Automatic transmission and engine interface structure and vehicle driveline system

Abstract

The application relates to the technical field of vehicle transmission systems, and discloses an automatic transmission and engine docking structure and a vehicle transmission system. The docking structure comprises an engine flywheel, a flexible disc and a torque converter, the engine flywheel is fixedly connected with an engine crankshaft, the flexible disc is connected between the engine flywheel and the torque converter, a bushing is arranged in the inner hole of the engine flywheel, and the front end positioning part of the torque converter is inserted into the inner hole of the bushing and matched with the bushing. The bushing is preferably made of polyether ether ketone material, is in interference fit with the inner hole of the flywheel, and is in gap fit with the front end of the torque converter. The application changes direct contact between metals into indirect contact by additionally arranging the high-molecular material bushing, effectively absorbs vibration, fundamentally solves the fretting wear problem of the front end of the torque converter and the positioning surface of the flywheel caused by vibration, and significantly improves the reliability and service life of the transmission system.

Description

Technical Field

[0001] This invention relates to the field of vehicle transmission system technology, and more specifically, to a docking structure for connecting an automatic transmission and an engine, and a vehicle transmission system including the docking structure. Background Technology

[0002] In automotive transmission systems, the connection between the automatic transmission and the engine is one of the core components of power transmission. This structure is primarily used to smoothly and reliably transmit the power output from the engine crankshaft to the torque converter of the automatic transmission, thereby driving the transmission and the entire drivetrain. A typical connection structure usually includes components such as the engine crankshaft, flywheel, flexible disc, and the automatic transmission torque converter and torque converter housing.

[0003] With the development of automotive technology, increasingly higher requirements are being placed on the smoothness, reliability, and NVH (noise, vibration, and harshness) performance of power transmission. Simultaneously, to meet the needs of vehicle lightweighting and space allocation, the docking structure also needs to be designed as compactly as possible. Existing technologies, such as the patent with announcement number CN202628987U, disclose a connection structure for an automatic transmission. This structure effectively shortens the axial connection distance and improves structural compactness by attaching a speed signal disc to the crankshaft, welding the starter gear ring to the outer edge of the hydraulic torque converter, and making the flexible disc surface concave. Another example is the patent with announcement number CN207195595U, which discloses a diesel engine flexible disc assembly that transmits speed signals through an integrally molded annular signal disc and utilizes the flexibility of the flexible disc to compensate for axial displacement and absorb vibration.

[0004] However, long-term practice has revealed a common and easily overlooked problem in the existing automatic transmission-engine docking structure. The torque converter's front end is typically inserted directly into the central bore of the engine flywheel for positioning, forming a rigid "metal-to-metal" fit. Due to the inevitable multi-directional and complex vibrations generated by the engine and automatic transmission during operation, this long-term, continuous micro-motion causes fretting wear on the mating surface between the torque converter's front end and the flywheel's inner bore. Fretting wear leads to damage to the mating surface, a gradual increase in clearance, and consequently, decreased positioning accuracy, abnormal noise, and in severe cases, even affects the smoothness of power transmission, reducing the reliability and service life of the entire transmission system. In existing technologies, neither CN202628987U nor CN207195595U has recognized or proposed a technical solution to this problem of fretting wear on the metal mating surface caused by vibration. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an automatic transmission and engine docking structure and vehicle transmission system that can effectively prevent fretting wear between the front end of the torque converter and the positioning surface of the engine flywheel due to vibration, thereby improving the reliability and durability of the transmission system.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: In a first aspect, an automatic transmission docking structure for an engine includes an engine flywheel, a flexible disk, and a torque converter. The engine flywheel is fixedly connected to the engine crankshaft, and the flexible disk is connected between the engine flywheel and the torque converter. The key improvement is that a bushing is also provided in the inner hole of the engine flywheel, and the front end positioning part of the torque converter is inserted into the inner hole of the bushing and cooperates with the bushing.

[0007] As a preferred embodiment, the bushing is made of polyetheretherketone (PEEK). PEEK is a high-performance thermoplastic engineering plastic with excellent high-temperature resistance, extremely high tensile and impact strength, good wear resistance, and a low coefficient of thermal expansion. These properties enable it to operate stably for extended periods under harsh conditions in the engine compartment, including high temperatures, high loads, and oily environments, effectively absorbing vibrations and fundamentally preventing direct contact and wear between metal parts.

[0008] As a preferred embodiment, the bushing has a hardness of HRR105-120. Within this hardness range, the bushing provides sufficient support strength to maintain positioning accuracy while also maintaining good self-lubricating and anti-friction properties, making it a sacrificial protective component that transfers wear to itself, thereby protecting the more valuable engine flywheel and torque converter.

[0009] As a preferred embodiment, the bushing is interference-fitted with the inner bore of the engine flywheel. This secure fit ensures that the bushing is tightly fixed in the flywheel's inner bore and rotates with the flywheel without any relative rotation or axial movement, guaranteeing the reliability and dynamic balance of the connection.

[0010] As a preferred embodiment, the bushing and the front end positioning part of the torque converter are clearance-fitted. This fit allows the front end of the torque converter a certain amount of radial float and axial expansion and contraction space within the bushing. This effectively compensates for relative displacement caused by manufacturing tolerances, installation errors, and thermal expansion and contraction and vibration during operation, avoiding additional stress caused by "stiffness". At the same time, the bushing isolates the components and prevents direct metal-to-metal contact and wear.

[0011] As a preferred embodiment, the engine flywheel is fixedly connected to the end face of the engine crankshaft via multiple first bolts, and spring washers are provided at the connection points to prevent loosening. This connection method can reliably transmit the enormous torque output by the engine, and the spring washers can effectively prevent the bolts from loosening due to vibration.

[0012] As a preferred embodiment, the flexible disc is fixedly connected to the torque converter by a plurality of second bolts, and a spring washer is provided at the connection to prevent loosening; the flexible disc is fixedly connected to the engine flywheel by a plurality of third bolts, and a spring washer is provided at the connection to prevent loosening, the third bolts passing through the spring washer, the engine flywheel, and the flexible disc in sequence and then being screwed with a fastening nut.

[0013] As a preferred embodiment, the fastening nut is welded to the flexible disk. Pre-welding the nut to the flexible disk greatly simplifies the assembly process. During final assembly, only the third bolt needs to be screwed in from the engine flywheel side, eliminating the need to use tools to fix the nut on the other side of the flexible disk, thus improving assembly efficiency and convenience.

[0014] As a preferred embodiment, the docking structure further includes an engine flywheel housing, a spacer ring, a connecting section, a gear ring, and a torque converter housing. The engine flywheel housing and the spacer ring are fixedly connected by bolts, and the spacer ring, connecting section, and torque converter housing are fixedly connected as a single unit by a bolt assembly. The gear ring is fitted onto the outer circumference of the engine flywheel using an interference fit. These components constitute a complete support and protection system. The gear ring meshes with the starter gear to start the engine; stationary components such as the flywheel housing and spacer ring provide precise mounting references and protection for the internal rotating parts.

[0015] Secondly, the present invention also provides a vehicle transmission system comprising the automatic transmission and engine docking structure described in any of the above embodiments.

[0016] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows: (1) Fundamentally solves the problem of fretting wear: A bushing made of polymer materials such as polyetheretherketone (PEEK) is added to the inner hole of the engine flywheel. This design transforms the traditional direct metal-to-metal contact positioning into an indirect contact positioning of metal (torque converter) - polymer material (bushing) - metal (flywheel). As an intermediate isolation and buffer layer, the PEEK bushing can efficiently absorb and attenuate the complex vibration energy generated by the operation of the engine and transmission, fundamentally eliminating fretting wear between the metal positioning surfaces, thereby permanently protecting the flywheel and the front positioning part of the torque converter and significantly extending their service life.

[0017] (2) Improved positioning reliability and system stability: The bushing and flywheel are interference-fitted, while the bushing and torque converter front end are clearance-fitted. This differentiated fit design ensures the absolute reliability of the bushing as it rotates with the flywheel, while also providing the necessary radial and axial compensation space for the torque converter. This allows the entire mating structure to maintain a precise and stable fit under complex vibration conditions, effectively reducing abnormal noises caused by wear or deformation, and significantly improving the smoothness of power transmission and the overall NVH performance of the vehicle.

[0018] (3) Excellent material performance and adaptability to harsh environments: PEEK material has excellent comprehensive performance. Its characteristics of high temperature resistance (long-term operating temperature can reach 260℃), high strength, high wear resistance, oil resistance, corrosion resistance and low expansion coefficient are perfectly matched to the extreme working environment of high temperature, high load and oil splash in the engine compartment. This ensures that the bushing can work stably and reliably for a long time, and becomes a long-term solution.

[0019] (4) Minimal structural modifications, easy to implement and promote: This technical solution only requires adding a simple bushing part to the existing mature docking structure. The engine flywheel only needs to have its inner hole size slightly adjusted to fit the bushing, while the torque converter does not require any modification. The production process is simple, the assembly is convenient, and the cost increase is negligible, but it can bring a huge improvement in reliability, with extremely high practical value and prospects for large-scale promotion and application. Attached Figure Description

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

[0021] Figure 1 This is a schematic diagram of the automatic transmission and engine docking structure provided by the present invention.

[0022] Explanation of reference numerals: 1-Engine flywheel housing; 2-Engine flywheel; 3-Engine crankshaft; 4-Flexible disc; 5-Spacer ring; 6-Connecting section; 7-Torque converter; 8-Torque converter housing; 9-Bushing; 10-First bolt; 11-Gear ring; 12-Second bolt; 13-Third bolt; 14-Fastening nut; 15-Bolt assembly. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0025] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0026] Combination Figure 1 As shown, in the first aspect, this embodiment provides an automatic transmission and engine docking structure. Its core design is to isolate and buffer the vibration between the front end of the torque converter 7 and the flywheel 2 by setting a bushing 9 made of high-performance material in the inner hole of the engine flywheel 2, thereby completely solving the long-standing problem of fretting wear on the metal mating surface.

[0027] The docking structure consists of two main parts: a stationary part for support and protection, and a rotating part for power transmission.

[0028] The stationary support section includes the engine flywheel housing 1, spacer 5, connecting section 6, and torque converter housing 8. The engine flywheel housing 1 is typically fixedly connected to the rear end of the engine block. The rear end face of the engine flywheel housing 1 abuts against the front end face of the spacer 5 and is secured by multiple bolts, with spring washers at the bolt connections to prevent loosening. The rear end face of the spacer 5 abuts against the front end face of the connecting section 6, and the rear end face of the connecting section 6 abuts against the flange edge on the torque converter housing 8. These three components are connected and secured together by multiple circumferentially distributed bolt assemblies 15 (including bolts, nuts, and spring washers). Thus, these parts form a rigid, fixed support frame, providing precise installation positioning and a reliable operating environment for the internal rotating components.

[0029] Rotary power transmission section: This section includes the engine crankshaft 3, engine flywheel 2, flexible disc 4, and torque converter 7. Its specific connection method and innovative structure are as follows: (a) Connection between crankshaft and flywheel: The engine flywheel 2 is connected to the rear end of the engine crankshaft 3 via multiple circumferentially evenly distributed first bolts 10. Specifically, the engine flywheel 2 has mounting countersunk holes, in which the engine crankshaft 3 is inserted. The first bolts 10 pass through the engine flywheel 2 from back to front and are screwed into the threaded holes on the rear end face of the engine crankshaft 3. To ensure connection reliability under high-speed rotation and torque fluctuation conditions, a spring washer is provided between the head of each first bolt 10 and the contact surface of the flywheel 2, effectively preventing loosening.

[0030] (ii) Innovative friction-reducing structure: This is the core improvement of the present invention. A bushing 9 is press-fitted into the central inner hole of the engine flywheel 2 using an interference fit. In this embodiment, the bushing 9 is made of polyetheretherketone (PEEK) material, and its hardness is controlled within the HRR range of 105-120. The interference fit ensures that the bushing 9 and the flywheel 2 form a single unit, enabling synchronous, high-speed rotation without relative motion. The excellent properties of PEEK material, such as high temperature resistance (allowing for long-term operation in the engine compartment), high strength, high wear resistance, low coefficient of friction, and low coefficient of thermal expansion, make it an ideal choice for withstanding vibration and preventing wear.

[0031] (III) Positioning and connection of the torque converter: The torque converter 7 has a protruding locating part at its front end. During assembly, this locating part is inserted into the inner hole of the bushing 9, which is fixed to the flywheel 2, with a clearance fit. This fit forms a "metal-bushing-metal" connection chain. Its advantages are: A. Complete isolation: The PEEK bushing 9 completely isolates the metal positioning part of the torque converter 7 from the metal inner hole of the engine flywheel 2, fundamentally eliminating direct metal contact and avoiding fretting wear.

[0032] B. Effective buffering: The elasticity and toughness of PEEK material itself can effectively absorb and buffer radial and axial vibrations from the engine and transmission.

[0033] C. Automatic compensation: The clearance fit provides the necessary floating space for the torque converter 7, which can automatically compensate for the coaxiality deviation caused by manufacturing and assembly errors as well as thermal deformation and vibration during operation, so that the torque converter 7 is always in a "free" state, avoiding the additional stress caused by forced constraints and ensuring the smoothness of transmission.

[0034] (iv) Connection of the power transmission path: The complete torque transmission path is: engine crankshaft 3 → engine flywheel 2 → flexible disc 4 → torque converter 7.

[0035] 1. Connection between flywheel and flexible plate: The flexible plate 4 is located behind the engine flywheel 2. The flexible plate 4 is fixedly connected to the engine flywheel 2 by multiple circumferentially evenly distributed third bolts 13. A key process improvement is that the fastening nuts 14 that mate with the third bolts 13 are pre-welded to the rear surface of the flexible plate 4. Thus, on the assembly line, workers only need to screw the third bolts 13 (through the spring washer and the through hole on the flywheel 2) into the fastening nuts 14 already fixed on the flexible plate 4 from the front side of the engine flywheel 2. This provides ample operating space, high efficiency, and eliminates the need for two-handed tightening operations between the narrow flywheel and torque converter.

[0036] 2. Connection between the flexible disc and the torque converter: The rear side of the flexible disc 4 is fixedly connected to the front end face of the torque converter 7 housing by multiple circumferentially evenly distributed second bolts 12. Similarly, a spring washer is provided at the connection of each second bolt 12 to prevent the bolt from loosening due to vibration.

[0037] (v) Other auxiliary components: A gear ring 11 is press-fitted onto the outer periphery of the engine flywheel 2 with an interference fit. The gear ring 11 is used to mesh with the drive gear of the starter motor. When the engine is started, the starter motor drives the crankshaft to rotate, completing the ignition and starting process.

[0038] In summary, the automatic transmission and engine docking structure of this embodiment cleverly solves the long-standing problem of fretting wear on metal positioning surfaces in this technical field by adding a bushing 9 made of PEEK material into the inner hole of the engine flywheel 2, fixing it to the engine flywheel 2 with an interference fit and engaging with the front end of the torque converter 7 with a clearance fit. This solution is simple in structure, low in cost, and easy to implement, while greatly improving the reliability, smoothness, and service life of the entire transmission system.

[0039] Secondly, this embodiment also provides a vehicle transmission system, which includes the automatic transmission and engine docking structure described in any of the above solutions.

[0040] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. An automatic transmission and engine docking structure, comprising an engine flywheel (2), a flexible disk (4), and a torque converter (7), wherein the engine flywheel (2) is fixedly connected to an engine crankshaft (3), and the flexible disk (4) is connected between the engine flywheel (2) and the torque converter (7), characterized in that, A bushing (9) is also provided in the inner hole of the engine flywheel (2), and the front end positioning part of the torque converter (7) is inserted into the inner hole of the bushing (9) and cooperates with the bushing (9).

2. The automatic transmission and engine docking structure according to claim 1, characterized in that, The bushing (9) is made of polyetheretherketone material.

3. The automatic transmission and engine docking structure according to claim 2, characterized in that, The hardness of the bushing (9) is HRR105-120.

4. The automatic transmission and engine docking structure according to claim 1, characterized in that, The bushing (9) and the inner hole of the engine flywheel (2) are interference fit.

5. The automatic transmission and engine docking structure according to claim 1, characterized in that, The bushing (9) and the front end positioning part of the torque converter (7) are in clearance fit.

6. The automatic transmission and engine docking structure according to claim 1, characterized in that, The engine flywheel (2) is fixedly connected to the end face of the engine crankshaft (3) by a plurality of first bolts (10), and a spring washer is provided at the connection point for relaxation.

7. The automatic transmission and engine docking structure according to claim 1, characterized in that, The flexible disc (4) is fixedly connected to the torque converter (7) by a plurality of second bolts (12), and spring washers are provided at the connection to prevent loosening; The flexible disk (4) is fixedly connected to the engine flywheel (2) by multiple third bolts (13), and a spring washer is provided at the connection to prevent loosening. The third bolts (13) pass through the spring washer, the engine flywheel (2), and the flexible disk (4) in sequence, and are then screwed with a fastening nut (14).

8. The automatic transmission and engine docking structure according to claim 7, characterized in that, The fastening nut (14) is welded to the flexible disc (4).

9. The automatic transmission and engine docking structure according to claim 1, characterized in that, It also includes an engine flywheel housing (1), a spacer ring (5), a connecting section (6), a gear ring (11), and a torque converter housing (8); the engine flywheel housing (1) and the spacer ring (5) are fixedly connected by bolts, and the spacer ring (5), the connecting section (6), and the torque converter housing (8) are fixedly connected as a whole by bolt assembly (15); the gear ring (11) is fitted onto the outer circumference of the engine flywheel (2) in an interference fit manner.

10. A vehicle transmission system, characterized in that, It includes an automatic transmission and engine docking structure as described in any one of claims 1 to 9.

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