Engine and motorcycle using the same

Abstract

The application discloses an engine and a motorcycle adopting the engine. The engine comprises a shell, a crankshaft, a piston and a magneto. The shell comprises a crankcase and a cylinder block. The crankshaft and the piston are arranged in the crankcase and the cylinder block respectively. The magneto comprises a rotor and a stator. The rotor comprises a rotor bushing connected with the crankshaft, a rotor body connected with the rotor bushing and a magnetic steel installed in the rotor body. The stator is supported by the crankcase and arranged at least partially around the rotor bushing. The magnetic steel is arranged around the stator. The stator is provided with a coil winding. An oil injection cooling hole is arranged on the rotor bushing and communicated with the inner wall of the rotor bushing. The oil injection cooling hole can deliver cooling oil to the coil winding. The service life of the magneto can be prolonged through the above arrangement.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to an engine and a motorcycle using the engine. Background Technology

[0002] Motorcycles are vehicles that are steered by using handlebars to turn the front wheel. They are lightweight, agile, and fast, and are widely used in patrol, passenger and freight transportation, and other fields.

[0003] Motorcycles typically consist of a frame, body panels, a running gear, a suspension system, a seat, an electrical system, and an engine. The engine includes a magneto, which powers the motorcycle's electrical equipment. In existing technology, when the magneto is running, the coil windings within the magneto generate heat. If the heat from the coil windings becomes excessive, the magneto can be damaged, thus reducing its lifespan. Utility Model Content

[0004] In order to overcome the shortcomings of the prior art, the purpose of this application is to provide an engine and a motorcycle using the engine, wherein the magneto has a long service life.

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

[0006] An engine includes a housing, a crankshaft, a piston, and a magneto. The housing includes a crankcase and a cylinder block connected to the crankcase. The crankshaft is located within the crankcase and rotatably connected to it. The piston is at least partially located within the cylinder block and driven by the crankshaft. The reciprocating motion of the piston can drive the crankshaft to rotate about its own centerline. The magneto includes a rotor and a stator. The rotor includes a rotor bushing driven by the crankshaft, a rotor body connected to the rotor bushing, and magnets installed within the rotor body. The stator is supported by the crankcase and at least partially surrounds the rotor bushing. The magnets are arranged around the stator, and coil windings are mounted on the stator.

[0007] The rotor bushing has oil injection cooling holes that communicate with the inner wall of the rotor bushing, allowing cooling oil to be delivered to the coil windings. The length of the coil windings along the radial direction of the rotor bushing is defined as the first distance. The intersection of the centerline of the oil injection cooling hole and the surface of the coil windings near the oil injection cooling hole is defined as the cooling point. The minimum distance along the radial direction of the rotor bushing between the cooling point and the side of the coil windings near the centerline of the rotor bushing is defined as the second distance. The ratio of the second distance to the first distance ranges from 0.26 to 0.4. Furthermore, a horizontally positioned plane passing through the crankshaft's centerline is defined as the reference plane. When the oil injection cooling hole is at its lowest point, the acute angle between the centerline of the oil injection cooling hole and the reference plane ranges from 50° to 75°.

[0008] Furthermore, there are two oil injection cooling holes, which are defined as the first hole and the second hole. When the first hole is at its lowest point, the acute angle between the center line of the first hole and the reference plane is in the range of 50° to 75°. When the second hole is at its lowest point, the acute angle between the center line of the second hole and the reference plane is in the range of 50° to 75°.

[0009] Furthermore, a keyway is provided on the rotor bushing to mate with the crankshaft. The center line of the keyway is defined as a preset straight line, which is parallel to the center line of the rotor bushing. A projection plane is defined perpendicular to the center line of the rotor bushing. The orthographic projection of the center line of the first hole onto the projection plane is the first projection point, the orthographic projection of the center line of the second hole onto the projection plane is the second projection point, and the orthographic projection of the preset straight line onto the projection plane is the third projection point. A symmetry plane is defined, with the first and second projection points set approximately symmetrically about the symmetry plane, and the third projection point located within the symmetry plane.

[0010] Furthermore, the angle between the first projection point and the second projection point around the center line of the rotor bushing ranges from 100° to 140°, and the angle between the first projection point and the third projection point around the center line of the rotor bushing ranges from 100° to 140°.

[0011] Furthermore, the rotor bushing has a keyway hole that mates with the crankshaft, and one oil injection cooling hole is provided. The oil injection cooling hole and the keyway hole are basically symmetrical about the center line of the rotor bushing.

[0012] Furthermore, the oil injection cooling hole includes a first cooling hole and a second cooling hole distributed along its axial direction. The first cooling hole is closer to the inner wall of the rotor bushing than the second cooling hole, and the inner diameter of the first cooling hole is larger than the inner diameter of the second cooling hole.

[0013] Furthermore, there is a gap between the centerline of the oil injection cooling hole and the surface of the rotor bushing near the crankshaft, and the gap is larger than the radius of the oil injection cooling hole.

[0014] Furthermore, the location where the cooling oil output from the oil injection cooling hole lands on the coil winding is defined as the oil injection point; along the radial direction of the rotor bushing, the minimum distance between the oil injection point and the side of the coil winding closest to the center line of the rotor bushing is defined as the third distance, and the ratio of the third distance to the first distance ranges from 0.1 to 1.

[0015] To achieve the above objectives, this application also adopts the following technical solution:

[0016] A motorcycle includes a frame, a body panel, a running gear, and an engine according to any of the above embodiments, wherein the body panel at least partially covers the frame; the running gear is at least partially located below the frame; and the engine is supported by the frame and drivenly connected to the running gear.

[0017] In this application, by opening oil spray cooling holes on the rotor bushing, the cooling oil overflowing from the crankshaft can be sprayed from the oil spray cooling holes to the coil winding through centrifugal force to achieve oil cooling of the coil winding, thereby reducing the temperature of the coil winding and thus helping to improve the service life of the magneto. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of a motorcycle provided in an embodiment of this application.

[0019] Figure 2 This is a schematic diagram of the overall structure of a motorcycle engine provided in an embodiment of this application.

[0020] Figure 3 This is an exploded schematic diagram of a motorcycle engine provided in an embodiment of this application.

[0021] Figure 4 This is a schematic cross-sectional view of the combination of the magneto and crankshaft of a motorcycle provided in an embodiment of this application.

[0022] Figure 5 This is a cross-sectional schematic diagram of a motorcycle magneto provided in an embodiment of this application. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present application, the technical solutions in specific embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0024] like Figure 1 and Figure 2 As shown, this application provides a motorcycle 100, which includes a frame 11, a body panel 12, a running system 13, a suspension system 14, a seat 15, an electrical system 16, a transmission system (not shown) and an engine 200.

[0025] For ease of description, this application defines the directions of front, back, left, right, up, and down. The front-back direction refers to the length direction of the motorcycle frame 11, the left-right direction refers to the width direction of the motorcycle frame 11, and the up-down direction refers to the height direction of the motorcycle frame 11. In this embodiment, the directions of front, back, left, right, up, and down are based on the motorcycle 100 traveling on a level road surface, not on a sloping road surface.

[0026] The frame 11 serves as the basic framework of the motorcycle 100, supporting the body panel 12, running system 13, suspension system 14, seat 15, electrical system 16, transmission system, and engine 200. The body panel 12 is at least partially located on and connected to the frame 11, protecting the internal components of the motorcycle 100. The running system 13 is at least partially located below the frame 11, and the suspension system 14 connects the running system 13 to the frame 11. The engine 200 is supported by the frame 11. The electrical system 16 is supported by the frame 11 and is at least partially mounted on the body panel 12 or the frame 11. The electrical system 16 is used to display the motorcycle 100's driving data and control the motorcycle 100's operation. The seat 15 is supported by the frame 11 and is used to support the driver and / or passenger. The transmission system is used to transmit power from the engine 200. The transmission system includes a gear shift mechanism, which is supported by the frame 11 and connects the engine 200 to the running system 13.

[0027] like Figure 3 As shown, the engine 200 includes a housing 21, a crankshaft 22, an intake mechanism 23, an ignition mechanism (not shown), a timing mechanism 25, and a piston mechanism 26. The housing 21 serves as the basic frame of the engine, supporting the crankshaft 22, intake mechanism 23, ignition mechanism, timing mechanism 25, and piston mechanism 26. Specifically, the housing 21 includes a cylinder head cover 211, a cylinder head 212, a cylinder block 213, a crankcase 214, and an oil pan 215, which are connected sequentially. The cylinder head 212 and cylinder block 213 are connected to form a combustion chamber. The intake mechanism 23 is connected to the cylinder head 212 and supplies air to the combustion chamber to mix air and fuel to form an air-fuel mixture. The ignition mechanism is at least partially located within the combustion chamber and is used to ignite the air-fuel mixture. A piston mechanism 26 is at least partially located within the cylinder block 213. The piston mechanism 26 converts the thermal energy generated by the combustion of the air-fuel mixture into mechanical energy. Specifically, the piston mechanism 26 includes a piston that converts thermal energy into reciprocating mechanical energy. A crankshaft 22 is at least partially located within a crankcase 214 and is rotatably connected to the crankcase 214. The crankshaft 22 converts the reciprocating motion of the piston into rotational motion and is drive-connected to a transmission mechanism. A timing mechanism 25 is at least partially located within the cylinder head 212 and is drive-connected to the crankshaft 22. The timing mechanism 25 controls the intake and exhaust of the engine.

[0028] like Figure 4 and Figure 5As shown, in one embodiment, the engine also includes a magneto 42 for powering the battery in the motorcycle 100. Specifically, the magneto 42 includes a rotor 421 and a stator 422. The rotor 421 includes a rotor bushing 4211, a rotor body 4212, and magnets 4213. The rotor bushing 4211 is driveably connected to the crankshaft 22, causing the crankshaft 22 to drive the rotor bushing 4211 to rotate. The rotor body 4212 is connected to the rotor bushing 4211, causing the rotor body 4212 and the rotor bushing 4211 to rotate synchronously. The magnets 4213 are mounted within the rotor body 4212 and are used to generate a magnetic field. The stator 422 is supported by the crankcase 214 and is at least partially disposed around the rotor bushing 4211. More specifically, magnet 4213 is arranged around stator 422, and coil winding 4221 is mounted on stator 422. Magnet 4213 rotates around coil winding 4221 so that coil winding 4221 generates current, thereby enabling magneto 42 to power battery.

[0029] In this embodiment, the rotor bushing 4211 is provided with an oil spray cooling hole 4211a that communicates with the inner wall of the rotor bushing 4211. The oil spray cooling hole 4211a can deliver cooling oil to the coil winding 4221. With this configuration, by spraying oil onto the coil winding 4221, the coil winding 4221 is oil-cooled, which helps to reduce the temperature of the coil winding 4221 and thus avoids damage to the coil winding 4221 due to excessive temperature, thereby improving the service life of the coil winding 4221.

[0030] Specifically, the length of the coil winding 4221 along the radial direction of the rotor bushing 4211 is defined as the first distance D1, and the intersection of the centerline of the oil injection cooling hole 4211a and the surface of the coil winding 4221 near the oil injection cooling hole 4211a is defined as the cooling point. The minimum distance between the cooling point and the side of the coil winding 4221 near the centerline of the rotor bushing 4211 along the radial direction of the rotor bushing 4211 is defined as the second distance D2, and the ratio of the second distance D2 to the first distance D1 ranges from 0.26 to 0.4. More specifically, the ratio of the second distance D2 to the first distance D1 ranges from 0.3 to 0.37. More specifically, the ratio of the second distance D2 to the first distance D1 is 0.33. This setting avoids the situation where the ratio is too small, resulting in an excessively large distance between the end of the coil winding 4221 away from the center line of the rotor bushing 4211 and the cooling oil sprayed from the oil spraying cooling hole 4211a. This prevents the cooling oil from having insufficient cooling effect on the end of the coil winding 4221 away from the center line of the rotor bushing 4211, thereby improving the overall cooling effect of the cooling oil on the coil winding 4221.

[0031] Secondly, it can also avoid the above ratio being too large, which would result in an excessive distance between the end of the coil winding 4221 near the center line of the rotor bushing 4211 and the cooling oil sprayed from the oil spraying cooling hole 4211a. This avoids insufficient cooling effect of the cooling oil on the end of the coil winding 4221 near the center line of the rotor bushing 4211, and thus helps to improve the overall cooling effect of the cooling oil on the coil winding 4221.

[0032] Furthermore, by setting the ratio of the second distance D2 to the first distance D1 within the aforementioned range, the cooling oil sprayed from the oil injection cooling hole 4211a can be sprayed onto the center position of the coil winding 4221 along the radial direction of the rotor bushing 4211 after being subjected to the centrifugal force of the rotor bushing 4211's rotation. This facilitates the uniform heat dissipation of the coil winding 4221 on both sides of the radial direction of the rotor bushing 4211 by the cooling oil, thereby improving the cooling effect of the cooling oil on the coil winding 4221.

[0033] It should be noted that the cooling oil sprayed from the oil injection cooling hole 4211a is the oil overflowing from the crankshaft 22.

[0034] As one implementation, a horizontally positioned plane passing through the centerline of the crankshaft 22 is defined as the reference plane 10b. Along the height direction of the frame 11, when the oil injection cooling hole 4211a is at its lowest point, the acute angle δ formed by the centerline of the oil injection cooling hole 4211a and the reference plane 10b ranges from 50° to 75°. Specifically, the acute angle δ formed by the centerline of the oil injection cooling hole 4211a and the reference plane 10b ranges from 55° to 67.5°. More specifically, the acute angle δ formed by the centerline of the oil injection cooling hole 4211a and the reference plane 10b is 63°. This configuration avoids an excessively large acute angle δ formed by the centerline of the oil injection cooling hole 4211a and the reference plane 10b, which would result in an excessive distance between the end of the coil winding 4221 closest to the centerline of the rotor bushing 4211 and the cooling oil sprayed from the oil injection cooling hole 4211a, thus improving the overall cooling effect of the cooling oil on the coil winding 4221.

[0035] Secondly, it can also avoid the acute angle δ formed by the center line of the oil cooling hole and the reference plane 10b being too small, which would result in the end of the coil winding 4221 that is far from the center line of the rotor bushing 4211 being too far from the cooling oil sprayed from the oil spraying cooling hole 4211a. This can further improve the overall cooling effect of the cooling oil on the coil winding 4221.

[0036] Furthermore, by setting the acute angle δ between the center line of the oil injection cooling hole 4211a and the reference plane 10b within the aforementioned range, the oil injection cooling can be sprayed onto the center position of the coil winding 4221 along the radial direction of the rotor bushing 4211 after passing through the centrifugal force of the rotor bushing 4211's rotation, thereby improving the cooling effect of the cooling oil on the coil winding 4221.

[0037] As an optional implementation, two oil injection cooling holes 4211a are provided. The two oil injection cooling holes 4211a are defined as the first hole 4211b and the second hole 4211c. Along the height direction of the frame 11, when the first hole 4211b is at its lowest point, the acute angle between the centerline of the first hole 4211b and the reference plane 10b ranges from 50° to 75°. When the second hole 4211c is at its lowest point, the acute angle between the centerline of the second hole 4211c and the reference plane 10b also ranges from 50° to 75°. This arrangement ensures that the cooling oil injected from both the first hole 4211b and the second hole 4211c can reach the center position of the coil winding 4221 along the radial direction of the rotor bushing 4211, thereby improving the cooling effect of the cooling oil on the coil winding 4221.

[0038] It should be noted that when the power of the magneto 42 is greater than or equal to 680W, the heat generated by the coil winding 4221 is relatively high. Therefore, by setting two oil injection cooling holes 4211a, the heat dissipation efficiency of the coil winding 4221 can be improved, thereby avoiding damage to the coil winding 4221 due to excessive power of the magneto 42, which in turn helps to improve the service life of the magneto 42.

[0039] In one embodiment, a keyway 4211d is provided on the rotor bushing 4211 for mating with the crankshaft 22. The centerline of the keyway 4211d is defined as a preset straight line 10c, which is parallel to the centerline of the rotor bushing 4211. A projection plane 10d perpendicular to the axial direction of the rotor bushing 4211 is defined. The orthographic projection of the centerline of the first hole 4211b onto the projection plane 10d is the first projection point; the orthographic projection of the centerline of the second hole 4211c onto the projection plane 10d is the second projection point; and the orthographic projection of the preset straight line 10c onto the projection plane 10d is the third projection point. A symmetry plane 10e is defined, with the first and second projection points arranged approximately symmetrically about the symmetry plane 10e, and the third projection point located within the symmetry plane 10e.

[0040] Specifically, the angle between the first projection point and the second projection point around the center line of the rotor bushing 4211 ranges from 100° to 140°, and the angle between the first projection point and the third projection point around the center line of the rotor bushing 4211 ranges from 100° to 140°. This arrangement allows the first hole 4211b, the second hole 4211c, and the key hole 4211d to be evenly distributed along the circumference of the rotor bushing 4211. This helps to balance the weight at the key hole 4211d by the first hole 4211b and the second hole 4211c, preventing the rotor bushing 4211 from deflecting due to weight imbalance. This, in turn, improves the rotational stability and dynamic balance of the rotor bushing 4211. In one embodiment, the angle between the first projection point and the second projection point around the axis of the crankshaft 22 is 120°, and the angle between the first projection point and the third projection point around the center line of the crankshaft 22 is also 120°.

[0041] In another embodiment, one oil injection cooling hole 4211a is provided, and the oil injection cooling hole 4211a and the key hole 4211d are arranged symmetrically about the center line of the rotor bushing 4211. This arrangement, by symmetrically arranging the cooling hole 4211a and the key hole 4211d, allows the weight of the rotor bushing 4211 to be balanced, thereby improving the rotational stability of the rotor bushing 4211.

[0042] It should be noted that this application does not limit the number of oil injection cooling holes 4211a, as long as the heat dissipation requirements of the coil winding 4221 are met. Furthermore, the oil injection cooling holes 4211a and the key hole 4211d are evenly distributed along the circumference of the rotor bushing 4211, so that the oil injection cooling holes 4211a can balance the weight at the key hole 4211d.

[0043] In one embodiment, the rotor body 4212 includes a first fixing portion 4212a, which is substantially annular. The rotor bushing 4211 includes a bushing body 4211e and a second fixing portion 4211f, which is disposed around the bushing body 4211e. Specifically, the first fixing portion 4212a is at least partially sleeved on the bushing body 4211e and fixedly connected to the second fixing portion 4211f. This arrangement allows the rotor bushing 4211 to synchronously drive the rotor body 4212 to rotate.

[0044] As an optional implementation, the magneto 42 also includes a fastener 423, which is used to fix the first fixing part 4212a and the second fixing part 4211f. Specifically, the fastener 423 includes a through part 4231 and an abutting part 4232. The through part 4231 passes through the first fixing part 4212a and is press-fitted with the second fixing part 4211f. The abutting part 4232 abuts against the side of the first fixing part 4212a away from the second fixing part 4211f. Since a one-way clutch or other components are installed on the side of the second fixing part 4211f away from the first fixing part 4212a, the above arrangement can prevent interference between the abutting part 4232 and the one-way clutch or other components, thereby improving the space utilization rate of the side of the second fixing part 4211f away from the first fixing part 4212a.

[0045] In one embodiment, the rotor body 4212 includes a mounting portion 4212b, which is integrally formed with the first fixing portion 4212a. The mounting portion 4212b is located on the side of the first fixing portion 4212a away from the second fixing portion 4211f. The mounting portion 4212b is at least partially disposed around the stator 422, and the magnet 4213 is mounted on the side of the mounting portion 4212b closest to the stator 422. This arrangement allows the magnet 4213 to form a magnetic field around the stator 422, which facilitates the generation of induced current for power generation.

[0046] In one embodiment, the crankcase 214 includes a housing 2141 and a side cover 2142, with the side cover 2142 mounted on one side of the housing 2141. Specifically, the magneto 42 is at least partially located within the side cover 2142, and the stator 422 is fixedly connected to the side cover 2142. This arrangement improves the protection of the magneto 42 through the side cover 2142, thereby helping to extend the service life of the magneto 42.

[0047] In one embodiment, the oil injection cooling hole 4211a includes a first cooling hole 4211g and a second cooling hole 4211h distributed along its axial direction. The first cooling hole 4211g is closer to the inner wall of the rotor bushing 4211 than the second cooling hole 4211h, and the inner diameter of the first cooling hole 4211g is larger than the inner diameter of the second cooling hole 4211h. This arrangement allows the larger inner diameter of the first cooling hole 4211g to increase the amount of cooling oil converging at the oil injection cooling hole 4211a, and the smaller inner diameter of the second cooling hole 4211h to increase the flow rate of the sprayed cooling oil. This facilitates the spraying of cooling oil onto more coil windings 4221, thereby improving the cooling effect on the coil windings 4221.

[0048] In one implementation, a gap D3 exists between the centerline of the oil injection cooling hole 4211a and the surface of the rotor bushing 4211 near the crankshaft 22, and the gap D3 is larger than the radius of the oil injection cooling hole 4211a. This arrangement prevents interference between the rotor bushing 4211a and the machining tools (e.g., punches) used for machining the oil injection cooling hole 4211a, thus improving the ease of machining the oil injection cooling hole 4211a.

[0049] As one implementation, the landing point of the cooling oil output from the oil injection cooling hole 4211a on the coil winding 4221 is defined as the oil injection point; along the radial direction of the rotor bushing 4211, the minimum distance between the oil injection point and the side of the coil winding 4221 closest to the center line of the rotor bushing 4211 is defined as the third distance D20, and the ratio of the third distance D20 to the first distance D1 ranges from 0.1 to 1. Specifically, the ratio of the third distance D20 to the first distance D1 ranges from 0.3 to 0.7. More specifically, the ratio of the third distance D20 to the first distance D1 is 0.5. This setting can avoid the above ratio being too large or too small, which would cause the landing point of the cooling oil on the coil winding 4221 to deviate from the center of the coil winding 4221, thereby avoiding insufficient cooling effect of the cooling oil on the coil winding 4221 and thus improving the cooling effect on the coil winding 4221.

[0050] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. An engine, comprising: A housing, the housing including a crankcase and a cylinder block connected to the crankcase; A crankshaft located within the crankcase and rotatably connected to the crankcase; A piston, at least partially located within the cylinder body and connected to the crankshaft via a drive mechanism, wherein the reciprocating motion of the piston can drive the crankshaft to rotate about its own centerline; A magneto motor, comprising a rotor and a stator, wherein the rotor comprises a rotor bushing connected to the crankshaft, a rotor body connected to the rotor bushing, and a magnet installed within the rotor body; the stator is supported by the crankcase and at least partially arranged around the rotor bushing, the magnet is arranged around the stator, and a coil winding is installed on the stator; Its features are, The rotor bushing has an oil spray cooling hole that communicates with the inner wall of the rotor bushing. The oil spray cooling hole can deliver cooling oil to the coil winding. The length of the coil winding along the radial direction of the rotor bushing is a first distance. The intersection of the center line of the oil spray cooling hole and the surface of the coil winding near the oil spray cooling hole is defined as the cooling point. The minimum distance between the cooling point and the side of the coil winding near the center line of the rotor bushing along the radial direction of the rotor bushing is a second distance. The ratio of the second distance to the first distance is in the range of 0.26 to 0.

4.

2. The engine according to claim 1, characterized in that, Define a horizontal plane passing through the centerline of the crankshaft as a reference plane. When the oil injection cooling hole is at its lowest point, the acute angle between the centerline of the oil injection cooling hole and the reference plane is in the range of 50° to 75°.

3. The engine according to claim 2, characterized in that, The oil injection cooling hole is provided in two parts, which are defined as the first hole and the second hole. When the first hole is located at the lowest point, the acute angle between the center line of the first hole and the reference plane is in the range of 50° to 75°. When the second hole is located at the lowest point, the acute angle between the center line of the second hole and the reference plane is in the range of 50° to 75°.

4. The engine according to claim 3, characterized in that, The rotor bushing has a keyway hole that mates with the crankshaft. The centerline of the keyway hole is defined as a preset straight line, which is parallel to the centerline of the rotor bushing. A projection plane is defined perpendicular to the centerline of the rotor bushing. The orthographic projection of the centerline of the first hole onto the projection plane is the first projection point, the orthographic projection of the centerline of the second hole onto the projection plane is the second projection point, and the orthographic projection of the preset straight line onto the projection plane is the third projection point. A symmetry plane is defined, with the first and second projection points being substantially symmetrical about the symmetry plane, and the third projection point located within the symmetry plane.

5. The engine according to claim 4, characterized in that, The angle between the first projection point and the second projection point around the center line of the rotor bushing ranges from 100° to 140°, and the angle between the first projection point and the third projection point around the center line of the rotor bushing ranges from 100° to 140°.

6. The engine according to claim 1 or 2, characterized in that, The rotor bushing has a keyway that mates with the crankshaft, and there is one oil injection cooling hole. The oil injection cooling hole and the keyway are arranged symmetrically about the center line of the rotor bushing.

7. The engine according to claim 1, characterized in that, The oil injection cooling hole includes a first cooling hole and a second cooling hole distributed along its axial direction. The first cooling hole is closer to the inner wall of the rotor bushing than the second cooling hole, and the inner diameter of the first cooling hole is larger than the inner diameter of the second cooling hole.

8. The engine according to claim 1, characterized in that, There is a gap between the centerline of the oil injection cooling hole and the surface of the rotor bushing near the crankshaft, and the gap is larger than the radius of the oil injection cooling hole.

9. The engine according to claim 1, characterized in that, The location where the cooling oil output from the oil injection cooling hole lands on the coil winding is defined as the oil injection point; along the radial direction of the rotor bushing, the minimum distance between the oil injection point and the side of the coil winding closest to the center line of the rotor bushing is defined as the third distance, and the ratio of the third distance to the first distance ranges from 0.1 to 1.

10. A motorcycle, comprising: Frame; A body panel that at least partially covers the vehicle frame; A walking system, at least partially located below the vehicle frame; Its features are, The motorcycle also includes an engine as described in any one of claims 1 to 9, the engine being supported by the frame and connected in drive to the running system.

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