Power assembly and motorcycle adopting the same
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG CFMOTO POWER CO LTD
- Filing Date
- 2025-05-19
- Publication Date
- 2026-06-02
Smart Images
Figure CN224315070U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of vehicle technology, and in particular to a powertrain and a motorcycle using the powertrain. 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, running gear, suspension system, seat, and powertrain. The powertrain includes an engine and a water pump, with the water pump used to cool the engine. The engine usually includes a housing, crankshaft, and balance shaft, while the water pump includes a pump shaft and pump body. By connecting the balance shaft and pump shaft, the balance shaft can drive the pump shaft to rotate, thus moving the fluid within the pump body. The balance shaft and pump shaft are usually connected by a stamped interference fit. However, because the balance shaft is typically hollow, its structural strength is relatively low. Using a stamped connection can cause deformation of the balance shaft after stamping, reducing its reliability and consequently its operational stability. Utility Model Content
[0004] In order to overcome the shortcomings of the prior art, the purpose of this application is to provide a powertrain and a motorcycle using the powertrain, wherein the balance shaft has high operational reliability.
[0005] To achieve the above objectives, this application adopts the following technical solution:
[0006] A powertrain includes an engine and a water pump. The water pump delivers coolant to the engine. The water pump includes a pump body and a water pump shaft. The water pump shaft is at least partially located within the pump body and rotatably connected to the pump body. The engine includes a housing, a crankshaft, and a balance shaft. The crankshaft is located within the housing and rotatably connected to the housing. The balance shaft is at least partially located within the housing and rotatably connected to the housing, and is also drively connected to the crankshaft. The water pump shaft includes a connecting end located outside the pump body, with a plug-in portion provided on the connecting end. One end of the balance shaft has a shaft hole, and the inner wall of the shaft hole has a first threaded portion. The balance shaft also includes an insert, the outer periphery of which has a second threaded portion. The insert is installed in the shaft hole, and the first threaded portion and the second threaded portion are threadedly connected. The plug-in portion is plugged into the insert, and the balance shaft can drive the water pump shaft to rotate through the insert.
[0007] Furthermore, the insert has a socket for engaging with the plug part. The socket is a square slot, and the plug part is a flat block structure. The inner contour of the socket is basically matched with the outer contour of the plug part.
[0008] Furthermore, the insert has a insertion groove for insertion into the insertion part, and several outer walls on the insertion part that contact the insertion groove and surround the outer periphery of the insertion part are defined as contact surfaces. At least one contact surface forms an acute angle with the axis of the water pump shaft. The distance between the contact surface and the axis of the water pump shaft gradually increases towards the direction closer to the pump body.
[0009] Furthermore, a sealing groove for installing a sealing ring is provided at one end of the shaft hole near the pump body. The sealing groove forms a lubrication space for filling with lubricating oil and a force application space for disassembling and assembling the insert.
[0010] Furthermore, the balance shaft is hollow and has a hollow hole, the shaft hole is connected to the hollow hole and is located at the end of the hollow hole; an abutment platform is provided inside the hollow hole, inside the shaft hole or at the junction of the hollow hole and the shaft hole, and the side wall of the insert away from the pump body is pressed against the side wall of the abutment platform facing the pump body to separate the hollow hole and the shaft hole.
[0011] Furthermore, an auxiliary balancing shaft positioning pin hole is provided at the opening of the shaft hole. The inner diameter of the pin hole gradually decreases from near the pump body to far away from the pump body until it is basically consistent with the inner diameter of the shaft hole.
[0012] Furthermore, an annular receiving groove is provided on the hole wall at the end of the shaft hole near the abutment platform, and the receiving groove is arranged around the center line of the shaft hole; the outer peripheral wall of the insert at the end near the abutment platform is sealed to the opening of the receiving groove.
[0013] Furthermore, the insert is detachably connected to the shaft hole; the inner wall of the shaft hole near the abutment platform is provided with a first threaded portion, and the outer periphery of the insert is provided with a second threaded portion. The first threaded portion and the second threaded portion are threadedly connected to form a threaded assembly; the shaft hole wall is provided with a receiving groove, and the receiving groove and the threaded assembly are arranged adjacent to each other along the center line direction of the shaft hole.
[0014] Furthermore, the diameter of the hollow hole is smaller than the diameter of the shaft hole, the distance between the abutment platform and the center line of the hollow hole is equal to the diameter of the hollow hole, and the abutment platform is formed at the junction of the hollow hole and the shaft hole; the outer diameter of the balance shaft at the hollow hole is smaller than the outer diameter of the balance shaft at the shaft hole.
[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 a powertrain 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 powertrain is supported by the frame and drivenly connected to the running gear.
[0017] In this application, the connection between the pump shaft and the balance shaft is achieved by inserting the connector and the insert, thereby avoiding deformation of the end of the balance shaft connected to the pump shaft due to the interference fit of the stamping, which in turn helps to improve the working reliability of the balance shaft. 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 the powertrain of the motorcycle provided in an embodiment of this application.
[0020] Figure 3 An exploded view of the powertrain of a motorcycle provided in an embodiment of this application.
[0021] Figure 4 This is a schematic diagram of the internal structure of a motorcycle engine provided in an embodiment of this application.
[0022] Figure 5 This is a schematic diagram of the combination of the balance shaft and water pump of the engine provided in an embodiment of this application.
[0023] Figure 6 This is a schematic diagram of the combination of the engine's balance shaft and the water pump from another perspective, provided as an embodiment of this application.
[0024] Figure 7 This is a schematic cross-sectional view of the combination of the engine's balance shaft and water pump provided in an embodiment of this application.
[0025] Figure 8 A schematic diagram of the combination of the balance shaft, water pump and crankshaft of the engine provided in the embodiments of this application. Detailed Implementation
[0026] 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.
[0027] 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 a powertrain 200.
[0028] 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.
[0029] 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 powertrain 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 powertrain 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 to the powertrain 200. The transmission system includes a gear shift mechanism, which is supported by the frame 11 and drives the powertrain 200 to the running system 13.
[0030] like Figure 3As shown, the powertrain 200 includes an engine and a water pump 28. The engine is supported by the frame 11 and is connected to the transmission mechanism. Specifically, the engine 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, the intake mechanism 23, the ignition mechanism, the timing mechanism 25, and the 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. An intake mechanism 23 is connected to the cylinder head 212 and supplies air to the combustion chamber to mix with fuel to form an air-fuel mixture. An ignition mechanism is at least partially located within the combustion chamber and ignites the air-fuel mixture. A piston mechanism 26 is at least partially located within the cylinder block 213 and converts the heat energy generated by the combustion of the air-fuel mixture into mechanical energy. Specifically, the piston mechanism 26 includes a piston that converts the heat energy into reciprocating mechanical energy. A crankshaft 22 is at least partially located within and rotatably connected to a housing 21. The crankshaft 22 converts the reciprocating motion of the piston into rotational motion and is drively connected to a transmission mechanism. A timing mechanism 25 is at least partially located within the cylinder head 212 and drively connected to the crankshaft 22. The timing mechanism 25 controls the engine's intake and exhaust.
[0031] like Figure 4 , Figure 5 and Figure 6 As shown, in one embodiment, the water pump 28 is used to deliver coolant to the engine. The engine includes a balance shaft 29. The balance shaft 29 is used to reduce vibrations generated during engine operation, thereby improving the operational stability of the power engine.
[0032] Specifically, the balance shaft 29 is at least partially located inside the housing 21 and rotatably connected to the housing 21. The balance shaft 29 is also connected to the crankshaft 22 for transmission. The vibration of the crankshaft 22 can be reduced by the balance shaft 29, so as to improve the operating stability of the crankshaft 22.
[0033] More specifically, the water pump 28 includes a pump body 281 and a pump shaft 282. The pump body 281 is filled with coolant. The pump shaft 282 is at least partially located within and rotatably connected to the pump body 281. The pump shaft 282 is also connected to a balance shaft 29, enabling the pump shaft 282 to transmit power from the balance shaft 29 to the pump body 281, thereby delivering the coolant within the pump body 281 to components within the powertrain 200 that require cooling.
[0034] In this embodiment, the pump shaft 282 includes a connecting end 2821. The connecting end 2821 is located outside the pump body 281, and a plug-in portion 2821a is provided on the connecting end 2821. The plug-in portion 2821a is used to connect the pump shaft 282 to the balance shaft 29. In some embodiments, the connecting end 2821 and the plug-in portion 2821a are integrally formed to improve the connection stability between the connecting end 2821 and the plug-in portion 2821a, thereby improving the connection stability between the pump shaft 282 and the plug-in portion 2821a, and further improving the connection stability between the pump shaft 282 and the balance shaft 29 through the plug-in portion 2821a.
[0035] It should be noted that the plug-in part 2821a can also be fixed to the connecting end 2821 by welding or other means. Therefore, this application does not limit the connection form between the plug-in part 2821a and the connecting end 2821, as long as the plug-in part 2821a and the connecting end 2821 can be fixedly connected.
[0036] Specifically, one end of the balance shaft 29 has a shaft hole 291. The balance shaft 29 also includes an insert 292, which is installed in the shaft hole 291. The insert 292 is detachably connected to the shaft hole 291 and is used to connect the pump shaft 282 and the balance shaft 29. The insert 292 is also detachably connected to the pump shaft 282. This design improves the ease of assembly and disassembly between the pump shaft 282 and the balance shaft 29.
[0037] More specifically, the plug-in portion 2821a engages with the insert 292, allowing the balance shaft 29 to drive the water pump shaft 282 to rotate via the insert 292. This configuration enables the connection between the water pump shaft 282 and the balance shaft 29 through the plug-in portion 2821a and the insert 292. This avoids deformation at the end of the balance shaft 29 connected to the water pump shaft 282 due to interference fit during stamping, thereby preventing the balance shaft 29 from failing to reduce crankshaft 22 vibration due to deformation and improving the operational reliability of the balance shaft 29.
[0038] In addition, the above settings can also prevent the deformation of the balance shaft 29 from causing inaccurate clamping and positioning of the balance shaft 29 on the lathe, thereby improving the ease of machining the balance shaft 29 and improving the machining accuracy of the balance shaft 29.
[0039] It should be noted that, in order to control its own weight, the balance shaft 29 adopts a hollow structure, which reduces its structural strength. Furthermore, the balance shaft 29 and the water pump shaft 282 are typically connected by a stamping interference fit. Due to the reduced structural strength of the balance shaft 29, its outer contour is prone to deformation during the stamping process. A deformed balance shaft 29 cannot reduce the vibration of the crankshaft 22, thus causing the balance shaft 29 to fail. Therefore, in this application, an insert 292 is installed inside the balance shaft 29, and the insert 292 is inserted into the insertion part 2821a to connect the balance shaft 29 and the water pump shaft 282. This avoids the failure of the balance shaft 29 caused by the stamping connection between the balance shaft 29 and the water pump shaft 282, thereby improving the operational reliability of the balance shaft 29.
[0040] In one embodiment, the inner wall of the shaft hole 291 is provided with a first threaded portion, and the outer periphery of the insert 292 is provided with a second threaded portion, with the first threaded portion and the second threaded portion being threadedly connected. This arrangement, using a threaded connection to achieve the connection between the insert 292 and the balance shaft 29, improves the ease of assembly and disassembly between the insert 292 and the balance shaft 29. Furthermore, the threaded connection avoids the use of an interference fit between the insert 292 and the balance shaft 29, thus preventing deformation of the balance shaft 29 due to stamping. Therefore, by inserting the insert 292 into the insertion part 2821a, and through the threaded connection between the insert 292 and the balance shaft 29, the pump shaft 282 and the balance shaft 29 do not require a stamping interference fit, preventing deformation of the balance shaft 29 during stamping and thus improving the operational reliability of the balance shaft 29.
[0041] It should be noted that when the balance shaft 29 drives the water pump shaft 282 to rotate, the torque force between the balance shaft 29 and the water pump shaft 282 is less than the tightening force of the threaded connection between the insert 292 and the shaft hole 291, so as to avoid loosening between the insert 292 and the balance shaft 29, thereby improving the connection stability between the insert 292 and the balance shaft 29. Furthermore, the insert 292 and the shaft hole 291 can also be connected by a detachable connection method such as a snap-fit, and this application does not impose any restrictions on this.
[0042] In one implementation, the direction of rotation when the insert 292 is screwed into the shaft hole 291 is defined as the forward rotation, and the direction of rotation when the insert 292 is screwed out of the shaft hole 291 is defined as the reverse rotation. When the water pump 28 pumps coolant, the direction of rotation of the water pump shaft 282 is consistent with the forward rotation, so that the water pump shaft 282 can drive the insert 292 to rotate in the forward rotation direction. This avoids the water pump shaft 282 driving the insert 292 to rotate in the reverse rotation direction, which would cause the insert 292 to separate from the shaft hole 291. This helps to improve the connection stability between the insert 292 and the shaft hole 291, and thus improves the connection stability between the water pump shaft 282 and the balance shaft 29.
[0043] In one embodiment, the insert 292 has a insertion slot 2921 for insertion into the insertion part 2821a. With this configuration, the insertion slot 2921 and the insertion part 2821a are connected to the insert 292 and the pump shaft 282, and the connection between the insert 292 and the balance shaft 29 is achieved, thus enabling the balance shaft 29 to drive the pump shaft 282 to rotate.
[0044] As an optional implementation, the insertion slot 2921 is a square slot, and the insertion part 2821a is a flat block structure. The inner contour of the insertion slot 2921 basically matches the outer contour of the insertion part 2821a. With this configuration, the square slot, in conjunction with the insertion part 2821a, enables the insert 292 to drive the water pump shaft 282 to rotate. Furthermore, the square slot and flat block structure are simple, which helps to reduce the machining difficulty of the insertion slot 2921 and the insertion part 2821a, thereby improving the machining efficiency of the insertion slot 2921 and the insertion part 2821a.
[0045] As another implementation, several surfaces that contact the insertion part 2821a with the insertion groove 2921 and surround the outer periphery of the insertion part 2821a are defined as contact surfaces. Specifically, at least one contact surface forms an acute angle α with the axis of the pump shaft 282. More specifically, the distance between the contact surface and the axis of the pump shaft 282 gradually increases towards the pump body 281. That is, the distance between the end of the contact surface away from the pump body 281 and the axis of the pump shaft 282 is smaller than the distance between the end of the contact surface near the pump body 281 and the axis of the pump shaft 282. It can also be understood that the thickness of the end of the insertion part 2821a near the pump body 281 is increased. This arrangement can increase the connection area between the insertion part 2821a and the pump shaft 282, thereby improving the connection strength between the insertion part 2821a and the pump shaft 282, and further improving the transmission stability between the balance shaft 29 and the pump shaft 282.
[0046] Furthermore, the above-mentioned configuration can increase the structural thickness of the plug portion 2821a to improve its structural strength. This will prevent the plug portion 2821a from breaking due to insufficient strength during the transmission between the balance shaft 29 and the water pump shaft 282, thereby further improving the transmission stability between the balance shaft 29 and the water pump shaft 282.
[0047] It should be noted that the insertion groove 2921 can be any shape of groove other than a circular groove. For example, the insertion groove 2921 can be a triangular groove. The shape of the insertion part 2821a can be adapted to the insertion groove 2921. This application does not impose any restrictions on this.
[0048] like Figure 7 As shown, in one embodiment, a pin hole 2911 is provided at the opening of the shaft hole 291 near the pump body 281. During the machining of the balance shaft 29, the pin hole 2911 is used to assist in positioning the balance shaft 29. Specifically, the inner diameter of the pin hole 2911 gradually decreases from near the pump body 281 to away from the pump body 281 until it is essentially the same as the inner diameter of the shaft hole 291. This arrangement allows the inner diameter at the opening of the shaft hole 291 to be enlarged through the pin hole 2911, thereby facilitating the connection between the insert 292 and the shaft hole 291 and improving the ease of assembly of the insert 292.
[0049] In some embodiments, a first ejector hole 2912 is provided at the end of the shaft hole 291 away from the ejector hole 2911. This arrangement facilitates the lathe's clamping of the balance shaft 29 through the ejector hole 2911 and the first ejector hole 2912, thereby improving the ease of machining the balance shaft 29.
[0050] In one embodiment, the insertion portion 2821a is provided with a second ejector hole 2821b, which is used to assist in the positioning of the water pump shaft 282. In some embodiments, a third ejector hole 2821c is provided at the end of the water pump shaft 282 away from the second ejector hole 2821b. This arrangement facilitates the lathe's clamping of the water pump shaft 282 through the second ejector hole 2821b and the third ejector hole 2821c, thereby improving the ease of machining the water pump shaft 282.
[0051] In one embodiment, the water pump 28 includes an impeller 283 for driving the flow of cooling liquid within the pump body 281. Specifically, the impeller 283 is located within the pump body 281 and is fixedly connected to one end of the water pump shaft 282, with a connector 2821a located at the end of the water pump shaft 282 away from the impeller 283. This arrangement allows the balance shaft 29 to drive the impeller 283 to rotate via the water pump shaft 282, thereby causing the cooling liquid within the pump body 281 to flow and thus cooling the power assembly 200.
[0052] As an optional implementation, the water pump 28 also includes a bearing 284, an oil seal 285, and a water seal 286. The bearing 284 supports the rotation of the pump shaft 282, the oil seal 285 prevents lubricating oil from entering the pump body 281, and the water seal 286 prevents coolant leakage. Specifically, the pump shaft 282 and the pump body 281 are rotatably connected via the bearing 284. Along the axial direction of the pump shaft 282, the oil seal 285 is located between the bearing 284 and the impeller 283. This arrangement prevents lubricating oil from the bearing 284 from entering the pump body 281, thus avoiding contamination of the coolant inside the pump body 281. Along the axial direction of the pump shaft 282, the water seal 286 is located between the oil seal 285 and the impeller 283. This arrangement prevents coolant leakage from the pump body 281, thereby improving the sealing performance of the pump body 281.
[0053] It should be noted that the pump shaft 282 in this embodiment is a solid shaft, and the bearing 284 includes an inner ring and an outer ring. The inner ring is interference-fitted with the pump shaft 282, and the outer ring is interference-fitted with the pump body 281. The solid pump shaft 282 has higher structural strength, which can prevent deformation of the pump shaft 282 when it is interference-fitted with the inner ring of the bearing 284. This avoids reducing the balance of the pump shaft 282 due to deformation, thereby improving the working reliability of the pump shaft 282 and the transmission stability between the pump shaft 282 and the balance shaft 29.
[0054] It should be noted that, since the pump shaft 282 in this embodiment is a solid shaft, its structural strength is greater than that of the inner ring. Therefore, when the pump shaft 282 and the inner ring are connected by an interference fit, the inner ring, which has lower structural strength, will deform. However, this deformation will not affect the transmission between the pump shaft 282 and the balance shaft 29. Similarly, the deformation of the outer ring or pump body 281 caused by the interference fit between the outer ring and the pump body 281 will not affect the transmission between the pump shaft 282 and the balance shaft 29. Furthermore, the interference fit method is simple to operate. In summary, under the premise of improving the transmission stability between the pump shaft 282 and the balance shaft 29, using an interference fit method to connect the outer ring to the pump body 281 and the inner ring to the pump shaft 282 can simplify the assembly process of the bearing 284.
[0055] like Figure 8As shown, in one embodiment, a balance gear 293 is provided at one end of the balance shaft 29, and the balance gear 293 is connected to the crankshaft 22 in a transmission manner. The insert 292 is located at the end of the balance shaft 29 away from the balance gear 293. In some embodiments, the crankshaft 22 is provided with a transmission gear 221, which meshes with the balance gear 293 for transmission. With this configuration, the crankshaft 22 and the balance shaft 29 can be connected in a transmission manner through the balance gear 293 and the transmission gear 221, so that the balance shaft 29 can reduce the vibration generated by the crankshaft 22 during operation, thereby improving the operating stability of the crankshaft 22.
[0056] In one embodiment, a sealing groove 291b is provided at the end of the shaft hole 291 near the pump body 281. The sealing groove 291b is used to install a sealing ring. The sealing groove 291b is located at the end of the shaft hole 291 near the water pump 28, and the sealing groove 291b forms a lubrication space for filling with lubricating oil and a force application space for disassembling and assembling the insert 292. This arrangement facilitates the addition of lubricating oil into the shaft hole 291 through the sealing groove 291b, thereby improving the service life of the balance shaft. Furthermore, the sealing groove 291b can expand the force application space at the opening of the shaft hole 291, which facilitates the disassembly and assembly of the insert 292 and the shaft hole 291.
[0057] In one embodiment, the balance shaft 29 is hollow and has a hollow hole 294. A shaft hole 291 communicates with the hollow hole 294 and is located at the end of the hollow hole 294. Specifically, an abutment platform 295 is provided inside the hollow hole 294, inside the shaft hole 291, or at the junction of the hollow hole 294 and the shaft hole 291. The sidewall of the insert 292 away from the pump body 281 abuts against the sidewall of the abutment platform 295 facing the pump body 281 to separate the hollow hole 294 and the shaft hole 291. In some embodiments, lubricating fluid flows through the hollow hole 294. The abutment platform 295 separates the hollow hole 294 and the shaft hole 291 to prevent the lubricating fluid in the hollow hole 294 from entering the shaft hole 291 and causing lubricating fluid leakage.
[0058] In one embodiment, an annular receiving groove 291a is provided on the wall of the shaft hole 291 near the abutment platform 295, and the receiving groove 291a is arranged around the center line of the shaft hole 291; the outer peripheral wall of the insert 292 near the abutment platform 295 seals the opening of the receiving groove 291a. With this arrangement, when leakage occurs between the hollow hole 294 and the shaft hole 291, the receiving groove 291a can receive the leaked lubricating fluid, thereby preventing the lubricating fluid from leaking from the shaft hole 291 and improving the sealing performance of the balance shaft 29.
[0059] In one embodiment, the inner wall of the shaft hole 291 near the abutment platform 295 is provided with a first threaded portion, and the outer periphery of the insert 292 is provided with a second threaded portion. The first threaded portion and the second threaded portion are threadedly connected to form a threaded coupling. Specifically, the shaft hole 291 has a receiving groove 291a on its hole wall, and the receiving groove 291a is arranged adjacent to the threaded coupling along the centerline direction of the shaft hole 291. With this arrangement, the receiving groove 291a can collect and store the wear powder generated when the insert 292 is threadedly connected to the shaft hole 291, so as to avoid the accumulation of powder on the contact surface between the insert 292 and the shaft hole 291, which would cause wear between the insert 292 and the shaft hole 291.
[0060] In one implementation, the diameter of the hollow hole 294 is smaller than the diameter of the shaft hole 291, and the distance between the centerline of the abutment platform 295 and the centerline of the hollow hole 294 is equal to the diameter of the hollow hole 294. The abutment platform 295 is formed at the junction of the hollow hole 294 and the shaft hole 291. This arrangement allows the abutment platform 295 to be formed at the junction of the hollow hole 294 and the shaft hole 291, thus eliminating the need for additional manufacturing processes for the abutment platform 295 and simplifying the machining process of the balance shaft 29.
[0061] Specifically, the outer diameter of the balance shaft 29 at the hollow hole 294 is smaller than the outer diameter of the balance shaft 29 at the shaft hole 291. This design ensures that the hole wall of the balance shaft 29 at the shaft hole 291 is not too thin, thus meeting the strength requirements of the balance shaft 29.
[0062] 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. A powertrain comprising an engine and a water pump, the water pump being used to deliver coolant for cooling the engine, the water pump including a pump body and a water pump shaft, the water pump shaft being at least partially located within the pump body and rotatably connected to the pump body, the engine comprising: case; A crankshaft, which is located within the housing and rotatably connected to the housing; A balance shaft, at least partially located within the housing and rotatably connected to the housing, and also connected to the crankshaft drive; Its features are, The pump shaft includes a connecting end located outside the pump body, and the connecting end is provided with a plug-in portion; one end of the balance shaft is provided with a shaft hole, the inner wall of the shaft hole is provided with a first threaded portion, the balance shaft also includes an insert, the outer periphery of the insert is provided with a second threaded portion, the insert is installed in the shaft hole, and the first threaded portion and the second threaded portion are threadedly connected; the plug-in portion is plugged into the insert, and the balance shaft can drive the pump shaft to rotate through the insert.
2. The powertrain according to claim 1, characterized in that, The insert has a socket for insertion into the plug part. The socket is a square slot, and the plug part is a flat block structure. The inner contour of the socket is basically matched with the outer contour of the plug part.
3. The powertrain according to claim 1, characterized in that, The insert has a slot for insertion into the plug-in part. Several outer walls on the plug-in part that are in contact with the slot and surround the plug-in part are defined as contact surfaces. At least one of the contact surfaces forms an acute angle with the axis of the water pump shaft. The distance between the contact surface and the axis of the water pump shaft gradually increases towards the direction closer to the pump body.
4. The powertrain according to claim 1, characterized in that, The shaft hole is provided with a sealing groove for installing a sealing ring at one end near the pump body. The sealing groove forms a lubrication space for filling with lubricating oil and a force application space for assembling and disassembling the insert.
5. The powertrain according to claim 1, characterized in that, The balance shaft is hollow and has a hollow hole. The shaft hole communicates with the hollow hole and is located at the end of the hollow hole. An abutment is provided in the hollow hole, in the shaft hole, or at the junction of the hollow hole and the shaft hole. The insert abuts against the side wall of the pump body away from the pump body, facing the abutment, to separate the hollow hole and the shaft hole.
6. The powertrain according to claim 5, characterized in that, The shaft hole is provided with a pin hole to assist in the positioning of the balance shaft. The inner diameter of the pin hole gradually decreases from near the pump body to away from the pump body until it is basically consistent with the inner diameter of the shaft hole.
7. The powertrain according to claim 6, characterized in that, The shaft hole has an annular receiving groove on the hole wall at the end near the abutment platform, and the receiving groove is arranged around the center line of the shaft hole; the outer peripheral wall of the insert at the end near the abutment platform is sealed to the opening of the receiving groove.
8. The powertrain according to claim 6, characterized in that, The insert is detachably connected to the shaft hole; the inner wall of the shaft hole near the abutment is provided with a first threaded portion, and the outer periphery of the insert is provided with a second threaded portion. The first threaded portion and the second threaded portion are threadedly connected to form a threaded assembly; the shaft hole wall is provided with a receiving groove, and the receiving groove is arranged adjacent to the threaded assembly along the center line direction of the shaft hole.
9. The powertrain according to claim 6, characterized in that, The diameter of the hollow hole is smaller than the diameter of the shaft hole, the distance between the abutment platform and the center line of the hollow hole is equal to the diameter of the hollow hole, and the abutment platform is formed at the junction of the hollow hole and the shaft hole; the outer diameter of the balance shaft at the hollow hole is smaller than the outer diameter of the balance shaft at the shaft hole.
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 further includes a powertrain as described in any one of claims 1 to 9, the powertrain being supported by the frame and connected in drive to the running system.