Differential case and planetary gear shaft strength detection fixture and method

Abstract

A differential housing and planetary gear shaft strength detection fixture, comprising a torque loading device, a differential housing is fixedly installed on the torque loading device, a gear fixing device with a planetary gear fixedly installed in the differential housing is arranged in the differential housing, a gear shaft passes through the planetary gear and the gear fixing device, and is fixed in the differential housing through a gear shaft pin, the gear fixing device extends out of both ends of the differential housing and is supported on a fixed support, and tapered bearings at both ends of the differential housing are respectively supported on a bearing support.

Description

Technical Field

[0001] This invention relates to the field of differential testing technology, and in particular to a fixture and method for testing the strength of differential housings and planetary gear shafts. Background Technology

[0002] The rear drive axle final drive is a crucial component of a vehicle's transmission system. The differential within the final drive houses the driven gear and transmits the load input from the driven gear via the differential housing, planetary gear shaft, planetary gears, and axle gears to the half-shafts and the vehicle end. Furthermore, when the wheels on both sides rotate at different speeds, the differential assembly provides differential function to ensure stable vehicle operation.

[0003] Currently, neither industry nor national standards specify testing methods for the static torsional strength and fatigue strength of differential housings and differential planetary gear shafts. Conventional gear fatigue and differential fatigue tests cannot effectively verify the lifespan of differential housings and differential planetary gear shafts. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a strength testing fixture and method for differential housings and planetary gear shafts, which can effectively verify the strength and service life of differential housings and planetary gear shafts.

[0005] One technical solution of the present invention is: a strength testing fixture for a differential housing and a planetary gear shaft, comprising a torque loading device, on which the differential housing is fixedly mounted, and a gear fixing device for fixing a planetary gear is provided inside the differential housing, a gear shaft passing through the planetary gear and the gear fixing device, and fixed inside the differential housing by a gear shaft pin, the gear fixing device extending out of both ends of the differential housing and supported on a fixed bracket, and the tapered bearings at both ends of the differential housing respectively supported on a bearing bracket.

[0006] Furthermore, the torque loading device includes an actuator and a connecting arm, and one end of the actuator equipped with a load sensor is hinged to the connecting arm through a test fixture.

[0007] Furthermore, the upper end of the connecting arm is hinged to the test fixture, and the lower end is provided with a stepped relief hole. The differential housing passes through the relief hole and is fixed to the shoulder of the relief hole by screws.

[0008] Furthermore, the gear fixing device includes two fixing parts, an upper one and an lower one. A planetary gear is fixedly mounted on the upper end face of the upper fixing part and the lower end face of the lower fixing part, and the two fixing parts are connected and fixed by adjusting bolts.

[0009] Further, the fixing support is in a "U" shape, and the two straight arms of the "U" shape fixing support are respectively provided with recesses on one side facing each other, so that the two ends of the gear fixing device are respectively supported in the recesses.

[0010] Further, the upper ends of the two straight arms of the fixing support are respectively provided with openings, and the upper end faces of the two straight arms are respectively provided with a pressing block, and the lower end of the pressing block is provided with a boss extending downward into the recess, so that the boss is in contact with the gear fixing device.

[0011] Further, the bearing support is located on the two sides of the fixing support, and the bearing support comprises a base and a gland, and the base and the gland are provided with a semicircular hole facing each other, and the gland is fixedly installed on the upper end face of the base, so that the two semicircular holes are folded to form a circular hole for supporting the taper bearing of the differential housing.

[0012] Further, the base is provided with a reinforcing rib.

[0013] Further, a bottom plate is further included, and the fixing support and the bearing support are fixedly installed on the bottom plate.

[0014] The beneficial effects of the above technical scheme are: the device fixes the planetary gear on the gear fixing device, installs the planetary gear in the differential housing through the gear fixing device, ensures that the assembly of the planetary gear and the differential housing is consistent with the actual assembly structure, then makes the gear shaft pass through the planetary gear and the two fixing members, and is fixed in the differential housing through the gear shaft pin, thereby simulating the actual assembly structure of the planetary gear and the gear shaft in the differential housing, supporting the assembled differential housing on the fixing support and the bearing support, and applying alternating load to the differential housing and the gear shaft through the actuator on the torque loading device, so as to detect the strength of the differential housing and the gear shaft, and the device only needs to install the planetary gear through the gear fixing device to realize the detection of the differential housing and the gear shaft, without the need to assemble other parts in the differential, thereby reducing the assembly difficulty and improving the detection efficiency, and the gear fixing device of the device can be reused, that is, even if the strength of the differential housing or the gear shaft is unqualified, the gears and other parts of the differential itself will not be damaged.

[0015] Another technical scheme of the present application is: a differential housing and planetary gear shaft strength detection method, wherein a torque loading device is used to apply alternating load to the differential housing and the planetary gear shaft, and a load sensor in the torque loading device is used to monitor the torque size, so that the actual torque borne by the differential housing is 0.1M~1.2M, wherein M is the maximum engine torque that the differential housing can bear.

[0016] The beneficial effects of the above technical scheme are as follows: the actuator applies an alternating load to the differential shell, and the load in the range between the maximum engine torque that the differential shell can withstand and the maximum engine torque is detected to affect the differential shell and the gear shaft, if the service life of the gear shaft is shorter than that of the differential shell, the strength of the differential shell can still be detected after the planetary gear shaft is broken.

[0017] The application will be further described below in connection with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The figure is a structural schematic diagram of the application;

[0019] Figure 2 The figure is an assembly schematic diagram of the differential shell and the gear fixing device of the application;

[0020] Figure 3 The figure is a side view of the assembly of the differential shell and the gear fixing device of the application;

[0021] Figure 4 The figure is an A-A sectional view of Figure 3

[0022] Figure 5 The figure is a structural schematic diagram of the connecting arm;

[0023] Figure 6 The figure is a structural schematic diagram of the fixing support. DETAILED DESCRIPTION

[0024] Referring to Figures 1 to 6 ​The embodiment of differential housing and planetary gear shaft strength detection clamp comprises a torque loading device 1, a differential housing 2 is fixedly installed on the torque loading device 1, the torque loading device 1 comprises an actuator 9, a connecting arm 10, one end of the actuator 9 is hinged with the connecting arm 10 through a test tool 12, the actuator 9 is a linear actuator and can be driven by a hydraulic cylinder or an electric motor, the upper end of the connecting arm 10 is hinged with the test tool 12, the lower end is provided with a stepped clearance hole 13, the differential housing 2 passes through the clearance hole 13 and is connected and fixed with the hole shoulder of the clearance hole 13 through a screw, the hole shoulder of the clearance hole 13 forms axial limiting for the differential housing 2, the actuator 9 is used for applying torque to the differential housing 2, and a load sensor 11 is used for monitoring the actual torque size in real time. Gear fixing devices 4 are arranged in the differential housing 2 and are fixed with planetary gears 3, the gear fixing devices 4 comprise upper and lower fixing members, the upper end surface of the upper fixing member 14 and the lower end surface of the lower fixing member 15 are respectively fixed with one planetary gear 3, the two fixing members are connected and fixed through adjusting bolts 16, the adjusting bolts 16 can be used for adjusting the assembly position of the planetary gears 3 in the differential housing 2, so that the planetary gears 3 are consistent with the actual assembly in cooperation with the differential housing 2, and the accuracy of the detection result is ensured. A gear shaft 5 passes through the planetary gears 3 and the gear fixing devices 4 and is fixed in the differential housing 2 through a gear shaft pin 6, one end of the gear shaft pin 6 is inserted into the gear shaft 5 radially from the outside of the differential housing 2, the other end of the gear shaft pin 6 is limited on the outside of the differential housing 2, so that the gear shaft 5 is fixed in the differential housing 2. The gear fixing devices 4 extend out of the two ends of the differential housing 2 and are supported on fixed supports 7, the fixed supports 7 are in the shape of “U”, recesses 17 are arranged on the two straight arms of the “U”-shaped fixed supports 7 on the side facing each other, so that the two ends of the gear fixing devices 4 are supported in the recesses 17, that is, the two ends of the two fixing members are supported in the recesses 17, the upper ends of the two straight arms of the fixed supports 7 are respectively provided with openings, and the upper end surfaces of the two straight arms are respectively provided with pressing blocks 18, the lower ends of the pressing blocks 18 are provided with bosses 19 extending downward into the recesses 17, the bosses 19 are in contact with the gear fixing devices 4, the pressing blocks 18 limit the gear fixing devices 4 in the longitudinal direction, so that the gear fixing devices are kept balanced through the pressing blocks 18 and the load of the differential housing 2 is stable during the detection process. Tapered bearings at the two ends of the differential housing 2 are respectively supported on bearing supports 8, the bearing supports 8 are located on the two sides of the fixed supports 7, the bearing supports 8 comprise bases 20 and press covers 21, the bases 20 and the press covers 21 are provided with semicircular holes facing each other, the press covers 21 are fixedly installed on the upper end surfaces of the bases 20, so that the two semicircular holes are combined to form a circular hole 22 for supporting the tapered bearings of the differential housing 2, the bearing supports 8 limit the differential housing 2 in the transverse direction, and in addition, the bases 20 are provided with reinforcing ribs 23 to improve the strength of the bearing supports 8.The differential housing 2 is limited in the longitudinal and transverse directions by the fixed support 7 and the bearing support 8 respectively, improving the stability during detection, so that it can only bear the load applied by the actuator 9, so that the force conditions of the differential housing 2 and the gear shaft 5 are consistent with the actual force conditions during operation of the drive axle. The fixed support 7 and the bearing support 8 are both fixedly installed on the bottom plate 24.

[0025] During assembly of the detection device, the upper fixing member 14 and the lower fixing member 15 are first placed in the differential housing 2, then the position of the planetary gear 3 in the differential housing 2 is adjusted by the adjusting bolt 16 so that it is consistent with the actual assembly state, and the two fixing members are fixed, then the gear shaft 5 is passed through the differential housing 2, the planetary gear 3 and the two fixing members, and is fixed in the differential housing 2 by the gear shaft pin 6, then the connecting arm 10 is fixedly connected to the differential housing 2 by a bolt, then the differential housing 2 is supported on the bearing support 8, and at the same time the two fixing members are supported on the fixed support 7, and finally the actuator 9 is hinged to the connecting arm 10 by the test tool 12, and the assembly is completed. The load can be applied to the differential housing 2 by the actuator 9.

[0026] A differential housing and planetary gear shaft strength detection method, wherein a torque loading device is used to apply alternating loads to the differential housing and the planetary gear shaft, and a load sensor in the torque loading device is used to monitor the torque, so that the actual torque borne by the differential housing is 0.1M~1.2M, where M is the maximum engine torque that the differential housing can bear. Based on the maximum engine torque that the differential housing can bear, the influence of loads lower than the maximum engine torque and higher than the maximum engine torque on the differential housing and the gear shaft is detected. If the service life of the gear shaft 5 is lower than that of the differential housing, the strength of the differential housing 2 can still be detected after the gear shaft 5 breaks.

Claims

1. A strength testing fixture for differential housing and planetary gear shaft, characterized in that: Includes a torque loading device (1), on which a differential housing (2) is fixedly mounted. A gear fixing device (4) is provided inside the differential housing (2) and a planetary gear (3) is fixed therein. A gear shaft (5) passes through the planetary gear (3) and the gear fixing device (4) and is fixed inside the differential housing (2) by a gear shaft pin (6). The gear fixing device (4) extends out of the two ends of the differential housing (2) and is supported on a fixed bracket (7). The tapered bearings at both ends of the differential housing (2) are respectively supported on a bearing bracket (8). The torque loading device (1) includes an actuator (9) and a connecting arm (10). One end of the actuator (9) equipped with a load sensor (11) is hinged to the connecting arm (10) through a test fixture (12). The gear fixing device (4) includes two fixing parts, an upper and a lower fixing part. A planetary gear (3) is fixedly installed on the upper end face of the upper fixing part (14) and the lower end face of the lower fixing part (15), and the two fixing parts are connected and fixed by adjusting bolts (16). The bearing bracket (8) is located on both sides of the fixed bracket (7). The bearing bracket (8) includes a base (20) and a cover (21). The base (20) and the cover (21) are provided with semi-circular holes facing each other. The cover (21) is fixedly installed on the upper end face of the base (20) so that the two semi-circular holes are closed to form a round hole (22) for supporting the tapered bearing of the differential housing (2).

2. The differential housing and planetary gear shaft strength testing fixture according to claim 1, characterized in that: The upper end of the connecting arm (10) is hinged to the test fixture (12), and the lower end is provided with a stepped relief hole (13). The differential housing (2) passes through the relief hole (13) and is fixed to the shoulder of the relief hole (13) by screws.

3. The differential housing and planetary gear shaft strength testing fixture according to claim 1, characterized in that: The fixed bracket (7) is U-shaped. The two straight arms of the U-shaped fixed bracket (7) are respectively provided with grooves (17) on one side, so that the two ends of the gear fixing device (4) are respectively supported in the grooves (17).

4. The differential housing and planetary gear shaft strength testing fixture according to claim 3, characterized in that: The upper ends of the two straight arms of the fixed bracket (7) are respectively provided with openings, and the upper end surfaces of the two straight arms are respectively provided with a pressure block (18). The lower end of the pressure block (18) is provided with a boss (19) extending downward into the groove (17), so that the boss (19) contacts the gear fixing device (4).

5. The differential housing and planetary gear shaft strength testing fixture according to claim 1, characterized in that: The base (20) is provided with reinforcing ribs (23).

6. The differential housing and planetary gear shaft strength testing fixture according to claim 1, characterized in that: It also includes a base plate (24), on which the fixed bracket (7) and the bearing bracket (8) are both fixedly installed.

7. A method for testing the strength of a differential housing and a planetary gear shaft using the strength testing fixture for differential housing and planetary gear shaft as described in any one of claims 1 to 6, characterized in that: An alternating load is applied to the differential housing and planetary gear shaft by a torque loading device, and the torque magnitude is monitored by a load sensor in the torque loading device, so that the actual torque borne by the differential housing is 0.1M to 1.2M, where M is the maximum engine torque that the differential housing can withstand.

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