Design method and structure of sealing strip for sealing between engine and gearbox

Abstract

The present invention provides a design method and structure for a sealing strip used to seal an engine with a transmission. This method, which belongs to the field of engine and transmission sealing technology, addresses the problem of matching an engine with transmissions of varying specifications. By designing a dual sealing strip structure on the engine's sealing end face, the outer sealing strip can seal with the end face to be sealed on a transmission with a large center-to-center distance, while the inner sealing strip can seal with the end face to be sealed on a transmission with a small center-to-center distance. Excess sealing strips are then machined away. This method not only allows matching the engine with transmissions of varying sizes, but also rationally determines the position and width of the dual sealing strips, thereby reducing the amount of sealing strips that require machining.

Description

Technical Field

[0001] The invention belongs to the technical field of engine and gearbox sealing, and relates to a design method and structure of a sealing belt on an engine for sealing with a gearbox. Background Art

[0002] The engine and gearbox are the core components of a car. The engine includes a cylinder body, a flywheel housing fixed to the rear end of the cylinder body, and a power shaft rotatably set on the cylinder body and passing through the flywheel housing. The flywheel housing has a sealing end face. The gearbox includes a housing, an input shaft and an output shaft. The housing has a front end face for sealing with the sealing end face of the flywheel housing. The input shaft is rotatably set on the housing and one end of it passes through the front end face and is connected to the engine output shaft. The output shaft is rotatably set on the housing. After the power shaft is connected to the input shaft, the front end face is sealed with the sealing end face to prevent water, dust and other debris from entering from between the rear end of the engine cylinder body and the front end of the gearbox housing.

[0003] However, as traditional and hybrid vehicles have diversified their powertrain configuration requirements, engines need to match gearboxes of different specifications. The center distances of gearboxes of different specifications are different, which makes the positions of the front end faces of each gearbox different. This will cause the front end faces of gearboxes of different specifications to be staggered with the sealing end face of the engine, making it impossible for the front end face and the sealing end face to fit and seal.

[0004] In order to solve the problem that the engine cannot be matched with gearboxes of different specifications, there are several technical means in the prior art:

[0005] 1. A structure in which a connecting plate is added between the sealing end face and the front end face. A connecting plate is provided between the sealing end face and the rear end face. Connecting plates of different specifications are designed to adapt to different types of gearboxes, such as the engine flywheel housing conversion device disclosed in the Chinese patent document [Application No.: 201821864493];

[0006] 2. Directly replace the entire flywheel housing by optimizing the connection structure between the flywheel housing and the engine block to achieve rapid disassembly of the flywheel housing, such as the modular flywheel housing suitable for various vehicle configurations disclosed in Chinese patent literature [Application No.: 201320723160];

[0007] 3. Design the flywheel housing into a split structure. By replacing part of the flywheel housing, the connection between the flywheel housing and gearboxes of different specifications can be achieved, such as the split flywheel housing disclosed in the Chinese patent document [Application No.: 201220461670].

[0008] To solve the above problems, the width of the sealing end face can also be expanded so that the sealing end face can fit with the front end faces of gearboxes of different specifications. However, the overall structure of the existing gearbox is compact, the available space between the output shaft and the input shaft is small, and the center distances between gearboxes of different specifications are different, and the space between the output shaft and the input shaft is different. For the convenience of expression, the position on the front end face of the gearbox located between the output shaft and the input shaft is defined as the end face to be sealed. By expanding the width of the sealing end face, the position on the sealing end face that is sealed with the end face to be sealed is prone to interfere with the output shaft and the flywheel mounted on the input shaft. Therefore, the excess sealing end face needs to be removed by machining. The larger the width of the sealing end face, the more parts that need to be machined, the greater the workload and the more material wasted. Summary of the Invention

[0009] The purpose of the present invention is to address the above-mentioned problems in the existing technology and propose a design method and structure for a sealing belt on the engine for sealing with the gearbox. The technical problem to be solved by the present invention is: how to match the engine with gearboxes of different specifications.

[0010] The object of the present invention can be achieved by the following technical solution: A method for designing a sealing strip on an engine for sealing with a gearbox, characterized in that it comprises the following steps:

[0011] Preselect and obtain model parameters of multiple types of gearboxes and establish each gearbox model, merge all gearbox models and make the axis centers of input shafts in all gearbox models coincide to form an overall model;

[0012] Adjust and unify the position of the output shaft in all gearbox models to unify the vertical height difference between the input and output shaft axes in all gearbox models. Calculate the width of the end face to be sealed on each gearbox model based on the model parameters. All end faces to be sealed are combined in the overall model to form a sealing zone area.

[0013] A sealing strip structure symmetrical to the sealing strip area is designed on the sealing end face of the engine.

[0014] This method first obtains multiple types of gearboxes, establishes each gearbox model, merges the gearbox models into an overall model, and makes the input shaft axes of all gearbox models coincide, that is, it is predetermined that all gearbox models are merged with the input shaft axis as a reference, so as to facilitate the subsequent determination of the position of the end face to be sealed on each gearbox. The input shaft axis is selected as the reference because the position of the engine remains unchanged during the powertrain assembly process, so that the position of the gearbox input shaft connected to the engine remains unchanged, which is quantitative, while the output shaft of the gearbox can be appropriately rotated around the input shaft by a certain angle to meet the powertrain assembly requirements, that is, the position of the output shaft is adjustable. Using this feature, the input shaft axis position is selected as the reference. Ensure that a suitable sealing strip area can be selected; because the position of the gearbox output shaft is adjustable, the position of the output shaft in all gearbox models is pre-adjusted so that the height difference arrangement angle between the input shaft axis and the output shaft axis of each gearbox is adjusted and unified in the vertical direction, so as to reduce the variable parameters between the gearboxes and facilitate the calculation of the position and width of the end face to be sealed on each gearbox model. Then, based on the calculated positions and widths of all the end faces to be sealed, they are integrated into the overall model, and the sealing strip area formed by the merger of all the end faces to be sealed can be selected. Then, the sealing strip area is symmetrically designed to the sealing end face of the engine to form a sealing strip structure, thereby realizing the design of the sealing strip on the sealing end face of the engine.

[0015] In the early stage of design, the sealing belt structure obtained model data of various types of gearboxes in advance. The obtained sealing belt structure can fit and seal with the end faces to be sealed of these gearboxes, and has strong applicability. The layout angle of the output shaft is pre-adjusted and unified in the design process, which not only reduces the variable parameters, but also allows the output shafts of each gearbox to be neatly arranged, making it easy to accurately obtain the position of the appropriate end face to be sealed, thereby calculating the appropriate width of the end face to be sealed, reducing the machining workload as much as possible and achieving the economy of the sealing belt design. In addition, the height difference between the output shaft axis and the input shaft axis of the gearbox in the vertical direction during the powertrain assembly process is pre-unified, and the height difference is the height required in the actual powertrain assembly. The difference in degree can ensure that the sealing belt structure can fit with the end face to be sealed of the gearbox to achieve sealing and ensure the sealing effect; at the same time, the sealing belt area corresponding to the present sealing belt structure is the synthesis of all the end faces to be sealed, that is, by reasonably selecting the position and width of the end face to be sealed, the sealing belt structure can just fit with the selected largest model gearbox end face to be sealed or the smallest model gearbox end face to be sealed. After fitting with the end face to be sealed of the gearbox, the sealing belt structure that leaks out of the end face to be sealed can be machined off, so that the machining workload is minimized and the manufacturing material of the sealing belt structure on the engine can be saved, thereby improving the adaptability of the engine sealing end face while saving machining workload.

[0016] In the aforementioned method for designing a sealing strip for sealing an engine with a transmission, establishing each transmission model includes establishing an output shaft clearance space model and an input shaft clearance space model, with the end face to be sealed formed between the output shaft clearance space model and the input shaft clearance space model. The space between the output shaft clearance space model and the output shaft clearance space model is minimal and the layout is most difficult. Directly extracting the end face to be sealed at this location facilitates accurate alignment of the designed sealing strip position with it, allowing for accurate determination of the design position of the sealing strip on the engine's sealing end face. Accordingly, the output shaft clearance space model and the input shaft clearance space model also impose limits on the maximum width of the end face to be sealed, allowing for the determination of the most appropriate width of the end face to be sealed. This avoids the situation where the sealing strip width is excessively large due to an oversized end face to be sealed, allowing for the design of an appropriate sealing strip and reducing machining workload. Simultaneously, the end face to be sealed forms an offset between the output shaft, the input shaft, and components mounted thereon, ensuring that the sealing strip accurately aligns with the end face to be sealed, achieving effective sealing.

[0017] In the aforementioned design method for a sealing strip used to seal an engine with a transmission, the model parameters include the center distance between the output and input shafts, the output shaft radius, and the envelope radius of the flywheel. The output shaft clearance radius and the flywheel envelope radius are respectively obtained by superimposing the required spatial clearance data. The output shaft clearance radius and the input shaft clearance radius are then used to establish the output shaft clearance model and the input shaft clearance model. The center distance between the input and output shafts of the transmission determines the respective axial positions of the output and input shafts in the transmission model. A flywheel is mounted on the input shaft. Using the flywheel envelope radius as a model parameter, the sealing strip is positioned away from the flywheel after sealing against the end face to be sealed. Accordingly, the sealing strip is positioned away from the output shaft. Furthermore, by superimposing the required spatial clearance data, interference between the sealing strip and the flywheel and output shaft is avoided while allowing for a certain adjustment clearance for the end face to be sealed, thereby allowing for manufacturing errors in the sealing strip. The required spatial clearance data is based on the transmission layout specifications.

[0018] In the above-mentioned design method for the sealing strip used to seal the engine with the gearbox, the operation of adjusting the position of the output shaft in each gearbox model is as follows:

[0019] Determine the vertical height difference between the input shaft and the output shaft in each gearbox;

[0020] With the input shaft in the gearbox model as the origin, rotate the gearbox and adjust the height difference in each gearbox model to be consistent.

[0021] The height difference between the output shaft axis and the input shaft axis in different types of gearboxes is different. The height difference directly affects the layout angle of the output shaft. The layout angle of the output shaft is the angle between the line connecting the output shaft axis and the input shaft axis and the horizontal plane. By adjusting the height difference to adjust the layout angle of the output shaft, the output shaft layout angle of all gearbox models is unified, thereby obtaining the appropriate position and width of the sealing surface to be sealed, and realizing the economic design of the sealing belt.

[0022] In the above-mentioned design method for the sealing strip used to seal the transmission on the engine, the width of the end face to be sealed on each transmission model is calculated according to the following formula: W = abc, where W is the width of the end face to be sealed, a is the center distance between the output shaft and the input shaft, b is the output shaft avoidance space radius, and c is the input shaft avoidance space radius. Since the above-mentioned end face to be sealed is located between the output shaft avoidance space model and the input shaft avoidance space model, the width of the end face to be sealed can be calculated using the above formula, and the position of the end face to be sealed can be accurately obtained, thereby accurately obtaining the sealing strip area. The width of the end face to be sealed is maximized by directly subtracting the output shaft avoidance space radius and the input shaft avoidance space radius from the center distance, ensuring that the sealing end faces on different models of transmissions can be sealed and fitted with the sealing strip.

[0023] In the aforementioned design method for the sealing strip used to seal the engine with the transmission, the sealing strip area is defined as the area covered by all the end faces to be sealed within the overall model. The location of the sealing strip area varies depending on the transmission model. If the selected transmission model results in the end faces to be sealed covering multiple areas within the overall model, these areas are selected as the sealing strip areas. Specifically, when collecting the sealing strip areas, the areas are categorized and the areas not covered by the end faces to be sealed are hollowed out to reduce subsequent machining workload.

[0024] In the above-mentioned method for designing a sealing strip for sealing a transmission on an engine, the steps of preselecting and obtaining model parameters for multiple transmission models include obtaining center distance data for several transmissions and screening and classifying the center distance data to form a large center distance transmission category and a small center distance transmission category. Then, within the large center distance transmission category and the small center distance transmission category, the maximum center distance transmission category and the minimum center distance transmission category are selected and model parameters are obtained. By screening out the large center distance transmission category and the small center distance transmission category, the sealing strip of this engine can be designed for both large center distance transmissions and small center distance transmissions to meet the needs of various center distance transmission models on the market. Then, within the large center distance transmission category and the small center distance transmission category, the maximum center distance transmission category and the minimum center distance transmission category are selected and model parameters are obtained. Transmission models are established for each of these, and after merging them into an overall model, the selected sealing strip area encompasses all large center distance transmissions and all small center distance transmissions, streamlining the design process of the sealing end face.

[0025] The structure of a sealing strip used to seal an engine with a transmission is characterized by comprising an outer sealing strip capable of conforming to the end faces to be sealed in all types of transmissions with large center distances, and an inner sealing strip capable of conforming to the end faces to be sealed in all types of transmissions with small center distances. The outer sealing strip is arranged radially outward of the inner sealing strip along the engine output shaft. Both the inner and outer sealing strips, arranged radially inward and outward along the engine output shaft, are used to conform to and seal the transmission end faces to be sealed. Appropriate sealing strips are selected based on the center distance of the transmission to be assembled with the engine. The inner sealing strip seals with the end faces to be sealed in all types of transmissions with small center distances, while the outer sealing strip seals with the end faces to be sealed in all types of transmissions with large center distances. This allows the sealing end faces on the engine to conform to and seal with transmissions with different center distances, improving the adaptability of the sealing end faces. Both the inner and outer sealing strips cover all types of transmissions with large and small center distances selected during the design process. Based on the transmission specifications selected for actual assembly, after the transmission end faces to be sealed are conformed to and sealed with the sealing strips, the exposed portions of the sealing strip are machined away.

[0026] In the aforementioned sealing strip structure used to seal the engine with the transmission, a gap is provided between the outer side of the inner sealing strip and the inner side of the outer sealing strip. This gap is located in an area not covered by the sealing strip during the design process. This gap not only saves sealing strip material but also creates a gap in advance, improving machining efficiency.

[0027] Compared with the existing technology, the design method and structure of the sealing belt used for sealing the engine and the gearbox have the following advantages:

[0028] 1. The sealing belt on the sealing end face of the engine can fit with the sealing surface of various types of gearboxes, and has good applicability. The design process of the sealing belt area avoids the sealing belt width being too large, reasonably determines the required width of the sealing belt, reduces the machining workload and achieves economy.

[0029] 2. During the design process, the adjustable output shaft layout angle of the gearbox is utilized to combine the gearbox models into an overall model, which facilitates the determination of the position of the end face to be sealed. Then, the layout angle of the output shaft is unified to reduce variables, which enables the accurate acquisition of the position of the end face to be sealed and the calculation of its width, thereby minimizing the machining workload. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a gearbox model.

[0031] Figure 2 It is the overall model.

[0032] Figure 3 It is the overall model after unifying the output shaft arrangement angle.

[0033] Figure 4 It is the overall model after the sealing zone area is formed.

[0034] Figure 5 It is the sealing end face of the engine.

[0035] Figure 6 This is the front view of the gearbox.

[0036] In the figure, 1. Output shaft avoidance space model; 2. Input shaft avoidance space model; 3. End face to be sealed; 4. Sealing band area; 5. Outer sealing band; 6. Inner sealing band; 7. Gap; 8. Input shaft; 9. Output shaft. DETAILED DESCRIPTION

[0037] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0038] like Figure 5 、 Figure 6As shown, the gearbox includes a large center distance gearbox and a small center distance gearbox, both of which have an end face 3 to be sealed. The structure of the sealing belt used for sealing with the gearbox on the engine includes an outer sealing belt 5 that can fit with the end face 3 to be sealed of all large center distance gearbox categories and an inner sealing belt 6 that can fit with the end face 3 to be sealed of all small center distance gearbox categories. The outer sealing belt 4 is arranged on the outside of the inner sealing belt 6 along the radial direction of the engine output shaft 9, and a gap 7 is left between the outer edge of the inner sealing belt 6 and the inner edge of the outer sealing belt 5. In application, when all small center distance gearbox categories are selected, the end face 3 to be sealed on the gearbox is fitted and sealed with the inner sealing belt 6, and the outer sealing belt 5 is removed in advance by machining so that the end face 3 to be sealed and the inner sealing belt 6 are fixed. When all large center distance gearbox categories are selected, the end face 3 to be sealed on the gearbox is fitted and sealed with the outer sealing belt 5, and the inner sealing belt 6 located on the inner side of the outer sealing belt 5 is set by the engine cover, so that the inner sealing belt 6 does not need to be removed. All small center distance gearbox categories and all large center distance gearbox categories respectively include all small center distance gearboxes and all large center distance gearboxes obtained in the sealing belt design process.

[0039] The above-mentioned sealing belt design method includes obtaining center distance data of several gearboxes, and screening and classifying the center distance data according to the classification standards currently available on the market to form a large center distance gearbox category and a small center distance gearbox category, and then selecting the largest center distance gearbox and the smallest center distance gearbox within the large center distance gearbox category and the small center distance category, respectively, and obtaining the flywheel envelope radius and output shaft radius of the four gearboxes, respectively. The classification standards have a certain degree of flexibility and are different for different vehicle models. In this embodiment, for general passenger cars, the center distance between the input shaft and the output shaft in the gearbox is about 195 mm, which is a large center distance, and the center distance between the input shaft and the output shaft in the gearbox is about 180 mm, which is a small center distance.

[0040] like Figure 1 As shown, each gearbox model is established. First, the input shaft avoidance space radius is calculated according to the formula: input shaft avoidance space radius = flywheel envelope radius + space clearance requirement parameter. The output shaft avoidance space radius is calculated according to the formula: output shaft radius + space clearance requirement parameter = output shaft avoidance space radius, where the space clearance requirement parameter is the layout specification of the gearbox. The space clearance requirement parameter in the output shaft avoidance space needs to be greater than or equal to 3mm, and the space clearance requirement parameter in the input shaft avoidance space needs to be greater than or equal to 10mm. The respective axial positions of the output shaft 9 and the input shaft 8 are determined based on the obtained center distance between the output shaft 9 and the input shaft 8. Then, the output shaft avoidance space model 1 is established with the axis center of the output shaft 9 as the center and the output shaft avoidance space radius as the radius. The input shaft avoidance space model 2 is established with the axis center of the input shaft 8 as the center and the input shaft avoidance space radius as the radius. Figure 2 As shown, all the gearbox models are then merged and the axis centers of the input shafts in all the gearbox models are made coincident to form an overall model; and the height difference data of the axis centers of the input shaft 8 and the output shaft 9 in each gearbox are determined in the vertical direction, as shown in FIG. Figure 3 As shown, according to the height difference data in the actual gearbox assembly, the input shaft 8 in the gearbox model is taken as the origin, the gearbox is rotated and the height difference in each gearbox model is adjusted to be consistent, so that the layout angle of the output shaft 9 in all gearbox models is unified. The layout angle of the output shaft 9 in the gearbox model is the angle between the line between the axis center of the output shaft 9 and the axis center of the input shaft 8 and the horizontal plane. Then, the front end face between the output shaft avoidance space model 1 and the input shaft avoidance space model 2 in each gearbox model is selected as the end face to be sealed 3. After determining the position of the end face to be sealed 3, the width of the end face to be sealed of each gearbox model is calculated according to the formula: W=abc, where W is the width of the end face to be sealed, a is the center distance between the output shaft and the input shaft, b is the output shaft avoidance space radius, and c is the input shaft avoidance space radius; as shown Figure 4 As shown, finally, the area covered by all the end faces 3 to be sealed in the overall model is selected as the sealing belt area 4, and the sealing belt area 4 is symmetrically set on the sealing end face of the engine to form a sealing belt structure. After the engine power shaft and the gearbox input shaft are fixedly connected, the sealing belt structure on the engine just fits and seals with the end face 4 to be sealed on the front end face of the gearbox, ensuring the applicability of the sealing belt structure.

[0041] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

[0042] Although this document frequently uses terms such as sealing belt and gearbox model, the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitations is contrary to the spirit of the present invention.

Claims

1. A design method for a sealing strip on an engine for sealing with a gearbox, characterized in that: The steps include: Preselecting and obtaining model parameters of multiple types of gearboxes and establishing each gearbox model, merging all gearbox models and aligning the axis centers of input shafts (8) in all gearbox models to form an overall model; The position of the output shaft (9) in each gearbox model is adjusted to unify the height difference between the axis of the input shaft (8) and the axis of the output shaft (9) in all gearbox models in the vertical direction, the position of the end face (3) to be sealed on each gearbox model is determined, the width of the end face (3) to be sealed on each gearbox model is calculated based on the model parameters, and all the end faces (3) to be sealed are combined in the overall model to form a sealing belt area (4); A sealing belt structure symmetrical to the sealing belt area (4) is designed on the sealing end surface of the engine.

2. The design method of a sealing strip for sealing an engine with a gearbox according to claim 1, characterized in that: The above-mentioned establishment of each gearbox model includes establishing an output shaft avoidance space model (1) and establishing an input shaft avoidance space model (2), and the end face to be sealed (3) is formed between the output shaft avoidance space model (1) and the input shaft avoidance space model (2).

3. The design method of a sealing strip for sealing an engine with a gearbox according to claim 2, characterized in that: The model parameters include the center distance between the output shaft and the input shaft, the output shaft radius and the envelope radius of the flywheel. The output shaft avoidance space radius and the input shaft avoidance space radius are respectively obtained by superimposing the spatial clearance requirement data on the output shaft radius and the envelope radius of the flywheel. The output shaft avoidance space model (1) and the input shaft avoidance space model (2) are established based on the obtained output shaft avoidance space radius and the input shaft avoidance space radius.

4. The design method of a sealing strip for sealing an engine with a gearbox according to claim 3, characterized in that: The operation to adjust the position of the output shaft (9) in each gearbox model is: Determine the vertical height difference between the axis center of the input shaft (8) and the axis center of the output shaft (9) in each gearbox; Taking the input shaft (8) in the gearbox model as the origin, rotate the gearbox and make the height difference in each gearbox model consistent.

5. The design method of a sealing strip for sealing an engine with a gearbox according to claim 3, characterized in that: The width of the end face to be sealed (3) on each gearbox model is calculated according to the following formula: W = abc, where W is the width of the end face to be sealed, a is the center distance between the output shaft and the input shaft, b is the output shaft avoidance space radius, and c is the input shaft avoidance space radius.

6. The method for designing a sealing strip for sealing an engine with a gearbox according to any one of claims 1 to 5, characterized in that: The sealing zone area (4) is the area covered by all the end faces (3) to be sealed in the overall model.

7. The method for designing a sealing strip for sealing an engine and a gearbox according to any one of claims 1 to 5, characterized in that: The steps of preselecting and obtaining model parameters of multiple types of gearboxes include obtaining center distance data of several gearboxes and screening and classifying the center distance data to form a large center distance gearbox category and a small center distance gearbox category, and then selecting the maximum center distance gearbox and the minimum center distance gearbox in the large center distance gearbox category and the small center distance category respectively and obtaining the model parameters.

8. The structure of the sealing strip on the engine for sealing with the gearbox is characterized by: The sealing strip comprises an outer sealing strip (5) capable of being fitted with the end face (3) to be sealed in all types of gearboxes with large center distances, and an inner sealing strip (6) capable of being fitted with the end face (3) to be sealed in all types of gearboxes with small center distances, wherein the outer sealing strip (5) is arranged on the outer side of the inner sealing strip (6) along the radial direction of the engine output shaft (9).

9. The sealing strip structure for sealing an engine and a gearbox according to claim 8, characterized in that: A gap (7) is left between the outer edge of the inner sealing belt (6) and the inner edge of the outer sealing belt (5).

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