Differential gear backlash dynamic measuring device and measuring method thereof
By designing a dynamic measurement device for differential tooth backlash, and utilizing the shaft expansion mechanism and drive mechanism, the backlash between each tooth of the half-shaft gear and the planetary gear is measured. This solves the problem that static measurement cannot detect the backlash of each tooth, and achieves more complete measurement results.
Patent Information
- Application Number
- CN202411129715.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-16
- Publication Date
- 2026-03-03
AI Technical Summary
Existing differential tooth backlash measurement devices are static measurements and cannot detect the backlash corresponding to each tooth of the half-shaft gear and planetary gear. The results are limited and incomplete.
Design a dynamic measurement device for differential tooth backlash, including a frame, a fixed unit and symmetrically arranged measurement units. The device uses a shaft expansion mechanism and a drive mechanism to tension the half-shaft gears respectively, and reads the rotation angle value through a circular grating reading head and a circular grating disk to realize the measurement of the backlash between each tooth of the half-shaft gear and each tooth of the planetary gear.
Dynamic measurement of differential tooth backlash has been achieved, which can accurately measure the backlash between each tooth of the half-shaft gear and each tooth of the planetary gear, resulting in more complete results and improving the accuracy and comprehensiveness of the measurement.
Smart Images
Figure CN121594774A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of differential testing technology, and in particular to a dynamic measuring device and method for differential tooth backlash. Background Technology
[0002] In the assembly process of a differential, measuring the differential tooth backlash is a crucial step. Currently, differential tooth backlash measurement devices are typically static, meaning one half-shaft gear is fixed while the other half-shaft gear is driven to rotate forward and backward, and a set of tooth backlashes is measured. However, each tooth of the half-shaft gear in a differential engages with each tooth of the planetary gears on both sides at certain moments, and the backlash between the two corresponding meshing teeth is different each time. Static measurement cannot measure the backlash corresponding to each tooth of the half-shaft gear and planetary gears, resulting in a single and incomplete measurement. Summary of the Invention
[0003] The main objective of this invention is to propose a dynamic measurement device and method for differential tooth backlash, aiming to solve the problem that existing differential tooth backlash measurement devices are static and cannot detect the backlash corresponding to each tooth of the half-shaft gear and planetary gear, resulting in a single and incomplete measurement.
[0004] To achieve the above objectives, the present invention proposes a dynamic measurement device for differential tooth backlash, comprising:
[0005] frame;
[0006] A mounting unit, disposed on the frame, for securing the differential housing; and,
[0007] A pair of measuring units are disposed opposite to each other on the frame, and respectively located above and below the fixed unit; each measuring unit includes a mounting frame, a shaft expansion mechanism, a drive mechanism, and a measuring mechanism. The mounting frame is movably mounted on the frame and has a vertical travel. The shaft expansion mechanism is rotatably mounted on the mounting frame and is used to tension the corresponding half-shaft gear in the differential. The drive mechanism is disposed on the mounting frame and connected to the shaft expansion mechanism. The measuring mechanism includes a circular grating reading head and a circular grating disk disposed opposite to each other. The circular grating reading head is disposed on the mounting frame, and the circular grating disk is disposed on the shaft expansion mechanism.
[0008] One of the measuring units has a drive mechanism for driving the expansion shaft mechanism to rotate, and the other measuring unit has a drive mechanism for applying a reverse torque force to the expansion shaft mechanism.
[0009] In one embodiment, each of the expansion shaft mechanisms includes an expansion sleeve and a spindle. The expansion sleeve is rotatably mounted on the mounting bracket, and the spindle is movably mounted inside the expansion sleeve, having a vertical travel relative to the expansion sleeve.
[0010] In one embodiment, each of the expansion shaft mechanisms further includes a first cylinder, which is disposed on the mounting bracket and is used to drive the mandrel to move in the vertical direction.
[0011] In one embodiment, the expansion mechanism further includes an outer sleeve and an inner sleeve. The inner sleeve is sleeved outside the mandrel, and the outer sleeve is sleeved outside the inner sleeve. The outer sleeve is rotatably mounted on the mounting bracket. The expansion sleeve is disposed at one end of the inner sleeve near the fixing unit and located outside the outer sleeve; wherein:
[0012] The inner wall of the outer sleeve is provided with a plurality of first semicircular grooves along the circumference, and the outer wall of the inner sleeve is provided with a plurality of second semicircular grooves corresponding to the plurality of first semicircular grooves. A ball bearing is installed in each of the first semicircular grooves and the corresponding second semicircular groove; and / or,
[0013] A spring is fitted between the inner sleeve and the outer sleeve, and the two ends of the spring are respectively connected to the inner sleeve and the outer sleeve.
[0014] In one embodiment, the drive mechanism includes a motor and a transmission assembly. The motor is mounted on the mounting bracket, and the output shaft of the motor is connected to the outer sleeve via the transmission assembly.
[0015] In one embodiment, the transmission assembly includes a first pulley, a second pulley, and a multi-ribbed belt. The first pulley is fixedly sleeved on the output shaft of the motor, the second pulley is fixedly sleeved on the outer sleeve, and the multi-ribbed belt is stretched on the first pulley and the second pulley.
[0016] In one embodiment, a connecting bearing is provided at one end of the inner sleeve away from the fixing unit, and the inner ring of the connecting bearing is connected to the inner sleeve; the measuring unit further includes a fine-tuning mechanism, which includes an electric cylinder, a support, and a rocker. The electric cylinder is disposed on the mounting frame, the support is disposed on the mounting frame and located between the electric cylinder and the shaft expansion mechanism, and the rocker is hinged to the support to form a fulcrum. The two ends of the rocker are respectively connected to the output end of the electric cylinder and the outer ring of the bearing.
[0017] In one embodiment, the distance from the fulcrum to the output end of the electric cylinder is equal to the distance from the fulcrum to the axis of the inner sleeve.
[0018] In one embodiment, the fixing unit includes a fixing platform, a pressure plate, and a second cylinder. The fixing platform is disposed on the frame and has a positioning hole for placing the differential. The pressure plate is movably mounted above the fixing platform. The second cylinder is disposed on the frame and is used to drive the pressure plate to move up and down to fix the housing of the differential.
[0019] This invention also proposes a method for dynamically measuring differential tooth backlash, using the aforementioned device for dynamically measuring differential tooth backlash. The method includes the following steps:
[0020] The housing of the differential is fixed by a control unit;
[0021] Control the movement of a pair of test units and cause each shaft expansion mechanism to tighten the corresponding half-shaft gear;
[0022] The drive mechanism of one of the measuring units drives the expansion shaft mechanism to rotate in the forward and reverse directions, while the drive mechanism of the other measuring unit outputs a corresponding reverse torsional force as a load.
[0023] Obtain the rotation angle values measured by two measuring mechanisms, and obtain the differential tooth backlash based on the rotation angle values.
[0024] In the technical solution of this invention, each shaft-expanding mechanism is equipped with a driving mechanism and a measuring mechanism. Two shaft-expanding mechanisms can respectively tension and connect two half-shaft gears. The driving mechanism of one shaft-expanding mechanism drives the corresponding shaft-expanding mechanism to rotate the half-shaft gear. The driving mechanism of the other shaft-expanding mechanism outputs a reverse torque force as a load, causing the half-shaft gear of the other shaft-expanding mechanism to rotate passively. The half-shaft gear is always under force, and the meshing state is stable. During measurement, the driving mechanism of one shaft-expanding mechanism drives the corresponding half-shaft gear to rotate in both the forward and reverse directions. During these rotations, the circular grating reading heads of the two measuring mechanisms read the rotation angle value of the corresponding half-shaft gear through the circular grating disk on the corresponding shaft-expanding mechanism. When one of the axle gears corresponding to the shaft expansion mechanism rotates in the forward and reverse directions, it can match two different angle values at the same angular position with the other axle gear corresponding to the shaft expansion mechanism. The deviation between the two angle values is the tooth flank clearance of the differential at that angle. Moreover, by taking one revolution in the forward direction and one revolution in the reverse direction as a measurement revolution, and making the measurement revolution reach the least common multiple of the sum of the number of teeth of the two axle gears in the differential, the complete tooth flank clearance data of the differential (the clearance data corresponding to each tooth of the axle gear and each tooth of the planetary gear) can be measured. The technical solution of the present invention can realize the dynamic measurement of the differential tooth flank clearance, and can measure the clearance corresponding to each tooth of the axle gear and each tooth of the planetary gear, resulting in a more complete measurement. Attached Figure Description
[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0026] Figure 1 A schematic diagram of an embodiment of the differential tooth backlash dynamic measurement device provided by the present invention;
[0027] Figure 2 for Figure 1 A three-dimensional structural diagram of the measurement unit;
[0028] Figure 3 for Figure 2 A cross-sectional structural diagram;
[0029] Figure 4 for Figure 2 Another cross-sectional structural diagram;
[0030] Figure 5 for Figure 1 A schematic diagram of the structure of the fixed unit.
[0031] Explanation of icon numbers:
[0032] 1000. Dynamic Measurement Device for Differential Gear Backlash; 1. Frame; 2. Fixing Unit; 21. Pressure Plate; 22. Second Cylinder; 3. Measurement Unit; 31. Mounting Frame; 32. Shaft Expansion Mechanism; 321. Expansion Sleeve; 322. Mandrel; 323. First Cylinder; 324. Outer Sleeve; 325. Inner Sleeve; 326. Spring; 33. Drive Mechanism; 331. Motor; 332. First Pulley; 333. Second Pulley; 334. Multi-Wedge Belt; 34. Measurement Mechanism; 341. Circular Grating Reading Head; 342. Circular Grating Disc; 35. Fine Adjustment Mechanism; 351. Electric Cylinder; 352. Support; 353. Rocker.
[0033] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0035] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.
[0036] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.
[0037] In the assembly process of a differential, measuring the differential tooth backlash is a crucial step. Currently, differential tooth backlash measurement devices are typically static, meaning one half-shaft gear is fixed while the other half-shaft gear is driven to rotate forward and backward, and a set of tooth backlashes is measured. However, each tooth of the half-shaft gear in a differential engages with each tooth of the planetary gears on both sides at certain moments, and the backlash between the two corresponding meshing teeth is different each time. Static measurement cannot measure the backlash corresponding to each tooth of the half-shaft gear and planetary gears, resulting in a single and incomplete measurement.
[0038] In view of this, the present invention proposes a dynamic measurement device for differential tooth backlash, which realizes dynamic measurement of differential tooth backlash and can measure the backlash corresponding to each tooth of the half-shaft gear and each tooth of the planetary gear, resulting in more complete results. Figure 1 A schematic diagram of an embodiment of the differential tooth backlash dynamic measurement device provided by the present invention; Figure 2 for Figure 1 A three-dimensional structural diagram of the measurement unit; Figure 3 for Figure 2 A cross-sectional structural diagram; Figure 4 for Figure 2 Another cross-sectional structural diagram; Figure 5 for Figure 1 A schematic diagram of the structure of the fixed unit.
[0039] Please see Figures 1 to 4In one embodiment of the present invention, the differential backlash dynamic measuring device 100 includes a frame 1, a fixing unit 2, and a pair of measuring units 3. The fixing unit 2 is disposed on the frame 1 for fixing the differential housing. The pair of measuring units 3 are disposed opposite to each other on the frame 1, and are respectively located above and below the fixing unit 2. Each measuring unit 3 includes a mounting bracket 31, a shaft expansion mechanism 32, a drive mechanism 33, and a measuring mechanism 34. The mounting bracket 31 is movably mounted on the frame 1 and has a vertical travel. The shaft expansion mechanism 32 is rotatably mounted on the mounting bracket 1. The mounting bracket 31 is used to tension the corresponding half-shaft gear in the differential; the drive mechanism 33 is mounted on the mounting bracket 31 and connected to the shaft tensioning mechanism 32; the measuring mechanism 34 includes a circular grating reading head 341 and a circular grating disk 342 arranged opposite to each other, the circular grating reading head 341 is mounted on the mounting bracket 31, and the circular grating disk 342 is mounted on the shaft tensioning mechanism 32; the drive mechanism 33 of one of the measuring units 3 is used to drive the shaft tensioning mechanism 32 to rotate, and the drive mechanism 33 of the other measuring unit 3 is used to load the shaft tensioning mechanism 32 with a reverse torque force.
[0040] In the technical solution of this invention, a driving mechanism 33 and a measuring mechanism 34 are provided on each shaft expansion mechanism 32. The two shaft expansion mechanisms 32 can respectively tension and connect two half-shaft gears. The driving mechanism 33 of one shaft expansion mechanism 32 drives the corresponding shaft expansion mechanism 32 to rotate the half-shaft gear. The driving mechanism 33 of the other shaft expansion mechanism 32 outputs a reverse torque force as a load, and the half-shaft gear of the other shaft expansion mechanism 32 rotates passively. The half-shaft gear is always under force, and the meshing state is stable. During measurement, the driving mechanism 33 of one shaft expansion mechanism 32 drives the corresponding half-shaft gear to rotate in the forward direction and in the reverse direction. During the forward and reverse rotation, the circular grating reading heads 341 of the two measuring mechanisms 34 pass through the circular grating disks 34 on the corresponding shaft expansion mechanism 32. 2. Read the rotation angle value of the corresponding half-shaft gear. When one of the half-shaft gears corresponding to the shaft expansion mechanism 32 rotates in the forward and reverse directions, it can match two rotation angle values with deviations at the same rotation angle position with the half-shaft gear corresponding to the other shaft expansion mechanism 32. The deviation between the two rotation angle values is the tooth flank clearance of the differential at that rotation angle. Moreover, taking one rotation in the forward direction and one rotation in the reverse direction as a measurement circle, and making the measurement circle reach the least common multiple of the sum of the number of teeth of the two half-shaft gears in the differential, the complete tooth flank clearance data of the differential (the clearance data corresponding to each tooth of the half-shaft gear and each tooth of the planetary gear) can be measured. The technical solution of the present invention can realize the dynamic measurement of the tooth flank clearance of the differential, and can measure the clearance corresponding to each tooth of the half-shaft gear and each tooth of the planetary gear, and the result is more complete.
[0041] Understandably, when the drive mechanism 33 of one of the shaft expansion mechanisms 32 drives the corresponding half-shaft gear to rotate in the forward or reverse direction, the drive mechanism 33 of the other shaft expansion mechanism 32 outputs a corresponding reverse torque force as a load. During measurement, the forward rotation followed by the reverse rotation can be used, or the reverse rotation followed by the forward rotation can be used. The differential tooth backlash dynamic measurement device 100 may also include a control unit to control the actions of the fixed unit 2, the shaft expansion mechanism 32, and the drive mechanism 33 for easy operation. The differential tooth backlash dynamic measurement device 100 may also include a host computer to collect, analyze, and store data, thereby improving measurement efficiency.
[0042] In embodiments of the present invention, each of the expansion shaft mechanisms 32 includes an expansion sleeve 321 and a spindle 322. The expansion sleeve 321 is rotatably mounted on the mounting bracket 31, and the spindle 322 is movably mounted inside the expansion sleeve 321, having a vertical travel relative to the expansion sleeve 321. By moving the spindle 322 in the vertical direction, the expansion sleeve 321 is tightened or loosened from the half-shaft gear. The structure is simple and easy to operate.
[0043] In embodiments of the present invention, each of the expansion shaft mechanisms 32 further includes a first cylinder 323, which is mounted on the mounting bracket 31 and used to drive the mandrel 322 to move in the vertical direction. The movement of the mandrel 322 in the vertical direction is controlled by the movement of the piston rod of the first cylinder 323, which is simple to operate and easy to control. It is understood that the first cylinder 323 does not interfere with the rotation of the mandrel 322 and the expansion sleeve 321; furthermore, the free end of the piston rod of the first cylinder 323 can abut against the mandrel 322, and a disc spring can also be provided between the mandrel 322 and the free end of the piston rod of the first cylinder 323 to make the vertical movement of the mandrel 322 more stable and gentle. In addition, adjusting the disc spring can adjust the output force.
[0044] In an embodiment of the present invention, the expansion shaft mechanism 32 further includes an outer sleeve 324 and an inner sleeve 325. The inner sleeve 325 is sleeved outside the mandrel 322, and the outer sleeve 324 is sleeved outside the inner sleeve 325. The outer sleeve 324 is rotatably mounted on the mounting bracket 31. The expansion sleeve 321 is disposed at one end of the inner sleeve 325 near the fixing unit 2 and is located outside the outer sleeve 324. The inner sidewall of the outer sleeve 324 is provided with a plurality of first semi-circular grooves along the circumference, and the outer sidewall of the inner sleeve 325 is provided with a plurality of second semi-circular grooves corresponding to the plurality of first semi-circular grooves. Each first semi-circular groove and the corresponding second semi-circular groove are equipped with a ball bearing. The expansion sleeve 321 and the mandrel 322 are mounted on the mounting bracket 31 using an inner sleeve 325 and an outer sleeve 324. The inner sleeve 325 and the outer sleeve 324 are fitted with multiple ball bearings in the circumferential direction to ensure the horizontal floating of the expansion sleeve 321 and the mandrel 322. This avoids the influence of the coaxial error of the two half-shaft gears of the differential on the measurement results within a certain range, which helps to improve the accuracy of the measurement.
[0045] Understandably, the mounting bracket 31 may be provided with mounting holes, and a mounting cylinder is fixed in the mounting holes. The expansion shaft mechanism 32 is located inside the mounting cylinder, and the outer sleeve 324 is rotatably connected to the mounting cylinder through a bearing. The circular grating disk 341 is provided at the end of the mounting cylinder, and the circular grating reading head 342 is correspondingly provided at the end of the outer sleeve 324.
[0046] In an embodiment of the present invention, the expansion shaft mechanism 32 further includes an outer sleeve 324 and an inner sleeve 325. The inner sleeve 325 is sleeved outside the mandrel 322, and the outer sleeve 324 is sleeved outside the inner sleeve 325. The outer sleeve 324 is rotatably mounted on the mounting bracket 31. The expansion sleeve 321 is disposed at one end of the inner sleeve 325 near the fixing unit 2 and is located outside the outer sleeve 324. A spring 326 is sleeved between the inner sleeve 325 and the outer sleeve 324, and the two ends of the spring 326 are respectively connected to the inner sleeve 325 and the outer sleeve 324. An inner sleeve 325 and an outer sleeve 324 are used to mount the expansion sleeve 321 and the mandrel 322 onto the mounting bracket 31. A spring 326 is used between the inner sleeve 325 and the outer sleeve 324 to ensure the vertical floating of the expansion sleeve 321 and the mandrel 322. This allows for more accurate application of additional axial tension to the half-shaft gear, which helps improve measurement accuracy. It is understood that the spring 326 is located between the inner sleeve 325 and the outer sleeve 324, and is sleeved on the outside of the inner sleeve 325.
[0047] In an embodiment of the present invention, the expansion mechanism 32 further includes an outer sleeve 324 and an inner sleeve 325. The inner sleeve 325 is sleeved outside the mandrel 322, and the outer sleeve 324 is sleeved outside the inner sleeve 325. The outer sleeve 324 is rotatably mounted on the mounting bracket 31. The expansion sleeve 321 is disposed at one end of the inner sleeve 325 near the fixing unit 2 and is located outside the outer sleeve 324. The inner sidewall of the outer sleeve 324 is provided with a plurality of first semi-circular grooves along the circumference, and the outer sidewall of the inner sleeve 325 corresponds to a plurality of first semi-circular grooves. A first semicircular groove is provided with multiple second semicircular grooves, and each first semicircular groove and its corresponding second semicircular groove are equipped with ball bearings; a spring 326 is sleeved between the inner sleeve 325 and the outer sleeve 324, and the two ends of the spring 326 are respectively connected to the inner sleeve 325 and the outer sleeve 324; the inner sleeve 325 and the outer sleeve 324 are connected by multiple circumferentially arranged ball bearings to ensure the horizontal floating of the expansion sleeve 321 and the spindle 322, and the spring 326 is connected by ensuring the vertical floating of the expansion sleeve 321 and the spindle 322, which can further improve the accuracy of measurement.
[0048] In an embodiment of the present invention, the drive mechanism 33 includes a motor 331 and a transmission assembly. The motor 331 is mounted on the mounting bracket 31, and the output shaft of the motor 331 is connected to the outer sleeve 324 via the transmission assembly. The connection between the motor 331 and the outer sleeve 324 via the transmission assembly facilitates installation. The motor 331 outputs forward rotational speed or reverse torque, making operation simple and easy to control.
[0049] In an embodiment of the present invention, the transmission assembly includes a first pulley 332, a second pulley 333, and a multi-ribbed belt 334. The first pulley 332 is fixedly sleeved on the output shaft of the motor 331, the second pulley 333 is fixedly sleeved on the outer sleeve 324, and the multi-ribbed belt 334 is stretched between the first pulley 332 and the second pulley 333. The multi-ribbed belt 334 enables the transmission connection between the motor 331 and the outer sleeve 324, resulting in stable and smooth rotation, which is beneficial to improving the accuracy of measurement. It is understood that the motor 331 can be mounted on a movable plate; by adjusting the position of the movable plate, the multi-ribbed belt 334 can be tightened to ensure that the torque transmission is not distorted.
[0050] In an embodiment of the present invention, a connecting bearing is provided at one end of the inner sleeve 325 away from the fixed unit 2, and the inner ring of the connecting bearing is connected to the inner sleeve 325. The measuring unit 3 further includes a fine-tuning mechanism 35, which includes an electric cylinder 351, a support 352, and a rocker 353. The electric cylinder 351 is mounted on the mounting frame 31, and the support 352 is mounted on the mounting frame 31 and located between the electric cylinder 351 and the expansion shaft mechanism 32. The rocker 353 is hinged to the support 352 to form a fulcrum, and both ends of the rocker 353 are respectively connected to the output end of the electric cylinder 351 and the outer ring of the bearing. By controlling the electric cylinder 351, the rocker 353 is driven, causing the inner sleeve 325, the expansion sleeve 321, and the spindle 322 to move slightly away from the differential, so as to flatten the shims in the differential and eliminate the gaps caused by the unevenness of the shims. Understandably, the electric cylinder 351 can be selected as a precision force-controlled electric cylinder 351, which facilitates the output of precise pulling force; furthermore, the rocker 353 is a thin-walled part with elasticity. The rocker has a certain degree of elasticity, which can eliminate the influence of vibration on the pulling force of the precision force-controlled electric cylinder during dynamic measurement.
[0051] In an embodiment of the present invention, the distance from the fulcrum to the output end of the electric cylinder 351 is equal to the distance from the fulcrum to the axis of the inner sleeve 325. The distance ratio on both sides is controlled at 1:1, which facilitates confirmation of the actual tensile force acting on the inner sleeve 325, the expansion sleeve 321, and the mandrel 322.
[0052] In an embodiment of the present invention, please refer to Figure 5 The fixing unit 2 includes a fixing platform, a pressure plate 21, and a second cylinder 22. The fixing platform is mounted on the frame 1 and has a positioning hole for placing the differential. The pressure plate 21 is movably mounted above the fixing platform. The second cylinder 22 is mounted on the frame 1 and drives the pressure plate 21 to move up and down to fix the differential housing. When fixing the differential housing, the differential is first placed in the positioning hole of the fixing platform. The second cylinder 22 then drives the pressure plate 21 downwards, pressing it onto the housing of the differential, thus fixing the housing between the fixing platform and the pressure plate 21. The fixing unit 2 has a simple structure, is easy to operate, and provides a stable fixation for the differential. It is understood that the pressure plate 21 can be slidably connected to the frame 1 in the vertical direction via a slide, which can improve the stability of the structure.
[0053] This invention also proposes a dynamic measurement method for differential tooth backlash, using the aforementioned dynamic measurement device 100 for differential tooth backlash. The specific structure of the dynamic measurement device 100 is as described in the above embodiments. Since the dynamic measurement method for differential tooth backlash adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated upon here. The dynamic measurement method for differential tooth backlash includes the following steps:
[0054] S10, Control and fixing unit 2, housing of the differential;
[0055] S20, control the movement of a pair of test units and cause each shaft expansion mechanism 32 to tighten the corresponding half-shaft gear;
[0056] S30. Control the drive mechanism 33 of one of the measuring units 3 to drive the expansion shaft mechanism 32 to rotate in the forward and reverse directions, and the drive mechanism 33 of the other measuring unit 3 outputs a reverse torsional force as a load.
[0057] S40. Obtain the rotation angle values measured by the two measuring mechanisms 34, and obtain the differential tooth backlash based on the rotation angle values.
[0058] Using the differential tooth backlash dynamic measuring device 100, the differential tooth backlash can be dynamically measured through the above steps; wherein, in step S40, the differential tooth backlash is obtained based on the rotation angle value as follows: when the half-shaft gear corresponding to one of the measuring units 3 rotates in the forward direction and in the reverse direction, it can match two rotation angle values with deviations between the half-shaft gear corresponding to the other measuring unit 3 at the same rotation angle position, and the deviation between the two rotation angle values is the tooth backlash of the differential at that rotation angle.
[0059] Furthermore, in step S30, one rotation in the forward direction and one rotation in the reverse direction constitute one measurement rotation. The measurement rotation is the least common multiple of the sum of the number of teeth of the two half-shaft gears in the differential; the complete tooth backlash data of the differential (the backlash data corresponding to each tooth of the half-shaft gear and each tooth of the planetary gear) can be measured.
[0060] Understandably, when the measuring unit 3 also includes a fine-tuning mechanism 35, after each shaft tensioning mechanism 32 tensions the corresponding half-shaft gear, it also includes: a control electric cylinder 351, driving a rocker plate 353, which drives the inner sleeve 325 to move away from the differential, so as to flatten the gasket in the differential.
[0061] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.
Claims
1. A dynamic measurement device for differential tooth backlash, characterized in that, include: frame; A fixing unit, mounted on the frame, is used to fix the housing of the differential; as well as, A pair of measuring units are disposed opposite to each other on the frame, and respectively located above and below the fixed unit; each measuring unit includes a mounting frame, a shaft expansion mechanism, a drive mechanism, and a measuring mechanism. The mounting frame is movably mounted on the frame and has a vertical travel. The shaft expansion mechanism is rotatably mounted on the mounting frame and is used to tension the corresponding half-shaft gear in the differential. The drive mechanism is disposed on the mounting frame and connected to the shaft expansion mechanism. The measuring mechanism includes a circular grating reading head and a circular grating disk disposed opposite to each other. The circular grating reading head is disposed on the mounting frame, and the circular grating disk is disposed on the shaft expansion mechanism. One of the measuring units has a drive mechanism for driving the expansion shaft mechanism to rotate, and the other measuring unit has a drive mechanism for applying a reverse torque force to the expansion shaft mechanism.
2. The differential tooth backlash dynamic measuring device as described in claim 1, characterized in that, Each of the aforementioned expansion shaft mechanisms includes an expansion sleeve and a spindle. The expansion sleeve is rotatably mounted on the mounting bracket, and the spindle is movably mounted inside the expansion sleeve, having a vertical stroke relative to the expansion sleeve.
3. The differential tooth backlash dynamic measuring device as described in claim 2, characterized in that, Each of the aforementioned expansion shaft mechanisms further includes a first cylinder, which is disposed on the mounting bracket and is used to drive the mandrel to move in the up-down direction.
4. The differential tooth backlash dynamic measuring device as described in claim 2, characterized in that, The expansion mechanism further includes an outer sleeve and an inner sleeve. The inner sleeve is sleeved outside the mandrel, and the outer sleeve is sleeved outside the inner sleeve. The outer sleeve is rotatably mounted on the mounting bracket. The expansion sleeve is located at one end of the inner sleeve near the fixing unit and outside the outer sleeve; wherein: The inner wall of the outer sleeve is provided with a plurality of first semicircular grooves along the circumference, and the outer wall of the inner sleeve is provided with a plurality of second semicircular grooves corresponding to the plurality of first semicircular grooves. A ball bearing is installed in each of the first semicircular grooves and the corresponding second semicircular groove; and / or, A spring is fitted between the inner sleeve and the outer sleeve, and the two ends of the spring are respectively connected to the inner sleeve and the outer sleeve.
5. The differential tooth backlash dynamic measuring device as described in claim 4, characterized in that, The drive mechanism includes a motor and a transmission assembly. The motor is mounted on the mounting bracket, and the output shaft of the motor is connected to the outer sleeve via the transmission assembly.
6. The differential tooth backlash dynamic measuring device as described in claim 5, characterized in that, The transmission assembly includes a first pulley, a second pulley, and a multi-ribbed belt. The first pulley is fixedly sleeved on the output shaft of the motor, the second pulley is fixedly sleeved on the outer sleeve, and the multi-ribbed belt is stretched on the first pulley and the second pulley.
7. The differential tooth backlash dynamic measuring device as described in claim 4, characterized in that, A connecting bearing is provided at one end of the inner sleeve away from the fixed unit, and the inner ring of the connecting bearing is connected to the inner sleeve; the measuring unit also includes a fine-tuning mechanism, which includes an electric cylinder, a support, and a rocker. The electric cylinder is mounted on the mounting frame, the support is mounted on the mounting frame and located between the electric cylinder and the shaft expansion mechanism, and the rocker is hinged to the support to form a fulcrum. The two ends of the rocker are respectively connected to the output end of the electric cylinder and the outer ring of the bearing.
8. The differential tooth backlash dynamic measuring device as described in claim 7, characterized in that, The distance from the fulcrum to the output end of the electric cylinder is equal to the distance from the fulcrum to the axis of the inner sleeve.
9. The differential tooth backlash dynamic measuring device as described in claim 1, characterized in that, The fixing unit includes a fixing platform, a pressure plate, and a second cylinder. The fixing platform is mounted on the frame and has a positioning hole for placing the differential. The pressure plate is movably mounted above the fixing platform. The second cylinder is mounted on the frame and is used to drive the pressure plate to move up and down to fix the housing of the differential.
10. A method for dynamically measuring differential tooth backlash, characterized in that, Using the differential tooth backlash dynamic measurement device as described in any one of claims 1 to 9, the differential tooth backlash dynamic measurement method includes the following steps: The housing of the differential is fixed by the control unit; Control the movement of a pair of test units and cause each shaft expansion mechanism to tighten the corresponding half-shaft gear; The drive mechanism of one of the measuring units drives the expansion shaft mechanism to rotate in the forward and reverse directions, while the drive mechanism of the other measuring unit outputs a corresponding reverse torsional force as a load. Obtain the rotation angle values measured by two measuring mechanisms, and obtain the differential tooth backlash based on the rotation angle values.