Hybrid engine balance shaft system assembling method, balance shaft double gear assembling method and hybrid engine balance shaft system and timing chain system collaborative assembling method

Abstract

This application relates to the field of vehicle technology, and in particular to a method for assembling and adjusting a hybrid engine balance shaft system, a method for assembling a balance shaft double-layer gear, and a method for coordinating the assembly and adjustment of a hybrid engine balance shaft system and a timing chain system. The method for assembling and adjusting the hybrid engine balance shaft system includes the following steps: heating the balance shaft housing; placing the balance shaft front bearing in the front bearing mounting position on the balance shaft housing; setting the pressing parameters for the pressing fixture and pressing the balance shaft front bearing into the front bearing mounting position; installing the balance shaft rear bearing into the rear bearing support position of the balance shaft housing; inserting the left and right balance shafts into their respective bearing inner holes; aligning the balance shaft timing pin with the balance shaft positioning hole and installing it into the balance shaft housing, thus fixing the left and right balance shafts to the balance shaft housing. The hybrid engine balance shaft system assembly and adjustment method provided in this application uses hot pressing in conjunction with a pressing fixture to press the balance shaft, significantly improving the assembly accuracy of the balance shaft system.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to a method for assembling and adjusting a hybrid engine balance shaft system, a method for assembling a balance shaft double-layer gear, and a method for coordinating the assembly and adjustment of a hybrid engine balance shaft system and a timing chain system. Background Technology

[0002] Currently, in the development of new energy hybrid engines, the balance shaft and chain system are core components for achieving smooth engine operation, reducing vibration and noise, and improving valve timing accuracy. Their accuracy directly determines the engine's intake efficiency, combustion performance, and NVH performance, ultimately affecting its power, fuel economy, reliability, and durability. Currently, the assembly and adjustment of the balance shaft and chain system for hybrid engines mainly follows the assembly and adjustment processes of traditional internal combustion engines. This approach is not fully adapted to the multi-condition (engine operating alone, motor operating alone, hybrid drive) structural characteristics of hybrid engines, which involve large speed fluctuations and complex power coupling. Furthermore, existing assembly and adjustment technologies suffer from the following significant drawbacks: 1. Insufficient assembly precision of the balance shaft: In existing technologies, balance shaft bearings are mostly assembled by hammering. Excessive deviations in press-fit perpendicularity and depth can easily lead to damage to the inner hole, resulting in bearing fit tolerances. This causes additional vibrations during subsequent operation and may even lead to bearing loosening and accelerated wear. This problem is particularly prominent in hybrid engines with frequent start-stop cycles and sudden speed changes, severely affecting the balance shaft's core function of counteracting engine inertial vibrations.

[0003] 2. Excessive noise from the balance shaft gear meshing: Hybrid engines use a dual balance shaft structure to improve NVH performance. The right balance shaft meshes with two sets of sprockets on the crankshaft, and its rotational speed is twice that of the crankshaft. Conventional single-tooth meshing causes significant vibration and noise, affecting the second-order balance effect and even causing abnormal wear on the tooth surface.

[0004] 3. Large timing assembly accuracy deviation: The existing assembly and adjustment methods involve independent assembly and adjustment of the balance shaft chain and the engine timing chain, lacking systematic coordinated positioning and assembly. During the assembly and adjustment process, timing phase deviations of the camshaft, balance shaft and crankshaft are prone to occur, resulting in polygonal effects in the chain drive, generating additional dynamic loads and vibration noise, such as howling and metallic knocking sounds. At the same time, it affects the accuracy of engine valve timing and dynamic balance, reducing power output efficiency and NVH performance. Summary of the Invention

[0005] The purpose of this application is to provide a method for assembling and adjusting a hybrid engine balance shaft system, a method for assembling a balance shaft double-layer gear, and a method for coordinating the assembly and adjustment of a hybrid engine balance shaft system and a timing chain system, so as to solve the above-mentioned problems existing in the prior art to a certain extent.

[0006] This application provides a method for assembling and adjusting a balance shaft system for a hybrid engine, including the following steps: Heat the balance shaft housing and place the heated balance shaft housing into the press-fitting fixture; Place the front bearing of the balance shaft in the front bearing mounting position on the balance shaft housing; Set the pressing parameters for the pressing tool and press the balance shaft front bearing into the front bearing mounting position; Install the rear bearing of the balance shaft into the rear bearing support position of the balance shaft housing; Insert the left and right balance shafts into their respective bearing bores; Align the balance shaft timing pin with the balance shaft positioning hole and install it into the balance shaft housing. Fix the left and right balance shafts to the balance shaft housing.

[0007] In the above technical solution, the press-fitting fixture further includes: Base plate; Multiple columns are spaced apart on the base plate; Support beams and support plates, the column being connected to the support beams via the support plates; A drive assembly is disposed on the support beam; A bearing pressure head is disposed on the drive assembly, and the drive assembly is capable of driving the bearing pressure head toward or away from the base plate; A detection component for monitoring the pressing force and / or displacement of the bearing indenter. In any of the above technical solutions, the press-fitting parameters further include: The pressing force is 55-65kN; The pressing speed is 15-25 mm / min; The pressing depth is ±0.02mm of the design value. This application also provides a method for assembling a balance shaft with a double-layer gear, including the following steps: The tensioning ring is assembled to the main gear or the auxiliary gear; The main gear and the auxiliary gear are assembled into one unit. The tensioning ring can provide a preset tension force between the main gear and the auxiliary gear so that the main gear and the auxiliary gear can be displaced. The main gear and the auxiliary gear are simultaneously engaged with the counter gear. The counterspindle gear is the intermediate gear of the oil pump.

[0008] This application also provides a method for coordinating the assembly and adjustment of a hybrid engine balance shaft system and a timing chain system, including the aforementioned hybrid engine balance shaft system assembly and adjustment method, a balance shaft system assembled and adjusted by the aforementioned hybrid engine balance shaft system assembly and adjustment method, and a balance shaft double-layer gear assembled by the aforementioned balance shaft double-layer gear assembly method. Therefore, it has all the beneficial technical effects of the hybrid engine balance shaft system assembly and adjustment method and the balance shaft double-layer gear assembly method, which will not be elaborated here.

[0009] The method for coordinating the hybrid engine balance shaft system and timing chain system includes the following steps: S1. Adjust the crankshaft position and fix the crankshaft with timing fixture; S2. Install the balance shaft system. Install the assembled balance shaft system to the mounting position on the cylinder block. S3. Install the oil pump by attaching the oil pump with the sprocket to the balance shaft housing; S4. Install the crankshaft sprocket; S5. Install the balance shaft chain, then install the balance shaft chain moving rail, the balance shaft chain stationary rail, and the balance shaft tensioner; S6. Install the camshaft, install the camshaft into the camshaft hole of the cover, and install the cover onto the cylinder head; S7. Install the timing chain, as well as the timing chain drive rail, timing chain stationary rail, and timing chain tensioner; S8, tensioning chain system, which tensions the balance shaft chain layer and the camshaft chain layer in the fixed timing initial position of the camshaft, crankshaft, and balance shaft system; S9. Tighten the chain layer bolts.

[0010] In any of the above technical solutions, step S5 further includes: S501. First, install the balance shaft chain onto the crankshaft sprocket, left balance shaft sprocket, and oil pump sprocket in sequence. S502, then install the balance shaft chain drive rail, balance shaft chain stationary rail, and balance shaft tensioner in sequence; S503, Tighten the balance shaft tensioner bolts, balance shaft chain moving rail bolts, and balance shaft chain stationary rail bolts.

[0011] In any of the above technical solutions, step S6 further includes: S601, the camshaft is divided into intake camshaft and exhaust camshaft. The intake camshaft and exhaust camshaft are installed in the corresponding positions on the cover, and the cover is installed in the cylinder head; S602. Install the intake camshaft sprocket, loosen the intake camshaft sprocket bolts but do not tighten them; install the exhaust camshaft sprocket, loosen the exhaust camshaft sprocket bolts but do not tighten them.

[0012] In any of the above technical solutions, step S7 further includes: S701. Mount the timing chain onto the intake camshaft sprocket, exhaust camshaft sprocket, and crankshaft sprocket. S702. Install the timing chain moving rail, timing chain stationary rail, and timing chain tensioner to ensure that the intake camshaft sprocket, exhaust camshaft sprocket, timing chain, timing chain moving rail, and timing chain stationary rail are all in the same plane.

[0013] In any of the above technical solutions, step S8 further includes: S801, Tension the balance shaft chain layer, remove the pin on the balance shaft tensioner, the balance shaft tensioner pushes the balance shaft moving rail, and the balance shaft moving rail pushes the balance shaft chain; S802, Tighten the camshaft chain layer: Remove the pin on the timing chain tensioner L7 of the camshaft chain layer to release the tension of the timing chain tensioner.

[0014] In any of the above technical solutions, step S9 further includes: S901. First, tighten the balance shaft chain layer, and then tighten the right balance shaft bolt, left balance shaft bolt, and oil pump sprocket bolt in a clockwise direction in sequence. S902. Next, tighten the camshaft chain layer, and tighten the exhaust camshaft sprocket and intake camshaft sprocket in a clockwise direction in sequence. S903, Release the tension force of the right balance sprocket; S904. Finally, tighten the crankshaft sprocket, rotate the crankshaft 720°, and observe and confirm that the positions of each timing pin hole are the initial timing positions.

[0015] Compared with the prior art, the beneficial effects of this application are as follows: The hybrid engine balance shaft system assembly and adjustment method provided in this application includes the following steps: heating the balance shaft housing and placing the heated balance shaft housing on a press-fitting fixture; placing the balance shaft front bearing on the front bearing mounting position on the balance shaft housing; setting the press-fitting parameters for the press-fitting fixture and press-fitting the balance shaft front bearing to the front bearing mounting position; installing the balance shaft rear bearing to the rear bearing support position of the balance shaft housing; inserting the left and right balance shafts into their respective bearing inner holes; aligning the balance shaft timing pin with the balance shaft positioning hole and installing it into the balance shaft housing, thus fixing the left and right balance shafts to the balance shaft housing.

[0016] The hybrid engine balance shaft system assembly and adjustment method provided in this application first heats the balance shaft housing, then uses hot pressing in conjunction with pressing fixtures to press the balance shaft, and monitors the pressing parameters in conjunction with detection components during the pressing process, which significantly improves the pressing accuracy and thus significantly improves the assembly accuracy of the engine's balance shaft system. The balance shaft double-layer gear assembly method provided in this application adopts a double-layer gear structure. The tensioning structure causes the inner and outer gears to be relatively displaced, realizing the staggered meshing with the counter gear, namely the intermediate gear of the oil pump, and specifically solving the problems of meshing impact and noise at high speed.

[0017] The method for co-assembling and adjusting the balance shaft system and timing chain system of a hybrid engine provided in this application achieves precise positioning of the timing positions of the balance shaft, camshaft, and crankshaft through sequential co-assembly, layered chain tensioning, and sequential locking of the sprockets. This effectively eliminates assembly gaps in the chain system and solves the timing error problem caused by independent assembly and adjustment of the two systems. It significantly improves the timing transmission accuracy of the chain system, reduces the polygonal effect and additional dynamic load of chain drive, suppresses abnormal noises such as whistling and metallic knocking, ensures accurate valve timing and good dynamic balance, thereby improving engine intake efficiency and combustion performance, optimizing power output efficiency and fuel economy, and further improving engine NVH performance and reliability. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the timing chain system assembly and adjustment in the hybrid engine balance shaft system and timing chain system co-assembly and adjustment method provided in the embodiments of this application. Figure 2 This is a schematic diagram of the balance shaft system assembly and adjustment method for a hybrid engine balance shaft system provided in the embodiments of this application; Figure 3 This is a schematic diagram of the balance shaft bearing press-fit structure in the hybrid engine balance shaft system assembly and adjustment method provided in this application embodiment; Figure 4 This is a schematic diagram of the sub-assembly structure of the balance shaft system in the hybrid engine balance shaft system assembly and adjustment method provided in the embodiments of this application; Figure 5 This is a schematic diagram of the positioning structure of the balance shaft system in the method for co-assembling and adjusting the balance shaft system and timing chain system of a hybrid engine provided in an embodiment of this application. Figure 6 This is a schematic diagram of the structure of the balance shaft double-layer gear in the balance shaft double-layer gear assembly method provided in the embodiments of this application.

[0020] Figure label: 1-Cylinder block; 2-Crankshaft; 3-Cylinder head; 4-Cylinder cover; 5-Balance shaft system; 6-Oil pump; L1-Exhaust camshaft sprocket; L2-Intake camshaft sprocket; L3-Timing chain; L4-Timing chain moving rail; L5-Timing chain fixed rail; L6-Crankshaft sprocket; L7-Timing chain tensioner; L8-Balance shaft chain; L9-Balance shaft chain fixed rail; L10-Balance shaft moving rail; L11-Balance shaft tensioner; L12-Oil pump sprocket; L13-Oil pump intermediate pulley; P1-Right balance shaft sprocket P2 - Right balance shaft; P3 - Front bearing; P4 - Rear bearing of balance shaft; P5 - Left balance shaft; P6 - Left balance shaft sprocket; P7 - Balance shaft timing pin; P1-1 - Main gear; P1-2 - Secondary gear; P1-3 - Tensioning ring; P1-4 - Connecting pin; G1 - Base plate; G2 - First column; G3 - Second column; G4 - Third column; G5 - Fourth column; G6 - First support plate; G7 - Second support plate; G8 - Support beam; G9 - Connecting rod; G10 - Rotary rod; G11 - Bearing pressure head. Detailed Implementation

[0021] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.

[0022] The components of the embodiments of this application described and shown in the accompanying drawings can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of this application provided in the drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application.

[0023] Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0026] The following reference Figures 1 to 6 This application describes the hybrid engine balance shaft system assembly and adjustment method, the balance shaft double-layer gear assembly method, and the hybrid engine balance shaft system and timing chain system coordinated assembly and adjustment method according to embodiments of the present application.

[0027] Example 1: Example 1 of this application provides a method for assembling and adjusting a balance shaft system for a hybrid engine, including the following steps: Heat the balance shaft housing and place the heated balance shaft housing into the press fitting fixture.

[0028] Specifically, the balance shaft housing is placed in a heating oven and heated at a temperature controlled within the range of 75-85℃, preferably 80℃. The housing is then kept at this temperature for 40-50 minutes, preferably 45 minutes, to allow the balance shaft housing to expand thermally and control the assembly gap.

[0029] Place the front bearing P3 of the balance shaft in the front bearing mounting position on the balance shaft housing.

[0030] Specifically, the balance shaft housing is provided with a front bearing mounting position. After the balance shaft housing is heated, it is taken out and placed on the press-fit fixture. Then, the front bearing P3 is placed stably on the front bearing mounting position. The press-fit fixture is operated to heat-press the front bearing P3 to the front bearing mounting position.

[0031] The press-fitting fixture includes: a base plate G1, multiple columns, a support beam G8, a support plate, a bearing press head G11, and a drive assembly. Preferably, there are four columns: a first column G2, a second column G3, a third column G4, and a fourth column G5. The first column G2 and the second column G3 are positioned near one end of the base plate G1 and are parallel to each other along the width direction of the base plate G1. The third column G4 and the fourth column G5 are positioned near the other end of the base plate G1 and are parallel to each other along the width direction of the base plate G1. The first column G2, the second column G3, the third column G4, and the fourth column G5 are all vertically mounted on the base plate G1. There are two support plates, namely the first support plate G6 and the second support plate G7. The upper ends of the first column G2 and the second column G3 are connected to the first support plate G6. The upper ends of the third column G4 and the fourth column G5 are connected to the second support plate G7. The support beam G8 is long and narrow. One end of the support beam G8 is connected to the first support plate G6, and the other end of the support beam G8 is connected to the second support plate G7. The support beam G8 is parallel to the base plate G1.

[0032] The drive assembly includes a servo motor, a connecting rod G9, and a rotating rod G10. The connecting rod G9 passes through the support beam G8, and its axis extends vertically. The rotating rod G10 is located at the upper end of the connecting rod G9 and is perpendicular to the connecting rod G9. The servo motor is connected to the rotating rod G10, enabling the servo motor to drive the connecting rod G9 to move up and down relative to the support beam G8. The bearing pressure head G11 is located at the bottom end of the connecting rod G9, allowing the bearing pressure head G11 to move up and down synchronously with the connecting rod G9 to move closer to or away from the base plate G1 and the workpiece on the base plate G1, thereby completing the workpiece pressing.

[0033] Furthermore, the press-fitting fixture also includes a detection component, which includes a pressure sensor and a displacement sensor. The pressure sensor and the displacement sensor are disposed on the bearing press head G11. The pressure sensor is used to detect the press-fitting pressure of the bearing press head G11, and the displacement sensor is used to detect the lifting stroke of the bearing press head G11.

[0034] Optionally, the drive assembly and detection assembly are connected to the control system, which can be a PLC commonly used in the field. The pressure sensor and displacement sensor are electrically or communicatively connected to the control system, and the servo motor is electrically or communicatively connected to the control system. The control system can control the start and stop of the servo motor, and the detection assembly can transmit the detection results to the control system in real time. This allows for digital press-fitting by controlling the drive assembly through the control system, and the press-fitting process can be monitored. Press-fitting stops when the press-fitting parameters reach the set parameters. Combined with the above-mentioned hot pressing process, a small-gap assembly method combining digital press-fitting and hot fitting is used to achieve quantitative control of bearing press-fitting depth and press-fitting force. The assembly gap is controlled by heating the balance shaft housing, completely avoiding assembly deviations caused by manual hammering. At the same time, by assembling the left and right balance shafts sequentially and positioning them with a dedicated timing tool, the assembly accuracy and consistency of the balance shaft are significantly improved, avoiding bearing inner hole damage and misalignment. This ensures that the balance shaft stably performs its core function of counteracting engine inertial vibration, effectively improving engine running stability, adapting to the frequent start-stop and speed change requirements of hybrid engines, extending bearing life, and reducing the incidence of related failures.

[0035] During the press-fitting of the front bearing P3, the balance shaft housing is placed on the base plate G1 and aligned with its position. After the front bearing P3 is stably placed on the front bearing mounting position on the balance shaft housing, the height of the bearing pressure head G11 is adjusted so that the bearing pressure head G11 is in contact with the end face of the front bearing P3, ensuring uniform pressure distribution. Press-fitting parameters are set as follows: Based on the design fit requirements of the hybrid engine balance shaft and bearing, the press-fitting force is set to 55-65kN, preferably 60kN; the press-fitting speed is set to 15-25mm / min, preferably 20mm / min; and the press-fitting depth is the design value ±0.02mm. Pressure and displacement sensors are used to monitor the press-fitting force and displacement of the bearing pressure head G11 in real time. Press-fitting automatically stops when the set parameters are reached. After press-fitting, a dial indicator is used to check the fit clearance between the bearing and the balance shaft, ensuring the clearance is within the range of 0.005-0.015mm. Simultaneously, the fit between the bearing end face and the balance shaft step is checked, with a fit surface gap ≤0.003mm.

[0036] Install the rear bearing P4 of the balance shaft into the rear bearing support position of the balance shaft housing.

[0037] Specifically, in this embodiment, the rear bearing P4 of the balance shaft is a combined needle roller bearing. The combined cage is opened, and the rear bearing P4 is installed in the rear bearing support position. Lubricating oil is applied to the corresponding position on the balance shaft housing used to install the rear bearing P4. The balance shaft housing also has a first bearing inner hole and a second bearing inner hole. The left balance shaft P5 is inserted into the first bearing inner hole, and the right balance shaft P2 is inserted into the second bearing inner hole. A rubber hammer is used to gently tap the shafts to ensure they are properly seated. The two balance shafts are rotated to check their smoothness of rotation. Finally, the balance shaft timing pin P7 is aligned with the balance shaft positioning hole and installed onto the balance shaft housing to fix the two balance shafts to the lower housing.

[0038] It should be noted that the inner holes of the first and second bearings are respectively press-fitted with the front bearings P3, the left balance shaft is actually inserted into the inner hole of one of the front bearings P3, and the right balance shaft P2 is actually inserted into the inner hole of the other front bearing P3.

[0039] In summary, the hybrid engine balance shaft system assembly and adjustment method provided in this application first heats the balance shaft housing, then uses hot pressing in conjunction with pressing fixtures to press the balance shaft, and monitors the pressing parameters in conjunction with detection components during the pressing process, which significantly improves the pressing accuracy and thus significantly improves the assembly accuracy of the engine's balance shaft system 5.

[0040] Example 2: Example 2 of this application provides a method for assembling a balance shaft with a double-layer gear, including the following steps: Assemble the tensioning ring P1-3 onto the main gear P1-1 or the auxiliary gear P1-2; Specifically, this embodiment provides a balance shaft double-layer gear, which can be used as the right balance shaft sprocket P1. The balance shaft double-layer gear includes a main gear P1-1, a secondary gear P1-2, and a tension ring P1-3. The tension ring P1-3 has elasticity, similar to a snap ring structure. The tension ring P1-3 is disposed on the main gear P1-1 or the secondary gear P1-2. Preferably, in this embodiment, the tension ring P1-3 is disposed on the secondary gear P1-2.

[0041] The main gear P1-1 and the auxiliary gear P1-2 are assembled into one unit. The tensioning ring P1-3 can provide a preset tension force between the main gear P1-1 and the auxiliary gear P1-2 so that the main gear P1-1 and the auxiliary gear P1-2 are displaced. The main gear P1-1 and the auxiliary gear P1-2 are simultaneously engaged with the counter gear.

[0042] Specifically, the main gear P1-1 is assembled with the secondary gear P1-2, which has a tension ring P1-3. During assembly, the tension ring P1-3 deforms to provide a preset tension force, causing relative movement and rotational displacement between the secondary gear P1-2 and the main gear P1-1. This allows the main and secondary double-layer gears to mesh with the opposing gear, achieving staggered meshing. This effectively reduces the impact caused by gear meshing clearance, especially under high-speed conditions, resulting in significant vibration reduction and noise reduction. It can also effectively protect the tooth surface and reduce tooth surface wear. Optionally, The counter-gear is specifically the intermediate pulley L13 of the oil pump. After the main gear P1-1 and the counter-gear P1-2 are simultaneously engaged with the intermediate pulley L13 of the oil pump, under the action of tension, the counter-gear P1-2 moves relative to the main gear P1-1 and the intermediate pulley L13 of the oil pump to a certain extent. This movement of the counter-gear P1-2 can compensate for the time gap and play between the main gear P1-1 and the intermediate pulley L13 of the oil pump, thereby significantly improving the second-order balance performance of the engine and ensuring the stability of the balance shaft operation.

[0043] Furthermore, the balance shaft double-layer gear also includes a connecting pin P1-4, which is used to sequentially pass through the main gear P1-1 and the auxiliary gear P1-2. It can limit the attitude of the main gear P1-1 and the auxiliary gear P1-2, and the connecting pin P1-4 can be removed relative to the main gear P1-1 and the auxiliary gear P1-2. The connecting pin P1-4 can be removed after the balance shaft double-layer gear itself and the opponent are installed in place.

[0044] By employing a double-gear structure on the right balance shaft sprocket and setting a tensioning structure between the double-gears, the inner paper wheel is always in contact with the counter sprocket when the double-gears mesh, effectively reducing gear meshing impact, reducing meshing vibration noise, and optimizing the second-order balance effect; at the same time, it protects the tooth surface and avoids abnormal tooth surface wear, further improving the NVH performance of the hybrid engine and meeting the core requirement of low noise for hybrid engines.

[0045] Alternatively, spring-type or elastic washer-type tensioning structures can be used to replace tensioning ring P1-3. These structures can provide a preset tension force, cause relative displacement between the inner and outer wheels, and achieve interlocking engagement, all of which fall within the same protection scope of this application.

[0046] The combination of "elastic gear ring + fixed gear ring" can replace the double-layer gear structure of main gear P1-1 and auxiliary gear P1-2. The form of achieving interlocking meshing through the slight deformation of the elastic gear ring, and thus achieving the effects of vibration reduction, noise reduction and tooth surface protection, can all fall within the same protection scope of this application.

[0047] In summary, the balance shaft double-layer gear assembly method provided in this application adopts a double-layer gear structure. The tensioning structure causes relative displacement between the inner and outer gears, achieving staggered meshing with the counter gear, namely the intermediate gear L13 of the oil pump, and specifically solves the problems of meshing impact and noise at high speeds.

[0048] Example 3: Example 3 of this application also provides a method for coordinating the installation and adjustment of a hybrid engine balance shaft system and a timing chain system, including the following steps: S1. Adjust the position of crankshaft 2 and fix crankshaft 2 with timing fixture.

[0049] S2. Install the balance shaft system 5. Install the assembled balance shaft system 5 to the installation position of the cylinder block 1.

[0050] Specifically, S2 includes the following steps: S201. Install the assembled balance shaft housing to the corresponding position on the engine block 1 for mounting the balance shaft system 5, and tighten the balance shaft bolts using the diagonal method.

[0051] S202. Install the left balance shaft sprocket P6 onto the left balance shaft P5, and install the right balance shaft sprocket P1 onto the right balance shaft P2. The bolts used to fix the left balance shaft sprocket P6 and the right balance shaft sprocket P1 are currently only tightened but not fully tightened, so that the left and right balance sprockets can rotate freely.

[0052] S3. Install oil pump 6. Install oil pump 6 onto the balance shaft housing.

[0053] Specifically, the oil pump 6 with sprocket is installed at the designated position on the balance shaft housing, so that the intermediate pulley L13 of the oil pump meshes with the right balance shaft sprocket P1, and then the corresponding bolts of the oil pump 6 are tightened to fix the oil pump 6.

[0054] S4. Install crankshaft sprocket L6. Install crankshaft sprocket L6 to the designated position on the engine.

[0055] S5. Install the balance shaft chain L8, then install the balance shaft chain moving rail, the balance shaft chain stationary rail L9, and the balance shaft tensioner L11.

[0056] Specifically, S5 includes the following steps: S501. First, install the balance shaft chain L8 onto the crankshaft sprocket L6, the left balance shaft sprocket P6, and the oil pump sprocket L12 in sequence. S502, then install the balance shaft chain moving rail, balance shaft chain stationary rail, and balance shaft tensioner L11; S503, Tighten the balance shaft tensioner L11 bolt, balance shaft chain moving rail bolt, and balance shaft chain stationary rail L9 bolt.

[0057] S6. Install the camshaft, install the camshaft onto the cover 4, and install the cover 4 onto the cylinder head 3.

[0058] Specifically, S6 includes the following steps: S601, the camshaft is specifically divided into intake camshaft and exhaust camshaft. The cover 4 is provided with a first camshaft hole for installing the intake camshaft and a second camshaft hole for installing the exhaust camshaft. Install the intake camshaft and exhaust camshaft into the corresponding camshaft holes on the cover 4, and fix the two camshafts with a camshaft timing tool. Install the cover 4 onto the cylinder head 3 and tighten it with bolts.

[0059] S602. Install the intake camshaft sprocket L2 onto the intake camshaft and the exhaust camshaft sprocket L1 onto the exhaust camshaft. Install bolts to secure the intake camshaft sprocket L2 and the exhaust camshaft sprocket L1, respectively, but do not fully tighten the bolts to ensure that the two camshaft sprockets can rotate freely.

[0060] S7. Install timing chain L3, timing chain drive rail L4, timing chain stationary rail L5, and timing chain tensioner L7.

[0061] Specifically, S7 includes the following steps: S701. Mount the timing chain L3 onto the intake camshaft sprocket L2, exhaust camshaft sprocket L1, and crankshaft sprocket L6, keeping the timing chain L3 in its natural state. Check and ensure that the teeth of the timing chain L3 rotate freely without any jamming.

[0062] S702. Install timing chain moving rail L4, timing chain fixed rail L5, and timing chain tensioner L7 to ensure that the intake camshaft sprocket L2, exhaust camshaft sprocket L1, timing chain L3, timing chain moving rail L4, and timing chain fixed rail L5 are all in the same plane. This ensures that they can move freely after subsequent tensioning, and that the intake camshaft sprocket L2, exhaust camshaft sprocket L1, and timing chain L3 are in close contact.

[0063] S8, tensioning chain system, which tensions the balance shaft chain layer and the camshaft chain layer by fixing the camshaft, crankshaft 2, and balance shaft system 5 to the initial timing position.

[0064] Specifically, S8 includes the following steps: S801. Tighten the balance shaft chain layer. Remove the pin on the balance shaft tensioner L11. The balance shaft tensioner L11 pushes the balance shaft moving rail L10, which in turn pushes the balance shaft chain L8. Thus, the balance shaft chain L8 sequentially drives the left balance shaft sprocket P6, the oil pump sprocket L12, and the crankshaft sprocket L6 to rotate. Through the sequential engagement of the chains and sprockets, the assembly gap of the balance shaft chain layer is eliminated. At the same time, the crankshaft sprocket L6 also drives the relative movement of the camshaft chain layer, realizing the coordinated adjustment of the two sets of chain layers and further eliminating the assembly gap error between the chains.

[0065] S802. Tighten the camshaft chain layer: Remove the pin on the timing chain tensioner L3 of the camshaft chain layer, releasing the tension of the timing chain tensioner L7. This pushes the timing chain moving rail L4 to move, which in turn pushes the timing chain L3 to move, causing the exhaust camshaft sprocket L1, intake camshaft sprocket L2, and crankshaft sprocket L6 to rotate. This achieves sequential and tight engagement between each chain and sprocket in the camshaft chain layer, eliminating assembly gaps in the camshaft chain layer. Through the tensioning of the camshaft chain layer, the balance shaft chain layer is driven to rotate again, thus achieving synchronous tensioning of the two sets of chain layers, eliminating assembly gaps between the chain and the wheel, and between the chains. This ensures that the chain is taut before tightening, enabling accurate transmission of power and timing.

[0066] It should be noted that the tensioning process of the chain layers above follows the layered tensioning sequence logic of the tensioning chain system from the inside to the outside and from the small to the large. Layered tensioning can also adopt the sequence of "from the outside to the inside", as long as it can achieve synchronous tensioning of the two sets of chain layers and eliminate assembly gaps.

[0067] S9. Tighten the chain layer bolts.

[0068] Specifically, S9 includes the following steps: S901. First, tighten the balance shaft chain layer. In the direction of engine-crankshaft 2 movement, i.e. clockwise, tighten the right balance shaft bolt, left balance shaft bolt, and oil pump sprocket bolt in sequence.

[0069] S902, tighten the camshaft chain layer clockwise, and then tighten the exhaust camshaft sprocket L1 and the intake camshaft sprocket L2 in sequence.

[0070] S903. Next, remove the connecting pin P1-4 of the right balance shaft sprocket P1 to release the tension inside the right balance shaft sprocket P1. The main gear P1-1 and the auxiliary gear P1-2 move relative to each other under the action of the tension, so that the auxiliary gear P1-2 and the intermediate pulley L13 of the oil pump are interleaved and meshed.

[0071] S904. Finally, tighten the crankshaft sprocket bolts to lock the crankshaft sprocket L6. Rotate the crankshaft 720° and observe and confirm that the positions of each timing pin hole are in the initial timing position to achieve timing synchronization of the crankshaft 2, camshaft, and balance shaft.

[0072] It should be noted that in steps S901 and S902 above, the bolts are tightened in a clockwise order. In addition, the bolts can all be tightened in a counterclockwise order, as long as it can be ensured that the sprocket and chain fit tightly after locking and the timing position remains unchanged.

[0073] The hybrid engine balance shaft system and timing chain system co-assembly and adjustment method provided in this application adopts a sequential co-assembly and adjustment process of "balance shaft system - timing chain system". First, the crankshaft 2 is fixed, the balance shaft system 5 is installed and the sprockets are pre-installed, and then the oil pump 6 is installed, and the chain and guide rail are assembled. The core adopts a layered tensioning method of "from the inside to the outside and from the small to the large" to achieve synchronous tensioning of the two sets of chain layers and eliminate assembly gaps. On the other hand, the operation logic of "tightening the chain first and then tightening each sprocket bolt in a clockwise sequence" is adopted to release the tension force inside the right balance shaft sprocket P1 to achieve staggered meshing. Finally, the timing synchronization of the crankshaft 2, camshaft, and balance shaft is ensured by rotating the crankshaft 720° for verification.

[0074] Furthermore, the hybrid engine balance shaft system and timing chain system co-assembly and adjustment method, combined with the aforementioned balance shaft double-layer gear assembly method, namely the hybrid engine balance shaft system assembly and adjustment method, uses special tooling and fixtures in multiple stages, such as press-fitting fixtures, balance shaft timing positioning fixtures, and camshaft timing tools, to ensure assembly accuracy at each step and adapt to the structural requirements of hybrid engines under multiple operating conditions and high speeds.

[0075] In summary, the hybrid engine balance shaft system and timing chain system co-assembly and adjustment method provided in this application achieves precise positioning of the balance shaft, camshaft, and crankshaft timing positions through sequential co-assembly, layered chain tensioning, and sequential sprocket locking. This effectively eliminates assembly gaps in the chain system and solves the timing deviation problem caused by independent assembly and adjustment of the two components. It significantly improves the timing transmission accuracy of the chain system, reduces the polygonal effect and additional dynamic load of chain drive, suppresses abnormal noises such as whistling and metallic knocking, ensures accurate valve timing and good dynamic balance, thereby improving engine intake efficiency and combustion performance, optimizing power output efficiency and fuel economy, and further improving engine NVH performance and reliability.

[0076] This application provides the above three embodiments, all of which are adapted to the structural characteristics of hybrid engines, such as multiple operating conditions, large speed fluctuations, and complex power coupling. Compared with the traditional fuel engine assembly and adjustment process, they significantly improve the stability and consistency of assembly and adjustment quality, provide reliable technical support for the development, assembly, and adjustment of new hybrid engine products, indirectly shorten the development and trial production cycle, reduce assembly, adjustment, and subsequent maintenance costs, and help promote the marketization of hybrid engines.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for assembling and adjusting a balance shaft system for a hybrid engine, characterized in that, Includes the following steps: Heat the balance shaft housing and place the heated balance shaft housing into the press-fitting fixture; Place the front bearing of the balance shaft in the front bearing mounting position on the balance shaft housing; Set the pressing parameters for the pressing tool and press the balance shaft front bearing into the front bearing mounting position; Install the rear bearing of the balance shaft into the rear bearing support position of the balance shaft housing; Insert the left and right balance shafts into their respective bearing bores; Align the balance shaft timing pin with the balance shaft positioning hole and install it into the balance shaft housing. Fix the left and right balance shafts to the balance shaft housing.

2. The method for assembling and adjusting the balance shaft system of a hybrid engine according to claim 1, characterized in that, Press fitting fixtures include: Base plate; Multiple columns are spaced apart on the base plate; Support beams and support plates, the column being connected to the support beams via the support plates; A drive assembly is disposed on the support beam; A bearing pressure head is disposed on the drive assembly, and the drive assembly is capable of driving the bearing pressure head toward or away from the base plate; A detection component for monitoring the pressing force and / or displacement of the bearing indenter.

3. The method for assembling and adjusting the balance shaft system of a hybrid engine according to claim 1, characterized in that, Press fitting parameters include: The pressing force is 55-65kN; The pressing speed is 15-25 mm / min; The pressing depth is ±0.02mm of the design value.

4. A method for assembling a double-layer gear on a balance shaft, characterized in that, Includes the following steps: The tensioning ring is assembled to the main gear or the auxiliary gear; The main gear and the auxiliary gear are assembled into one unit. The tensioning ring can provide a preset tension force between the main gear and the auxiliary gear so that the main gear and the auxiliary gear can be displaced. The main gear and the auxiliary gear are simultaneously engaged with the counter gear. The counterspindle gear is the intermediate gear of the oil pump.

5. A method for coordinating the assembly and adjustment of a hybrid engine balance shaft system and a timing chain system, characterized in that, Includes the following steps: S1. Adjust the crankshaft position and fix the crankshaft with timing fixture; S2. Install the balance shaft system. Install the assembled balance shaft system to the mounting position on the cylinder block. S3. Install the oil pump by attaching the oil pump with the sprocket to the balance shaft housing; S4. Install the crankshaft sprocket; S5. Install the balance shaft chain, then install the balance shaft chain moving rail, the balance shaft chain stationary rail, and the balance shaft tensioner; S6. Install the camshaft, install the camshaft into the camshaft hole of the cover, and install the cover onto the cylinder head; S7. Install the timing chain, as well as the timing chain drive rail, timing chain stationary rail, and timing chain tensioner; S8, tensioning chain system, which tensions the balance shaft chain layer and the camshaft chain layer in the fixed timing initial position of the camshaft, crankshaft, and balance shaft system; S9. Tighten the chain layer bolts.

6. The method for co-assembling and adjusting the balance shaft system and timing chain system of a hybrid engine according to claim 5, characterized in that, Step S5 includes: S501. First, install the balance shaft chain onto the crankshaft sprocket, left balance shaft sprocket, and oil pump sprocket in sequence. S502, then install the balance shaft chain drive rail, balance shaft chain stationary rail, and balance shaft tensioner in sequence; S503, Tighten the balance shaft tensioner bolts, balance shaft chain moving rail bolts, and balance shaft chain stationary rail bolts.

7. The method for co-assembling and adjusting the balance shaft system and timing chain system of a hybrid engine according to claim 5, characterized in that, Step S6 includes: S601, the camshaft is divided into intake camshaft and exhaust camshaft. The intake camshaft and exhaust camshaft are installed in the corresponding positions on the cover, and the cover is installed in the cylinder head; S602. Install the intake camshaft sprocket, loosen the intake camshaft sprocket bolts but do not tighten them; install the exhaust camshaft sprocket, loosen the exhaust camshaft sprocket bolts but do not tighten them.

8. The method for coordinating the balance shaft system and timing chain system of a hybrid engine according to claim 5, characterized in that, Step S7 includes: S701. Mount the timing chain onto the intake camshaft sprocket, exhaust camshaft sprocket, and crankshaft sprocket. S702. Install the timing chain moving rail, timing chain stationary rail, and timing chain tensioner to ensure that the intake camshaft sprocket, exhaust camshaft sprocket, timing chain, timing chain moving rail, and timing chain stationary rail are all in the same plane.

9. The method for coordinating the balance shaft system and timing chain system of a hybrid engine according to claim 5, characterized in that, Step S8 includes: S801, Tension the balance shaft chain layer, remove the pin on the balance shaft tensioner, the balance shaft tensioner pushes the balance shaft moving rail, and the balance shaft moving rail pushes the balance shaft chain; S802. Tension the camshaft chain layer by removing the pin on the timing chain tensioner of the camshaft chain layer to release the tension of the timing chain tensioner.

10. The method for coordinating the balance shaft system and timing chain system of a hybrid engine according to claim 5, characterized in that, Step S9 includes: S901. First, tighten the balance shaft chain layer, and then tighten the right balance shaft bolt, left balance shaft bolt, and oil pump sprocket bolt in a clockwise direction in sequence. S902. Next, tighten the camshaft chain layer, and tighten the exhaust camshaft sprocket and intake camshaft sprocket in a clockwise direction in sequence. S903, Release the tension force of the right balance sprocket; S904. Finally, tighten the crankshaft sprocket, rotate the crankshaft 720°, and observe and confirm that the positions of each timing pin hole are the initial timing positions.

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