Helical tooth coupling assembly and hybrid powertrain

Abstract

The utility model belongs to power transmission technical field, concretely relates to a helical tooth coupling assembly and hybrid power system, wherein the helical tooth coupling assembly includes: helical tooth spline connecting shaft, the outer circle is provided with the helical tooth outer spline, one side is used for the shaft sleeve of the engine output shaft sleeve setting resistance or connection, the helical tooth spline hollow shaft, one side inner circle is provided with the helical tooth inner spline, the other side outer circle is provided with the first helical tooth for the meshing connection of the output end of output motor, the helical tooth spline connecting shaft is inserted in one side inside the helical tooth spline hollow shaft, and the helical tooth outer spline is meshed with the helical tooth inner spline and connects.The utility model connects through the helical tooth coupling assembly between the engine and output motor, utilizes the helical gear engagement, and through the engine, output motor and machine case jointly bear axial tension, realize the dispersion transmission of force, not only has improved the stress uniformity and structural reliability of transmission system, also is favorable to reduce the axial load peak value of bearing, thereby prolongs the service life of bearing.

Description

Technical Field

[0001] This utility model belongs to the field of power transmission technology, specifically relating to a helical gear coupling assembly and a hybrid power system. Background Technology

[0002] In a hybrid power system, the power generated by the engine drives the electric motor to generate electricity and output electrical energy. Specifically, the mechanical output shaft of the power turbine can be connected to the input shaft of the motor so that the output shaft of the power turbine rotates and the output motor shaft rotates to output electrical energy.

[0003] However, the engine operation generates a very large axial tensile force, such as 603N, which is transmitted to the high-speed motor through the shaft. Therefore, a reasonable coupling scheme needs to be designed to mitigate this axial tensile force. Utility Model Content

[0004] The present invention addresses the aforementioned technical problems by providing a helical gear coupling assembly and a hybrid power system.

[0005] A helical gear coupling assembly, the helical gear coupling assembly comprising:

[0006] A helical spline connecting shaft, wherein the outer circle of the helical spline connecting shaft is provided with helical external splines; the end face of the helical spline connecting shaft near the engine is used to abut or connect with a bushing fitted around the engine output shaft.

[0007] A helical spline hollow shaft, wherein the inner circle of the helical spline hollow shaft near the engine is provided with helical internal splines, and the outer circle of the helical spline hollow shaft away from the engine is provided with a first helical tooth for meshing with the output end of the output motor.

[0008] The helical spline connecting shaft extends into the interior of the helical spline hollow shaft near the engine, and the external helical spline meshes with the internal helical spline to form a helical spline pair.

[0009] Optionally, the helical gear coupling assembly further includes:

[0010] A bearing assembly is disposed on the outer surface of the helical spline hollow shaft near the engine. The bearing assembly is used to fix the helical spline hollow shaft in a mounting housing. The housing is disposed between the engine and the output motor. One end of the housing is fixedly connected to the housing of the engine, and the other end of the housing is fixedly connected to the housing of the output motor.

[0011] Optionally, the helical internal spline has a helix angle of 8° and a module of 1.5 mm, the number of teeth of the helical internal spline is 20, and the tooth thickness of the helical internal spline is 2.36 mm.

[0012] Optionally, the first helical tooth has a helix angle of 8° and a module of 0.5 mm, the first helical tooth has 36 teeth, and the tooth thickness of the first helical tooth is 0.75 mm.

[0013] Optionally, the helical spline connecting shaft is provided with clearance through holes extending axially through both ends. The clearance through holes are coaxially arranged with the engine output shaft and are used for the engine output shaft to pass through. A locking nut is provided on the other end of the helical spline connecting shaft away from the engine. The locking nut is used to thread the external thread section of the engine output shaft. The locking nut is used to axially press the end face of the helical spline connecting shaft near the engine against the end face of the bushing.

[0014] Optionally, the outer diameter of the helical spline hollow shaft on the side closer to the engine is larger than the outer diameter on the side farther from the engine.

[0015] Optionally, the inner diameter of the helical spline hollow shaft on the side closer to the engine is larger than the inner diameter on the side farther from the engine.

[0016] A hybrid power system includes an engine and an output motor, wherein the engine and the output motor are connected via the helical gear coupling assembly;

[0017] The power turbine output shaft of the engine is connected to a bushing via a spur spline or interference fit, and the bushing abuts against or connects to the helical spline connecting shaft on the side near the engine.

[0018] The output end of the output motor is provided with a second helical tooth, which meshes with the first helical tooth of the helical spline hollow shaft to form a helical gear pair.

[0019] Optionally, the helical spline connecting shaft is provided with a clearance through hole extending axially through both ends of the shaft. The clearance through hole is coaxially arranged with the power turbine output shaft. A locking nut is provided on the other end of the helical spline connecting shaft away from the engine. The end of the power turbine output shaft away from the engine passes through the clearance through hole from the side of the helical spline connecting shaft near the engine. The external thread section on the power turbine output shaft is threaded to the locking nut to achieve a fixed connection between the power turbine output shaft and the helical spline connecting shaft. The locking nut axially presses the end face of the helical spline connecting shaft near the engine against the end face of the bushing.

[0020] Optionally, the shaft end of the output motor is connected to a motor spline, and the inner circle of the motor spline is provided with the second helical tooth.

[0021] Optionally, the hybrid power system further includes a casing disposed between the engine and the output motor, one end of the casing being fixedly connected to the housing of the engine, and the other end of the casing being fixedly connected to the housing of the output motor;

[0022] The helical gear coupling assembly is fixed to the casing by a bearing assembly located on the outer circumference of the helical spline hollow shaft near the engine.

[0023] Optionally, the casing is provided with a stepped mounting cavity extending along the axial direction, the mounting cavity including an open hole section for pressing in the bearing steel sleeve, and forming an annular stepped surface in the hole;

[0024] The bearing assembly includes a bearing body and a bearing sleeve. The outer ring of the bearing body is installed in the inner hole of the bearing sleeve. The inner ring of the bearing body is fitted onto the outer circumference of the helical spline hollow shaft near the engine. The outer circumference of the bearing sleeve is pressed into the mounting cavity. The side of the bearing sleeve near the engine abuts against the annular stepped surface. A limiting plate is detachably fixed to the outer end face of the mounting cavity opening on the other side of the bearing sleeve away from the engine. The limiting plate axially limits the bearing sleeve on the other side away from the engine. There is a gap between the limiting plate and the helical spline hollow shaft.

[0025] Optionally, the casing is a hollow structure, and the lower space of the casing forms a cooling oil chamber. The lower part of the casing is provided with an oil suction port that communicates with the cooling oil chamber. The oil suction port is connected to the suction port of an external cooling oil pump, and the oil outlet of the external cooling oil pump supplies oil to each target position of the engine and the output motor through an oil supply pipeline.

[0026] The helical spline hollow shaft is provided with a through hole along the axial direction. The helical spline hollow shaft is provided with an oil return opening on the side near the casing and communicates with the inside of the casing. The inside of the helical spline hollow shaft is connected to the oil passage of the output end of the output motor through the internal oil passage of the helical spline connecting shaft. The helical spline hollow shaft is connected to the internal oil passage of the engine output shaft through the other end.

[0027] Optionally, the helical spline hollow shaft or the helical spline connecting shaft is provided with an oil injection hole or an oil injection groove facing the helical gear spoke meshing area.

[0028] Beneficial effects: This utility model has at least one or more of the following advantages:

[0029] 1. This utility model connects the engine and the output motor through a helical gear coupling assembly. By utilizing the meshing of helical gears, the engine, the output motor, and the casing jointly bear the axial tensile force, thereby achieving the distributed transmission of force.

[0030] Specifically, during engine operation, the torque output by the power turbine acts on the helical gear pair and the helical spline pair via the helical gear coupling assembly. During helical gear meshing, the tooth surface contact force acts along the tooth direction, which can be geometrically decomposed into circumferential and axial components. The circumferential component forms the driving torque, which drives the output motor rotor to rotate through the helical spline hollow shaft, realizing the power transmission from the engine to the output motor. The axial component is transmitted along the shaft system to the bearings at each stage, and then from the bearings to the casing and the overall frame, so that the axial load is dispersed and absorbed in the structure, avoiding concentrated action on a single component. Through helical gear meshing and reasonable support arrangement, not only is the stress uniformity and structural reliability of the transmission system improved, but the peak axial load of the bearings is also reduced, thereby extending the service life of the bearings.

[0031] 2. The helical gear coupling assembly of this utility model is supported in the housing by a bearing assembly arranged on the outside of the helical spline hollow shaft, so that the output shaft of the power turbine and the output motor shaft maintain good coaxiality and stable torque transmission during operation. Specifically, the bearing steel sleeve of the bearing assembly is limited on both sides of the axial direction by the steps and limiting plates of the housing, ensuring the radial support and axial positioning of the helical gear coupling assembly in the housing.

[0032] 3. This invention cools the helical gear coupling assembly by spraying cooling oil through the cooling oil passages within the engine and output motor shafts, effectively improving cooling efficiency and ensuring stable tooth surface temperature under high-speed conditions. Specifically, this invention sets the lower space of the casing as a cooling oil chamber, with the oil inlet located on the non-contact side of the helical gear coupling assembly and the outlet located at the corresponding tooth tip. Under gravity, the cooling oil flows back into the cooling oil chamber from one side opening of the helical spline hollow shaft, thus forming a convection circulation. Attached Figure Description

[0033] Figure 1A This is a partial structural schematic diagram of the hybrid power system of this utility model;

[0034] Figure 1B for Figure 1A A magnified view of a portion of the image;

[0035] Figure 2 This is a partial perspective sectional view of the hybrid power system of this utility model;

[0036] Figure 3 This is a partial structural connection diagram of the hybrid power system of this utility model;

[0037] Figure 4 for Figure 3 Exploded view;

[0038] Figure 5 for Figure 4 A sectional view;

[0039] Figure 6 This is a schematic diagram of one structure of the helical spline connecting shaft of this utility model;

[0040] Figure 7 This is a schematic diagram of a helical spline hollow shaft according to the present invention;

[0041] Figures 8A to 8D This is a simulation diagram of the helical spline connection shaft under static stress according to this utility model;

[0042] Figures 9A to 9D This is a simulation diagram of the helical internal spline of the helical spline hollow shaft of this utility model under static stress.

[0043] Figures 10A to 10D This is a simulation diagram of the first helical tooth of the hollow helical spline shaft of this utility model under static stress.

[0044] Figures 11A to 11D This utility model Figure 3 Multibody dynamics simulation diagram of the structure excluding the output motor and bushing;

[0045] Figure 12 A cross-sectional view of a connection using a spur gear coupling assembly in a hybrid power system;

[0046] Figure 13 for Figure 12 A magnified view of a portion of the image;

[0047] Figures 14A to 14D This is a multibody dynamics simulation diagram of the spur gear coupling assembly used in this utility model. Detailed Implementation

[0048] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, so as to better understand the purpose, features and advantages of the present invention. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of the present invention, but are only for illustrating the essential spirit of the technical solution of the present invention.

[0049] In the following description, certain specific details are set forth for the purpose of illustrating various disclosed embodiments in order to provide a thorough understanding of the various disclosed embodiments. However, those skilled in the art will recognize that the embodiments may be practiced without one or more of these specific details. In other instances, well-known apparatuses, structures, and techniques associated with this application may not have been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

[0050] Throughout this specification, references to "an embodiment" or "an embodiment" indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Therefore, the appearance of "in an embodiment" or "an embodiment" in various places throughout the specification does not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic may be combined in any manner in one or more embodiments.

[0051] In the following description, in order to clearly demonstrate the structure and working method of this utility model, a number of directional terms will be used. However, terms such as "front", "back", "left", "right", "outside", "inside", "outward", "inward", "up", and "down" should be understood as convenient terms and not as limiting terms.

[0052] Reference Figures 1A to 7 This utility model provides a helical gear coupling assembly, which includes a helical spline connecting shaft 10 and a helical spline hollow shaft 20.

[0053] The outer circumference of the helical spline connecting shaft 10 is provided with helical external splines 11. The side of the helical spline connecting shaft 10 closest to the engine is used to abut against the bushing 40 that is fitted over the engine output shaft 30. It can be relatively fixed by any of the following methods: spline, key connection, threaded locking, interference fit, or bolt connection, thereby transmitting torque from the bushing 40 to the helical spline connecting shaft 10. That is, when the engine output shaft 30 rotates, the bushing 40 and the helical spline connecting shaft 10 that are fitted over it rotate with it, so that the torque is transmitted from the engine output shaft 30, such as the power turbine output shaft, to the helical spline connecting shaft 10 through the bushing 40.

[0054] The helical spline hollow shaft 20 has an internal helical spline 21 on its inner circumference near the engine, and a first helical tooth 22 on its outer circumference away from the engine for meshing with the output end 50 of the output motor. The helical spline connecting shaft 10 extends into the interior of the helical spline hollow shaft 20 on the engine side, and is connected to the helical spline 21 on the inner circumference of the helical spline hollow shaft 20 via the external helical spline 11 on the outer circumference of the connecting shaft 10 meshing with the internal helical spline 21 on the inner circumference of the helical spline hollow shaft 20.

[0055] When this utility model is used, the bushing 40 of the engine output shaft 30, such as the power turbine output shaft, is abutted or connected to the side of the helical spline connecting shaft 10 near the engine, and the second helical tooth 51 provided on the output end 50 of the output motor is meshed with the first helical tooth 22.

[0056] The helical external spline 11 meshes with the helical internal spline 21 to form a helical spline pair; the first helical tooth 22 meshes with the second helical tooth 51 to form a helical gear pair. The helical spline pair and the helical gear pair together constitute the torque transmission path of the helical gear coupling assembly.

[0057] Typically, an engine includes an exhaust assembly, a compressor, a starter motor, a diffuser, guide vanes, a combustion chamber, a gas turbine, a power turbine, and an integrated intake shroud. The gas turbine is connected to the compressor via a shaft, and the power turbine output shaft (i.e., the engine output shaft 30) is connected to the output motor via the helical gear coupling assembly of this invention. When the engine is running, the compressor compresses the air, which then enters the diffuser for further compression. The diffuser passes the further compressed gas to the guide vanes, which in turn pass the gas into the combustion chamber. The gas mixes with fuel and ignites, and the combustion of air in the combustion chamber forms high-temperature, high-pressure gas. The high-temperature, high-pressure gas generated by the rotation of the gas turbine drives the power turbine to rotate.

[0058] The torque generated by the power turbine is first transmitted through the power turbine output shaft. A bushing 40 is fitted over the power turbine output shaft, and the two are fixedly connected by a spur spline or an interference fit, so that the bushing 40 and the power turbine output shaft rotate synchronously, thereby transmitting the torque from the power turbine output shaft to the bushing 40. Since the bushing 40 abuts or connects with the helical spline connecting shaft 10, the torque continues to be transmitted to the helical spline connecting shaft 10.

[0059] The helical external spline 11 on the outer circle of the helical spline connecting shaft 10 meshes with the helical internal spline 21 on the inner circle of the helical internal spline hollow shaft 20 to form a helical spline pair, transmitting torque from the helical spline connecting shaft 10 to the helical internal spline hollow shaft 20 in a coaxial state. The first helical tooth 22 on the outer circle of the helical internal spline hollow shaft 20 away from the engine meshes with the second helical tooth 51 provided on the output end 50 of the output motor to form a helical gear pair, thereby further transmitting torque to the output motor shaft.

[0060] When the output motor works as a drive motor, the torque output by the motor shaft is transmitted in the reverse direction along the above path, through the helical gear pair, helical spline pair, bushing 40 and spur spline to the power turbine output shaft, thereby realizing the starting or power assist drive of the engine.

[0061] During engine operation, the torque output by the power turbine is transmitted through the helical gear coupling assembly of this invention, with torque coupling achieved by the helical spline pair and the helical gear pair. During the meshing of the helical gear pair and the helical spline pair, the tooth surface contact force acts along the tooth direction. This force can be geometrically decomposed into a circumferential component and an axial component. The circumferential component is used to transmit torque; the axial component is transmitted along the shaft system and borne by the corresponding support structure (e.g., bearing / thrust structure and its mounting housing), thereby avoiding the axial load from being concentrated on a single connection point. The circumferential component forms a driving torque, which drives the output motor rotor to rotate through the helical spline hollow shaft 20, realizing the power transmission from the engine to the output motor; the axial component is transmitted along the shaft system to the bearings at each stage, and then from the bearings to the casing and the overall frame, so that the axial load is dispersed and absorbed in the structure, avoiding the concentration of force on a single component. Through helical gear meshing and reasonable support arrangement, not only is the force uniformity and structural reliability of the transmission system improved, but the peak axial load of the bearings is also reduced, thereby extending the service life of the bearings.

[0062] Therefore, this utility model uses a helical gear coupling assembly to distribute axial tensile force to multiple support points, reducing stress concentration at a single point. Due to the distributed transmission of force, the force on each component of the system is more uniform, reducing fatigue damage caused by excessive local stress and improving the overall lifespan of the system. The helical gear design ensures smooth gear meshing and low noise, improving the overall operating comfort. The helical gear design also enhances the structure's impact resistance, enabling it to better maintain stability and reliability under complex and changing working conditions.

[0063] In one embodiment, reference is made to Figures 1A to 2 The helical gear coupling assembly also includes a bearing assembly 60, which is disposed on the outer surface of the helical spline hollow shaft 20 near the engine. The bearing assembly 60 is used to fix the helical spline hollow shaft 20 within a mounting housing 70. In this embodiment, the housing 70 is disposed between the engine and the output motor. One end of the housing 70 is fixedly connected to the engine housing, and the other end of the housing is fixedly connected to the output motor housing.

[0064] In this embodiment, the entire helical gear coupling assembly is supported in the housing 70 by the bearing assembly 60 arranged on the outside of the helical spline hollow shaft 20, so that the power turbine output shaft and the output motor shaft maintain good coaxiality and stable torque transmission during operation.

[0065] In one embodiment, the helical internal spline 21 has a helix angle of 8° and a module of 1.5 mm, the number of teeth of the helical internal spline 21 is 20, and the tooth thickness of the helical internal spline 21 is 2.36 mm.

[0066] This embodiment describes one design parameter for the helical internal spline 21. Of course, other design parameters for the helical internal spline 21 can be selected according to the actual application scenario.

[0067] In one embodiment, the first helical tooth 22 has a helix angle of 8° and a module of 0.5 mm, the number of teeth of the first helical tooth 22 is 36, and the tooth thickness of the first helical tooth 22 is 0.75 mm.

[0068] This embodiment describes one design parameter for the first helical tooth 22. Of course, other design parameters for the first helical tooth 22 can be selected according to the actual application scenario.

[0069] In one embodiment, the helical spline connecting shaft 10 is provided with clearance through holes extending axially through both ends of the shaft. These clearance through holes are coaxially arranged with the engine output shaft 30, allowing the engine output shaft 30 to pass through to avoid assembly interference. A locking nut is provided on the end of the helical spline connecting shaft 10 away from the engine. The locking nut is threadedly engaged with the external thread section of the engine output shaft 30. When the locking nut is tightened, the helical spline connecting shaft 10 is pulled / pressed axially, causing the end face of the helical spline connecting shaft 10 closest to the engine to axially press against the end face of the bushing 40, thereby achieving axial clamping and reliable connection between the helical spline connecting shaft 10 and the bushing 40.

[0070] In this embodiment, a bushing 40 is fitted over the power turbine output shaft, and the two are connected by a spur spline or an interference fit, so that the torque is transmitted from the power turbine output shaft to the bushing 40. The end of the power turbine output shaft away from the engine passes through the other end of the bushing 40 and extends into the helical spline connecting shaft 10, and then passes through the other end of the helical spline connecting shaft 10. The threaded section at the end of the power turbine output shaft that passes through is fixedly connected to the helical spline connecting shaft 10 by a lock nut. At the same time, the end face of the helical spline connecting shaft 10 near the engine is pressed against the end face of the bushing 40, thereby clamping the power turbine output shaft, bushing 40 and helical spline connecting shaft 10 into a whole in the axial direction and achieving a rigid connection in the circumferential direction.

[0071] Of course, other contact or connection methods can be selected according to the actual application scenario to enable the bushing 40 to transmit torque to the helical spline connecting shaft 10.

[0072] In one embodiment, the outer diameter of the helical spline hollow shaft 20 on the side closer to the engine is larger than the outer diameter on the side farther from the engine.

[0073] In one embodiment, the inner diameter of the helical spline hollow shaft 20 on the side closer to the engine is larger than the inner diameter on the side farther from the engine.

[0074] Reference Figures 1A to 7This utility model embodiment also provides a hybrid power system, which includes an engine and an output motor, and the engine and the output motor are connected by a helical gear coupling assembly provided in the above embodiments of this utility model.

[0075] During connection, the engine's power turbine output shaft is connected to the bushing 40 via a spur spline or interference fit. The bushing 40 abuts against or connects to the helical spline connecting shaft 10 on the side closest to the engine. The output end 50 of the output motor is provided with a second helical tooth 51, which meshes with the first helical tooth 22 of the helical spline hollow shaft 20 to form a helical gear pair.

[0076] In one embodiment, the helical spline connecting shaft 10 is provided with clearance through holes extending axially through both ends. These clearance through holes are coaxially arranged with the power turbine output shaft, allowing the power turbine output shaft to pass through to avoid assembly interference. A lock nut is provided on the end of the helical spline connecting shaft 10 away from the engine. The lock nut is used to engage with the external threaded section of the power turbine output shaft. The end of the power turbine output shaft away from the engine passes through the clearance through holes from the side of the helical spline connecting shaft 10 closest to the engine and is threadedly connected to the lock nut, thus achieving a fixed connection between the power turbine output shaft and the helical spline connecting shaft 10. When the lock nut is tightened, the helical spline connecting shaft 10 is stretched / pressed axially, causing the end face of the helical spline connecting shaft 10 closest to the engine to axially press against the end face of the bushing 40, thereby achieving axial clamping and reliable connection between the helical spline connecting shaft 10 and the bushing 40.

[0077] In one embodiment, reference is made to Figures 1A to 5 The output motor shaft is connected to a motor spline, which serves as the output end 50 of the output motor. The inner circle of the motor spline is provided with a second helical tooth 51.

[0078] In one embodiment, reference is made to Figures 1A to 2 The hybrid power system also includes a housing 70, which is disposed between the engine and the output motor. One end of the housing 70 is fixedly connected to the engine housing, and the other end of the housing 70 is fixedly connected to the output motor housing. The helical gear coupling assembly is fixed to the housing 70 by a bearing assembly 60 disposed on the outer surface of the helical spline hollow shaft 20 near the engine.

[0079] The housing 70 is used for mounting and fixing, that is, mounting bracket. In this embodiment, the housing 70 integrates the various components of the hybrid power system together.

[0080] In one embodiment, reference is made to Figure 2 The casing 70 is provided with a stepped mounting cavity 73 extending axially. The mounting cavity 73 includes an open hole section for pressing in the bearing steel sleeve 62 and forms an annular stepped surface in the hole.

[0081] The bearing assembly 60 includes a bearing body 61 and a bearing sleeve 62. The outer ring of the bearing body 61 is installed in the inner hole of the bearing sleeve 62. The inner ring of the bearing body 61 is fitted onto the outer circle of the helical spline hollow shaft 20 near the engine. The outer circle of the bearing sleeve 62 is pressed into the mounting cavity. The side of the bearing sleeve 62 near the engine abuts against the annular stepped surface in the mounting cavity. A limiting plate 71 is detachably fixed to the outer end face of the mounting cavity opening on the other side of the bearing sleeve 62 away from the engine. The limiting plate 71 axially limits the bearing sleeve 62 on the other side away from the engine. There is a gap between the limiting plate 71 and the helical spline hollow shaft 20 so as not to affect the rotation of the helical spline hollow shaft 20.

[0082] In this embodiment, the bearing steel sleeve 62 of the bearing assembly 60 is limited on both sides of the axial direction by the annular stepped surface of the housing 70 and the limiting plate 71, so as to ensure the radial support and axial positioning of the helical gear coupling assembly in the housing 70.

[0083] In one embodiment, the casing 70 has a hollow structure, and its lower space forms a cooling oil chamber 72. The lower part of the casing 70 is provided with an oil suction port (oil extraction port) that communicates with the cooling oil chamber 72, for communicating with the suction port of an external cooling oil pump; the oil outlet of the external cooling oil pump supplies oil to the predetermined cooling / lubrication positions (e.g., the bearing positions) of the engine and output motor through an oil supply pipeline to achieve cooling and lubrication.

[0084] The helical spline hollow shaft 20 has a through hole along its axial direction, and an oil return opening on the side near the casing 70, which communicates with the interior of the casing 70. The interior of the helical spline hollow shaft 20 is connected to the oil passage of the output motor output end 50 via the internal oil passage of the helical spline connecting shaft 10, and also connected to the internal oil passage of the engine output shaft 30 via its other end. Cooling oil flowing into the helical spline hollow shaft 20 from the engine-side oil passage and the motor-side oil passage flows back to the cooling oil chamber 72 through the oil return opening under gravity, thus forming a circulation loop in conjunction with the external cooling oil pump.

[0085] In one embodiment, the helical spline hollow shaft 20 or the helical spline connecting shaft 10 is provided with an oil injection hole / oil outlet groove facing the meshing area, so that cooling oil can be sprayed onto the tooth surface / tooth tip area of ​​the helical gear pair.

[0086] In this embodiment, cooling oil is sprayed out through the cooling oil passage in the engine and output motor shaft to cool the helical gear coupling assembly, which can effectively improve the cooling efficiency and ensure that the tooth surface temperature remains stable under high speed conditions.

[0087] Reference Figure 12 and Figure 13This utility model provides a spur gear coupling assembly for use in a hybrid power system. The engine and the output motor are connected through the spur gear coupling assembly, which includes a spur gear spline hollow shaft 91, a spur gear coupling 92, a spur gear bushing 93, and a spur gear bearing assembly 94.

[0088] In the comparative example, one side of the spur-spline hollow shaft 91 abuts against or connects to the spur-spline sleeve 93. The connection between the spur-spline hollow shaft 91 and the spur-spline sleeve 93 can be the same as the helical-spline connection between the helical-spline shaft 10 and the sleeve 40 in the helical-spline coupling assembly of this utility model. The spur-spline sleeve 93 is sleeved on the outside of the engine output shaft 30, and the spur-spline sleeve 93 and the engine output shaft 30 are connected by a spur-spline or interference fit.

[0089] One side of the spur gear coupling 92 extends into the other side of the spur spline hollow shaft 91 and is connected to the spur gear hollow shaft 91 with straight teeth. The other side of the spur gear coupling 92 is splined to the output end 50 of the output motor and is not connected by a helical spline.

[0090] The spur gear bearing assembly 94 is disposed outside the spur gear sleeve 93, and the spur gear coupling assembly is fixed inside the housing 70 by the spur gear bearing assembly 94. The specific structure of the spur gear bearing assembly 94 can adopt the bearing assembly 60 in the helical gear coupling assembly of this utility model.

[0091] Because proportional spur gear couplings use spur gear meshing, the transmission structure is simpler, easier to process and assemble, and can effectively reduce manufacturing costs. At the same time, this design provides a clear force transmission path during operation, facilitating mechanical analysis and troubleshooting of the system. However, due to the use of spur gear meshing, the engine alone bears the axial tension, while the output motor and casing do not bear axial force. Under normal operating conditions, spur gear couplings can stably transmit power, meeting basic transmission requirements. However, because the engine alone bears the axial tension, after long-term operation, engine components may experience some wear, requiring regular maintenance and inspection. Therefore, spur gear couplings are suitable for applications where transmission accuracy requirements are not particularly high, operating conditions are relatively stable, and axial force variations are small.

[0092] After applying the helical gear coupling assembly of this invention and the spur gear coupling assembly of the comparative example to the same hybrid power system, the parameters were compared, and the comparison results are shown in the table below:

[0093]

[0094] As can be seen, with the helical gear coupling assembly, the maximum stress in the casing (120 MPa) is lower than the material yield strength (250 MPa), meeting the design requirements. Although the helical gear coupling assembly slightly reduces the transmission efficiency, it can still achieve effective power transmission and effectively balance axial forces, thereby extending the service life of the bearings.

[0095] Reference Figures 14A to 14D This is a proportional multibody dynamics simulation diagram of a spur gear coupling assembly, in which... Figure 14A This is a diagram showing the stress and stress distribution. Figure 14B This is a diagram illustrating the strain. Figure 14C This is a diagram illustrating the displacement. Figure 14D This is a schematic diagram of the mesh quality. Because the spur gear coupling assembly uses spur gear meshing, the peak impact force of the gear meshing reaches 1200N, requiring optimization of the tooth surface profile. This demonstrates that the spur gear coupling assembly is relatively weak in axial force dissipation, affecting its service life.

[0096] Reference Figures 8A to 8D This is a simulation diagram of the helical spline connecting shaft 10 in the helical gear coupling assembly of this utility model under static stress. Figure 8A This is a diagram showing the stress and stress distribution. Figure 8B This is a diagram illustrating the strain. Figure 8C This is a diagram illustrating the displacement. Figure 8D This is a schematic diagram of the grid quality.

[0097] Depend on Figures 8A to 8D It can be seen that the maximum stress on the helical external spline 11 of the helical spline connecting shaft 10 is 300 MPa, the yield strength is 885 MPa, and the safety factor is 2.85, which meets the design requirements.

[0098] Reference Figures 9A to 9D This is a simulation diagram of the helical internal spline 21 of the helical spline hollow shaft 20 in the helical gear coupling assembly of this utility model under static stress. Figure 9A This is a diagram showing the stress and stress distribution. Figure 9B This is a diagram illustrating the strain. Figure 9C This is a diagram illustrating the displacement. Figure 9D This is a schematic diagram of the grid quality.

[0099] Depend on Figures 9A to 9D It can be seen that the maximum stress on the helical internal spline 21 of the helical spline hollow shaft 20 is 142.3 MPa, the yield strength is 885 MPa, and the safety factor is 6.2, which meets the design requirements.

[0100] Reference Figures 10A to 10D This is a simulation diagram of the first helical tooth 22 of the helical spline hollow shaft 20 in the helical gear coupling assembly of this utility model under static stress. Figure 10A This is a diagram showing the stress and stress distribution. Figure 10B This is a diagram illustrating the strain. Figure 10C This is a diagram illustrating the displacement. Figure 10D This is a schematic diagram of the grid quality.

[0101] Depend on Figures 10A to 10D It can be seen that the maximum stress on the first helical tooth 22 of the helical spline hollow shaft 20 is 276.2 MPa, the yield strength is 885 MPa, and the safety factor is 3.2, which meets the design requirements.

[0102] Reference Figures 11A to 11D This is a multibody dynamics simulation diagram of a helical gear coupling assembly, in which... Figure 11A This is a diagram showing the stress and stress distribution. Figure 11B This is a diagram illustrating the strain. Figure 11C This is a diagram illustrating the displacement. Figure 11D This is a schematic diagram of the mesh quality. Because the helical gear coupling assembly uses helical gear meshing, the axial force fluctuation amplitude is reduced by 40% compared with the spur gear coupling assembly, achieving a dynamic balance between torque and axial force. However, the tooth surface hardness needs to be optimized.

[0103] The preferred embodiments of this utility model have been described in detail above. However, it should be understood that after reading the above teachings, those skilled in the art can make various alterations or modifications to this utility model. These equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A helical gear coupling assembly, characterized in that, The helical gear coupling assembly includes: A helical spline connecting shaft, wherein the outer circle of the helical spline connecting shaft is provided with helical external splines; the side of the helical spline connecting shaft near the engine is used to abut or connect with a bushing fitted around the engine output shaft; A helical spline hollow shaft, wherein the inner circle of the helical spline hollow shaft near the engine is provided with helical internal splines, and the outer circle of the helical spline hollow shaft away from the engine is provided with a first helical tooth for meshing with the output end of the output motor. The helical spline connecting shaft extends into the interior of the helical spline hollow shaft near the engine, and the external helical spline meshes with the internal helical spline to form a helical spline pair.

2. The helical gear coupling assembly as described in claim 1, characterized in that, The helical gear coupling assembly also includes: A bearing assembly is disposed on the outer surface of the helical spline hollow shaft near the engine. The bearing assembly is used to fix the helical spline hollow shaft in a mounting housing. The housing is disposed between the engine and the output motor. One end of the housing is fixedly connected to the housing of the engine, and the other end of the housing is fixedly connected to the housing of the output motor.

3. The helical gear coupling assembly as described in claim 1, characterized in that, The helical internal spline has a helix angle of 8° and a module of 1.5mm, has 20 teeth, and has a tooth thickness of 2.36mm. And / or, The first helical tooth has a helix angle of 8° and a module of 0.5 mm, has 36 teeth, and has a tooth thickness of 0.75 mm.

4. The helical gear coupling assembly as described in any one of claims 1 to 3, characterized in that, The helical spline connecting shaft is provided with clearance through holes extending through both ends along the axial direction. The clearance through holes are coaxially arranged with the engine output shaft and are used for the engine output shaft to pass through. A locking nut is provided on the other end of the helical spline connecting shaft away from the engine. The locking nut is used to thread the external thread section of the engine output shaft. The locking nut is used to axially press the end face of the helical spline connecting shaft near the engine against the end face of the bushing. And / or, the outer diameter of the helical spline hollow shaft on the side closer to the engine is larger than the outer diameter on the side farther from the engine; And / or, the inner diameter of the helical spline hollow shaft on the side closer to the engine is larger than the inner diameter on the side farther from the engine.

5. A hybrid power system, the hybrid power system comprising an engine and an output motor, characterized in that, The engine and the output motor are connected by a helical gear coupling assembly as described in any one of claims 1 to 4; The power turbine output shaft of the engine is connected to a bushing via a spur spline or interference fit, and the bushing abuts against or connects to the helical spline connecting shaft on the side near the engine. The output end of the output motor is provided with a second helical tooth, which meshes with the first helical tooth of the helical spline hollow shaft to form a helical gear pair.

6. The hybrid power system as described in claim 5, characterized in that, The helical spline connecting shaft is provided with clearance through holes extending axially through both ends. The clearance through holes are coaxially arranged with the power turbine output shaft. A locking nut is provided on the other end of the helical spline connecting shaft away from the engine. The end of the power turbine output shaft away from the engine passes through the clearance through holes from the side of the helical spline connecting shaft closer to the engine. The external thread section on the power turbine output shaft is threaded to the locking nut to achieve a fixed connection between the power turbine output shaft and the helical spline connecting shaft. The locking nut axially presses the end face of the helical spline connecting shaft closer to the engine against the end face of the bushing.

7. The hybrid power system as described in claim 5, characterized in that, The output motor shaft is connected to a motor spline, and the inner circle of the motor spline is provided with the second helical tooth.

8. The hybrid power system according to any one of claims 5 to 7, characterized in that, The hybrid power system also includes a housing disposed between the engine and the output motor, one end of the housing being fixedly connected to the housing of the engine, and the other end of the housing being fixedly connected to the housing of the output motor; The helical gear coupling assembly is fixed to the casing by a bearing assembly located on the outer circumference of the helical spline hollow shaft near the engine.

9. The hybrid power system as described in claim 8, characterized in that, The casing is provided with a stepped mounting cavity extending along the axial direction. The mounting cavity includes an open hole section for pressing in the bearing steel sleeve, and an annular stepped surface is formed in the hole. The bearing assembly includes a bearing body and a bearing sleeve. The outer ring of the bearing body is installed in the inner hole of the bearing sleeve. The inner ring of the bearing body is fitted onto the outer circumference of the helical spline hollow shaft near the engine. The outer circumference of the bearing sleeve is pressed into the mounting cavity. The side of the bearing sleeve near the engine abuts against the annular stepped surface. A limiting plate is detachably fixed to the outer end face of the mounting cavity opening on the other side of the bearing sleeve away from the engine. The limiting plate axially limits the bearing sleeve on the other side away from the engine. There is a gap between the limiting plate and the helical spline hollow shaft.

10. The hybrid power system as claimed in claim 8, characterized in that, The casing has a hollow structure, and the lower space of the casing forms a cooling oil chamber. The lower part of the casing is provided with an oil suction port that communicates with the cooling oil chamber. The oil suction port is connected to the suction port of an external cooling oil pump. The oil outlet of the external cooling oil pump supplies oil to each target position of the engine and the output motor through the oil supply pipeline. The helical spline hollow shaft is provided with a through hole along the axial direction. The helical spline hollow shaft is provided with an oil return opening on the side near the casing and communicates with the inside of the casing. The inside of the helical spline hollow shaft is connected to the oil passage of the output end of the output motor through the internal oil passage of the helical spline connecting shaft. The helical spline hollow shaft is connected to the internal oil passage of the engine output shaft through the other end. Preferably, the helical spline hollow shaft or the helical spline connecting shaft is provided with an oil injection hole or an oil injection groove facing the helical gear spoke meshing area.

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