Spindle box with reduction gearbox arranged in oil-cooled motor

Abstract

The utility model belongs to the technical field of drilling machines, and particularly relates to a spindle box of an oil-cooled motor built-in reduction gearbox, which comprises a shell, an oil-cooled motor arranged in the shell, a mounting plate for dividing the internal space of the shell into a driving part and a transmission part, and a cooling mechanism arranged on the side surface of the shell, an intermediate shaft penetrating through the mounting plate is arranged in the shell, at least one part of the intermediate shaft extends out of the shell, and the intermediate shaft is rotationally supported in the transmission part and is in transmission connection with an output shaft of the oil cooling motor in the driving part through a gear pair; one end, extending out of the shell, of the intermediate shaft is in direct driving connection with a gear pump; an oil storage cavity is formed in the bottom of the shell, and a closed-loop oil cooling system which is completely self-sustaining, free of additional energy and self-adaptive in load is constructed in the spindle box.

Description

Technical Field

[0001] This utility model belongs to the field of drilling rig technology, specifically relating to a spindle box with an oil-cooled motor and an internal gearbox. Background Technology

[0002] Horizontal coring rigs for mining are key equipment in mine exploration, mining and engineering inspection. They are primarily used for horizontal drilling to obtain rock core samples from rock strata and mineral layers, which are then used to analyze geological structure, mineral reserves and rock mass stability. They are suitable for various mining scenarios such as underground tunnels and open-pit mines.

[0003] Especially in the application of mobile trolleys for horizontal coring drills in mines, traditional solutions generally use permanent magnet motors externally mounted on the spindle housing and directly connected to it via flanges, forming a significant long cantilever structure. This structure is subjected to intense machine vibration during drilling, leading to repeated bending of the motor bracket and high-frequency fatigue of the fastening bolts. Actual measurements show that after 500 hours of operation, the bolt preload decay rate reaches 12.6%, and in severe cases, loosening and detachment occur, or even the entire motor falls from the spindle housing, causing equipment downtime, personnel safety hazards, and high maintenance costs. This problem stems from the irreconcilable contradiction between "external power source" and "intense vibration environment," becoming a key bottleneck restricting the reliability of intelligent drilling equipment in mines. Furthermore, existing drilling rigs currently use external air cooling for heat dissipation, which is not only inefficient but also requires significant installation space, lacking practicality. Utility Model Content

[0004] The technical problem solved by this utility model is how to overcome the defects of existing cooling systems that rely on external power sources, such as bulky structure, low energy efficiency, complex sealing and sluggish cooling response, in a compact spindle box that integrates an oil-cooled motor and a reduction mechanism. The goal is to achieve a built-in closed-loop oil-cooling architecture that requires no additional power supply, whose cooling capacity is synchronized with the spindle load in real time, has a high degree of spatial integration and reliable operation.

[0005] To achieve the above objectives, this application provides the following technical solution:

[0006] A spindle housing with an integrated gearbox for an oil-cooled motor includes a housing, an oil-cooled motor disposed inside the housing, a mounting plate dividing the internal space of the housing into a drive section and a transmission section, and a cooling mechanism disposed on the side of the housing. The housing contains an intermediate shaft that penetrates the mounting plate and extends at least partially out of the housing. This intermediate shaft is rotatably supported within the transmission section and is connected to the output shaft of the oil-cooled motor within the drive section via a gear pair. One end of the intermediate shaft extending out of the housing is directly connected to a gear pump. An oil storage chamber is provided at the bottom of the housing.

[0007] The cooling mechanism includes a gear pump, an input pipe, an output pipe, and a spray pipe. One end of the input pipe is connected to the oil storage chamber at the bottom of the housing, and the other end is connected to the oil inlet of the gear pump. One end of the output pipe is connected to the oil outlet of the gear pump, and the other end is connected to a spray pipe located on the inner wall of the top of the housing. The spray pipe has multiple spray holes, and the axis of each spray hole is vertically downward and points towards the surface of the oil-cooled motor housing. The bottom of the mounting plate has a notch that connects the drive unit and the transmission unit, so that the cooling oil, driven by the gear pump, can form a continuous closed-loop circulation along the path of "oil storage chamber at the bottom of the housing → input pipe → gear pump → output pipe → spray pipe → spray hole → oil-cooled motor housing → return through the notch → oil storage chamber at the bottom of the housing".

[0008] Preferably, one end of the intermediate shaft extending outside the housing is connected to the input shaft of the gear pump via a flat key or involute spline; the housing of the gear pump is rigidly fixed to the side of the housing via a flange structure.

[0009] Preferably, the portion of the intermediate shaft that protrudes from the housing is provided with a double-layer dynamic sealing structure, including two O-rings, and the space between the O-rings and the intermediate shaft is filled with sealant.

[0010] Preferably, the spray pipe is arranged in an arc shape along the inner wall of the top of the housing, and its radius of curvature matches the radius of curvature of the maximum outer contour of the oil-cooled motor housing; the spray pipe has no less than 8 spray holes with a diameter of 5–10 mm, the center distance between adjacent spray holes is ≤20 mm, and the total width of the area covered by the projection of the axis of each spray hole onto the surface of the oil-cooled motor housing is ≥95% of the maximum diameter of the oil-cooled motor housing.

[0011] Preferably, the bottom notch of the mounting plate is a U-shaped through groove with a width of 15–25 mm and a depth that penetrates the entire thickness of the mounting plate. The groove edge is rounded with a radius of R≥2 mm. The bottom edge of the U-shaped through groove is parallel to the lower surface of the mounting plate, and the two straight edges are perpendicular to the lower surface of the mounting plate.

[0012] Preferably, the outer surface of the oil-cooled motor is provided with axial heat dissipation grooves, the groove depth is 8–12 mm, the groove width is 12–16 mm, the groove spacing is 18–24 mm, and the groove extension direction is consistent with the flow direction of the sprayed oil on the outer surface of the oil-cooled motor.

[0013] Preferably, the spray pipe has two rows of symmetrically distributed spray holes, one row of spray holes with its axis pointing vertically downwards, and the other row of spray holes with its axis pointing horizontally and extending radially along the housing of the oil-cooled motor. The included angle between the central axes of the two rows of spray holes is 100°–130°. The number of spray holes in each row is 10–16.

[0014] Preferably, at least one side of the housing is provided with heat dissipation fins.

[0015] Preferably, the output end of the oil-cooled motor is provided with an input gear, the outer side of the intermediate shaft is fitted with a second large gear and a second small gear, the bottom of the housing is also rotatably provided with a drill shaft, the outer side of the drill shaft is fitted with an output gear, the input gear meshes with the second large gear, and the second small gear meshes with the output gear.

[0016] Compared with the prior art, this application has at least the following beneficial effects:

[0017] This invention innovatively designs the intermediate shaft of the reduction transmission system as a "one-shaft-two-use" structure—it not only undertakes the power transmission function from the oil-cooled motor to the drill spindle, but also directly extends out of the housing to drive the gear pump—and for the first time constructs a completely self-sufficient, zero-external-energy, load-adaptive closed-loop oil-cooling system inside the spindle box. Specifically, the design of the intermediate shaft direct-drive gear pump eliminates the need for an independent cooling motor and its power supply lines, control module, and multi-point dynamic seals, resulting in an 18.3% reduction in overall volume, a 9.6 kg weight reduction, and a 15.7% improvement in overall system energy efficiency. The top vertical spray pipe, combined with the U-shaped through-slot on the mounting plate, forms a natural collaborative path of "pressurized spraying—gravity film coating—free collection," achieving a measured liquid film coverage rate of ≥96.3% on the motor housing surface and a heat transfer coefficient of 1320 W / (m²·K). More importantly, the cooling flow rate is strictly positively correlated with the intermediate shaft speed; that is, the higher the spindle load, the faster the speed, the larger the pump oil volume, and the stronger the heat dissipation. This achieves a physical-level automatic matching between cooling capacity and mechanical power consumption, completely solving the inherent defects of traditional constant flow systems such as "overcooling under light load and lag under heavy load." The entire architecture is simple, highly reliable, and requires no external intervention, significantly improving the spindle box's operational stability, energy efficiency, and space adaptability in harsh industrial scenarios such as high-speed milling, heavy cutting, and 24 / 7 unattended operation.

[0018] Furthermore, this invention completely eliminates the long cantilever structure formed by the external direct connection of the permanent magnet motor in the moving trolley of traditional horizontal coring drills. The oil-cooled motor is completely built into the spindle box housing, sharing the same rigid housing and mounting reference surface with the reduction transmission system, making the center of gravity of the motor highly coincident with the center of gravity of the spindle box, resulting in a better distribution of the rotational inertia of the entire machine; all core moving components such as the intermediate shaft, gears, and motor are constrained inside the closed housing, forming a high-rigidity integrated power unit. Actual measurements show that under simulated typical mining conditions (ISO 5344 standard impact spectrum, peak acceleration 15 g, frequency 5–200 Hz), the effective value (RMS) of vibration acceleration in key parts of this spindle box (motor stator bracket, mounting plate, intermediate shaft bearing seat) is reduced by 68.3% compared to the external motor solution, and the bolt preload attenuation rate is <0.7% / 1000 hours, completely eliminating the risk of motor loosening, displacement, or falling due to vibration. This structure significantly improves the robustness and inherent safety of the equipment in harsh outdoor environments, greatly reduces the frequency of on-site downtime maintenance, and lowers the total lifecycle maintenance cost.

[0019] This utility model also brings significant engineering practical value: all key components (motor, gears, bearings, pump) are located in the same housing. Routine maintenance only requires opening the top inspection cover. There is no need to disassemble the flange, hoist the motor, or recalibrate the coaxiality. The maintenance time for a single maintenance is reduced from 2.5 hours in the traditional solution to 0.4 hours, truly realizing "tool-free rapid maintenance in mining scenarios". Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model;

[0022] Figure 2 This is a cross-sectional view of an embodiment of the present utility model;

[0023] Figure 3 This is a cross-sectional view from another angle of an embodiment of the present utility model;

[0024] Explanation of main reference numerals: 10, housing; 11, oil reservoir; 20, gear pump; 21, output pipe; 22, input pipe; 23, spray pipe; 30, oil-cooled motor; 31, input gear; 40, intermediate shaft; 41, large gear of shaft two; 42, small gear of shaft two; 50, drill shaft; 51, output gear; Detailed Implementation

[0025] The technical solutions of this application 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 application, and not all of the embodiments. The components of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. It should be noted that similar reference numerals and letters in the following drawings indicate similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0026] Please refer to Figures 1-3 This utility model provides a spindle box for an oil-cooled motor with a built-in gearbox, including a housing 10, an oil-cooled motor 30 disposed inside the housing 10, a mounting plate dividing the internal space of the housing 10 into a drive section and a transmission section, and a cooling mechanism disposed on the side of the housing 10; the housing 10 is provided with an intermediate shaft 40 that penetrates the mounting plate and extends at least partly out of the housing 10, the intermediate shaft 40 is rotatably supported in the transmission section, and is connected to the output shaft of the oil-cooled motor 30 in the drive section through a gear pair; one end of the intermediate shaft 40 extending out of the housing 10 is directly driven and connected to a gear pump 20; an oil storage chamber 11 is provided at the bottom of the housing 10; The cooling mechanism includes the gear pump 20, input pipe 22, output pipe 21, and spray pipe 23. One end of the input pipe 22 is connected to the oil storage chamber 11 at the bottom of the housing 10, and the other end is connected to the oil inlet of the gear pump 20. One end of the output pipe 21 is connected to the oil outlet of the gear pump 20, and the other end is connected to the spray pipe 23 located on the inner wall of the top of the housing 10. The spray pipe 23 has multiple spray holes, and the axis of each spray hole is vertically downward and points to the outer surface of the oil-cooled motor 30. The bottom of the mounting plate has a notch that connects the drive part and the transmission part, so that the cooling oil, driven by the gear pump 20, can form a continuous closed loop circulation along the path of "oil storage chamber 11 at the bottom of the housing 10 → input pipe 22 → gear pump 20 → output pipe 21 → spray pipe 23 → spray hole → outer shell of oil-cooled motor 30 → return through the notch → oil storage chamber 11 at the bottom of the housing 10".

[0027] In this embodiment, the spray pipe has eight spray holes, which are equidistantly distributed in a single row along the axial direction of the spray pipe. The distance between the first hole and the front end of the spray pipe is 20 mm, the distance between the last hole and the rear end of the spray pipe is 20 mm, and the center distance between two adjacent holes is 25 mm. All spray holes have a diameter of Φ1.0 mm, a hole wall roughness Ra≤0.4 μm, and the axis of each hole is strictly vertical downward.

[0028] The output end of the oil-cooled motor 30 is provided with an input gear 31. The outer side of the intermediate shaft 40 is fitted with a second shaft large gear 41 and a second shaft small gear 42. The bottom of the housing 10 is also rotatably provided with a drill shaft 50. The outer side of the drill shaft 50 is fitted with an output gear 51. The input gear 31 meshes with the second shaft large gear 41, and the second shaft small gear 42 meshes with the output gear 51.

[0029] During operation, the oil-cooled motor 30 drives the input gear 31 to rotate, which in turn drives the large gear 41 and the small gear 42 of the second shaft, which are sleeved on the outside of the intermediate shaft 40, to rotate together. Then, the small gear 42 of the second shaft meshes with the output gear 51 sleeved on the outside of the drill shaft 50, which drives the output gear 51 to rotate, thereby driving the drill shaft 50 to rotate.

[0030] In existing integrated structures of oil-cooled motors 30 and built-in gearboxes, the common approach is to use an external independent oil pump or a motor-driven impeller to circulate the cooling oil. This results in problems such as system complexity, high energy consumption, and poor cooling uniformity. Especially when the motor and gearbox share the same oil circuit, the long oil flow path, high pressure loss, and poor oil return can easily lead to localized overheating of the motor. Furthermore, traditional spray structures are mostly single-point or linear arrangements, failing to cover the entire heat dissipation surface of the motor casing and lacking effective return channels, causing cooling oil accumulation and reduced heat dissipation efficiency. In addition, the section of the intermediate shaft 40 that protrudes from the housing 10 often leaks oil due to unreliable sealing, affecting the long-term operational reliability of the equipment.

[0031] In this embodiment, the housing 10 is made of cast iron (ZG45) and has an overall rectangular box structure. An internally mounted steel plate serves as a mounting plate, strictly dividing the interior into a left drive section (accommodating the oil-cooled motor 30) and a right transmission section (accommodating the gear reduction mechanism). The intermediate shaft 40 is made of 40Cr tempered steel, with a diameter of φ52mm and a total length of 169mm. 144mm of this shaft is located inside the housing 10, and 25mm extends from the center hole on the right side of the housing 10. It is supported by tapered roller bearings within the transmission section. The extended end of the intermediate shaft 40 is machined with external splines, which mate with the internal splines of the input shaft of the gear pump 20. The gear pump 20 is a CBK type external gear pump (displacement 25mL / r, rated pressure 2.5MPa), and its housing 10 is rigidly connected to the side flange of the housing 10 via M8×25 hex bolts. The bottom of the housing 10 has a concave oil reservoir 11 with a volume of 3.2L, and a drain plug (M16×1.5) is installed at the lowest point of the reservoir. The input pipe 22 is a steel wire hose, with both ends fixed to the side wall interface of the oil storage chamber 11 and the oil inlet flange of the gear pump 20, respectively. The output pipe 21 is also a steel wire hose, connecting the oil outlet of the gear pump 20 and the inlet of the spray pipe 23. The spray pipe 23 is a galvanized hollow pipe with an inner diameter of Φ15.7mm and a wall thickness of 2.8mm. It is arranged along the inner wall of the top of the shell 10, with a radius of curvature R=180mm, which matches the curvature height of the maximum outer contour (φ220mm) of the oil-cooled motor 30 shell. There are 26 spray holes evenly distributed on the pipe body, with a hole diameter of Φ6mm and a center distance of 18.5mm between adjacent holes. The axis of all spray holes is strictly vertical downward, and its projection on the surface of the motor shell covers a width of 210mm (≥95% of the diameter of the motor shell 220mm). A U-shaped through-slot is formed at the bottom of the mounting plate. The slot is 20mm wide and penetrates the full thickness (35mm) of the mounting plate. The edges of the slot are rounded with a radius of 2.5mm. The bottom edge of the through-slot is horizontal, and the two straight edges are perpendicular to the lower surface of the mounting plate, ensuring that the cooling oil can flow back to the oil storage chamber 11 without obstruction after flowing down from the spray area. In practical applications, the gear pump 20 can also be replaced by a CBF type variable pump or a cycloidal rotor pump. This application embodiment does not limit this.

[0032] The working principle of this structure is as follows: When the oil-cooled motor 30 is running, it drives the intermediate shaft 40 to rotate. The intermediate shaft 40 synchronously drives the gear pump 20 to work, so that the cooling oil in the oil storage chamber 11 is sucked in through the input pipe 22, pressurized, and then transported to the spray pipe 23 through the output pipe 21. The high-pressure oil is sprayed vertically from each spray hole onto the surface of the oil-cooled motor 30 housing, forming a full-coverage liquid film cooling. After spraying, the oil flows naturally down the motor housing, enters the transmission space through the U-shaped through groove at the bottom of the mounting plate, and then flows back to the bottom oil storage chamber 11 along the inner wall of the housing 10, completing a single cycle. The entire process does not require an additional power source and is driven entirely by the mechanical energy of the motor output shaft, resulting in high energy efficiency. The closed-loop path design ensures stable flow and eliminates the risk of cavitation. The U-shaped through groove serves as a dedicated return channel to prevent oil stagnation or short circuits.

[0033] The technical benefits of this implementation include: achieving deep coupling between the cooling system and the transmission system, eliminating the need for an external oil pump and matching motor, reducing the overall size by approximately 18% and the weight by 12%; achieving a spray coverage rate of over 95%, and reducing the motor winding temperature rise by 14K compared to traditional solutions (test conditions: rated load, ambient temperature 40℃); and the mechanical connection between the intermediate shaft 40 and the gear pump 20 avoids electrical control delays and power losses, resulting in faster response, higher control precision, and significantly improved dynamic cooling adaptability.

[0034] One end of the intermediate shaft 40 extending outside the housing 10 is connected to the input shaft of the gear pump 20 via a flat key or involute spline; the housing 10 of the gear pump 20 is rigidly fixed to the side of the housing 10 via a flange structure.

[0035] In the existing technology, the intermediate shaft 40 and the external oil pump are mostly connected by a coupling, which has problems such as high requirements for alignment accuracy, obvious vibration transmission, and inconvenience in disassembly and assembly. In addition, if the flange fixing method is not rigid enough, it is easy to cause the pump body to deviate, resulting in abnormal wear or leakage of the gear pump 20.

[0036] The specific implementation of this technical feature is as follows: An 8-tooth involute spline (GB / T3478.1-2008, module 2.5mm, pressure angle 30°) is machined on the extended end of the intermediate shaft 40. A corresponding internal spline is machined on the input shaft of the gear pump 20, with a fit tolerance of H7 / h6. During assembly, molybdenum disulfide grease (model Molykote G-Rapid Plus) is applied to ensure smooth insertion and removal and prevent seizing. An annular flange is provided on the right side of the gear pump housing 10, with four Φ8.5mm through holes evenly distributed on the flange surface, corresponding to the M8 threaded holes pre-drilled on the side of the housing 10. It is fastened with four 8.8 grade high-strength bolts (M8×30, galvanized and passivated surface), with a preload torque of 22N·m±1N·m. The flatness of the flange contact surface is ≤0.05mm, ensuring that the coaxiality error between the pump body and the housing 10 is ≤0.03mm. In practical applications, this spline structure can also be replaced with a rectangular spline of GB / T 1144 standard or an involute spline of DIN 5480. This application embodiment does not limit this.

[0037] The intermediate shaft 40 is provided with a double-layer dynamic sealing structure at the part that protrudes from the housing 10, including two O-rings, and the space between the O-rings and the intermediate shaft 40 is filled with sealant.

[0038] Traditional single-channel lip seals or single O-ring structures are prone to extrusion, aging, and dry friction failure under long-term high-speed rotation conditions, leading to cooling oil leakage, environmental pollution, and equipment safety.

[0039] The specific implementation of this technical feature is as follows: A sealing cavity is set at the center hole on the right side of the housing 10. Two fluororubber (FKM) O-rings (AS568A-330 specification, wire diameter 3.53mm, inner diameter 55.0mm) are installed sequentially inside the cavity, with a spacing of 8mm between the two rings. The O-ring grooves are designed according to GB / T 3452.3-2005, and the compression rate is controlled at 22% to 25%. Room temperature vulcanizing silicone rubber sealant (Dow Corning DC-93-500, viscosity 15000cP, Shore A hardness 40 after curing) is injected into the annular gap between the two O-rings. The sealant completely fills the gap and overflows to the end face of the cavity, forming an elastic buffer layer after curing. The surface of the intermediate shaft 40 is treated and plated with hard chrome (thickness 30μm, hardness ≥800HV) to enhance wear resistance and corrosion resistance. In practical applications, the O-ring can also be made of hydrogenated nitrile butadiene rubber (HNBR) or perfluoroether rubber (FFKM), but this application does not limit this.

[0040] The working principle of this structure is as follows: the first O-ring bears the main sealing pressure, the second O-ring serves as a redundant backup; the sealant fills the micro gaps and absorbs the micro vibration of the shaft system, suppressing the creep and displacement of the O-ring. The three work together to form a composite dynamic sealing system of "mechanical seal + elastic filling + surface strengthening".

[0041] The technical benefits of this design are: the sealing life is increased by 3.2 times compared to the single O-ring solution; and the risk of motor insulation deterioration caused by oil leakage is effectively eliminated.

[0042] Based on the above embodiments, this embodiment further provides that: the spray pipe 23 is arranged in an arc shape along the inner wall of the top of the housing 10, and its radius of curvature matches the maximum outer contour radius of curvature of the oil-cooled motor 30 housing; the spray pipe 23 is provided with 26 spray holes with a diameter of 6 mm, the center distance between adjacent spray holes is 18.5 mm, and the total width of the area covered by the projection of the axis of each spray hole onto the surface of the oil-cooled motor 30 housing is ≥ 95% of the maximum diameter of the oil-cooled motor 30 housing.

[0043] The specific implementation of this technical feature is as follows: The spray pipe 23 is made of 6061-T6 aluminum alloy by extrusion, with an elliptical cross-section (major axis 16mm, minor axis 10mm). The bending process is carried out by cold bending using a CNC pipe bending machine (model CNC-60B), and the bending radius tolerance is controlled within ±0.3mm. The measured maximum outer contour of the oil-cooled motor 30 housing is a φ220mm cylindrical surface, corresponding to a curvature radius R=110mm. Therefore, the curvature radius R of the spray pipe 23 is set to 110mm. The axes of all spray holes are strictly perpendicular to the axis of the spray pipe 23 and are calibrated by a three-dimensional coordinate measuring instrument to ensure that the projection coverage width on the surface of the oil-cooled motor 30 housing is 212mm (220mm×96.4%). In practical applications, the spray pipe 23 can also be made of stainless steel 304 or copper alloy H62, and this application embodiment does not limit this.

[0044] The working principle of this structure is as follows: the arc arrangement makes the distance from each spray hole to the outer casing of the oil-cooled motor 30 basically the same (deviation ≤1.5mm), and combined with the design of equidistant small holes, a uniform flow density distribution is formed; the projected coverage width meets the standard to ensure no cooling blind spots and avoid the generation of local hot spots.

[0045] Based on the above embodiments, this embodiment further provides: the bottom notch of the mounting plate is a U-shaped through groove with a width of 15–25 mm and a depth that penetrates the entire thickness of the mounting plate; the edge of the groove is rounded with a radius of R≥2 mm; the bottom edge of the U-shaped through groove is parallel to the lower surface of the mounting plate, and the two straight edges are perpendicular to the lower surface of the mounting plate.

[0046] The specific implementation is as follows: A U-shaped through-slot is centrally located at the bottom of the mounting plate, with a width of 20mm and a depth of 35mm (equal to the thickness of the mounting plate). The bottom of the slot is a horizontal straight line, and the two sides are vertical straight edges. The edges of the slot are CNC milled and rounded with a radius of 2.5mm (R=2.5mm). The surface of the slot is polished to a roughness Ra≤1.6μm to reduce flow resistance. The edge of the slot opening is flush with the inner wall of the housing 10 to avoid forming steps that obstruct oil flow. In practical applications, this U-shaped through-slot can also be machined by wire cutting or precision casting in one piece; this embodiment does not limit this.

[0047] The working principle of this structure is as follows: the U-shaped through groove provides a large cross-section, low resistance, and abrupt return channel, so that the oil flowing down after spraying can smoothly enter the transmission space under the dual action of gravity and fluid inertia, avoiding turbulence and air entrainment caused by local contraction.

[0048] Based on the above embodiments, this embodiment further provides that: the outer surface of the oil-cooled motor 30 is provided with axial heat dissipation grooves, the groove depth is 10 mm, the groove width is 14 mm, the groove spacing is 20 mm, and the groove extension direction is consistent with the flow direction of the sprayed oil on the outer surface of the oil-cooled motor 30.

[0049] The specific implementation of this technical feature is as follows: The surface of the oil-cooled motor 30 housing (stamped and welded from Q235B steel plate) is machined with 16 axial heat dissipation grooves using a CNC gantry milling machine. The grooves are 10mm deep, 14mm wide, and 20mm apart, with a circular arc bottom (R=3mm). The groove extension direction is strictly parallel to the axis of the oil-cooled motor 30 and completely consistent with the downward flow direction of the sprayed oil. The groove surface is shot-peened (120% coverage, residual compressive stress ≥350MPa) to improve fatigue resistance. In practical applications, the grooves can also be manufactured using roll forming or laser cladding additive manufacturing; this application does not limit this method.

[0050] The working principle of this structure is as follows: the axial groove increases the heat exchange area of ​​the oil-cooled motor housing by 42%, while guiding the oil to flow directionally along the groove, prolonging the residence time, and forming micro-turbulence in the groove, which destroys the boundary layer and significantly improves the convective heat transfer coefficient.

[0051] Specifically, the spray pipe 23 has two rows of symmetrically distributed spray holes, with the included angle between the central axes of the two rows of spray holes being 120°; each row has 13 spray holes.

[0052] A single row of spray holes makes it difficult to ensure uniform coverage of the front and rear halves of the oil-cooled motor 30 housing. Especially when the axial length of the oil-cooled motor 30 is large, weak cooling zones are likely to appear on both sides.

[0053] The specific implementation of this technical feature is as follows: The spray pipe 23 has a flat elliptical cross-section (12mm high, 20mm wide), with two rows of spray holes symmetrically arranged on both sides of its top center line, 13 holes per row, with a hole diameter of Φ6mm; the included angle between the central axes of the two rows of holes is 115°. Optical projection verification shows that this angle allows the width of the intersection area of ​​the two rows of spray oil jets on the surface of the oil-cooled motor 30 housing to reach 190mm, and the total coverage after superimposing the single-row coverage width reaches 215mm; the hole positions are processed using a five-axis laser drilling machine, with a positional error ≤±0.1mm; all spray hole inlets are chamfered at 0.3mm×45° to improve the oil injection flow pattern. In practical applications, this double-row structure can also be extended to a triple-row structure or replaced with fan-shaped nozzles; this application embodiment does not limit this.

[0054] The working principle of this structure is: the double-row inclined arrangement expands the lateral coverage angle, so that the oil jet forms a cross impact and superimposed wetting effect on the surface of the oil-cooled motor 30 housing, which enhances the adhesion of the liquid film and the depth of heat exchange, and avoids oil splash loss caused by unilateral scouring.

[0055] The technical effects of adopting this design are: the surface wettability of the oil-cooled motor 30 casing is increased from 82% to 99.3%; oil splash loss is reduced by 74%; the cooling uniformity index (UI = minimum / maximum temperature difference ratio) is increased from 0.61 to 0.93; and the overall cooling efficiency is improved by 28%.

[0056] Based on the above embodiments, this embodiment further provides that: heat dissipation fins are provided on the side of the housing 10.

[0057] Relying solely on internal oil cooling is insufficient to handle transient high-load conditions. Excessive surface temperature rise of the casing 10 will exacerbate the rise in internal oil temperature, creating a vicious cycle.

[0058] The specific implementation of this technical feature is as follows: The outer wall of the left side of the housing 10 is integrally cast with heat dissipation fins. The fins are rectangular straight ribs, 35mm high, 3.0mm thick, and 8mm apart. The root is integrated with the wall thickness of the housing 10 (12mm). There are a total of 24 fins, with a total heat dissipation area of ​​0.48m². In practical applications, the fins can also be made of copper alloy or have heat pipe inserts added. This application embodiment does not limit this.

[0059] The working principle of this structure is as follows: the heat dissipation fins dissipate the heat accumulated in the housing 10 to the environment through forced convection (air cooling) or natural convection, thereby reducing the temperature of the housing 10 body and reducing the temperature difference between the housing 10 and the internal cooling oil, and inhibiting the reverse transfer of heat into the oil passage.

[0060] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A spindle housing with an integrated gearbox for an oil-cooled motor, comprising a housing (10), an oil-cooled motor (30) disposed inside the housing (10), a mounting plate dividing the internal space of the housing (10) into a drive section and a transmission section, and a cooling mechanism disposed on the side of the housing (10); characterized in that, The housing (10) is provided with an intermediate shaft (40) that penetrates the mounting plate and extends at least partly out of the housing (10). The intermediate shaft (40) is rotatably supported in the transmission part and is connected to the output shaft of the oil-cooled motor (30) in the drive part through a gear pair. One end of the intermediate shaft (40) extending out of the housing (10) is directly driven to a gear pump (20). An oil storage chamber (11) is provided at the bottom of the housing (10). The cooling mechanism includes the gear pump (20), an input pipe (22), an output pipe (21), and a spray pipe (23). One end of the input pipe (22) is connected to the oil storage chamber (11) at the bottom of the housing (10), and the other end is connected to the oil inlet of the gear pump (20). One end of the output pipe (21) is connected to the oil outlet of the gear pump (20), and the other end is connected to the spray pipe (23) located on the inner wall of the top of the housing (10). The spray pipe (23) has multiple spray holes, and the axis of each spray hole is... Vertically downward and pointing towards the outer surface of the oil-cooled motor (30); the bottom of the mounting plate is provided with a notch that connects the drive part and the transmission part, so that the cooling oil, driven by the gear pump (20), can form a continuous closed loop circulation along the path of "bottom oil storage chamber (11) of the housing (10) → input pipe (22) → gear pump (20) → output pipe (21) → spray pipe (23) → spray hole → outer casing of the oil-cooled motor (30) → backflow through the notch → bottom oil storage chamber (11) of the housing (10)".

2. The spindle box with an internal gearbox for an oil-cooled motor according to claim 1, characterized in that, One end of the intermediate shaft (40) extending outside the housing (10) is connected to the input shaft of the gear pump (20) via a flat key or involute spline; the housing (10) of the gear pump (20) is rigidly fixed to the side of the housing (10) via a flange structure.

3. The spindle box with an internal gearbox for an oil-cooled motor according to claim 1, characterized in that, The intermediate shaft (40) is provided with a double-layer dynamic sealing structure at the part that protrudes from the housing (10), including two O-rings, and the O-rings and the intermediate shaft (40) are filled with sealant.

4. The spindle box with an internal gearbox for an oil-cooled motor according to claim 1, characterized in that, The spray pipe (23) is arranged in an arc shape along the inner wall of the top of the shell (10), and its radius of curvature matches the maximum outer contour radius of curvature of the oil-cooled motor (30) shell. The spray pipe (23) has no less than 8 spray holes with a diameter of 5–10 mm, the center distance between adjacent spray holes is ≤20 mm, and the total width of the area covered by the projection of the axis of each spray hole onto the surface of the oil-cooled motor (30) shell is ≥95% of the maximum diameter of the oil-cooled motor (30) shell.

5. The spindle box with an internal gearbox for an oil-cooled motor according to claim 1, characterized in that, The bottom notch of the mounting plate is a U-shaped through groove with a width of 15–25 mm and a depth that penetrates the entire thickness of the mounting plate. The edges of the groove are rounded with a radius of R≥2 mm. The bottom edge of the U-shaped through groove is parallel to the lower surface of the mounting plate, and the two straight edges are perpendicular to the lower surface of the mounting plate.

6. The spindle box with an internal gearbox for an oil-cooled motor according to claim 1, characterized in that, The surface of the outer casing of the oil-cooled motor (30) is provided with axial heat dissipation grooves. The groove depth is 8–12 mm, the groove width is 12–16 mm, and the groove spacing is 18–24 mm. The groove extension direction is consistent with the flow direction of the sprayed oil on the outer casing of the oil-cooled motor (30).

7. The spindle box with an internal gearbox for an oil-cooled motor according to claim 4, characterized in that, The spray pipe (23) has two rows of symmetrically distributed spray holes, with the included angle between the central axes of the two rows of spray holes being 100°–130°; each row has 10–16 spray holes.

8. The spindle box with an internal gearbox for an oil-cooled motor according to claim 1, characterized in that, At least one side of the housing (10) is provided with heat dissipation fins.

9. The spindle box with an internal gearbox for an oil-cooled motor according to claim 1, characterized in that, The output end of the oil-cooled motor (30) is provided with an input gear (31). The outer side of the intermediate shaft (40) is fitted with a second large gear (41) and a second small gear (42). The bottom of the housing (10) is also rotatably provided with a drill shaft (50). The outer side of the drill shaft (50) is fitted with an output gear (51). The input gear (31) meshes with the second large gear (41), and the second small gear (42) meshes with the output gear (51).

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