Pre-tightening force measuring device for transmission drive shaft and pre-tightening amount calibration method

Abstract

The application provides a pre-tightening force measuring device of a transmission drive shaft and a pre-tightening amount calibration method. The method is based on replacing the measuring device with the transmission drive shaft to be installed into a first housing and a second housing of the transmission, and comprises the following steps: after a first end surface of the measuring device is installed into the first housing, a first height and a second height are measured, the first height is a distance between a second end surface of the measuring device and a joint surface of the first housing, and the second height is a depth of a bearing hole of the second housing; an adjusting gasket is selected, the thickness of the adjusting gasket is obtained, the adjusting gasket is assembled between the second end surface of the measuring device and the second housing, and then the first housing and the second housing are assembled; the pre-tightening amount is calculated according to the thickness of the adjusting gasket, the first height and the second height; and the pre-tightening force detected by a sensor assembly in the measuring device is read as a pre-tightening force value corresponding to the calibrated pre-tightening amount. The pre-tightening force of the transmission drive shaft can be directly measured, and the pre-tightening amount can be calibrated with high accuracy.

Description

Technical Field

[0001] This application relates to the field of transmission technology, and in particular to a preload measuring device and a preload calibration method for a transmission drive shaft. Background Technology

[0002] In a transmission, the axial preload of the drive shaft is directly related to the bearing life, overall efficiency, and NVH (noise, vibration, and harshness). Appropriate preload can improve bearing life, while excessive preload will lead to lower transmission efficiency. Insufficient preload will cause excessive axial movement of the drive shaft during operation, resulting in abnormal noise, wear of parts, and other quality problems. Therefore, setting an appropriate preload value is crucial.

[0003] In the mass production of transmissions, due to cost and production efficiency constraints, it is impossible to measure the preload of each transmission driveshaft. The commonly used process in the industry is to indirectly control the target preload by controlling the preload amount. Therefore, finding the correlation between preload and preload amount (i.e., preload calibration) is particularly important.

[0004] However, since the driveshaft is installed inside the transmission housing, the preload is difficult to measure directly after assembly. In order to determine the relationship between preload and preload amount, it is often necessary to measure data such as drag torque to calibrate the relationship between preload and preload amount. However, the method of calibration using drag torque is greatly affected by factors such as operator and rotation speed, resulting in low measurement accuracy and low correlation with preload. Therefore, the calibration effect of preload amount is not good. Summary of the Invention

[0005] The main objective of this application is to provide a preload measuring device and a preload calibration method for a transmission drive shaft. The aim is to directly measure the axial preload of the transmission drive shaft using the preload measuring device, thereby enabling the calibration of the preload of the transmission drive shaft with high accuracy.

[0006] To achieve the above objectives, a first aspect of this application provides a preload measuring device for a transmission drive shaft. The measuring device has the same or similar height, material, size, weight, and shape as the transmission drive shaft to be measured. The measuring device includes: a first dummy shaft, a first bearing, a sensor assembly, a second dummy shaft, and a second bearing.

[0007] The first bearing is fixed to the first side of the first dummy shaft by an interference fit;

[0008] The second bearing is fixed to the first side of the second dummy shaft by an interference fit;

[0009] The sensor assembly is fitted tightly between the second side of the first dummy shaft and the second side of the second dummy shaft, and is used to measure the axial preload of the transmission shaft.

[0010] In some embodiments, the sensor assembly includes a pressure sensor, a first bracket, and a second bracket;

[0011] The first bracket is fixed to the first side of the pressure sensor, and the second bracket is fixed to the second side of the pressure sensor. The first bracket and the second bracket do not contact each other.

[0012] The first bracket is in close contact with the first side of the first dummy shaft, and the second bracket is in close contact with the first side of the second dummy shaft.

[0013] In some embodiments, the measuring device further includes a sensor display;

[0014] The sensor display is connected to the pressure sensor via a wiring harness passing through an opening in the transmission housing.

[0015] In some embodiments, the first dummy shaft includes a first shaft body and a first square protrusion that is in close contact with a first end face of the first shaft body;

[0016] The first bearing is fixed to the second end face of the first shaft by an interference fit;

[0017] The first square protrusion is in close contact with the first bracket;

[0018] The first shaft is the same as or similar in material, size and shape to the shaft corresponding to the transmission shaft of the gearbox to be measured.

[0019] In some embodiments, the first bearing is a first tapered roller bearing used for the drive shaft of the transmission to be measured;

[0020] The inner ring of the first tapered roller bearing is fixed to the second end face of the first shaft by an interference fit, and the interference amount of the interference fit is consistent with the interference amount of the transmission shaft to be measured.

[0021] In some embodiments, the material and dimensions of the first bracket are the same as or similar to those of the corresponding part of the transmission shaft of the gearbox to be measured, and the first bracket is configured as a first cylinder, with a first square groove provided on the first circular surface of the first cylinder.

[0022] The first square groove is used to connect with the first square protrusion through a concave-convex connection, so that the first cylinder and the first shaft are tightly assembled.

[0023] In some embodiments, the second dummy shaft includes a second shaft body and a second square protrusion that is closely attached to a first end face of the second shaft body;

[0024] The second bearing is fixed to the second end face of the second shaft body by an interference fit;

[0025] The second square protrusion is in close contact with the second bracket;

[0026] The second shaft is the same as or similar in material, size and shape to the shaft corresponding to the transmission shaft of the gearbox to be measured.

[0027] In some embodiments, the second bearing is a second tapered roller bearing used for the drive shaft of the transmission to be measured;

[0028] The inner ring of the second tapered roller bearing is fixed to the second end face of the second shaft by an interference fit, and the interference amount of the interference fit is consistent with the interference amount of the transmission shaft to be measured.

[0029] In some embodiments, the material and dimensions of the second bracket are the same as or similar to those of the corresponding part of the transmission shaft to be measured. The second bracket is configured as a second cylinder, and a second square groove is provided on the first circular surface of the second cylinder.

[0030] The second square groove is used to connect with the second square protrusion through a concave-convex connection, so that the second cylinder and the second shaft are tightly assembled.

[0031] In some embodiments, the second cylinder has a notch on its side for wiring the sensor assembly.

[0032] To achieve the above objectives, a second aspect of this application provides a method for calibrating the preload of a transmission driveshaft, which is based on replacing the measuring device described in the first aspect with the transmission driveshaft and installing it into the first and second housings of the transmission. The calibration method includes:

[0033] After the first end face of the measuring device is installed onto the first housing, a first height and a second height are measured. The first height is the distance between the second end face of the measuring device and the mating surface of the first housing, and the second height is the depth of the bearing hole of the second housing.

[0034] Select an adjustment shim, obtain the thickness of the adjustment shim, and assemble it between the second end face of the measuring device and the second housing. Then, assemble the first housing and the second housing together.

[0035] The preload is calculated based on the thickness of the adjusting shim, the first height, and the second height.

[0036] The preload force detected by the sensor assembly in the measuring device is read as the preload force value corresponding to the calibrated preload amount.

[0037] In some embodiments, the method further includes:

[0038] Replace the adjusting shims of different thicknesses and assemble them between the second end face of the measuring device and the second housing;

[0039] Based on the first height and the second height, the preload under different thicknesses of the adjusting shims is calculated;

[0040] The preload force detected by the sensor assembly under the adjustment shims of different thicknesses is read to obtain multiple sets of comparison data of the preload amount and the preload force;

[0041] Based on the comparison data of multiple sets of preload amount and preload force, the relationship curve between the preload amount and the preload force is obtained.

[0042] In some embodiments, the adjustment shim may include:

[0043] Select an adjusting shim of corresponding thickness based on the theoretical preload of the transmission shaft;

[0044] Alternatively, select an adjustment shim of the corresponding thickness based on the preset preload.

[0045] In some embodiments, the step of selecting an adjustment shim, obtaining the thickness of the adjustment shim, assembling it between the second end face of the measuring device and the second housing, and then assembling the first housing and the second housing together includes:

[0046] An adjustment shim is selected, and after obtaining the thickness of the adjustment shim, it is assembled between the second end face of the measuring device and the second housing.

[0047] According to the assembly requirements of the transmission drive shaft to be calibrated, determine the number of bolts, bolt type, and tightening torque to be used in the assembly;

[0048] According to the tightening torque, use the corresponding number and type of bolts to tighten and assemble the first housing and the second housing.

[0049] In some embodiments, the method includes, before reading the preload detected by the sensor assembly in the measuring device:

[0050] Rotate the second dummy axis in the measuring device until the value displayed on the sensor stabilizes, then stop rotating.

[0051] This application discloses a preload measuring device and a preload calibration method for a transmission driveshaft. The calibration method is based on replacing the transmission driveshaft with the measuring device and installing it into the first and second housings of the transmission. The method includes: installing the first end face of the measuring device into the first housing; measuring a first height and a second height, where the first height is the distance between the second end face of the measuring device and the mating surface of the first housing, and the second height is the depth of the bearing hole in the second housing; selecting an adjusting shim, obtaining its thickness, and assembling it between the second end face of the measuring device and the second housing; then assembling the first and second housings; calculating the preload based on the shim thickness, the first height, and the second height; and reading the preload detected by the sensor assembly in the measuring device as the preload value corresponding to the calibrated preload. This method can directly measure the axial preload of the transmission driveshaft, thereby enabling the calibration of the transmission driveshaft preload with high accuracy. Attached Figure Description

[0052] Figure 1 This is a partial cross-sectional view of a typical dual-clutch transmission provided in an embodiment of this application;

[0053] Figure 2 This is a perspective view of the preload measuring device for the transmission drive shaft provided in the embodiments of this application;

[0054] Figure 3 This is a cross-sectional view of the preload measuring device for the transmission shaft provided in this application embodiment;

[0055] Figure 4 This is a schematic diagram of the structure of the first dummy shaft provided in the embodiments of this application;

[0056] Figure 5 This is a schematic diagram of the structure of the transmission differential shaft provided in an embodiment of this application;

[0057] Figure 6 This is a schematic diagram of the structure of the second dummy shaft provided in the embodiments of this application;

[0058] Figure 7 This is a schematic diagram illustrating the process of installing the measuring device in the transmission housing, as provided in an embodiment of this application.

[0059] Figure 8 This is a cross-sectional view of the measuring device installed behind the transmission housing, provided in an embodiment of this application;

[0060] Figure 9 This is a flowchart of the calibration method for the preload of the transmission shaft provided in the embodiments of this application;

[0061] Figure 10 This is a schematic diagram of the first height provided in the embodiments of this application;

[0062] Figure 11 This is a schematic diagram of the second height provided in the embodiments of this application;

[0063] Figure 12 This is another flowchart of the calibration method for the preload of the transmission shaft provided in the embodiments of this application;

[0064] Figure 13 This is a graph showing the relationship between the preload and preload force obtained by measuring device in an embodiment of this application. Detailed Implementation

[0065] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0066] It should be noted that although functional modules are divided in the device schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart. The terms "first," "second," etc., in the specification, claims, and the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0067] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0068] In the field of shaft drives, the rotating shaft typically needs to be supported inside a housing by bearings. Figure 1 Taking a typical dual-clutch transmission as an example, a typical dual-clutch transmission refers to a transmission that uses two clutches connected to two input shafts respectively, achieving torque conversion and output via different output shafts to transmit engine power. The dual-clutch transmission uses tapered roller bearings to support the output shaft 2. The tapered roller bearing consists of three parts: an inner ring 3, an outer ring 4, and rollers 5. The inner ring 3 is press-fitted onto the output shaft 2, while the outer ring 4 is pressed into the bearing seat hole of the housing 1, which corresponds to the inner ring 3, and is secured by the housing 1. The rollers 5 are located between the inner ring 3 and the outer ring 4. The axial preload of the tapered roller bearing is adjusted by using adjusting shims 6 between the housing 1 and the outer ring 4.

[0069] Preloading bearings is crucial. Appropriate preload can extend bearing life, ensure smoother gearbox operation at high speeds, and reduce the risk of interference from component expansion due to high temperatures, thus minimizing the risk of misalignment within the gear system. Bearing preload is an indicator of whether the preload is appropriate after gearbox assembly.

[0070] Because preload is difficult to measure and control directly, the industry currently uses a common process to indirectly control the target preload by controlling the preload amount. To determine the correlation between preload and preload amount, it is often necessary to measure data such as drag torque to calibrate the correlation between preload and preload amount. However, the method of calibration using drag torque is greatly affected by factors such as operator and rotation speed, resulting in low measurement accuracy and a weak correlation with preload. Therefore, the calibration effect of preload amount is not good.

[0071] Reference Figures 2-3 , Figure 2 This is a perspective view of the preload measuring device for the transmission drive shaft provided in an embodiment of this application. Figure 3 This is a cross-sectional view of the preload measuring device for the transmission shaft provided in an embodiment of this application. Figure 2 As shown, the measuring device has the same or similar height, dimensions, material, weight, and shape as the transmission shaft to be measured. The measuring device 200 includes: a first dummy shaft 210, a first bearing 220, a sensor assembly 230, a second dummy shaft 240, and a second bearing 250;

[0072] The first bearing 220 is fixed to the first side of the first dummy shaft 210 by an interference fit;

[0073] The second bearing 250 is fixed to the first side of the second dummy shaft 240 by an interference fit;

[0074] The sensor assembly 230 is fitted tightly between the second side of the first dummy shaft 210 and the second side of the second dummy shaft 240, and is used to measure the axial preload of the transmission shaft.

[0075] In this embodiment of the application, Figures 2-3 The measuring device shown is installed in the transmission housing to replace the transmission drive shaft. It can directly measure the axial preload of the transmission drive shaft, and thus calibrate the preload of the transmission drive shaft with high accuracy.

[0076] This measuring device can be applied to preload calibration in various types of transmissions, such as the output shaft, intermediate shaft, and differential shaft of dual-clutch / hybrid / CVT / AT transmissions. Currently, transmission drive shafts commonly using tapered roller bearings (such as output shafts, intermediate shafts, and differential shafts) can all utilize this device. Figures 2-3The measuring device shown is used to calibrate its preload and preload amount.

[0077] It should be noted that, Figures 2-3 The overall height of the measuring device shown must be consistent with that of the transmission drive shaft to be measured. The size, material, weight and shape of the measuring device must be the same as or similar to that of the transmission drive shaft to be measured. The assembly relationship of the measuring device must be consistent with that of the transmission drive shaft to be measured. Only in this way can the axial force on the transmission drive shaft inside the housing be measured more accurately.

[0078] It should be noted that, in order to ensure that the size, material, weight, and shape of the measuring device are the same as or similar to the drive shaft of the transmission to be measured, the first and second bearings in the measuring device are directly the tapered roller bearings used on the drive shaft of the transmission to be measured. For example, if the measuring device is used to measure the preload of the differential shaft of the transmission, then the first and second bearings are directly the tapered roller bearings used on the differential shaft.

[0079] It should be noted that, to ensure the size, material, weight, and shape of the measuring device are the same as or similar to the transmission drive shaft being measured, the first dummy shaft of the measuring device should be the same as or similar to the material, size, and shape of the corresponding shaft of the transmission drive shaft being measured. Similarly, the second dummy shaft of the measuring device should be the same as or similar to the material, size, and shape of the corresponding shaft of the transmission drive shaft being measured. For example, if the measuring device is used to measure the preload of the differential shaft of the transmission, then the material, size, weight, and shape of the first dummy shaft need to be the same as or similar to the material, size, weight, and shape of the corresponding shaft of the differential shaft, and the material, size, weight, and shape of the second dummy shaft also need to be the same as or similar to the material, size, weight, and shape of the corresponding shaft of the differential shaft. In other words, depending on the type, model, size, etc. of the transmission drive shaft being calibrated, the material, size, weight, and shape of the first and second dummy shafts can be adjusted accordingly.

[0080] It should be noted that, in order to ensure that the size, material, weight, and shape of the measuring device are the same as or similar to those of the transmission driveshaft to be measured, the sensor assembly of the measuring device should be the same as or similar in material, size, and shape to the corresponding part of the transmission driveshaft to be measured. When the material, size, and shape characteristics of multiple transmission driveshafts to be measured are not significantly different, the sensor assembly can be used as a common component, that is, it can be disassembled and matched with first and second dummy shafts of different sizes, thereby reducing investment costs.

[0081] Reference Figure 3 The sensor assembly 230 includes a pressure sensor 231, a first bracket 232, and a second bracket 233;

[0082] The first bracket 232 is fixed on the first side of the pressure sensor 231, and the second bracket 233 is fixed on the second side of the pressure sensor 231. The first bracket 232 and the second bracket 233 do not contact each other.

[0083] The first bracket 232 is in close contact with the first side of the first dummy shaft 210, and the second bracket 233 is in close contact with the first side of the second dummy shaft 240.

[0084] In this embodiment, both the first bracket 232 and the second bracket 233 are bolted and fixed to both sides of the pressure sensor 231. After assembly, the first bracket 232 and the second bracket 233 do not contact each other. As supports for the pressure sensor 231, the first bracket 232 and the second bracket 233 can provide a certain degree of protection for the pressure sensor 231 and prevent it from being bumped or knocked during use.

[0085] It should be noted that, in order to ensure that the size, material, weight and shape of the measuring device are the same as or similar to the transmission shaft to be measured, the first bracket 232 and the second bracket 233 are the same as or similar to the corresponding parts of the transmission shaft to be measured in terms of material and external dimensions.

[0086] Reference Figure 3 Furthermore, the measuring device 200 also includes a sensor display 260, which is connected to the pressure sensor 231 via a wiring harness passing through an opening in the transmission housing.

[0087] Reference Figure 4 , Figure 4 This is a schematic diagram of the structure of the first dummy shaft provided in the embodiments of this application. The first dummy shaft 210 includes a first shaft body 211 and a first square protrusion 212 that is tightly attached to the first end face of the first shaft body 211;

[0088] The first bearing 220 is fixed to the second end face of the first shaft 211 by an interference fit;

[0089] The first square protrusion 212 is closely attached to the first bracket 232;

[0090] The first shaft 211 is the same or similar in material, size and shape to the corresponding shaft of the transmission shaft of the gearbox to be measured.

[0091] The first bearing 220 is the first tapered roller bearing used for the transmission shaft of the gearbox to be measured;

[0092] The inner ring of the first tapered roller bearing is fixed to the second end face of the first shaft 211 by an interference fit, and the interference amount of the interference fit is consistent with the interference amount of the transmission shaft of the gearbox to be measured.

[0093] It should be noted that in this embodiment, the first dummy shaft is configured as a first shaft body and a first square protrusion tightly attached to the first end face of the first shaft body. The first shaft body is made of the same or similar material, size, and shape as the corresponding shaft body of the transmission shaft to be measured. The first square protrusion is tightly attached to the first bracket. The first bearing directly adopts the tapered roller bearing used in the actual transmission shaft to be measured. (Refer to...) Figure 5 , Figure 5 This is a structural schematic diagram of the transmission differential shaft provided in an embodiment of this application. For example, if the transmission drive shaft to be measured is a differential shaft, then the first shaft body has the same or similar material, size, and shape as the corresponding shaft body of the differential shaft, and the first bearing is a tapered roller bearing used in the differential shaft.

[0094] It is understood that the dimensions of the first square protrusion can be adjusted accordingly based on the dimensions of the first shaft and the first bracket. This application does not specifically limit the dimensions of the first square protrusion in its embodiments.

[0095] In this embodiment, the material and dimensions of the first bracket 232 are the same as or similar to those of the corresponding part of the transmission shaft to be measured. The first bracket 232 is configured as a first cylinder, and a first square groove is provided on the first circular surface of the first cylinder; the first square groove is used to connect with the first square protrusion 212 through a concave-convex connection, so that the first cylinder and the first shaft are tightly assembled.

[0096] Reference Figure 6 , Figure 6 This is a schematic diagram of the structure of the second dummy shaft provided in an embodiment of this application. The second dummy shaft 240 includes a second shaft body 241 and a second square protrusion 242 that is tightly attached to the first end face of the second shaft body 241;

[0097] The second bearing 250 is fixed to the second end face of the second shaft 241 by an interference fit;

[0098] The second square protrusion 242 is closely attached to the second bracket 233;

[0099] The second shaft 241 is the same or similar in material, size and shape to the corresponding shaft of the transmission shaft to be measured.

[0100] The second bearing 250 is the second tapered roller bearing used for the transmission shaft of the gearbox to be measured;

[0101] The inner ring of the second tapered roller bearing is fixed to the second end face of the second shaft 241 by an interference fit, and the interference amount of the interference fit is consistent with the interference amount of the transmission shaft of the gearbox to be measured.

[0102] It should be noted that in this embodiment, the second dummy shaft is configured as a second shaft body and a second square protrusion tightly attached to the first end face of the second shaft body. The second shaft body is the same as or similar in material, size, and shape to the corresponding shaft body of the transmission shaft to be measured. The second square protrusion is tightly attached to the second bracket. The second bearing is directly adopted from the tapered roller bearing used in the actual transmission shaft to be measured. For example, if the transmission shaft to be measured is a differential shaft, then the second shaft body is the same as or similar in material, size, and shape to the corresponding shaft body of the differential shaft, and the second bearing is a tapered roller bearing used in differential shafts.

[0103] In this embodiment, the material and dimensions of the second bracket 233 are the same as or similar to those of the corresponding part of the transmission shaft to be measured. The second bracket 233 is configured as a second cylinder, and a second square groove is provided on the first circular surface of the second cylinder; the second square groove is used to connect with the second square protrusion 242 through a concave-convex connection, so that the second cylinder and the second shaft are tightly assembled.

[0104] It is understood that the dimensions of the second square protrusion can be adjusted accordingly based on the dimensions of the second shaft and the second bracket. This application does not specifically limit the dimensions of the second square protrusion in its embodiments.

[0105] In this embodiment, considering that most transmission drive shafts are roughly cylindrical, the first and second supports are set as cylinders. This ensures that the entire sensor assembly can be used as a single unit and can be disassembled to match other sizes of first and second dummy shafts to measure the preload of multiple similar transmission drive shafts, thereby reducing costs.

[0106] In this embodiment, a first square protrusion is provided on the first end face of the first shaft, and a first square groove is provided on the first circular surface of the first cylinder of the first bracket, so that the first square groove and the first square protrusion are connected by a concave-convex connection. Simultaneously, a second square protrusion is provided on the first end face of the second shaft, and a second square groove is provided on the first circular surface of the second cylinder of the second bracket, so that the second square groove and the second square protrusion are connected by a concave-convex connection. With this arrangement, when the second dummy shaft is rotated, the second square protrusion and the first square protrusion can drive the entire sensor assembly, the first dummy shaft, and the tapered roller bearing to rotate. Furthermore, the first and second square protrusions also serve a positioning function during the installation of the first and second brackets.

[0107] Furthermore, referring to Figure 3 The second cylinder has a notch on its side for wiring the pressure sensor in the sensor assembly.

[0108] In this embodiment, the measuring device needs to be replaced by the transmission drive shaft and installed in the transmission housing in order to measure the preload of the transmission drive shaft and calibrate the preload amount. (Refer to...) Figures 7-8 , Figure 7 This is a schematic diagram illustrating the process of installing the measuring device in the transmission housing, as provided in an embodiment of this application. Figure 8 This is a cross-sectional view of the measuring device installed behind the transmission housing, provided in an embodiment of this application. Figure 7 As shown, the transmission housing includes a first housing 270 and a second housing 280. The measuring device is replaced with the transmission drive shaft so that the first housing 270 and the second housing 280 enclose it.

[0109] Specifically, the installation process is as follows: First, connect the sensor display 260 to the pressure sensor 231. Then, replace the entire transmission drive shaft with the measuring device and install it into the transmission housing. Specifically, first, fit the end face of the first dummy shaft 210 tightly to the first housing 270. Then, install the adjusting shim between the outer ring of the tapered roller bearing on the second dummy shaft 240 and the second housing 280. Finally, assemble the first housing 270 and the second housing 280 together and tighten the bolts at both ends. Alternatively, fit the end face of the second dummy shaft 240 tightly to the first housing 270. Then, install the adjusting shim between the outer ring of the tapered roller bearing on the first dummy shaft 210 and the second housing 280. Finally, assemble the first housing 270 and the second housing 280 together. The number, type, and tightening torque of the bolts should be in accordance with the actual assembly requirements of the transmission drive shaft to be measured.

[0110] Taking the differential shaft of a transmission as an example, the shaft, which uses tapered roller bearings at both ends, must be assembled using a preload method. After assembly, the differential shaft will be subjected to axial pressure, which comes from the weight of the shaft itself, as well as the elastic deformation generated by the first housing 270 and the second housing 280 on both sides, and the first bearing 220 (tapered roller bearing) and the second bearing 250 (tapered roller bearing). By replacing the differential shaft with this measuring device and installing it inside the transmission housing, the axial force of the differential shaft in its static state can be simulated.

[0111] In this embodiment, after installation, the effectiveness of the installation can be detected by observing whether the real-time preload value is displayed on the sensor display. To obtain a more accurate preload measurement, the measuring device must first be rotated to ensure that the first and second bearings, i.e., the tapered roller bearings at both ends, are properly engaged. Figure 6As shown, the second dummy shaft has a second square protrusion. A common ratchet wrench can be used to rotate the second dummy shaft, thereby causing the sensor assembly, the first dummy shaft, and the tapered roller bearing to rotate via the second square protrusion. During rotation, as the tapered roller bearing gradually breaks in, the real-time preload value will gradually decrease until it stabilizes. This process typically takes 10-20 rotations. Observe the value displayed on the sensor display. Once the displayed value stabilizes, stop rotating and remove the ratchet wrench. At this point, the installation is complete.

[0112] It should be noted that when measuring the preload of the transmission driveshaft, a suitable adjusting shim needs to be selected and installed between the outer ring of the tapered roller bearing on the first dummy shaft side and the second housing, or between the outer ring of the tapered roller bearing on the second dummy shaft side and the second housing. The specific installation position is determined by the installation position of the adjusting shim on the transmission driveshaft to be measured. Therefore, before replacing the transmission driveshaft with this measuring device and installing it into the transmission housing, a suitable adjusting shim needs to be selected first.

[0113] Reference Figure 9 , Figure 9 This is a flowchart of a calibration method for the preload of a transmission shaft provided in an embodiment of this application, based on... Figures 2-3 The measuring device shown is installed in the first and second housings of the transmission to replace the transmission drive shaft and perform the following actions, including but not limited to steps S901 to S904.

[0114] Step S901: After installing the first end face of the measuring device onto the first housing, measure the first height and the second height. The first height is the distance between the second end face of the measuring device and the mating surface of the first housing, and the second height is the depth of the bearing hole of the second housing.

[0115] In this embodiment of the application, it is through Figures 2-3 The measuring device shown is used to calibrate the preload of the transmission drive shaft. First, the first end face of the measuring device must be installed onto the first housing. Then, the first height and the second height are measured. The first height is the distance between the second end face of the measuring device and the mating surface of the first housing. The second height is the depth of the bearing bore in the second housing. The first end face of the measuring device can be either the end face of the first dummy shaft side or the end face of the second dummy shaft side. The second end face of the measuring device is the opposite end face to the first end face; that is, the second end face is either the end face of the outer ring of the tapered roller bearing on the second dummy shaft side or the end face of the outer ring of the tapered roller bearing on the first dummy shaft side. In other words, when the end face of the measuring device on the first dummy shaft side is installed onto the first housing, the corresponding second end face is the end face of the outer ring of the tapered roller bearing on the second dummy shaft side. When the end face of the measuring device on the second dummy shaft side is installed onto the first housing, the corresponding second end face is the end face of the outer ring of the tapered roller bearing on the first dummy shaft side.

[0116] In this embodiment of the application, after the first end face of the measuring device is installed onto the first housing, the first height and the second height can be measured. For example... Figure 10 As shown, the first height is the distance between the end face of the first dummy shaft side of the measuring device and the mating surface of the first housing. Figure 11 As shown, the second height is the depth of the bearing hole of the second housing, that is, the distance from the bottom of the bearing hole of the second housing to the mating surface of the second housing.

[0117] Step S902: Select an adjustment shim, obtain the thickness of the adjustment shim, and assemble it between the second end face of the measuring device and the second housing. Then, assemble the first housing and the second housing together.

[0118] In this embodiment, after the first end face of the measuring device is installed onto the first housing, an adjustment shim is required. After obtaining the thickness of the adjustment shim, it is fitted between the second end face of the measuring device and the second housing. Then, the first housing and the second housing are assembled. For example, as shown... Figure 10 As shown, after the end face of the first dummy shaft side of the measuring device is installed onto the first housing, the selected adjusting shim needs to be installed between the outer ring of the tapered roller bearing on the second dummy shaft side of the measuring device and the second housing.

[0119] It should be noted that the specific assembly position of the adjusting shim is determined by the actual assembly position of the transmission drive shaft to be calibrated. For example, if the actual assembly position of the transmission drive shaft to be calibrated is between the outer ring of the tapered roller bearing on the first dummy shaft side of the measuring device and the second housing, then one adjusting shim is selected, its thickness is determined, and it is then assembled between the outer ring of the tapered roller bearing on the first dummy shaft side of the measuring device and the second housing. Conversely, if the actual assembly position of the transmission drive shaft to be calibrated is between the outer ring of the tapered roller bearing on the second dummy shaft side of the measuring device and the second housing, then one adjusting shim is selected, its thickness is determined, and it is then assembled between the outer ring of the tapered roller bearing on the second dummy shaft side of the measuring device and the second housing.

[0120] Specifically, regarding the selection of adjusting shims, shims of corresponding thickness can be selected based on the theoretical preload of the transmission drive shaft to be calibrated. Alternatively, shims of corresponding thickness can be selected based on the preset preload.

[0121] For example, the theoretical preload of the transmission driveshaft to be calibrated can be calculated based on its model, size, material, and related parameters. Then, an adjusting shim with a thickness corresponding to this theoretical preload can be selected. For instance, if the calculated theoretical preload is P, an adjusting shim with a thickness C corresponding to the theoretical preload P can be selected. Alternatively, a preload can be preset, for example, 0.15 mm, and an adjusting shim with a thickness corresponding to the preload of 0.15 mm can be selected.

[0122] In this embodiment, after the first end face of the measuring device is installed onto the first housing, an adjusting shim needs to be selected. The thickness of the adjusting shim is determined, and it is then assembled between the second end face of the measuring device and the second housing. Finally, the first housing and the second housing are assembled together. Specifically, after installing the first end face of the measuring device onto the first housing and assembling the selected adjusting shim between the second end face of the measuring device and the second housing after determining its thickness, the number, type, and tightening torque of the bolts used for assembly are determined according to the assembly requirements of the transmission shaft to be calibrated. Based on the tightening torque, the first housing and the second housing are tightened together using the corresponding number and type of bolts.

[0123] In this embodiment of the application, as described above, to make the measured preload more accurate, the second dummy shaft in the measuring device needs to be rotated to ensure that the tapered roller bearings at both ends are properly engaged until the value displayed on the sensor stabilizes, at which point rotation stops. That is, the measuring device needs to be rotated to ensure that the first and second bearings, i.e., the tapered roller bearings at both ends, are properly engaged. Figure 6 As shown, the second dummy shaft has a second square protrusion. A common ratchet wrench can be used to rotate the second dummy shaft, thereby causing the sensor assembly, the first dummy shaft, and the tapered roller bearing to rotate via the second square protrusion. During rotation, as the tapered roller bearing gradually breaks in, the real-time preload value will gradually decrease until it stabilizes. This process typically takes 10-20 revolutions. Observe the value displayed on the sensor display. Once the displayed value stabilizes, stop rotating. At this point, the stable value displayed on the sensor display is the real-time preload value.

[0124] Step S903: Calculate the preload amount based on the thickness of the adjusting shim, the first height, and the second height.

[0125] In this embodiment of the application, after measuring the thickness, first height and second height of the adjusting shim, the preload can be calculated based on the thickness, first height and second height of the adjusting shim.

[0126] For example, if the thickness of the adjusting shim is measured as C, the first height is measured as A, and the second height is measured as B, then the preload is the first height plus the thickness of the adjusting shim minus the second height, i.e., the preload X = A + CB.

[0127] Step S904: Read the preload force detected by the sensor assembly in the measuring device as the preload force value corresponding to the calibrated preload amount.

[0128] In this embodiment, after rotation stops, the preload detected by the sensor assembly is directly read, i.e., the stable value displayed on the sensor display. This value is the real-time preload of the transmission shaft, which can be denoted as Y. Thus, the comparison data (X—Y) between the preload amount and the preload force can be obtained.

[0129] Reference Figure 12 , Figure 12 This is another flowchart of the calibration method for the preload of the transmission shaft provided in the embodiments of this application, including but not limited to steps S1201 to S1204.

[0130] Step S1201: Replace the adjustment shims of different thicknesses and assemble them between the second end face of the measuring device and the second housing;

[0131] Step S1202: Calculate the preload amount under different thicknesses of the adjusting shims based on the first height and the second height.

[0132] Step S1203: Read the preload force detected by the sensor assembly under the adjustment shims of different thicknesses to obtain multiple sets of comparison data of preload amount and preload force;

[0133] Step S1204: Based on the comparison data of multiple sets of preload and preload, obtain the relationship curve between preload and preload.

[0134] In this embodiment, to obtain the correspondence between preload and preload force, it is necessary to replace the adjusting shims with those of different thicknesses and assemble them between the second end face of the measuring device and the second housing. Then, based on the first height and the second height, the preload under different thickness adjusting shims is calculated. Next, the preload force detected by the sensor assembly under different thickness adjusting shims is read, i.e., the value displayed on the sensor display, to obtain multiple sets of comparison data between preload and preload force. Based on these multiple sets of comparison data, the relationship curve between preload and preload force can be obtained.

[0135] For example, first, an adjusting shim of thickness C1 is selected, assembled into the measuring device, and then installed into the transmission housing. Then, based on the first height A and the second height B, the first preload X1 = A + C1 - B is calculated. The first preload force displayed on the sensor at this time is read as Y1, thus obtaining a set of preload and preload force comparison data X1-Y1. Next, an adjusting shim of thickness C2 is selected, assembled into the measuring device, and then installed into the transmission housing. Then, based on the first height A and the second height B, the second preload X2 = A + C2 - B is calculated. The second preload force displayed on the sensor at this time is read as Y2, thus obtaining a set of preload and preload force comparison data X2-Y2. In this way, multiple sets of preload and preload comparison data can be obtained, such as: X1-Y1, X2-Y2, X3-Y3, X4-Y4, X5-Y5, etc. Refer to Table 1, which is a comparison table of preload and preload force for the transmission drive shaft. Figure 13 , Figure 13 This is a graph showing the relationship between preload and preload force obtained by a measuring device in an embodiment of this application. The result is as follows... Figure 13 After viewing the relationship curves shown, the corresponding preload can be selected as the design target and process parameter for execution based on the design requirements of different preload amounts.

[0136] Table 1 Comparison of Preload and Preload Force for Transmission Driveshaft

[0137] X - Preload (mm) Y - Preload (N) 0.0159 197 0.0659 981 0.1059 2048 0.1659 4007 0.2109 5750

[0138] The embodiments provided in this application are based on Figures 2-3 The measuring device shown is installed in the first and second housings of the transmission to perform a preload calibration method. The calibration results are highly accurate and reliable, thereby improving the transmission's lifespan, transmission efficiency, and NVH levels. The calibration parts calibrated using the calibration method provided in this application can be used as calibration parts for transmission assembly line equipment to guide production and improve production quality.

[0139] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

[0140] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.

[0141] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0142] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0143] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0144] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0145] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0146] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0147] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. A device for measuring the pre-tension of a transmission drive shaft, characterized in that The measuring device is the same as the transmission shaft in height, material, size, weight and shape, and comprises a first dummy shaft, a first bearing, a sensor assembly, a second dummy shaft and a second bearing; The first bearing is fixed on the first side of the first dummy shaft by interference fit; The second bearing is fixed on the first side of the second dummy shaft by interference fit; The sensor assembly is tightly fitted between the second side of the first dummy shaft and the second side of the second dummy shaft for measuring the axial pre-tightening force of the transmission shaft; The measuring device is replaced between the first housing and the second housing of the transmission to which the transmission shaft to be measured is installed, wherein the end face of the first dummy shaft is tightly fitted to the first housing, and an adjusting gasket is installed between the outer ring of the second bearing on the second dummy shaft and the second housing; or the end face of the second dummy shaft is tightly fitted to the first housing, and an adjusting gasket is installed between the outer ring of the first bearing on the first dummy shaft and the second housing.

2. The apparatus of claim 1, wherein, The sensor assembly comprises a pressure sensor, a first bracket and a second bracket; The first bracket is fixed on the first side of the pressure sensor, and the second bracket is fixed on the second side of the pressure sensor, and the first bracket and the second bracket are not in contact with each other; The first bracket is tightly fitted to the first side of the first dummy shaft, and the second bracket is tightly fitted to the first side of the second dummy shaft.

3. The apparatus of claim 2, wherein, The measuring device further comprises a sensor display; The sensor display is connected with the pressure sensor through a wire harness passing through a housing opening of the transmission.

4. The apparatus of claim 2, wherein, The first dummy shaft comprises a first shaft body and a first square protrusion tightly fitted to the first end face of the first shaft body; The first bearing is fixed on the second end face of the first shaft body by interference fit; The first square protrusion is tightly fitted to the first bracket; The first shaft body is the same as the corresponding shaft body of the transmission shaft to be measured in material, size and shape.

5. The apparatus of claim 4, wherein, The first bearing is a first tapered roller bearing used for the transmission shaft to be measured; The inner ring of the first tapered roller bearing is fixed on the second end face of the first shaft body by interference fit, and the interference amount of the interference fit is consistent with the interference amount of the transmission shaft to be measured.

6. The apparatus of claim 4, wherein, The first bracket is the same as the corresponding part of the transmission shaft to be measured in material and size, and the first bracket is provided as a first cylinder, and a first square recess is arranged on the first circular face of the first cylinder; The first square recess is used to be connected with the first square protrusion by the concave-convex connection mode, so that the first cylinder is tightly fitted with the first shaft body.

7. The apparatus of claim 2, wherein, The second dummy shaft comprises a second shaft body and a second square protrusion tightly fitted to the first end face of the second shaft body; The second bearing is fixed on the second end face of the second shaft body by interference fit; The second square protrusion is tightly fitted to the second bracket; The second shaft body is the same as the corresponding shaft body of the transmission shaft to be measured in material, size and shape.

8. The apparatus of claim 7, wherein, The second bearing is a second tapered roller bearing corresponding to the transmission drive shaft to be measured; The inner ring of the second tapered roller bearing is fixed on the second end face of the second shaft body by interference fit, and the interference amount of the interference fit is consistent with the interference amount of the transmission drive shaft to be measured.

9. The apparatus of claim 7, wherein, The second support has the same or similar material and size as the corresponding part of the transmission drive shaft to be measured, the second support is provided as a second cylinder, and a second square recess is arranged on the first circular face of the second cylinder; The second square recess is used to be connected with the second square convex body by the connection mode of concave-convex combination, so that the second cylinder is tightly assembled with the second shaft body.

10. The apparatus of claim 9, wherein, The side surface of the second cylinder is provided with a notch for the wiring of the sensor assembly.

11. A method of calibrating the pre-tightening of a transmission drive shaft, based on replacing the measuring device according to any one of claims 1-10 in the installation of a transmission drive shaft into a first housing and a second housing of a transmission, characterized in that, The calibration method comprises: After the first end face of the measuring device is installed to the first shell, the first height and the second height are measured, the first height is the distance between the second end face of the measuring device and the closing face of the first shell, and the second height is the depth of the bearing hole of the second shell; An adjusting gasket is selected, the thickness of the adjusting gasket is obtained, and then the adjusting gasket is assembled between the second end face of the measuring device and the second shell, and finally the first shell and the second shell are assembled together; According to the thickness of the adjusting gasket, the first height and the second height, the pre-tightening amount is calculated; The pre-tightening force detected by the sensor assembly in the measuring device is read as the pre-tightening force value corresponding to the pre-tightening amount.

12. The method of claim 11, wherein, The method further comprises: An adjusting gasket with different thickness is assembled between the second end face of the measuring device and the second shell; According to the first height and the second height, the pre-tightening amount under the adjusting gasket with different thickness is calculated; The pre-tightening force detected by the sensor assembly under the adjusting gasket with different thickness is read to obtain a plurality of comparison data of the pre-tightening amount and the pre-tightening force; According to the comparison data of the pre-tightening amount and the pre-tightening force, the relationship curve of the pre-tightening amount and the pre-tightening force is obtained.

13. The method of claim 11, wherein, The selection of the adjusting gasket comprises: According to the theoretical pre-tightening amount of the transmission drive shaft, an adjusting gasket with corresponding thickness is selected; Or, according to the preset pre-tightening amount, an adjusting gasket with corresponding thickness is selected.

14. The method of claim 11, wherein, The selection of the adjusting gasket, the thickness of the adjusting gasket is obtained, and then the adjusting gasket is assembled between the second end face of the measuring device and the second shell, and finally the first shell and the second shell are assembled together, comprises: An adjusting gasket is selected, the thickness of the adjusting gasket is obtained, and then the adjusting gasket is assembled between the second end face of the measuring device and the second shell; According to the assembly requirements of the transmission drive shaft to be calibrated, the number, type and tightening torque of the bolts used for assembly are determined; According to the tightening torque, the first shell and the second shell are tightened and assembled together by using the corresponding number and type of bolts.

15. The method of claim 11, wherein, Before reading the pre-tightening force detected by the sensor assembly in the measuring device, the method further comprises: The second dummy shaft in the measuring device is rotated until the value displayed on the sensor display is stable, and then the rotation is stopped.

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