A multi-functional crank pulley assembly

Abstract

The utility model discloses a multifunctional crank pulley assembly, including pulley, wheel hub, signal disc, rubber layer and auxiliary function structure, and pulley and wheel hub are connected through the rubber elasticity, and signal disc is pressed into wheel hub outside in the interference, and the rubber adopts nitrile rubber and is fixed through vulcanization process. The pulley edge is equipped with the balance hole for dynamic balance adjustment, and the annular region is equipped with the slot hole and realizes the light weight, and the wheel hub end surface is equipped with bolt connection hole for with crank fixed. The utility model integrates power transmission, rotational speed signal acquisition, torsional vibration absorption, light weight and dynamic balance adjustment function, need not additional assembly friction plate, can promote operation stability, reduce cost and energy consumption.

Description

Technical Field

[0001] This utility model relates to the technical field of automotive engine transmission components, specifically to a multifunctional crankshaft pulley assembly. Background Technology

[0002] In automotive engine transmission systems, the crankshaft pulley assembly is the component connecting the crankshaft to external accessories (such as alternators, water pumps, and air conditioning compressors). Its performance directly affects the engine's power transmission efficiency, accessory operational stability, and overall vehicle energy consumption. As engines develop towards higher integration, lighter weight, and lower vibration, traditional crankshaft pulley assemblies are gradually revealing problems such as complex structures and insufficient operational stability, making it difficult to meet current technological requirements.

[0003] During engine crankshaft operation, the alternating power strokes of each cylinder generate periodic torsional vibrations. These vibrations are directly transmitted to the traditionally rigidly connected pulleys, causing significant fluctuations in pulley speed. To mitigate this problem, some existing technologies, such as the patent with publication number CN207880022U, add friction plates between the pulley and the signal disc to dissipate vibration energy through frictional damping. However, the addition of friction plates not only increases the number of components and assembly complexity but also presents the problem of performance degradation after the friction plates wear down.

[0004] It is evident that existing crankshaft pulley assemblies still have shortcomings in terms of functional integration, torsional vibration absorption, lightweight design, and long-term reliability. A new crankshaft pulley assembly design is needed that simplifies the structure, improves operational stability, and reduces costs. Utility Model Content

[0005] To address the aforementioned deficiencies in the prior art, this utility model proposes a multifunctional crankshaft pulley assembly, comprising a pulley, a hub, a signal disc, a rubber layer, and auxiliary functional structures. The pulley and hub are elastically connected via the rubber layer, the signal disc is mounted on the outside of the hub, and the rubber layer is fixed between the pulley and the hub. The auxiliary functional structures include bolt holes for inserting high-strength bolts to fix the pulley assembly to the engine crankshaft flange end face, the bolt holes being located on the hub end face.

[0006] Preferably, the outer circumferential surface of the pulley is machined with a groove adapted to the drive belt, and the inner wall of the groove has a smooth arc transition structure; the inner side of the pulley is provided with an annular groove, the depth of the annular groove is matched with the thickness of the rubber layer, and the rubber layer is made of nitrile rubber and is fixed in the annular groove by interference fit through vulcanization process.

[0007] Preferably, the inner diameter of the wheel hub is adapted to the output diameter of the engine crankshaft, and the outer wall of the wheel hub is press-fitted to the inner ring of the signal disc; the bolt connection holes are evenly arranged along the circumferential direction of the wheel hub end face.

[0008] Preferably, the signal disk is formed by stamping thin steel plate; multiple protruding teeth are evenly distributed on the outer periphery of the signal disk, and at least one missing tooth is provided, the width of the missing tooth is greater than or equal to twice the distance between adjacent protruding teeth; the protruding part of the protruding tooth has a square rounded corner structure, and the concave part between the protruding teeth has an arc-shaped structure.

[0009] Preferably, the auxiliary functional structure further includes a balancing hole and a slot; the balancing hole is located on the edge of the pulley, and the slot is located in the annular region in the center of the hub.

[0010] Preferably, the balance hole has six holes closely spaced along the circumferential direction of the pulley edge.

[0011] Preferably, the slot is an oblong structure; six slots are evenly distributed along the circumference of the hub, and the included angle between adjacent slots is set to 60°.

[0012] The present invention has the following beneficial effects:

[0013] (1) Simplified structure and assembly. This utility model's multi-functional crankshaft pulley assembly integrates power transmission, speed signal acquisition, torsional vibration absorption, lightweight adjustment, and dynamic balance control functions into a single assembly through an integrated design, eliminating the need for additional friction plates or external balancing components. This reduces the risk of assembly errors and manufacturing costs.

[0014] (2) Excellent torsional vibration absorption effect, improving operational stability. Relying on the elastic connection structure of hub-rubber-pulley, nitrile rubber with strong oil resistance and elastic recovery is selected as the damping medium, which can effectively buffer the periodic torsional vibration during crankshaft operation and effectively reduce accessory noise and failure probability.

[0015] (3) The signal disc is made of thin steel plate by stamping. The outer circumference is evenly distributed with protruding teeth and missing teeth. The structure of protruding teeth and missing teeth facilitates the identification of the speed sensor and reduces the air resistance of rotation. The interference fit ensures that the signal disc rotates synchronously with the hub, avoiding the problem of power fluctuation caused by signal deviation.

[0016] (4) Balancing lightweight design with structural strength. Multiple elongated oval slots are made in the annular area of ​​the pulley to achieve effective weight reduction while ensuring structural strength. Combined with four balance holes on the edge, precise counterweights are added to avoid vibration and noise caused by dynamic imbalance, further improving the smoothness of the transmission system.

[0017] This utility model discloses a multifunctional crankshaft pulley assembly, which has the advantages of simple structure, good shock resistance, and light weight. Attached Figure Description

[0018] Figure 1 This is a front view of the crankshaft pulley assembly according to an embodiment of the present utility model;

[0019] Figure 2 This utility model provides an embodiment of the crankshaft pulley assembly. Figure 1 Cross-sectional view of XX.

[0020] Explanation of reference numerals in the attached diagram: 1-Pulley; 2-Hub; 3-Signal disc; 4-Rubber layer; 5-Missing tooth; 6-Balance hole; 7-Bolt connection hole; 8-Slot; 9-Protruding tooth. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Example 1

[0023] The multi-functional crankshaft pulley assembly disclosed in this embodiment aims to achieve power transmission, speed signal acquisition, lightweighting, and dynamic balance adjustment through an integrated structural design, while simplifying the assembly process and improving operational stability. This multi-functional crankshaft pulley assembly mainly consists of a pulley 1, a hub 2, a signal disc 3, a rubber layer 4, and matching connecting structures. The structural design and functional compatibility of each component are as follows:

[0024] (1) Pulley 1. As the carrier of power transmission, its outer circumferential surface is machined with a groove for fitting the transmission belt. The inner wall of the groove adopts a smooth arc transition design to reduce wear during belt operation. The inner side of the pulley 1 has a pre-reserved annular groove for installing the rubber layer 4. The groove depth matches the thickness of the rubber layer 4. Through interference fit, the rubber layer 4 is tightly fixed to the pulley 1. At the same time, the elastic deformation of the rubber layer 4 is used to absorb the torsional vibration during crankshaft operation, reducing the speed fluctuation of the pulley 1.

[0025] (2) Hub 2. Located at the center of pulley 1, it is elastically connected to pulley 1 via rubber layer 4. The inner diameter of hub 2 is matched with the output shaft diameter of engine crankshaft, ensuring that hub 2 rotates synchronously with crankshaft. In addition, the outer wall of hub 2 is connected to the inner ring of signal disk 3 by interference fit, ensuring that signal disk 3 rotates synchronously with hub 2, avoiding relative displacement from affecting the accuracy of speed signal acquisition.

[0026] (3) Signal disk 3: It is made of thin steel plate by stamping, with a thickness of 3mm, and is fixed in the annular area between the hub 2 and the pulley 1. Multiple protruding teeth 9 are evenly distributed on the outer periphery of the signal disk 3, and the protruding teeth are evenly and neatly arranged. There is one missing tooth 5 in it, and the width of the missing tooth is greater than or equal to twice the distance between adjacent protruding teeth. The protruding part of the protruding tooth 9 is designed as a square rounded corner structure, and the concave part is an arc shape. This structure not only facilitates the engine speed sensor to identify the tooth shape signal, but also reduces the air resistance when the signal disk 3 rotates. When the crankshaft drives the hub 2 to rotate, the signal disk 3 rotates synchronously with the hub 2. The speed sensor collects the engine speed signal in real time and transmits it to the ECU (engine control unit) by identifying the alternating changes of the protruding teeth 9 and the missing teeth 5.

[0027] (4) Rubber layer 4: Made of nitrile rubber (Shore hardness set to 65±5HA), it has excellent oil resistance and elastic recovery. The inner ring of rubber layer 4 is fixed to the outer wall of hub 2 and the inner groove of pulley 1 through vulcanization process, forming an elastic connection structure of hub 2-rubber layer 4-pulley 1. This structure allows for an angular displacement of ±3° between pulley 1 and hub 2, effectively buffering the impact of crankshaft torsional vibration on the belt drive system.

[0028] (5) Auxiliary functional structure, including:

[0029] Balance holes 6: Multiple balance holes 6 are evenly distributed along the circumference of the pulley 1. The hole diameter can be 8mm, and the distance from the center of the hole to the outer ring of the pulley 1 can be 12mm. By installing balance weights of different weights, such as copper or iron counterweights, in the balance holes 6, the center of gravity distribution of the pulley 1 is adjusted to ensure that the dynamic balance accuracy of the pulley reaches G2.5 grade (the allowable imbalance per revolution is ≤5g·mm) when the pulley rotates at high speed (maximum speed 6000rpm), thus avoiding vibration and noise caused by dynamic imbalance.

[0030] Slots 8: Six slots 8 are evenly distributed in the annular area in the middle of the pulley 1. The slots 8 have an elongated oval structure, and the included angle between adjacent slots 8 is 60°. The design of the slots 8 is mainly for weight reduction, without affecting the structural strength of the pulley 1.

[0031] Bolt connection holes 7: Three bolt connection holes 7 are evenly provided along the circumference on the end face of the hub 2. The bolt connection holes 7 are used to fix the entire pulley assembly to the flange end face of the engine crankshaft with high-strength bolts (model M10×25, performance grade 8.8), ensuring a reliable connection between the pulley assembly and the crankshaft and avoiding power transmission failure caused by loosening.

[0032] The assembly of the multi-functional crankshaft pulley assembly in this embodiment must follow the process of first making flexible connections, then making precise positioning, and finally fixing and locking. The specific steps and process control requirements are as follows:

[0033] (1) Pre-assembly of rubber layer 4 with pulley 1 and hub 2.

[0034] 1. First, clean the annular groove on the inner side of pulley 1 and the outer wall of hub 2 to remove surface oil and impurities.

[0035] 2. Heat the rubber layer 4 to 80-100℃ to soften the rubber material and reduce assembly resistance. Then, slowly press its outer ring into the annular groove of the pulley 1. During the pressing process, use special tooling to ensure the coaxiality of the rubber layer 4.

[0036] 3. After the rubber layer 4 has cooled to room temperature, apply a small amount of grease to the outer wall of the wheel hub 2, and then use a hydraulic press to press the wheel hub 2 into the inner ring of the rubber layer 4. After pressing in place, hold the pressure for 30 seconds to ensure that the rubber layer 4 is tightly fitted with the wheel hub 2 and the pulley 1.

[0037] (2) Pressing of signal disk 3.

[0038] 1. Deburr the inner ring of the signal disc 3 and the press-fit surface of the hub 2 to ensure that the surface roughness Ra≤1.6μm.

[0039] 2. Align the inner ring of the signal disc 3 with the outer pressing surface of the hub 2, and use a pneumatic pressing machine to perform interference fitting. Set the pressing force to 8-10kN. Monitor the end face runout of the signal disc 3 during the pressing process to ensure that the flatness of the signal disc 3 meets the requirements.

[0040] 3. After pressing, check whether the position of the missing tooth 5 on the signal disk 3 corresponds to the installation position of the engine speed sensor. If the deviation exceeds the range, the angle of the signal disk 3 needs to be finely adjusted by a special calibration tool.

[0041] (3) Balance adjustment and bolt fixing.

[0042] 1. Install the pre-assembled pulley assembly on the dynamic balancing machine and perform a dynamic balancing test. The test speed can be set to 1500 rpm.

[0043] 2. Based on the dynamic balance test results, install a balance block of corresponding weight in the balance hole 6 until the dynamic balance accuracy reaches G2.5 level.

[0044] 3. Align the dynamically balanced pulley assembly with the flange end face of the engine crankshaft, so that the inner hole of the hub 2 fits into the crankshaft output end, and then insert multiple high-strength bolts into the bolt connection holes 7 respectively, and tighten the bolts with a torque wrench.

[0045] 4. After tightening, check the end face runout and radial runout of the pulley assembly to ensure that the assembly accuracy meets the operating requirements.

[0046] This embodiment integrates power transmission, speed signal acquisition, torsional vibration absorption, lightweighting, and dynamic balance adjustment functions into a single pulley assembly through an integrated structural design. It eliminates the need for additional friction plates, simplifying the structure and reducing costs, making it suitable for the transmission system requirements of small and medium displacement engines.

[0047] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A multifunctional crankshaft pulley assembly, characterized in that, It includes a pulley (1), a hub (2), a signal disc (3), a rubber layer (4), and an auxiliary functional structure; the pulley (1) and the hub (2) are elastically connected by the rubber layer (4), the signal disc (3) is mounted on the outside of the hub (2), and the rubber layer (4) is fixed between the pulley (1) and the hub (2); the auxiliary functional structure includes a bolt connection hole (7) for passing through a high-strength bolt to fix the pulley assembly to the end face of the engine crankshaft flange, and the bolt connection hole (7) is located on the end face of the hub (2).

2. The multifunctional crankshaft pulley assembly according to claim 1, characterized in that, The outer circumferential surface of the pulley (1) is machined with a groove adapted to the transmission belt, and the inner wall of the groove is a smooth arc transition structure; the inner side of the pulley (1) is provided with an annular groove, the depth of the annular groove is matched with the thickness of the rubber layer (4), and the rubber layer (4) is made of nitrile rubber and is fixed in the annular groove by interference fit through vulcanization process.

3. The multifunctional crankshaft pulley assembly according to claim 1, characterized in that, The inner diameter of the hub (2) is adapted to the output shaft diameter of the engine crankshaft, and the outer wall of the hub (2) is press-fitted to the inner ring of the signal disc (3); the bolt connection holes (7) are evenly arranged along the circumferential direction of the end face of the hub (2).

4. The multifunctional crankshaft pulley assembly according to claim 1, characterized in that, The signal disk (3) is formed by stamping thin steel plate; the signal disk (3) has multiple protruding teeth (9) evenly distributed on its outer periphery, and at least one missing tooth (5) is provided. The width of the missing tooth (5) is greater than or equal to twice the distance between adjacent protruding teeth (9); the protruding part of the protruding tooth (9) is a square rounded corner structure, and the concave part between the protruding teeth (9) is an arc-shaped structure.

5. The multifunctional crankshaft pulley assembly according to claim 1, characterized in that, The auxiliary functional structure also includes a balance hole (6) and a slot (8); the balance hole (6) is located on the edge of the pulley (1), and the slot (8) is located in the annular area in the middle of the hub (2).

6. The multifunctional crankshaft pulley assembly according to claim 5, characterized in that, The balance hole (6) has six holes closely spaced along the circumferential direction of the edge of the pulley (1).

7. The multifunctional crankshaft pulley assembly according to claim 5, characterized in that, The slot (8) has an elongated oval structure; six slots (8) are evenly opened along the circumference of the hub (2), and the included angle between adjacent slots (8) is set to 60°.

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