Connecting structure of axial magnetic flux motor and extended-range engine

Abstract

The utility model discloses a connecting structure of an axial magnetic flux motor and an extended-range engine, which comprises the axial magnetic flux motor and the extended-range engine, the axial magnetic flux motor comprises a stator assembly I and a stator assembly II arranged in parallel, a rotor assembly is arranged between the stator assembly I and the stator assembly II, the rotor assembly is connected with the middle part of a motor rotating shaft, and the motor rotating shaft is connected with the extended-range engine. The end, close to the extended-range engine, of the motor rotating shaft is fixed to a crankshaft of the extended-range engine, and cooling pipelines are arranged in the first stator assembly and the second stator assembly. The range extender solves the problems that in the prior art, when an engine and a motor are connected, the axial length is long, the weight is large, the cost is high, the performance of an existing range extender is unstable, and the high-temperature heat dissipation requirement cannot be met.

Description

Technical Field

[0001] The utility model relates to the technical field of transmission devices of engines, and in particular to a connection structure of an axial flux motor and a range-extending engine. Background Art

[0002] With the development of electric vehicles, range extender technology has been favored by the market and has an increasingly larger share in the field of new energy vehicles. The range extender uses mature internal combustion engine technology, which has greatly improved the stability of the vehicle's power supply system. The Chinese patent document with the publication date of October 9, 2020 and the publication number CN111749785A discloses a connection structure in which the internal combustion engine and the generator of the range extender are connected through a planetary gear, including a planetary gear, a generator, a torque damper, an internal combustion engine, an internal combustion engine output shaft and an internal combustion engine flywheel. However, this structure uses a torsional vibration damper to realize the connection between the motor shaft and the crankshaft of the range extender engine. This transmission method will cause the overall axial dimension to increase, resulting in a longer axial length of the structure in product application, a significant increase in the weight of the system, and a high cost of the motor. The Chinese patent document with publication date of September 24, 2021 and publication number CN118596883A discloses a dual-rotor single-stator axial flux hybrid excitation motor, including a stator, two rotors, a DC excitation unit, and a magnetic shield. The two rotors are placed on both sides of the stator, and the stator and rotor rotate in coordination. An axial flux motor with a dual-rotor structure is used for the connection structure, but the product application does not take into account the 0.2~0.3mm axial movement of the extended-range engine crankshaft. The motor air gap cannot be stabilized when the motor is running, which greatly affects the performance stability of the motor on the product. In addition, an intermediate stator structure is used for cooling, which cannot adapt to the high-temperature heat dissipation requirements of the direct connection of the extended-range engine. Utility Model Content

[0003] The purpose of the present utility model is to provide a connection structure between an axial flux motor and a range extender engine, so as to solve the problems proposed in the above background technology that the axial length is long, the weight is large and the cost is high when the engine and the motor are connected, and the performance of the existing range extender is unstable and cannot meet the high-temperature heat dissipation requirements.

[0004] The technical solution employed by the present invention to achieve the above-mentioned objectives is a connection structure between an axial flux motor and a range-extender engine, comprising an axial flux motor and a range-extender engine. The axial flux motor comprises a first stator assembly and a second stator assembly arranged in parallel, with a rotor assembly disposed between the first and second stator assemblies. The rotor assembly is connected to the middle portion of the motor shaft, and the end of the motor shaft proximate the range-extender engine is fixed to the crankshaft of the range-extender engine. Cooling ducts are provided within both the first and second stator assemblies. The present invention employs a dual-stator, single-rotor axial flux motor structure. By directly connecting the motor to the range-extender engine crankshaft, the axial space of the range-extender system is significantly reduced, thereby improving system integration, while reducing system weight, reducing connecting components, and lowering the overall cost of the product. In addition, the utility model is equipped with cooling pipes inside the stator assembly 1 and the stator assembly 2, and adopts a dual-stator water-cooling method, which greatly improves the cooling efficiency of the motor, solves the problems of long axial length, heavy weight and high cost when the engine and motor are connected in the existing range extender, and the unstable performance of the existing range extender and its inability to meet high-temperature heat dissipation requirements.

[0005] Preferably, the second stator assembly is located between the first stator assembly and the range extender engine, and an inertia disc is provided at the connection between the motor shaft and the range extender engine. The inertia disc, also known as a flywheel, is a mechanical element used to store and release kinetic energy. In an axial flux motor, the main function of the inertia disc is to increase the rotational inertia of the system, thereby smoothing movement and reducing vibration and shock. The inertia disc can store energy, and when the motor accelerates, part of the energy will be stored in the rotational kinetic energy of the inertia disc. When the motor decelerates, this part of the energy can be released again, thereby improving energy utilization efficiency. Due to the high rotational inertia of the inertia disc, it can resist rapid changes in speed, thereby making the motor run more smoothly and reducing vibration and shock.

[0006] Preferably, a first mounting plate is provided at the end of the motor shaft proximate the range-extender engine. The inertia plate is secured to the outer periphery of the first mounting plate. The first mounting plate also has fixing holes, and the first mounting plate is secured to the crankshaft of the range-extender engine via bolts. The first mounting plate is used to mount the inertia plate, and the fixing holes in the first mounting plate are used to receive bolts that secure the motor shaft to the crankshaft of the range-extender engine.

[0007] Preferably, a second mounting plate is provided in the middle of the motor shaft, and the rotor assembly is fixed on the mounting surface of the second mounting plate. The second mounting plate is used to fix the rotor assembly.

[0008] Preferably, a rear end cover is provided at the rear of the stator assembly, and a double-row angular contact bearing is provided at the end of the motor shaft near the rear end cover. A double-row angular contact bearing is a high-performance rolling bearing composed of two single-row angular contact ball bearings positioned back-to-back, with the inner and outer rings each integrally formed. This structure provides the bearing with increased rigidity and load-bearing capacity, enabling it to withstand both radial and axial loads and limiting axial displacement of the shaft in both directions. This significantly reduces axial play in the range-extended engine, resolving the issue of shaft play causing air gap changes in the motor, leading to unstable motor performance.

[0009] Preferably, the motor shaft has a stepped shaft at one end near the rear end cap. A bearing pressure plate is mounted on the stepped shaft, and one end of the double-row angular contact bearing abuts the bearing pressure plate. A bearing retainer is mounted on the end of the double-row angular contact bearing near the rear end cap. The stepped shaft ensures the bearings maintain a stable position on the shaft. The double-row angular contact bearing, with one end abutting the bearing pressure plate, can withstand both radial and axial loads while limiting bidirectional axial displacement of the shaft. The bearing retainer provides additional support and fixation, ensuring precise axial positioning of the bearings and thus maintaining a stable air gap in the motor.

[0010] Preferably, a resolver is provided on the motor shaft between the double-row angular contact bearing and the rear end cap, the resolver being located outside the bearing fixing block. A resolver is a precision angle, position, and speed detection device that converts the angular displacement and angular velocity of the shaft into electrical signals.

[0011] Preferably, the rotary transformer comprises a rotary transformer rotor fixed on the motor shaft, and the stator of the rotary transformer is fixed on the housing of a stator assembly corresponding to the rotary transformer rotor.

[0012] Preferably, stator assemblies 1 and 2 are equipped with a junction box on one side, which contains a low-voltage plug-in and waterproof connector. The outer shells of stator assemblies 1 and 2 also feature pipe connections that connect to the internal cooling pipes. The low-voltage plug-in and pipe connections provide power and cooling water, respectively, to the axial flux motor.

[0013] The beneficial effect of the utility model is that it effectively solves the problems of long axial length, heavy weight and high cost when the engine and motor are connected in the range extender of the prior art, and the unstable performance of the existing range extender and its inability to meet high-temperature heat dissipation requirements. The utility model has a compact overall structure, light weight, stable performance and good heat dissipation, and has high practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a three-dimensional schematic diagram of the appearance structure of the utility model.

[0015] Figure 2This is a schematic diagram of a half-section structure of the present utility model.

[0016] Figure 3 This is a three-dimensional exploded view of the present utility model.

[0017] Figure 4 This is a cross-sectional view of the present utility model.

[0018] Figure 5 This is a schematic diagram of the three-dimensional structure of the stator assembly of the present invention.

[0019] Figure 6 This is a schematic diagram of the three-dimensional structure of the stator assembly 2 of the present invention.

[0020] Figure 7 It is a three-dimensional structural schematic diagram of the rotor shaft system assembly of the utility model.

[0021] Figure 8 The figure is a schematic diagram of a three-dimensional structure of the range-extending engine connected to the output shaft of the utility model.

[0022] Figure: 11. Stator assembly 1, 12. Stator assembly 2, 13. Rear end cover, 14. Rear end cover gasket, 21. Inertia plate, 22. Rotor assembly, 23. Motor shaft, 24. Bearing pressure plate, 25. Double-row angular contact bearing, 26. Bearing retaining block, 27. Flat washer, 28. Retaining bolt, 29. Resolver rotor, 30. First mounting plate, 31. Second mounting plate, 32. Pipe interface, 41. Junction box cover, 42. Junction box gasket, 43. Low-voltage plug-in unit, 100. Range extender engine, 101. Crankshaft, 111. Waterproof connector, 112. Terminal block, 113. Resolver stator. DETAILED DESCRIPTION

[0023] The specific implementation of the technical solution of the utility model will be further described below through examples and in conjunction with the accompanying drawings.

[0024] Example

[0025] exist Figure 1 Figure 2 Figure 3 Figure 4 In the embodiment shown, a connection structure of an axial flux motor and a range-extending engine includes an axial flux motor and a range-extending engine 100. The axial flux motor includes a stator assembly 11 (see FIG. Figure 5 ) and the stator assembly 12 arranged in parallel (see Figure 6A rotor assembly 22 is disposed between stator assembly 11 and stator assembly 12. The rotor assembly 22 is connected to the middle of a motor shaft 23, the end of which, near the range extender engine 100, is fixed to the range extender engine's crankshaft 101. Both stator assembly 11 and stator assembly 12 are internally provided with cooling ducts. An axial flux motor is a motor with a unique magnetic flux path. Its air gap is planar, and the direction of the air gap magnetic field is parallel to the motor axis. This structure makes axial flux motors more compact, smaller, and lighter, and offers high torque density, which presents significant advantages in many applications. The direct connection of an axial flux motor to a range extender engine is an efficient and compact powertrain design. The axial flux motor's design enables it to provide higher torque density within the same size, generating greater torque and power with a smaller size and weight. Cooling ducts are internally provided within both stator assembly 11 and stator assembly 12 to effectively manage the heat generated by the motor, helping to improve its thermal efficiency and reliability. This new motor utilizes a dual-stator, single-rotor axial flux motor structure. By directly connecting the motor to the range-extending engine crankshaft, it significantly reduces the axial space required for the range-extending system, improving system integration while also reducing weight and connecting components, ultimately lowering overall product cost. Furthermore, this new motor utilizes dual-stator water cooling, with cooling ducts located within both stator assemblies. This significantly improves motor cooling efficiency.

[0026] In a preferred embodiment, the stator assembly 12 is located between the stator assembly 11 and the range-extending engine 100, and an inertia disk 21 is provided at the connection between the motor shaft 23 and the range-extending engine 100 (see FIG. Figure 7 An inertia disc 21 is installed at the connection between the motor shaft 23 and the range extender engine 100. This inertia disc 21 partially replaces the flywheel, increasing the system's rotational inertia, thereby helping to smooth engine speed fluctuations, reduce vibration and noise, and enhance the overall system's NVH performance. The inertia disc increases the system's rotational inertia, helping to reduce vibration during engine operation, thereby reducing noise and improving driving comfort. The inertia disc improves the connection reliability between the motor shaft 23 and the engine crankshaft 101 by absorbing and reducing the impact force and torque fluctuations generated by engine operation.

[0027] In a preferred embodiment, a first mounting plate 30 is provided at one end of the motor shaft 23 close to the range extender engine 100 (see FIG. Figure 8The inertia disc 21 is fixed to the outer periphery of a first mounting disc 30, which is also provided with fixing holes. The first mounting disc 30 is bolted to the crankshaft 101 of the range-extender engine 100. The design of directly connecting the axial flux motor to the range-extender engine crankshaft enables deep integration and optimization of the generator and engine. The first mounting disc 30 is provided at the end of the motor shaft 23, with the inertia disc 21 fixed to its outer periphery. The first mounting disc 30 also has fixing holes on its inner side. Bolts can be used to directly secure the first mounting disc 30 to the crankshaft 101 of the range-extender engine 100 through these fixing holes. This design helps to shorten the axial dimension of the system.

[0028] In a preferred embodiment, a second mounting disk 31 is provided in the middle of the motor shaft 23, and the rotor assembly 22 is fixed on the mounting surface of the second mounting disk 31. In the structure of the axial flux motor, the fixing method of the rotor assembly is crucial to the performance and stability of the motor. In this embodiment, a second mounting disk 31 is provided in the middle of the motor shaft 23, and the rotor assembly is fixed on the mounting surface of the second mounting disk 31. This structure helps to ensure the stability and reliability of the rotor assembly during the operation of the motor. In addition, the rotor of the axial flux motor is similar to the flywheel structure and can also partially replace the flywheel part of the range extender, which not only greatly reduces the manufacturing cost but also improves the energy conversion efficiency.

[0029] In a preferred embodiment, a rear end cover 13 is provided at the rear of the stator assembly 11. A double-row angular contact bearing 25 is mounted on the end of the motor shaft 23 near the rear end cover 13. A rear end cover seal 14 is provided between the rear end cover 13 and the housing of the stator assembly 11. The double-row angular contact bearing 25 is a high-performance rolling bearing composed of two single-row angular contact ball bearings mounted back-to-back, with the inner and outer rings each integrally formed. This structure provides the bearing with greater rigidity and load-bearing capacity, enabling it to simultaneously withstand radial and axial loads and limit axial displacement of the shaft in both directions. Double-row angular contact ball bearings can operate at high speeds and are more suitable than deep groove ball bearings for supporting large bidirectional axial forces. They can withstand higher radial loads, higher biaxial axial loads, and higher tilting moments, while requiring less axial space than comparable single-row angular contact ball bearings. Due to the double-row design, double-row angular contact bearings have higher rigidity and can provide good positioning capability in the axial direction. They can effectively reduce deformation and improve the operating accuracy and stability of the equipment, thereby greatly reducing the axial movement of the range-extended engine and solving the problem of shaft movement causing changes in the motor air gap and thus leading to unstable motor performance.

[0030] In a preferred embodiment, a stepped shaft is provided at one end of the motor shaft 23 near the rear end cover 13. A bearing pressure plate 24 is provided on the stepped shaft. One end of a double-row angular contact bearing 25 abuts against the bearing pressure plate 24. A bearing fixing block 27 is provided on the end of the double-row angular contact bearing 25 near the rear end cover 13. The stepped structure on the motor shaft 23 effectively positions the double-row angular contact bearing 25 axially. The bearing pressure plate 24 provided on the stepped shaft ensures the bearing's stable position on the shaft. The double-row angular contact bearing 25 abuts against the bearing pressure plate 24 at one end. Due to its angular contact design, this bearing can simultaneously withstand radial and axial loads and limit bidirectional axial displacement of the shaft. The bearing pressure plate 24 increases the axial contact area between the bearing and the motor shaft, preventing axial movement during operation. The bearing fixing block 27 secures the double-row angular contact bearing 25, ensuring its precise axial positioning. The stepped shaft structure design of the motor shaft of this embodiment, the use of the bearing pressure plate and the bearing fixing block can ensure the stability and efficiency of the axial flux motor during operation, and also facilitate the assembly and maintenance of the motor.

[0031] In a preferred embodiment, a rotary transformer is provided on the motor shaft 23 between the double-row angular contact bearing 25 and the rear end cover 13, and the rotary transformer is provided on the outside of the bearing fixing block 27. The rotary transformer is a key sensor used to provide position and speed information of the motor rotor. The rotary transformer is provided on the outside of the fixing block of the double-row angular contact bearing 25, that is, the rotary transformer is installed in an area close to the rear end cover 13, thereby ensuring that the motor control system can accurately obtain the position information of the rotor. The working principle of the rotary transformer is based on electromagnetic induction, and its output voltage is related to the angular displacement of the rotor. The rotary transformer has the advantages of high reliability, high precision and the ability to work in harsh environments. The precise position and speed feedback of the rotary transformer facilitates efficient and reliable motor control, improving the overall performance and reliability of the motor.

[0032] In a preferred embodiment, the resolver includes a resolver rotor 29 fixed to the motor shaft 23, and a resolver stator 113 fixed to the housing of the stator assembly 11, which rotates in response to the rotation. A resolver typically consists of two parts: a stator and a rotor. The stator is equipped with an excitation winding and an output winding, while the rotor is coaxially mounted with the motor shaft 23. When a sinusoidal current is applied to the excitation winding, the output winding induces a voltage signal proportional to the rotor position. These signals are then transmitted to the motor controller, which calculates the precise position and speed of the rotor based on these signals, thereby achieving precise motor control. The resolver stator winding serves as the primary side of the transformer, receiving the excitation voltage, while the rotor winding serves as the secondary side of the transformer, generating the induced voltage through electromagnetic coupling. The output voltage of this transformer varies with the angular displacement of the rotor. The output winding voltage amplitude is related to the rotor angle in a sinusoidal or cosine function, maintains a certain proportional relationship, or is linearly related to the angle within a certain range of rotation. A resolver typically includes three windings: a rotor winding and two stator windings. The rotor winding rotates with the motor, while the stator winding is fixed at a 90-degree angle to each other. This creates a transformer with an angularly dependent coefficient. A sinusoidal carrier applied to the rotor winding is coupled to the stator winding, modulating the stator winding output amplitude in a manner dependent on the rotor winding's angle. Due to their mounting positions, the modulated output signals of the two stator windings are 90 degrees out of phase. By demodulating these two signals, the motor's angular position can be determined.

[0033] In a preferred embodiment, a junction box is provided on one side of the stator assembly 11 and the stator assembly 2, and the junction box is provided with a low-voltage plug-in 43 and a waterproof connector 111 (see FIG. Figure 5 ); The outer shell of the stator assembly 1 and the stator assembly 2 is also provided with a pipe interface 32 connected to the internal cooling pipe (see Figure 1 ), wherein the internal cooling duct is arranged around the inner shell of the stator assembly 1 and the stator assembly 2, and is composed of two parallel annular grooves with rectangular cross sections and sealing plates at the groove openings (see Figure 2 ), for cooling water circulation; a junction box gasket 42 is installed between the junction box and the junction box cover 41. A low-voltage plug-in 43 connects the motor's power cord, while a waterproof connector 111 prevents moisture intrusion and improves power connection reliability. The pipe interface connects to the cooling pipe inside the motor, allowing coolant to circulate within the motor and dissipate heat generated during generator operation. The junction box, its internal low-voltage plug-in, waterproof connector, and cooling pipe interface together constitute a key component of the motor's electrical connection and thermal management, ensuring safe, stable, and efficient operation in various environments.

[0034] The assembly sequence of the connection structure between the axial flux motor and the range-extending engine of the utility model is as follows:

[0035] 1. The inertia plate 21 and the output shaft are pre-assembled into one piece using bolts. The inertia plate 21 is made of steel and is mainly used to match the inertia matching requirements of the range-extended engine control. Different masses of inertia plates can be matched according to the operating conditions of different range-extended engines, improving the interchangeability of the motor body with different range-extended engines.

[0036] 2. Fix the motor shaft 23 to the crankshaft 101 of the range extender engine 100 with bolts.

[0037] 3. Install the stator assembly 2 onto the housing surface of the range extender engine 100; a water channel is provided inside the stator assembly 2 to dissipate heat from the stator.

[0038] 4. The rotor assembly 22 is installed on the mounting surface of the motor shaft 23; the rotor assembly 22 is located between the stator assembly 11 and the stator assembly 2, serving as an axial flux motor structure with dual stators and a single rotor.

[0039] 5. The stepped portion of the motor shaft 23 is fitted with a bearing pressure plate 24, and then a double-row angular contact bearing 25. The double-row angular contact bearing 25 has an axial force resistance function and can withstand the axial force generated by the range-extending engine, ensuring stable operation of the motor.

[0040] 6. Install the bearing fixing block 27, rotary transformer rotor 29, flat washer 27, and fixing bolt 28 on the motor shaft 23 in sequence. The rotor assembly is now installed. The bearing pressure plate 24, the bearing fixing block 27, and the stator assembly-11 bearing chamber position form a four-point fixed bearing structure to ensure system stability.

[0041] 7. Install stator assembly 11 and secure the mounting bolts. Stator assembly 11 is internally provided with cooling ducts to dissipate heat from the stator. Stator assembly 11 includes terminal blocks 112 for motor lead installation and waterproof connectors 111. Stator assembly 11 also includes a resolver stator 113.

[0042] 8. Install the rear end cover gasket 14 and the rear end cover 13 in sequence.

[0043] 9. Install low-voltage plug-in 43.

[0044] 10. Install the junction box sealing gasket 42 and the junction box cover 41 in sequence.

[0045] In addition to the above-mentioned embodiments, within the scope disclosed in the claims and description of the present utility model, the technical features or technical data of the present utility model can be reselected and combined to form new embodiments. These can be achieved by those skilled in the art without creative work. Therefore, these embodiments that are not described in detail in the present utility model should also be regarded as specific embodiments of the present utility model and within the scope of protection of the present utility model.

Claims

1. A connection structure between an axial flux motor and a range-extending engine, comprising an axial flux motor and a range-extending engine, characterized in that: The axial flux motor includes a stator assembly 1 and a stator assembly 2 arranged in parallel. A rotor assembly is provided between the stator assembly 1 and the stator assembly 2. The rotor assembly is connected to the middle part of the motor shaft. The end of the motor shaft close to the range extender engine is fixed to the crankshaft of the range extender engine. Cooling pipes are provided inside the stator assembly 1 and the stator assembly 2.

2. The connection structure between the axial flux motor and the range extender engine according to claim 1, characterized in that: The second stator assembly is located between the first stator assembly and the range-extending engine, and an inertia disk is provided at the connection between the motor shaft and the range-extending engine.

3. The connection structure between the axial flux motor and the range extender engine according to claim 2, characterized in that: A first mounting plate is provided at one end of the motor shaft close to the range extender engine. The inertia plate is fixed to the outer periphery of the first mounting plate. A fixing hole is also provided on the first mounting plate. The first mounting plate is fixed to the crankshaft of the range extender engine by bolts.

4. The connection structure between the axial flux motor and the range extender engine according to claim 1, characterized in that: A second mounting plate is provided in the middle of the motor shaft, and the rotor assembly is fixed on the mounting surface of the second mounting plate.

5. The connection structure between the axial flux motor and the range extender engine according to claim 1, characterized in that: A rear end cover is provided on the rear side of the stator assembly 1, and a double-row angular contact bearing is provided on one end of the motor shaft close to the rear end cover.

6. The connection structure between the axial flux motor and the range extender engine according to claim 5, characterized in that: The motor shaft is provided with a stepped shaft at one end close to the rear end cover, a bearing pressure plate is provided on the stepped shaft, one end of the double-row angular contact bearing abuts against the bearing pressure plate, and a bearing fixing block is provided at one end of the double-row angular contact bearing close to the rear end cover.

7. The connection structure between the axial flux motor and the range extender engine according to claim 6, characterized in that: A rotary transformer is provided on the motor shaft between the double-row angular contact bearing and the rear end cover, and the rotary transformer is provided on the outside of the bearing fixing block.

8. The connection structure between the axial flux motor and the range extender engine according to claim 7, characterized in that: The rotary transformer includes a rotary transformer rotor fixed on a motor shaft, and the stator of the rotary transformer is fixed on a housing of a stator assembly corresponding to the rotary transformer rotor.

9. The connection structure of the axial flux motor and the range extender engine according to any one of claims 1 to 8, characterized in that: A junction box is provided on one side of stator assembly 1 and stator assembly 2, and the junction box is provided with a low-voltage plug-in and a waterproof connector; the outer casing of stator assembly 1 and stator assembly 2 is also provided with a pipe interface connected to the internal cooling pipe.

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