due to poor oil return and the heat generated by gear oil stirring, thereby improving the overall functionality of the gearbox. Attached Figure Description

[0086] Figure 1 shows a perspective view cut along the gearbox housing.

[0087] Figure 2 shows the arrangement of the radial stiffeners on the left housing and the analysis of the force type and direction of the bearing housing during gear meshing.

[0088] Figure 3 shows the force analysis and pressure angle annotation at the gear meshing point to explain the reason for the dense arrangement of stiffeners and bolts in the critical stress area.

[0089] Figure 4 shows a structural diagram of embedding built-in oil passages in radial stiffeners.

[0090] Figures 5A and 5B show the shape of the radial stiffener in the front view, and Figure 5C shows a sectional view of the housing to illustrate the distance between the bearing housing and the housing surface.

[0091] Figures 6-8B show the height design of radial stiffeners in different situations.

[0092] Figures 9A and 9B show the structure of the circumferential stiffeners on the left box body.

[0093] Figure 10 shows another structure of radial and circumferential stiffeners on the right box body.

[0094] Figure 11 shows the specific structure of the horizontal stiffener.

[0095] Figure 12 shows the structure of the axial stiffener and the turning stiffener.

[0096] Figure 13 shows the sealing structure in the joint surface of the housing.

[0097] Figures 14A and 14B show different cross-sectional shapes of the stiffener.

[0098] Figures 15A and 15B show the stepped structure of the parallel stage housing of a two-stage gearbox consisting of a parallel stage and a planetary stage.

[0099] Figures 16A and 16B show the stepped structure of the housing of a single parallel stage gearbox.

[0100] Figure 17 shows a perspective view of the present invention cut along the gearbox housing.

[0101] Figure 18 illustrates an exemplary front view of the first external shape structure of the box in this invention.

[0102] Figure 19 illustrates an exemplary front view of the second external shape structure of the box in this invention.

[0103] Figure 20 illustrates an exemplary front view of the third external shape structure of the box in this invention.

[0104] Figure 21 is a schematic diagram showing a gearbox according to an example of the present invention.

[0105] Figure 22 is an enlarged view of the oil return port in Figure 21.

[0106] Figure 23 is a schematic diagram showing a gearbox according to another example of the invention, in which the overall sunken oil return port is shown.

[0107] Figure 24 is a schematic diagram showing a gearbox according to another example of the invention, in which a partially sunken oil return port is shown.

[0108] Figure 25 is an enlarged view showing the partially sunken return port of Figure 24.

[0109] Figure 26 is a schematic diagram showing a gearbox according to another example of the invention, in which a partially sunken oil return port is shown.

[0110] Figure 27 is an enlarged view showing the partially sunken return port of Figure 26.

[0111] Figure 28 is a schematic diagram showing a gearbox according to another example of the invention, in which the oil return port is shown as seen from inside the gearbox housing.

[0112] Figure 29 is an enlarged view of the oil return port of Figure 28.

[0113] Figure 30 is a schematic diagram showing the gearbox of Figure 28, which shows the oil return port as seen from the outside of the gearbox housing.

[0114] Figure 31 is an enlarged view of the oil return port of Figure 30. Detailed Implementation

[0115] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0116] The technical solutions disclosed in various embodiments of the present invention will be described in detail below with reference to the accompanying drawings. For the sake of brevity, the reference numerals for each component are not necessarily shown in all the drawings. Generally, for the purpose of emphasis, some drawings only show the reference numerals for the relevant components described with reference to that drawing in the specification, while omitting the reference numerals for other components. However, the same reference numerals are used interchangeably for the same components in different drawings.

[0117] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. For example, the terms "horizontal," "vertical," and similar terms used in this invention do not indicate absolute directions, but are merely used to describe the directions in which the gearbox is conventionally used. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described object changes.

[0118] First, the gearbox housing, gearbox, and related features of the present invention will be described below in the following order.

[0119] I. A first embodiment of the gearbox housing according to the present invention

[0120] 1. Overview of the gearbox housing

[0121] 2. Reinforcing ribs on the gearbox housing

[0122] 2.1 Radial stiffeners and bolt positions

[0123] 2.2 Circumferential stiffening plate

[0124] 2.3 Horizontal stiffening slabs

[0125] 2.4 Vertical stiffeners

[0126] 2.5 Axial stiffeners

[0127] 2.6 Sealing Structure

[0128] 2.7 Stiff plate shape

[0129] 3. Stepped arrangement of the gearbox housing

[0130] 3.1 Stepped arrangement of parallel stage + planetary stage gearbox

[0131] 3.2 Stepped arrangement of a single parallel stage gearbox

[0132] II. Second embodiment of the gearbox housing according to the present invention

[0133] III. Embodiments of the Gearbox according to the present invention

[0134] The above content will be explained in the following text with reference to the accompanying drawings and reference numerals.

[0135] I. A first embodiment of the gearbox housing according to the present invention

[0136] 1. Overview of the gearbox housing

[0137] The gearbox housing contains various wheel assemblies, bearing assemblies, lubrication systems, and connectors, and is connected to the outside via connecting flanges.

[0138] Generally speaking, gearboxes are classified into two types: parallel stage + planetary stage gearboxes and single parallel stage gearboxes.

[0139] In a parallel-stage + planetary-stage gear reducer, the parallel-stage gears include a pinion as the input and a large gear meshing with the pinion. The reducer housing also has bearing housings for supporting the pinion and the large gear. The pinion bearing housing and the large gear bearing housing are arranged parallel to each other. Furthermore, the large gear meshes with the planetary-stage gear as the output to transmit power. The housing housing the parallel-stage gears and the connecting flange are connected via the planetary-stage gears.

[0140] In a single parallel-stage gear reducer, the parallel-stage gears include a pinion as the input and a large gear meshing with the pinion. The reducer housing also includes bearing housings for supporting the pinion and the large gear. The pinion bearing housing and the large gear bearing housing are arranged parallel to each other. The housing housing and connecting flange for accommodating the parallel-stage gears are formed as a single unit. Both types of housings have the same input / output interface, thus allowing for interchangeability within the same platform.

[0141] In this invention, a parallel-stage + planetary-stage gear reducer is mainly used as an example for illustration. The reducer housing is formed by integral casting or by a combination of steel plate welding and casting. As long as the housing has sufficient support rigidity and strength, any cast iron or cast steel material can be selected.

[0142] 2. Reinforcing ribs on the gearbox housing

[0143] Figure 1 shows a perspective view cut along the gearbox housing 1, which is cut along the line connecting the centers of the two bearing housings.

[0144] As shown in Figure 1, the gearbox housing 1 consists of a left housing 2 and a side housing 3 located on the input side of the gearbox, and a right housing 4 located on the output side of the gearbox. The left housing 2 and the right housing 4 are connected to the side housing 3 by bolts 9 arranged along the outer edge of the housing. Surface stiffeners with different orientations are provided on the left housing 2 and the right housing 4, and these surface stiffeners include, for example, radial stiffeners 5, circumferential stiffeners 6, horizontal stiffeners 7, and vertical stiffeners 8.

[0145] In the following description, the horizontal direction refers to the direction of the line connecting the center of the large gear bearing housing and the center of the small gear bearing housing in the parallel stage gearbox (this horizontal direction is the first direction in this invention), and the vertical direction refers to the direction perpendicular to this line (this vertical direction is the second direction in this invention).

[0146] The stiffening ribs installed on the gearbox housing 1 enable the housing to obtain greater strength and rigidity, thereby being able to withstand greater vibration, impact and torque, effectively suppressing the deformation of the gearbox housing 1 during operation, increasing the support rigidity of the housing while increasing the minimum material weight and ensuring that the transmitted torque remains unchanged, achieving lightweight design, preventing gear and bearing wear and transmission errors caused by housing deformation, and reducing noise generation.

[0147] Meanwhile, the various stiffening plates set on the outside of the gearbox can effectively increase the surface area of ​​the gearbox, which helps the gearbox to dissipate heat quickly.

[0148] In addition, the connection between the stiffener and the flat end face can effectively improve the flow properties of molten iron during casting. The stiffener can act as an internal flow path for the thin-walled flat end face, which is beneficial for cavity filling and can effectively avoid the generation of internal defects in the thin-walled casting box.

[0149] The following is a detailed description of each type of surface stiffener, with reference to the accompanying drawings.

[0150] 2.1 Radial stiffeners and bolt positions

[0151] Figure 2 shows the arrangement of the radial stiffeners 5 on the left housing 2 and the analysis of the force type and direction of the bearing housing during gear meshing. On the left housing 2, the radial stiffeners 5 are formed to extend radially outward from the center of the bearing housing until they are connected to the bolt position 9.

[0152] The structure connecting the radial stiffener 5 to the bolt position 9 can further improve the support stiffness of the bolt position 9 and resist the deformation of the box caused by the bolt tightening area. In addition, it can improve the casting process of the column with a sudden change in thickness in the bolt position 9. By using the radial stiffener 5 as a flow channel to improve the filling of molten iron in this area, it can avoid casting defects caused by the sudden change in thickness and improve the casting quality of the bolt connection surface.

[0153] Multiple bolt positions 9 are arranged along the side housing 3, forming a curve similar to the outer contour of the side housing 3, and are non-uniformly distributed on this curve, connecting the left housing 2, the side housing 3, and the right housing 4 together. By optimizing the position and layout of the bolt positions 9, loosening and slippage of the joint surface between the left housing 2 and the side housing 3 can be effectively suppressed.

[0154] Specifically, as shown in Figure 2, assuming the pinion rotates at an angular velocity of ω1 and the gear rotates at an angular velocity of ω2, with the vertical direction as the reference and the bearing housing center as the center, the radial stiffeners 5 and bolt positions 9 are arranged more densely in the fan-shaped area that deviates from the pressure angle α±30° relative to the vertical direction than in other areas.

[0155] Furthermore, the arrangement of bolt positions is not limited to the above structure. They can also be arranged evenly or staggered along the outer contour of the box body to achieve a tight connection between the boxes. The cross-section of the bolt positions is not limited to a circle. They can be set as a non-uniform frustum or column with a non-uniform cross-section, or they can be formed by irregular accumulation and thickening of local materials, as long as the connection rigidity of each threaded hole can be guaranteed.

[0156] A cylinder with a locally enlarged and thickened diameter can also be installed at the threaded blind hole. For example, the diameter of the cylinder is 1-3 times larger than the nominal diameter of the threaded hole to ensure machining allowance. This cylinder can increase the connection area between the threaded connection area and the cast housing, improve the connection rigidity of the threaded area, and thus suppress the deformation and slippage of the connection surfaces between the left housing, the right housing, and the side housing.

[0157] See Figures 2 and 3 to illustrate the formation of the pressure angle α.

[0158] As shown in Figure 3, when the pinion and gear in the parallel gearbox mesh, the pinion is subjected to a normal force F at the meshing point. n1 The positive pressure F n1 It can be equivalently decomposed into a radial force F toward the center of the circle. r1 and the tangential force F at the meshing pointt1 The positive pressure F n1 With tangential force F t1 The acute angle between the angles is the pressure angle α.

[0159] In addition, the large gear is subjected to a normal force F at the meshing point. n2 The positive pressure F n2 It can be equivalently decomposed into a radial force F toward the center of the circle. r2 and the tangential force F at the meshing point t2 The positive pressure F n1 With tangential force F t2 The acute angle between the angles is the pressure angle α.

[0160] The force exerted on the two gears at the meshing point is transmitted to the gear bearing, and then to the bearing housing. In the following text, unless otherwise specified, the normal force will be referred to as the normal force F. n Radial forces are collectively referred to as radial force F. r The tangential forces are collectively referred to as tangential force F. t .

[0161] Figure 2 illustrates the normal force F. n The equivalent diagram of the force acting on the bearing housing, where the normal force F acting on the bearing housing is... n With tangential force F t The included angle between them is the pressure angle α.

[0162] Since the area deviating from the pressure angle α±30° relative to the vertical direction is the critical area affected by the force, the dense arrangement of bolt positions 9 and radial stiffeners 5 in this area can improve the support stiffness of the bearing housing to the critical stress area on the housing, thereby suppressing the failure of the housing joint surface connection caused by housing deformation.

[0163] Although in the structure shown in Figure 2, both the radial stiffeners 5 extending radially from the pinion bearing housing and the radial stiffeners 5 extending radially from the large gear bearing housing are densified in the region of pressure angle α±30°, it is also possible to set the radial stiffeners 5 to be densified only on the side of the pinion bearing housing, or to be densified only on the side of the large gear bearing housing.

[0164] Therefore, the first bearing housing in this invention can refer to either the pinion bearing housing or the gear bearing housing. When the first bearing housing in this invention refers to the pinion bearing housing, the second bearing housing refers to the gear bearing housing; when the first bearing housing refers to the gear bearing housing, the second bearing housing refers to the pinion bearing housing.

[0165] Preferably, the included angle between the radial stiffeners 5, which are located in a critical area offset from the pressure angle α ± 30° relative to the vertical direction, is 15°-25°. This structure can effectively reduce the in-plane displacement deformation of the bearing housing and the front right housing under positive pressure. In areas outside this critical area, the included angle between the radial stiffeners 5 can be set to 20°-50°.

[0166] Furthermore, because the large gear at the output end of the gearbox rotates at a low speed, it requires a larger torque to drive subsequent components (such as the sun gear or the splines in the crankshaft). Also, the output gear and gearbox housing are larger and have lower structural rigidity, making this side of the gearbox more prone to deformation and vibration. Therefore, the radial stiffening plate 5 on the gearbox output end housing is reinforced and thickened to 2-5 times the width and thickness of the gearbox housing.

[0167] In addition, as shown in Figure 4, an internal oil passage 55 for lubrication can be embedded in the radial stiffener 5, which is integrally formed with the housing. In this case, the position of the radial stiffener 5 needs to be set with consideration for the layout of the external lubrication oil passages and joints.

[0168] The radial stiffener 5, connected to the lubrication steel pipe leading out from the lubrication distributor, forms an angle between 0 and 30° with the vertical direction, facilitating the arrangement of external lubrication pipelines. Considering the diameter and length of the oil passage, the single-sided allowance between the internal oil passage 55 and the radial stiffener needs to be more than 5mm.

[0169] Figures 5A and 5B show the shape of the radial stiffener 5 in the front view. As shown in Figure 5A, the two sides of the radial stiffener 5 perpendicular to the left box surface can be arranged in parallel.

[0170] Alternatively, as shown in Figure 5B, the two sides of the radial stiffener 5 perpendicular to the left housing surface are arranged at an angle, with the width gradually decreasing in the direction towards the side housing, and the included angle between the two sides being less than 5°. The radial stiffener 5 with this included angle can prevent the radial stiffeners themselves from squeezing against each other over a large area under load, prevent local stress concentration, and also strengthen the strength and rigidity of the connection between the stiffener and the bearing housing.

[0171] Since the radial stiffener 5 shown in Figure 1 is connected to both the bearing housing 20 and the bolt position 9, the height of the stiffener is affected by the distance between the bearing housing 20 and the housing surface and the distance between the bolt position 9 and the housing surface.

[0172] As shown in the cross-sectional view in Figure 5C, distance I1 is the distance from the bearing housing 20 above the housing surface. Additionally, distance I2 is marked in Figure 14A below; this distance I2 is the distance from the bolt position 9 above the housing surface.

[0173] Specifically, the height of the starting point (i.e., the connection point with the bearing housing) and the height of the ending point (i.e., the connection point with the bolt position 9) of the radial stiffener 5 are designed as follows:

[0174] (1) If |I1-I2|≤5mm, then as shown in Figure 6, the top surface of the radial stiffener 5 is parallel to the surface of the left box, and the height is the smaller of I1 and I2.

[0175] (2) If 5mm < |I1-I2| ≤ 20mm, then as shown in Figure 7, the top surface of the radial stiffener 5 near the bearing housing 20 is parallel to the surface of the left housing, and its height is the larger of I1 and I2. As the radial stiffener 5 gradually approaches the bolt position 9, the top surface of the radial stiffener 5 turns at point A, the top surface of the stiffener 5 tilts towards the housing surface, and the height of the stiffener gradually decreases linearly until it connects with the bolt position 9.

[0176] The turning point A is preferably located at a position where the length of the radial stiffener 5 is 1 / 5 to 1 / 3 of the distance from the termination point, and the angle between the top surface of the inclined radial stiffener 5 and the surface of the box is approximately in the range of 2° to 10°.

[0177] (3) If |I1-I2|≥20mm, then as shown in Figure 8A, the top surface of the radial stiffener 5 is inclined relative to the surface of the box from the starting point, so that the height of its top surface gradually decreases linearly from the bearing seat toward the bolt position 9 until it is connected to the bolt position 9.

[0178] Alternatively, when |I1-I2|≥20mm, the radial stiffener 5 can be configured as shown in Figure 8B. In this configuration, the top surface of the radial stiffener 5 is inclined relative to the box surface from the starting point. Unlike the configuration shown in Figure 8A, the radial stiffener 5 is not directly inclined to the bolt position 9. Instead, after reaching the turning point B, the top surface of the radial stiffener 5 extends parallel to the box surface until it connects with the bolt position 9.

[0179] The angle between the top surface of the inclined radial stiffener 5 and the surface of the box is approximately in the range of 2°-15°.

[0180] Although not shown in the diagram, radial stiffeners 5 arranged as described above are also formed on the right box body.

[0181] 2.2 Circumferential stiffening plate

[0182] As shown in Figure 1, the gearbox housing 1 can also be provided with circumferential stiffeners 6 that intersect with the radial stiffeners 5, which are used to connect the radial stiffeners 5 to each other, thereby connecting the radial stiffeners 5, the left housing 2, the side housing 3, the right housing 4 and the bolt positions 9 to each other, forming a reinforcing rib network with higher structural rigidity, which more effectively suppresses the bending, torsion and deformation of the thin-walled housing.

[0183] As shown in Figure 9A, the circumferential stiffener 6 can be set as a circle with the center of the bearing seat 20 as the center and intersects the radial stiffener 5 perpendicularly. Alternatively, as shown in Figure 9B, the circumferential stiffener 6 can also be set as a shape combining arc segments and straight line segments to surround the centers of the two bearing seats 20 in the direction along the side box 3.

[0184] However, the shape of the circumferential stiffener 6 is not limited to this; it can also be rectangular, polygonal, irregularly curved, trapezoidal, circular, etc., as long as it can effectively connect the radial stiffeners 5. In this invention, 1-5 circumferential stiffeners can be reasonably set, but the number of circumferential stiffeners can also be selected according to actual needs.

[0185] Furthermore, the top and bottom surfaces of the circumferential stiffener 6 are parallel, and its height from the surface of the gearbox is preferably 0.8-3 times the thickness of the gearbox wall. If the height of the circumferential stiffener 6 is below this range, it cannot effectively suppress the bending deformation of the gearbox and cannot effectively improve the structural rigidity of the gearbox. If it is above this range, it will weaken the rigidity of the axial stiffener itself. During the operation of the gearbox, the bending stress concentration at the connection between the stiffener and the gearbox surface will be aggravated due to the deformation of the circumferential stiffener itself.

[0186] Additionally, Figure 10 shows another structure for the radial stiffener 5 and circumferential stiffener 6 on the right housing 4. As shown in Figure 10, both the radial stiffener 5 and the axial stiffener 6 have a larger and thicker dimension than conventional stiffeners at the output end of the large gear housed in the right housing 4.

[0187] Furthermore, a weight-reducing opening 10 (which is the first opening in this invention) is provided in the area surrounded by the radial stiffener 5 and the circumferential stiffener 6 to reduce the weight of the housing. The lowest position of the weight-reducing opening 10 is located above the oil level of the planetary gears to ensure lubrication of the planetary shaft and its bearings.

[0188] A rib skirt 11 is provided along the portion of the radial stiffener 5 and circumferential stiffener 6 along the weight-reducing opening 10. The width of the rib skirt 11 is 1-5 times the thickness of the box wall. The arrangement of the rib skirt 11 can further enhance the structural rigidity of the stiffeners, further strengthen the connection point between the radial stiffener 5 and the circumferential stiffener 6, and suppress the mutual displacement deformation between the stiffeners that may be caused by the weight-reducing opening 10.

[0189] In addition, as shown in Figure 10, a flange boss 17 for connecting with other components is also formed on the right housing 4. Axial angle positioning is achieved by two or more locating pins, and axial positioning is achieved by the inner wall stop.

[0190] In this invention, all flange boss interfaces using parallel stage + planetary gearboxes have the same dimensions. Therefore, without disassembling and replacing the planetary gearbox, different transmission ratios of the entire pump can be quickly switched by replacing parallel stage gearboxes with different speed ratios. This helps the entire pump platform to achieve a modular, lightweight, and universal design for the gearbox.

[0191] 2.3 Horizontal stiffening slabs

[0192] As shown in Figure 1, a horizontal stiffener 7 may also be provided on the gearbox housing 1. The horizontal stiffener 7 is formed in the area between the upper and lower tangents of the two bearing seats 20, and preferably its thickness is 1.5-3 times the thickness of the housing wall.

[0193] Figure 11 shows the specific structure of the horizontal stiffener 7.

[0194] As shown in Figure 11, the horizontal stiffener 7 includes a key stiffener 71 and an auxiliary stiffener 72 on a straight line connecting the center of the bearing housing. The auxiliary stiffener 72 is symmetrically arranged with respect to the key stiffener 71. In this invention, the included angle between the auxiliary stiffener 72 and the key stiffener 71 is 0°-10° (inclusive of the values ​​at both ends). However, this invention is not limited to this angle range and can be set according to the diameter ratio of the bearing housing while ensuring structural rigidity and aesthetics.

[0195] A weight-reducing groove 73 is formed in the area surrounded by the key stiffener 71 and the auxiliary stiffener 72 (this opening is the weight-reducing groove in the present invention).

[0196] When two gears in a parallel gearbox are in operation, a horizontal component force is generated at the meshing point due to a reverse action, causing the two gears to tend to move away from each other. Therefore, adding a horizontal stiffener 7 between the two bearing housings can effectively resist this reverse horizontal component force and prevent transmission errors caused by changes in the gear center distance.

[0197] 2.4 Vertical stiffeners

[0198] As shown in Figure 1, the gearbox housing 1 may also be provided with a vertical stiffener 8. This vertical stiffener 8 is perpendicular to the line connecting the centers of the two bearing seats 20 and is connected to the bolt position 9.

[0199] Referring again to Figure 9B, it can be seen that a radial stiffener 5 extending from the center of the bearing housing 20 and connected to a vertical stiffener 8 can also be provided. Thus, the radial stiffener 5, the vertical stiffener 8 and the horizontal stiffener 7 form a stable triangular structure, which further suppresses the reverse phase displacement between gears and ensures the stability and accuracy of the transmission.

[0200] The present invention allows for the selection of the number of vertical stiffeners 8 based on the center distance of the bearing housings, thereby improving the rigidity of the connection and support between bearing housings.

[0201] 2.5 Axial stiffeners

[0202] In addition, as shown in Figure 12, axial stiffeners 12 and turning stiffeners 13 can also be provided inside the side box 3.

[0203] The axial stiffener 12 is perpendicular to the left housing (not shown) and the right housing 4, with one end connected to the bolt position 9 and the other end connected to the radial stiffener 5 via the turning stiffener 13. As shown in Figure 12, the turning stiffener 13 is located at the connection between the side housing 3 and the right housing 4.

[0204] However, the present invention is not limited to this. Both ends of the axial stiffener 12 can be connected to the radial stiffener 5 through the turning stiffener 13.

[0205] This structure not only improves the support stiffness of bolt position 9 on the box, but also suppresses bending, torsion and deformation of the thin-walled box.

[0206] 2.6 Sealing Structure

[0207] Figure 13 shows the sealing structure in the joint surface of the housing. As shown in Figure 13, the joint surface between the left or right housing and the side housing 3 contains a sealing structure.

[0208] The sealing structure shown in Figure 13 includes a sealing groove 14 and a sealing element 15. The sealing groove 14 is configured with a rectangular cross-section around the side housing 3 and contains the sealing element 15 within the groove. The sealing element 15 includes, but is not limited to, sealing rings, sealing strips, sealing rings, etc.

[0209] Although Figure 13 only shows the joint surface between the side box 3 and one side end face containing a sealing structure, a sealing structure can also be provided in the joint surface between the side box 3 and both side end faces, or the sealing structure can not include a sealing groove, but can be directly sealed with sealant.

[0210] The seal is pressed against the mating surface by external bolts. The elastic deformation generated by the pressure fills the gaps on the mating surface to generate contact pressure, thereby preventing the leakage of internal oil and gas and the intrusion of external dust and moisture. It also prevents adverse consequences such as lubricating oil contamination and gear pitting wear caused by moisture.

[0211] 2.7 Stiff plate shape

[0212] Figures 14A and 14B show different cross-sectional shapes of the stiffeners. As shown in Figure 14A, all stiffeners can have a rectangular cross-sectional shape. Compared to solid regular cross-sectional shapes (such as circles, squares, etc.) with the same area, rectangular cross-sections have a larger moment of inertia along their major axis, thus ensuring sufficient bending stiffness to suppress displacement and deformation of the thin-walled box.

[0213] In addition, as shown in Figure 14B, when there is a need for built-in oil passages, the cross section of the stiffener plate can also be set as a semi-circular cross section, and holes can be drilled inside to arrange the oil passages, so as to achieve the purpose of weight reduction while meeting the machining allowance.

[0214] In addition, the stiffener section can also be set as a trapezoidal section with beveled corners on both sides to strengthen the strength of the stiffener root, or it can be set as any cross-sectional shape to meet the support requirements and casting process as needed.

[0215] In this invention, the improvement idea for the parallel stage gearbox housing is roughly the same as that for the parallel stage + planetary stage gearbox housing. Therefore, the configuration structure described above for the parallel stage + planetary stage gearbox housing is also applicable to the parallel stage gearbox housing. This improves the connection rigidity of the housing, suppresses bending and torsional deformation of the housing, and ensures precise transmission of the internal gears while effectively maintaining the center distance of the bearing seats.

[0216] In addition, the various stiffeners and related structures such as radial stiffeners, circumferential stiffeners, horizontal stiffeners, and vertical stiffeners mentioned above can be freely selected and combined as needed, that is, some or all of the stiffeners and related structures can be used in the gearbox housing.

[0217] Furthermore, although only the left housing is described in the accompanying drawings, those skilled in the art will understand that the aforementioned stiffening ribs and other structures can also be adapted to be installed in the right housing. The description of the right housing follows the same principle.

[0218] 3. Stepped arrangement of the gearbox housing

[0219] To improve the gearbox's resistance to bending deformation, the gearbox can be designed as a stepped folded arrangement with multiple stepped planes, thus transforming the planar structure of the gearbox into a three-dimensional structure.

[0220] 3.1 Stepped arrangement of parallel stage + planetary stage gearbox

[0221] Figures 15A and 15B show the stepped structure of the parallel stage housing of a two-stage gearbox consisting of a parallel stage and a planetary stage.

[0222] Figure 15A shows an outer view of the stepped structure. As shown in Figure 15A, the input side housing for accommodating the pinion is formed as a stepped structure with multiple steps 16 in the direction from the center of the bearing housing to the side housing 3. In Figure 15A, the height of the stepped structure gradually decreases in the direction from the pinion bearing housing 20 to the side housing 3.

[0223] At least a portion of the circumferential stiffener 6 is formed on the stepped portion 16. The arrangement of the circumferential stiffener 6 is described above and will not be repeated here.

[0224] In other words, the number and spacing of the stepped sections 16 on the box body are related to the number and spacing of the circumferential stiffeners 6, and the number n of the stepped sections 16 is the same as the number of circumferential stiffeners 6. In this invention, it is preferred to set the number n of the stepped sections 16 to 2, but it is not limited to this, and n can be set to any integer ≥ 2 as needed.

[0225] The spacing between the multiple stepped portions 16 can be set to be equal to each other, or the spacing can be set to be different from each other, for example, the spacing gradually increases or decreases in the direction from the center of the bearing housing to the side housing 3.

[0226] To ensure uniform thickness at the corner of the step 16, the outer radius R1 of the outer corner of the box is twice the inner radius R2 of the inner corner of the box.

[0227] Furthermore, the height of each step 16 can be set to be the same or different from each other. When the total height of the steps 16 is fixed, the height of the steps 16 is inversely proportional to the number of steps 16. In this invention, it is preferable to set the height of the steps 16 to 0.5-2 times the thickness of the box wall.

[0228] When the box body is formed into a stepped structure, the radial stiffener 5 is also formed into a stepped structure, and its top surface is composed of alternating horizontal surfaces 51 and inclined surfaces 52. The horizontal surface 51 is parallel to the extended surface of the left box body, and the inclined surface 52 is formed on the plane of the stepped portion 16 that intersects with the extended surface. The angle between the inclined surface 52 and the horizontal surface 51 is preferably less than 45°, but the angle is not limited to this, as long as a smooth transition at the corner is ensured.

[0229] The structure of the radial stiffener 5 can better ensure the uniformity of the wall thickness change between the box and the radial stiffener 5, thereby avoiding casting defects caused by abrupt changes in the thickness of the radial stiffener 5 on the stepped surface.

[0230] Figure 15B shows an inner view of the stepped structure. As shown in Figure 15B, a stepped structure, circumferential stiffener 6, and radial stiffener 5 are also formed on the inner side of the input side housing for accommodating the pinion.

[0231] Corresponding to Figure 15A, the stepped structure gradually decreases in height in the direction from the pinion bearing seat 20 to the side housing 3. The circumferential stiffener 6 is formed at the step portion 16, and the radial stiffener 5 is also formed as a stepped structure, and its top surface is composed of alternating horizontal surfaces 51 and inclined surfaces 52, wherein the inclined surfaces 52 are formed on the aforementioned step portion 16.

[0232] By forming the box into the aforementioned stepped structure, the planar box can be transformed into a three-dimensional structure. The stepped portion and the stepped radial stiffeners enable multiple planes to support each other, significantly improving the structural rigidity of the box.

[0233] Furthermore, although a stepped structure is shown in the portion around the pinion bearing housing in Figures 15A-15B, a stepped structure can also be formed in the portion around the large gear bearing housing.

[0234] Therefore, similar to the previous description, the first bearing housing in this invention can refer to either the pinion bearing housing or the gear bearing housing. When the first bearing housing in this invention refers to the pinion bearing housing, the second bearing housing refers to the gear bearing housing; when the first bearing housing refers to the gear bearing housing, the second bearing housing refers to the pinion bearing housing.

[0235] 3.2 Stepped arrangement of a single parallel stage gearbox

[0236] Figures 16A and 16B show the stepped structure of the housing of a single parallel stage gearbox.

[0237] Although the improvement ideas for the parallel stage gearbox housing in this invention are roughly the same as those for the parallel stage + planetary stage gearbox housing, in the parallel stage gearbox, because the pinion is thicker than the gear and the thickness difference between the two gears is significant, the pair of bearing seats supporting the pinion are far apart in the axial direction, while the pair of bearing seats supporting the gear are closer together in the axial direction. This results in a large difference in the relative positions of the two gear bearing seats on the axis, which may lead to insufficient overall rigidity of the bearing seats. Under the condition of high-frequency meshing of the pinion and gear, the housing may vibrate and deform.

[0238] Therefore, it is necessary to further strengthen the weak points of the parallel stage gearbox.

[0239] Therefore, in addition to the configuration structure described above for the parallel-stage + planetary-stage gearbox housing, the present invention also configures the housing of the left housing 2 (input side) and the right housing 4 (output side) of the parallel-stage gearbox as a stepped structure with multiple stepped portions 16.

[0240] Figure 16A shows the stepped structure on the pinion side of the left housing 2 of the parallel gearbox. As shown in Figure 16A, on the pinion side of the left housing 2, the stepped structure is formed with multiple steps 16, and vertical stiffeners 8 are at least partially formed at these steps 16. The height of the stepped structure gradually decreases in the direction from the pinion to the gear.

[0241] Because the distance between the pinion side bearing housing and the side housing 3 is small, no circumferential stiffener 6 is formed on the pinion side.

[0242] Although only part of the structure of the left box 2 is shown in Figure 16A, in this invention, the vertical stiffener 8 is connected to two bolt positions 9 in the vertical direction.

[0243] To ensure uniform thickness at the corner of the step 16, the outer radius R1 of the outer corner of the box is twice the inner radius R2 of the inner corner of the box.

[0244] Figure 16B shows the stepped structure on the large gear side of the right housing 4 of the parallel gearbox. As shown in Figure 16B, the stepped structure on the large gear side of the right housing 4 is also formed with multiple steps 16. The height of this stepped structure gradually increases in the direction from the large gear to the small gear. However, unlike the structure shown in Figure 16A, circumferential stiffeners 6 are formed at these steps 16.

[0245] Furthermore, radial stiffeners 5 can also be formed in Figures 16A and 16B. The structure and formation of these radial stiffeners 5 are the same as those in Figures 15A and 15B, and will not be described again here. However, since the bearing housing of the parallel stage gearbox is far from the bolt position, the radial force it experiences gradually decreases as the radial stiffener extends towards the side of the gearbox. Therefore, to minimize weight, as shown in Figure 7 again, the width of the radial stiffener 5 gradually decreases along the radial direction.

[0246] Furthermore, within a range of ±30° relative to the vertical deviation from the pressure angle α, the width of the radial stiffener 5 is set to 1.1-2 times the width of the radial stiffener 5 in other ranges. Simultaneously, the housing is thickened relative to other ranges within the range between the two tangents of the two bearing seats 20, and the horizontal stiffener 7 between the two bearing seats 20 is also thickened.

[0247] This structure, with its thickened housing and horizontal stiffeners between the bearing seats, effectively resists the opposite phase displacement between the two gears, preventing transmission errors caused by changes in the gear center distance.

[0248] By forming the housing into the aforementioned stepped structure, the planar housing can be transformed into a three-dimensional structure, effectively shortening the distance between the bearing seat and the housing surface. Furthermore, the stepped portion and the stepped radial stiffeners enable multiple planes to support each other, significantly improving the structural rigidity of the housing.

[0249] Although different stepped structures on the pinion bearing housing side and the gear bearing housing side are shown in Figures 16A-16B respectively, in this invention, the stepped structure shown in Figure 16A can also be formed on the gear bearing housing side, and the stepped structure shown in Figure 16B can be formed on the pinion bearing housing side.

[0250] Alternatively, a stepped structure as shown in Figure 16A may be formed only on the side of the pinion bearing housing or the gear bearing housing, or a stepped structure as shown in Figure 16B may be formed only on the side of the pinion bearing housing or the gear bearing housing.

[0251] Therefore, as mentioned above, the first bearing housing in this invention can refer to either the pinion bearing housing or the gear bearing housing. When the first bearing housing in this invention refers to the pinion bearing housing, the second bearing housing refers to the gear bearing housing; conversely, when the first bearing housing refers to the gear bearing housing, the second bearing housing refers to the pinion bearing housing.

[0252] Furthermore, as shown in Figure 16A, the bolt post at bolt position 9 is raised upwards due to its stepped structure, causing the top bolt positioning surface to protrude above the box wall. This may result in inconsistent post heights at bolt position 9 across the entire left box 2. To standardize the bolt type, reduce component management costs, and improve assembly speed, the post heights at the bolt positions on the right box 4 are adjusted accordingly, ensuring that the post heights at the bolt positions of the left and right boxes 2 are consistent after assembly.

[0253] Although not illustrated, the structural features in Figures 1-14B can also be adapted to the stepped structures shown in Figures 16A-16B.

[0254] II. Second embodiment of the gearbox housing according to the present invention

[0255] Figure 17 shows a perspective view of another aspect of the invention, cut along the gearbox housing; Figure 18 shows a first front view of the housing's external shape in the invention; Figure 19 shows a second front view of the housing's external shape in the invention; Figure 20 shows a third front view of the housing's external shape in the invention.

[0256] As shown in Figure 17, the gearbox housing 1' consists of a left housing 2' and a side housing 3' located on the input side of the gearbox, and a right housing 4' located on the output side of the gearbox. In this invention, the left housing 2' and the right housing 4' are connected to the side housing 3' by bolts arranged along the outer edge of the housing.

[0257] Although bolts are used to connect the left and right housings and the side housings in the diagram, other methods can also be used for connection, such as welding.

[0258] In this invention, the gearbox housing contains at least a parallel gear reducer, the parallel gear comprising a pinion at the input end and a large gear meshing with the pinion. The gearbox housing also includes bearing housings for supporting the pinion and for supporting the large gear.

[0259] In Figures 18-20, the small gear on the left is the input gear, with the center of the small gear and its corresponding bearing seat on the left housing 2' being O1, and the radius of the small gear being R1. The large gear on the right is the output gear, with the center of the large gear and its corresponding bearing seat on the left housing 2' being O2, and the radius of the large gear being R2.

[0260] As shown in Figure 18, since the side housing 3' needs to surround the input gear and the output gear, its outer contour is formed into an arc shape near the input gear and the output gear. The center of the arc near the pinion bearing housing coincides with the center of the pinion bearing housing, both being O1, and the center of the arc near the large gear bearing housing coincides with the center of the large gear bearing housing, both being O2.

[0261] In addition, the side housing 3' also includes two straight sections, which are tangent to the arcuate sections near the pinion bearing housing and the arcuate sections near the large gear bearing housing, respectively. In other words, the side housing 3' is composed of an arcuate section near the pinion bearing housing, an arcuate section near the large gear bearing housing, and two straight sections tangent to the two arcuate sections.

[0262] In the structure shown in Figure 18, the center of the arc portion near the pinion bearing seat is made to coincide with the center of the pinion bearing seat. That is, the first bearing seat in this invention refers to the pinion bearing seat, and the first arc portion refers to the arc portion near the pinion bearing seat. Meanwhile, the second bearing seat refers to the large gear bearing seat, and the second arc portion refers to the arc portion near the large gear bearing seat.

[0263] However, the present invention is not limited thereto. The first bearing housing may also refer to the large gear bearing housing, in which case the second bearing housing refers to the small gear bearing housing. In this case, the first arc portion refers to the arc portion closer to the large gear bearing housing, and the second arc portion refers to the arc portion closer to the small gear bearing housing.

[0264] The same explanation applies to the first bearing housing, the second bearing housing, the first arc portion, and the second arc portion in the following structure, so it will not be repeated here.

[0265] Furthermore, the housing structure of the present invention is not limited to the structure shown in FIG18, and the arc portion of the side housing 3' may not coincide with the center of the bearing seat.

[0266] As shown in Figure 19, the center of the arc portion near the pinion bearing housing is O3, and the radius is R3. It can be seen from Figure 19 that the radius R3 of this arc portion is greater than the radius R1 of the pinion. Therefore, the center O3 of this arc portion lies on the line connecting the center O1 of the pinion bearing housing and the center O2 of the large gear bearing housing.

[0267] In this invention, R1 < R3 < R2, preferably the radius R3 is 1.2-1.8 times the radius R1, and more preferably the distance between the center O3 of the arc portion with radius R3 and the center of the pinion bearing seat O1 is between 50-150 mm.

[0268] The structure shown in Figure 19 allows for a reduction in the significant size difference between the portion accommodating the pinion and the portion accommodating the gear in terms of the housing's shape.

[0269] In addition, Figure 20 shows a further improvement based on the structure of Figure 19. As shown in Figure 20, at the point where the line connecting the center O1 and the center O2 (horizontal direction) intersects with the gearbox housing, the side housing 3' is formed into straight segments L2 and L3, while the left housing 2' and the right housing (not shown) are formed into shapes with corresponding straight segments.

[0270] Preferably, in the vertical direction perpendicular to the connecting line, at the point where the vertical line passing through the center O2 intersects with the gearbox housing, the side housing 3' is also formed as a straight segment L1. That is, as can be seen from Figure 20, this straight segment L1 overlaps with the center O2 in the vertical direction. Simultaneously, the left housing 2' and the right housing 4' are formed with corresponding portions having straight segments.

[0271] The lengths of straight segments L1, L2, and L3 are unlimited, as long as the distance between the side housing 3' and the top of the gear is greater than 10mm.

[0272] This structure not only reduces the overall size and weight of the gearbox, but also reduces the bulky appearance of the gearbox through its straight-line profile.

[0273] In addition, although Figure 20 shows an improved scheme based on the structure of Figure 19, the structure shown in Figure 18, in which the center of the arc of the side box overlaps with the center of the gear, can also be used in the box body including the straight segments L1-L3 shown in Figure 20.

[0274] In summary, by providing a gearbox housing, the present invention not only reduces the size and weight of the gearbox and saves costs by changing the shape of the gearbox housing, but also makes the gearbox more aesthetically pleasing.

[0275] III. Embodiments of the Gearbox according to the present invention

[0276] Figure 21 is a schematic diagram showing a reduction gearbox 1” according to an example of the present invention, and Figure 22 is an enlarged view showing the oil return port of Figure 21. As shown in Figure 21, the reduction gearbox 1” includes a housing 2” and a gear assembly 3”. In the example of Figure 21, the housing 2” includes a left arcuate portion A, a right arcuate portion B, an upper flat portion C, and a lower flat portion D, which are walls of the housing 2”, in the circumferential direction R. The upper flat portion C forms a tangential connection with the upper side of the left arcuate portion A and the upper side of the right arcuate portion B, and the lower flat portion D forms a tangential connection with the lower side of the left arcuate portion A and the lower side of the right arcuate portion B. Here, the upper flat portion C and the lower flat portion D are described relative to the left arcuate portion A and the right arcuate portion B, meaning that they are generally straight in the cross-sectional view shown in Figure 21, rather than curved as the left arcuate portion A and the right arcuate portion B. It should be noted that the upper flat portion C and the lower flat portion D described here are not limited to having absolutely flat surfaces, but their surfaces may have protrusions for connection, etc. The gear assembly 3” is disposed inside the housing 2” and typically includes, for example, a set of two gears. During gearbox operation, the two gears mesh and rotate, thereby transmitting power. Although not shown in detail, the gearbox 1” also includes a lubrication system that provides the necessary lubricating oil for the operation of the gearbox 1”, for example, providing lubricating oil to the rotating gear assembly 3” to reduce dry friction and dissipate heat. The amount of lubricating oil supplied to the housing 2” needs to be appropriate to ensure the gearbox operates normally and efficiently. When the amount of lubricating oil inside the gearbox 1” is too low, it may not provide sufficient lubrication and heat dissipation, while when the amount of lubricating oil inside the gearbox 1” is too high, it may increase the viscous resistance of the gears against the lubricating oil, and also increase the power loss caused by the pumping action of the gear meshing on the lubricating oil, which may affect the operating performance of the gearbox 1”. In this case, the excess lubricating oil needs to be drained from the housing 2”. Therefore, the gearbox 1” is also provided with an oil return port 4”, through which excess lubricating oil can be discharged from the housing 2”. As shown in Figure 21, the oil return port 4” is located on the wall of the housing 2” of the gearbox 1”. Although two oil return ports 4” are shown in Figure 21, this is only an example, and the number of oil return ports 4” is not limited to two, but can also be one or more.

[0277] To ensure smooth lubricating oil flow, the number and arrangement angle of the oil return ports 4" are not limited for gearboxes 1" with different installation angle requirements. At least one oil return port 4" must be located at the lowest point after the gearbox is installed. That is, in the installed state of gearbox 1", at least one oil return port 4" must be located on the bottom wall of the housing 2". Auxiliary oil return ports (not shown in the figure) can be arbitrarily arranged at other locations on the housing 2", including but not limited to the bottom of the side surfaces of the housing 2" (here, the side surfaces refer to the surfaces of the housing 2" that partially surround the gear device 3, such as the left and right sides of the housing 2" that partially surround the gear device 3" in the view of Figure 21), as shown at the bottom of the left arc portion A and the right arc portion B in Figure 21. Auxiliary oil return ports can also be opened at any angle on the rear end face of the housing 2" (the rear end face of the housing 2" is the end face connected to the power unit), as long as it ensures smooth oil return and meets the space requirements for the overall oil return pipe arrangement.

[0278] Additionally, as shown in Figures 21 and 22, an oil baffle 5” is installed near the oil return port 4” along the path of the lubricating oil flying out in the tangential direction of the gear (as indicated by the arrow in Figure 22). This baffle prevents the lubricating oil from being stirred up, allowing it to flow out through the oil return hole 6” along the oil baffle 5”. The oil baffle 5” is as high as possible without interfering with the gears of the gear assembly 3”. The higher the oil baffle 5”, the more lubricating oil with excessive tangential velocity it can block, thus achieving a better blocking effect. The thickness of the oil baffle 5” is not limited, provided it is manufactured using a casting process and uniform casting is considered (e.g., the thickness of the oil baffle 5” is typically ≥5mm). The cross-sectional shape of the oil baffle 5” is not limited to a regular rectangle; it can also be a trapezoidal cross-section reinforced at the root, or other cross-sections that can achieve the oil-blocking effect. Here, the oil baffle 5” can be integrally formed with the housing 2”, for example, by casting. Alternatively, the oil baffle 5” can also be formed by locally thickening and stacking to create a raised structure with oil-blocking function.

[0279] To achieve a lightweight design for the gearbox 1", the parallel stage housing is designed to be extremely compact, with the inner wall close to the internal rotating gears. To prevent lubricating oil from swirling in the gears due to insufficient space for it to fall into the bottom oil return port after flying out tangentially from the gear teeth, the oil return port 4" of this invention can have a recessed design. This increases the distance between the oil return port 4" and the addendum circle of the gear teeth, facilitating the settling and drainage of lubricating oil. The specific recessed height of the oil return port 4" is not limited, as long as it ensures smooth oil return and meets the space requirements for the overall oil return pipe arrangement. In addition, the recessed method of the oil return port 4" is not limited; it can be recessed entirely on the bottom surface or partially recessed around the oil return port 4".

[0280] Referring to the accompanying drawings, Figure 23 is a schematic diagram showing a gearbox according to another example of the invention, wherein the overall sunken oil return port is shown; Figure 24 is a schematic diagram showing a gearbox according to another example of the invention, wherein the partially sunken oil return port is shown; Figure 25 is an enlarged view showing the partially sunken oil return port of Figure 24; Figure 26 is a schematic diagram showing a gearbox according to another example of the invention, wherein the partially sunken oil return port is shown; Figure 27 is an enlarged view showing the partially sunken oil return port of Figure 26. In Figure 23, an example is shown where the two oil return ports 4” at the bottom of the gearbox 1” are sunken overall relative to the bottom wall of the gearbox 2”. As shown in Figure 23, two oil return ports 4” are located on the lower flat portion D of the housing 2”, i.e., on the bottom wall of the housing 2”. Here, the bottom wall of the housing 2” with two oil return ports 4” is recessed as a whole, specifically, its position is lower than the position when it forms a tangential connection with the lower side of the left arc portion A and the lower side of the right arc portion B of the housing 2”. In other words, the bottom wall of the housing 2” with two oil return ports 4” protrudes outward from the lower side of the left arc portion A and the lower side of the right arc portion B of the housing 2”, thereby increasing the distance between the gear device 3” and the bottom wall of the housing 2”, especially with the oil return ports 4”, to allow for a larger space for lubricating oil flow. Figures 24 and 25 show an example of partial recess of the oil return ports 4”, i.e., the oil return ports 4” are only recessed relative to the housing 2” in their vicinity. As shown in Figures 24 and 25, the oil return port 4” is located at the bottom of one side of the housing 2”, that is, on the bottom wall of the housing 2”. Here, the oil return port 4” is partially recessed relative to the housing 2” in its vicinity. Specifically, the oil return port 4” protrudes outward relative to the wall of the housing 2”, thereby increasing the distance between the gear device 3” and the oil return port 4”, so as to leave more space for lubricating oil flow. Figures 26 and 27 show another example of the partial recess of the oil return port 4”, in which the oil return port 4” is also located at the bottom of one side of the housing 2”, and the oil baffle 5” is also shown. That is to say, the recessed design of the oil return port 4” can be combined with the design of the oil baffle 5”.

[0281] The downward height of the oil return port 4”, i.e., the height by which the oil return port 4” protrudes from the wall of the housing 2” to the outside of the housing 2”, is related to factors such as gear speed, lubricating oil volume, and the distance between the gear tip circle and the inner wall of the housing 2”. Due to the limitation of the overall oil return pipe layout space, the downward height of the oil return port 4” is generally 1 to 5 times the wall thickness of the housing 2”. For the partial downward design of the oil return port 4”, it is preferable to have a partial downward design within the area of ​​the oil return port with a diameter of 1 to 3 times the wall thickness of the housing 2”, centered on the center of the oil return through hole 6”. The downward part and the housing 2” have a transition section that smoothly transitions along the direction of lubricating oil outflow. That is, the downward part and the housing 2” need to smoothly transition along the direction of lubricating oil outflow. The angle between this transition section and the tangent direction of the tip circle of the gear device 3” is 0 to 20°, and it can be a plane, inclined plane, arc surface, or any structure that can achieve stable lubricating oil outflow.

[0282] The connection method between the housing 2” and the recessed oil return port 4” is not limited; it can be a planar connection or a curved surface connection, such as an irregular curved surface connection. The starting range, extension range, and tilt angle of the curved surface are not limited, as long as the wall thickness change is uniform and the corner transition is slow. It should be noted that the curved surface here is a surface that is concave downward from the surface to ensure smooth flow of lubricating oil. For example, the present invention provides an implementation of an irregular curved surface connection, namely, using a curved surface transition. Referring to the accompanying drawings, Figure 28 is a schematic diagram of a gearbox according to another example of the present invention, showing the oil return port as seen from inside the gearbox housing; Figure 29 is an enlarged view of the oil return port of Figure 28; Figure 30 is a schematic diagram of the gearbox of Figure 28, showing the oil return port as seen from outside the gearbox housing; Figure 31 is an enlarged view of the oil return port of Figure 30. As shown in Figures 28-31, the oil return port 4 of the gearbox 1” has an oil baffle 5”, an oil return through hole 6” and a curved transition part 7”. The oil baffle 5” and the curved transition part 7” are arranged on opposite sides of the oil return through hole 6”, and the curved transition part 7” guides the lubricating oil to the oil return through hole 6”. That is, the lubricating oil from the inside of the gearbox 2” flows into the oil return through hole 6” through the curved transition part 7. The oil baffle 5” protrudes from the bottom wall of the gearbox 2” toward the inside of the gearbox 2” to block the lubricating oil and prevent the lubricating oil from being stirred up. That is, it prevents the lubricating oil from splashing forward due to inertia under the high speed rotation of the gear and failing to be discharged smoothly from the oil return port 4”. For example, the curved transition section 7” has a smooth curved surface that is recessed downwards from the wall of the housing 2” towards the interior of the housing and has a cup-shaped curved surface. The end adjacent to the oil return hole 6” is wider and recessed deeper than the end opposite to the end adjacent to the oil return hole 6”. The depth of the recess in the curved transition section 7” gradually increases from the end connected to the bottom wall of the housing 2 to the end connected to the oil return hole 6”, forming a smooth curved surface and thus creating a gradual drop. In this way, the cup-shaped curved surface transition of the oil return port 4” can guide and collect oil, guiding the lubricating oil to drain more quickly through the gradual height difference.

[0283] Although the shape of the return oil through hole 6” is shown as circular in the attached diagram, this is not limiting. The shape of the return oil through hole 6” can also be polygonal, elliptical, or any other shape that meets the oil drainage requirements. Furthermore, the cross-section of the mounting boss at the return oil port is not limited to a regular rectangle or circle; it can also be a non-uniform frustum or column with an unequal cross-section, or the rigidity of the return oil hole can be ensured simply by irregularly stacking and thickening local materials. The bolt hole positions for the return oil pipe connection are not limited to the rectangular four-corner arrangement shown in the diagram. The number and arrangement of the threaded holes are not limited; they can be arranged along the edge of the mounting boss at the return oil port, along the circumference, or staggered, as long as the connection and fixation of the return oil pipe can be achieved. The return oil through hole can be formed directly by casting or by machining.

[0284] The beneficial effects of this invention are as follows:

[0285] According to the present invention, the distance between the oil return port and the tooth tip circle is increased, which is conducive to the settling and drainage of lubricating oil. The cup-shaped curved surface transition can guide the lubricating oil to drain faster under the action of gravity through a slow height difference, so that the lubricating oil can be discharged smoothly and the overall functionality of the gearbox is improved.

[0286] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A gearbox housing, comprising an input-side housing (2), a side housing (3), and an output-side housing (4), in, The input side enclosure (2) and the output side enclosure (4) are connected to the side enclosure (3) by a plurality of bolt positions (9) arranged along the side enclosure (3). The input-side housing is provided with a first bearing seat (20), a second bearing seat (20), and multiple radial stiffeners (5). The plurality of radial stiffeners (5) include a plurality of first radial stiffeners (5) and a plurality of second radial stiffeners (5). Each first radial stiffener (5) extends radially outward from the center of the first bearing seat (20), and each second radial stiffener (5) extends radially outward from the center of the second bearing seat (20). The radial stiffener (5) is connected to the bolt position (9). The direction connecting the center of the first bearing housing (20) and the center of the second bearing housing (20) is the first direction, and the second direction is perpendicular to the first direction. Among them, with the center of the first bearing seat (20) as the center, in the region that deviates from the pressure angle by ±30° relative to the second direction, the first radial stiffener (5) and the bolt position (9) are arranged more densely than in other regions, and the pressure angle is the pressure angle of the pressure on the first bearing seat (20).

2. The housing according to claim 1, wherein, In the region, the included angle between the first radial stiffeners (5) is 15°-25°.

3. The housing according to claim 1, wherein, An internal oil passage integrally formed with the housing is provided in the radial stiffener (5) which is at an angle of 0-30° with the second direction.

4. The housing according to claim 1, wherein, The radial stiffeners (5) are arranged in parallel on two sides perpendicular to the surface of the input side box (2) or the distance between them gradually decreases in the direction toward the side box (3).

5. According to claim 1, wherein, The connection point between the first radial stiffener (5) and the first bearing seat (20) is the first connection point, and the height of the first connection point from the surface of the housing is the first height. The connection point between the first radial stiffener (5) and the bolt position (9) is the second connection point, and the height of the second connection point from the surface of the housing is the second height. Therefore, the third height of the first radial stiffener (5) from the surface of the housing is set as follows: i. When the difference between the first height and the second height is less than or equal to 5mm, the third height is the smaller value between the first height and the second height; ii. When the difference between the first height and the second height is greater than 5mm and less than or equal to 20mm, the third height is the first height between the first connection point and the turning point. Between the turning point and the second connection point, the top surface of the first radial stiffener (5) is inclined relative to the input side box (2), so that the third height decreases linearly from the first height to the second height. The turning point is located between the first connection point and the connection point; iii. When the difference between the first height and the second height is greater than 20mm, the top surface of the first radial stiffener (5) is inclined relative to the input side box (2), so that the third height is linearly reduced from the first height to the second height.

6. The housing according to claim 5, wherein, The distance between the turning point and the second connection point is 1 / 5 to 1 / 3 of the length of the first radial stiffener (5).

7. The housing according to claim 5, wherein, When the difference between the first height and the second height is greater than 5mm and less than or equal to 20mm, the angle of inclination of the first radial stiffener (5) relative to the input side housing (2) is in the range of 2°-10°, and When the difference between the first height and the second height is greater than 20mm, the angle of inclination of the first radial stiffener (5) relative to the input side box (2) is in the range of 2°-15°.

8. The housing according to claim 1, further comprising: Multiple circumferential stiffeners (6) intersect with the radial stiffeners (5), thereby connecting the multiple radial stiffeners (5) to each other. Wherein, the circumferential stiffener (6) is configured to intersect the radial stiffener (5) perpendicularly, or the circumferential stiffener (6) is configured to surround the center of the first bearing seat (20) and the center of the second bearing seat (20) in the direction along the side box (3).

9. The housing according to claim 8, wherein, A first opening (10) is provided in the area surrounded by the circumferential stiffener (6) and the radial stiffener (5).

10. The housing according to claim 9, wherein, A rib skirt (11) is provided on the circumferential rib (6) and the radial rib (5) along the portion of the first opening (10), and the width of the rib skirt (11) is 1-5 times the thickness of the input side box (2) or the output side box (4).

11. The housing according to claim 1, further comprising: A horizontal stiffening rib (7) is provided in the area between two tangents of the first bearing seat (20) and the second bearing seat (20). The horizontal stiffener (7) includes a first horizontal stiffener (7) and a second horizontal stiffener (7). The first horizontal stiffener (7) is located on the line connecting the center of the first bearing seat (20) and the center of the second bearing seat (20). The second horizontal stiffener (7) is symmetrically arranged with respect to the first horizontal stiffener (7).

12. The housing according to claim 11, wherein, The included angle between the first horizontal stiffener (7) and the second horizontal stiffener (7) is 0°-10°, and a weight-reducing groove (73) is provided between the first horizontal stiffener (7) and the second horizontal stiffener (7).

13. The housing according to claim 11, wherein, The thickness of the horizontal stiffener (7) is 1.5-3 times the thickness of the input side box (2) or the output side box (3).

14. The housing according to claim 11, further comprising: Multiple vertical stiffeners (8) are arranged in the second direction and connected to the bolt positions (9).

15. The housing according to claim 14, wherein, The radial stiffener (5) is connected to the vertical stiffener (8), thereby forming a triangular structure with the horizontal stiffener (7).

16. The housing according to claim 1, further comprising: Multiple axial stiffeners (12) are provided inside the side housing (3) and perpendicular to the input side housing (2) and the output side housing (4). One end of the axial stiffener (12) is connected to the bolt position (9), and the other end is connected to the radial stiffener (5) through the turning stiffener (13) located at the connection between the side box (3) and the output side box (4).

17. The housing according to claim 1, wherein, A sealing structure is included in the mating surface between the input side housing (2) and / or the output side housing (4) and the side housing (3), the sealing structure including at least a seal (15).

18. The housing according to claim 1, wherein, The radial stiffener (5) has a rectangular cross-sectional shape.

19. The housing according to claim 1, wherein, The thickness of the second radial stiffener (5) is 2-5 times the thickness of the output end housing (4).

20. The housing according to claim 1, wherein, Centered on the center of the second bearing housing (20), in the region that deviates from the pressure angle by ±30° relative to the second direction, the second radial stiffener (5) and the bolt positions (9) are arranged more densely than in other regions.

21. A gearbox housing, comprising an input-side housing (2), a side housing (3), and an output-side housing (4), in, The input-side enclosure (2) and the output-side enclosure (4) are connected together with the side enclosure (3). The input side housing (2) is provided with a first bearing seat (20), a second bearing seat (20), and a plurality of circumferential stiffeners (6). In the direction from the center of the first bearing seat (20) toward the outer periphery of the side housing (3), the input side housing (2) is formed as a stepped structure with a plurality of stepped portions (16). The circumferential stiffener (6) is at least partially formed on the stepped portion (16) and is configured to (i) surround the center of the first bearing seat (20) or the center of the second bearing seat (20), or (ii) surround the center of the first bearing seat (20) and the center of the second bearing seat (20) in the direction along the side box (3).

22. The housing according to claim 21, wherein, The height of the step (16) is 0.5-2 times the thickness of the input side box (2).

23. The housing according to claim 21, wherein, The spacing between the stepped portions (16) is either equal to or different from each other.

24. The housing according to claim 21, further comprising: Multiple radial stiffeners (5) extend radially outward from the center of the first bearing seat (20) and intersect with the circumferential stiffeners (6). The radial stiffener (5) is composed of alternating horizontal surfaces (51) and inclined surfaces (52). The horizontal surface (51) is parallel to the extension plane of the output side housing (4), and the inclined surface (52) is formed on the plane of the step portion (16) that intersects with the extension plane.

25. The housing according to claim 24, wherein, The angle between the inclined surface (52) and the horizontal surface (51) is less than 45°.

26. The housing according to claim 21, wherein, An opening (10) is provided in the area surrounded by the circumferential stiffener (6) and the radial stiffener (5).

27. The housing according to claim 24, further comprising: Multiple bolt positions (9) are arranged along the side housing (3) to connect the input side housing (2) and the output side housing (4) to the side housing (3). The radial stiffener (5) is connected to the bolt position (9).

28. The housing according to claim 27, further comprising: A horizontal stiffening rib (7) is provided in the area between two tangents of the first bearing seat (20) and the second bearing seat (20). The horizontal stiffener (7) includes a first horizontal stiffener (7) and a second horizontal stiffener (7). The first horizontal stiffener (7) is located on the line connecting the center of the first bearing seat (20) and the center of the second bearing seat (20), and the second horizontal stiffener (7) is symmetrically arranged with respect to the first horizontal stiffener (7).

29. The housing according to claim 28, further comprising: Multiple vertical stiffeners (8) are arranged in a direction perpendicular to the horizontal stiffeners (7) and connected to the bolt positions (9). The radial stiffener (5) is connected to the vertical stiffener (8), thereby forming a triangular structure with the horizontal stiffener (7).

30. A gearbox housing, comprising an input-side housing (2), a side housing (3), and an output-side housing (4), in, The input-side enclosure (2) and the output-side enclosure (4) are connected together with the side enclosure (3). The input-side housing (2) is provided with a first bearing seat (20), a second bearing seat (20), and a plurality of vertical stiffeners (8). In the direction from the center of the first bearing seat (20) to the center of the second bearing seat (20), the input-side housing (2) is formed as a stepped structure with a plurality of first step portions (16). The vertical stiffener (8) is formed on the line connecting the center of the first bearing seat (20) and the center of the second bearing seat (20) perpendicular to the line connecting the center of the first bearing seat (20) and the line connecting the center of the second bearing seat (20), and is at least partially formed on the first step portion (16).

31. The housing according to claim 30, further comprising: Multiple bolt positions (9) are arranged along the side housing (3) to connect the input side housing (2) and the output side housing (4) to the side housing (3). The vertical stiffener (8) is connected to the bolt position (9).

32. The housing according to claim 30, wherein, The stepped structure gradually decreases in height in the direction from the center of the first bearing seat (20) toward the center of the second bearing seat (20).

33. The housing according to claim 30, wherein, The output side housing (4) is provided with a third bearing seat (20), a fourth bearing seat (20), and a plurality of circumferential stiffeners (6). The third bearing seat (20) is opposite to the first bearing seat (20), and the fourth bearing seat (20) is opposite to the second bearing seat (20). In the direction from the center of the fourth bearing housing (20) toward the center of the third bearing housing (20), the output side housing (4) is formed as a stepped structure with multiple second step portions (16). Wherein, the circumferential stiffener (6) is at least partially formed on the second step portion (16), and The circumferential stiffener (6) is configured to (i) surround the center of the third bearing seat (20) or the center of the fourth bearing seat (20), or (ii) surround the center of the third bearing seat (20) and the center of the fourth bearing seat (20) in the direction along the side box (3).

34. The housing according to claim 33, wherein, The stepped structure on the output side housing (4) gradually increases in height in the direction from the center of the fourth bearing seat (20) toward the center of the third bearing seat (20).

35. The housing according to claim 31, further comprising: Multiple radial stiffeners (5) extend radially outward from the center of the first bearing seat (20) and the center of the second bearing seat (20) and are connected to the bolt position (9).

36. The housing according to claim 35, further comprising: A horizontal stiffening rib (7) is provided in the area between two tangents of the first bearing seat (20) and the second bearing seat (20). The horizontal stiffener (7) includes a first horizontal stiffener (7) and a second horizontal stiffener (7). The first horizontal stiffener (7) is located on the line connecting the center of the first bearing seat (20) and the center of the second bearing seat (20). The second horizontal stiffener (7) is symmetrical with respect to the first horizontal stiffener (7).

37. The housing according to claim 36, wherein, The radial stiffener (5) is connected to the vertical stiffener (8), thereby forming a triangular structure with the horizontal stiffener (7).

38. The housing according to claim 35, wherein, The width of the radial stiffener (5) gradually decreases in the direction outward from the center of the first bearing seat (20) and the center of the second bearing seat (20).

39. The housing according to claim 30, wherein, The thickness of the housing is greater in the region between the two tangents of the first bearing housing (20) and the second bearing housing (20) than in other regions.

40. The housing according to claim 35, wherein, Centered on the center of the first bearing seat (20) and the center of the second bearing seat (20), in the region where the direction of the vertical stiffener (8) deviates from the pressure angle by ±30°, the width of the radial stiffener (5) is set to 1.1-2 times the width of the radial stiffener (5) in other regions, and the pressure angle is the pressure angle of the pressure on the first bearing seat (20).

41. A gearbox, comprising: Box (2”); and An oil return port (4”) is provided on the wall at the bottom of the housing (2”) and is used to discharge lubricating oil from inside the housing (2”). The characteristic of this feature is that... The oil return port (4”) has an oil baffle plate (5”), an oil return through hole (6”) and a curved transition part (7”). The oil baffle plate (5”) and the curved transition part (7”) are arranged on opposite sides of the oil return through hole (6”), and the oil baffle plate (5”) protrudes from the bottom wall of the housing (2”) toward the interior of the housing (2”).

42. The gearbox according to claim 41, characterized in that, The gearbox also includes one or more auxiliary oil return ports, which are located on the gearbox body (2”) at a different position than the oil return port (4”).

43. The gearbox according to claim 41, characterized in that, The oil return port (4”) is lowered relative to the housing (2”).

44. The gearbox according to claim 43, characterized in that, The oil return port (4”) and the bottom wall of the box body (2”) are lowered together as a whole.

45. The gearbox according to claim 43, characterized in that, The oil return port (4”) is partially sunken within a range of 1 to 3 times the wall thickness of the box body (2”) radiating outward from the center of the oil return through hole (6”).

46. ​​The gearbox according to any one of claims 43-45, characterized in that, The height of the sinking is 1 to 5 times the wall thickness of the box (2”).

47. The gearbox according to claim 43, characterized in that, The oil return port (4”) has a transition portion that smoothly transitions with the housing of the housing (2”) along the direction of the lubricating oil ejection when it sinks relative to the housing (2”).

48. The gearbox according to claim 47, characterized in that, The gearbox also includes a gear assembly (3”) disposed inside the housing (2”), and the angle between the transition portion and the tangent direction of the addendum circle of the gear assembly (3”) is 0 to 20°.

49. The gearbox according to claim 41, characterized in that, The gearbox also includes a gear assembly (3”) disposed inside the housing (2”), and the height of the oil baffle (5”) is set as high as possible without interfering with the gear assembly (3”).

50. The gearbox according to claim 41, characterized in that, The oil return through hole (6”) is circular, polygonal or elliptical in shape.

51. The gearbox according to claim 41, characterized in that, The oil baffle (5”) is integrally formed with the housing (2”).

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