Load test method for parking mechanism of electric drive reduction gearbox

Abstract

The present invention relates to the field of reducer testing technology, and specifically refers to a load testing method for the parking mechanism of an electric drive reducer. The following steps are performed: S1, fixing the reducer to be tested and a load dynamometer on a base; S2, connecting one end of the input shaft of the reducer to be tested to the load dynamometer through a coupling; S3, putting the reducer to be tested into the parking gear, starting the load dynamometer to load a set torque on the input shaft of the reducer to be tested, unloading the torque after reaching the set torque and disengaging the parking gear at the same time, and completing a test cycle when the speed of the load dynamometer is 0; S4, performing a set number of cycles according to step S3. The testing method of the present invention is very simple, and multiple modes of testing experiments can be completed by connecting a load dynamometer to the input shaft of the reducer to be tested, which solves the problem of the parking mechanism pawl collision-prone to early failure in the existing testing method, improves the test accuracy, and has great promotion value.

Description

Technical Field

[0001] The present invention relates to the technical field of reduction gearbox testing, and in particular to a load testing method for a parking mechanism of an electric drive reduction gearbox. Background Art

[0002] Verification testing of the gearbox parking mechanism of electric vehicles plays a crucial role in new energy vehicle testing. When the vehicle is stationary, especially on a slope, the parking lock must be engaged to prevent the vehicle from rolling. Reliability testing of gearbox parking mechanisms typically involves direct installation and road testing. Repeated manual activation and deactivation of the parking mechanism on a slope requires significant testing space. This manual operation makes durability testing of the gearbox parking mechanism inconvenient, resulting in inefficient testing, long test cycles, and high costs.

[0003] Currently, durability tests of the gearbox's parking mechanism are also being conducted on a test bench. For example, the Chinese invention patent number "CN114624021A," entitled "Test Bench, Transmission Locking Mechanism Torsional Fatigue Test Method, and Related Equipment," describes a method for conducting torsional fatigue tests on the transmission's locking mechanism. The transmission is secured to a base, with a dynamometer mounted on each side of the base. The dynamometers are connected to both ends of the transmission's differential via couplings, and the dynamometers on each side apply loads from both ends of the differential. During the actual test, the transmission's parking mechanism is first engaged in P gear. Loads are then applied from both ends of the differential using load dynamometers, simulating the forces acting on the vehicle on a ramp. Once the set load is reached, the vehicle is quickly disengaged from P gear and the load dynamometers are unloaded, completing a ramp parking cycle. This cycle is repeated the required number of times to conduct the durability test.

[0004] This solution has some problems, because the existing bench test loads the differential from both ends. When the load dynamometer torque is unloaded, the speed of the reduction gearbox input shaft will fly (the transmission ratio between the differential and the input shaft on the reduction gearbox is greater than 10, and the speed of the differential is less than the speed of the reduction gearbox input shaft). This situation corresponds to the vehicle sliding on a slope, resulting in inaccurate test results and not meeting the requirements of the actual vehicle slope parking test. In addition, when the load dynamometer unloads the torque, the inertial force at the moment of unloading can cause the reduction gearbox input shaft to rotate rapidly, while also driving the reduction gearbox parking mechanism to rotate rapidly. The parking pawl will collide with the parking ratchet at a high frequency under the action of the rebound force, causing the parking mechanism to fail early and the parking mechanism ratchet pawl to collide, resulting in abnormal failure of the reduction gearbox test. Summary of the Invention

[0005] The purpose of the present invention is to solve the deficiencies of the above-mentioned background technology and to provide a load testing method for the parking mechanism of an electric drive reduction gearbox.

[0006] The technical solution of the present invention is: a method for testing the parking mechanism of an electric drive reduction gearbox under load, which is carried out according to the following steps: S1, fixing the reduction gearbox to be tested and the load dynamometer on a base;

[0007] S2. Connect one end of the input shaft of the gearbox to be tested to the load dynamometer through a coupling;

[0008] S3. Put the gearbox under test into the parking gear, start the load dynamometer and load the set torque on the input shaft of the gearbox under test. After reaching the set torque, unload the torque and simultaneously disengage the parking gear. When the speed of the load dynamometer reaches 0, one test cycle is completed.

[0009] S4. Repeat step S3 for a set number of times.

[0010] According to a load testing method for an electric drive reduction gearbox parking mechanism provided in the present application, in the step S1, the method of fixing the reduction gearbox to be tested on the base includes: fixing an L-shaped support plate including a bottom plate and a side plate on the base, placing two groups of brackets on both sides of the differential of the reduction gearbox to be tested, and fixing the reduction gearbox to be tested on the base by fixing the brackets to the differential.

[0011] According to a load testing method for an electric-driven reduction gearbox parking mechanism provided in the present application, in step S2, the method of connecting one end of the input shaft of the reduction gearbox to be tested to the load dynamometer through a coupling includes: arranging a connecting shaft, a coupling and a connecting flange between the reduction gearbox to be tested and the load dynamometer, transmittingly connecting one end of the connecting shaft to the input shaft end of the reduction gearbox to be tested, fixing the connecting flange to the power output part of the load dynamometer, fixing the connecting flange to the other end of the connecting shaft through a coupling, supporting the connecting shaft, and completing the transmission connection between the reduction gearbox to be tested and the load dynamometer.

[0012] According to a load testing method for an electric drive reduction gearbox parking mechanism provided in the present application, the method for supporting the connecting shaft includes: installing a support seat on the base, fixing the support seat on the base by a pin, the upper end of the support seat is a ring sleeve mounted on the connecting shaft, and several groups of bearings are arranged on the inner side of the ring sleeve, and the bearings are mounted on the connecting shaft to support the connecting shaft.

[0013] According to a load testing method for an electric drive reduction gearbox parking mechanism provided in the present application, the method of fixedly connecting the connecting flange to the other end of the connecting shaft through a coupling includes: the coupling includes a first sleeve and a second sleeve, the first sleeve is provided with a first groove on the inner side, and the second sleeve is provided with a second groove on the inner side; a protruding first flat key is provided at the end of the connecting shaft, and a second flat key is provided at the end of the connecting flange; the connecting shaft is inserted into the first sleeve so that the first flat key enters the first groove axially, and the end of the connecting flange is inserted into the second sleeve so that the second flat key enters the second groove axially; the first sleeve and the second sleeve are connected and fixed as a whole by bolts to complete the transmission connection between the connecting flange and the connecting shaft.

[0014] According to a load testing method for an electric drive reduction gearbox parking mechanism provided in the present application, the method of arranging several groups of bearings on the inner side of the ring sleeve includes: opening several groups of sliding grooves arranged axially at intervals on the inner side of the ring sleeve, arranging the outer ring of the bearing in the sliding groove, and arranging the inner ring of the bearing on the outer side of the circumference of the connecting shaft.

[0015] According to a load testing method for an electric drive reduction gearbox parking mechanism provided in the present application, two sets of bearings are arranged in the ring sleeve.

[0016] The advantages of the present application are as follows: 1. The present invention arranges a load dynamometer on one side of the reduction gearbox to be tested, and the load dynamometer is connected to the input shaft of the reduction gearbox to be tested. The load dynamometer drives the input shaft of the reduction gearbox to be tested to rotate for load testing. This test method has a simple structure and is easier to install. When the torque is unloaded, due to the transmission ratio between the input shaft and the output shaft of the reduction gearbox to be tested, the output shaft of the reduction gearbox to be tested can quickly stop rotating, and the parking mechanism can quickly stop, avoiding the failure problem caused by the impact of the pawl. Moreover, this test method can not only perform a durability test on the reduction gearbox to be tested, but also perform a static torsion test, a gear backlash measurement, etc. on the reduction gearbox to be tested. The experimental installation is extremely convenient and fast, and the experimental efficiency is greatly improved.

[0017] 2. In the process of fixing the gearbox to be tested, the present invention fixes the differential part of the gearbox to be tested by a support plate. This fixing method can easily expose the input shaft and is simpler to connect to the load dynamometer. The connection between the support plate and the base can also be adjusted in the axial and vertical axial directions to adapt to gearboxes of different specifications to be tested.

[0018] 3. The present invention is connected to the load dynamometer through a connecting flange and connected to the input shaft of the reduction gearbox to be tested through a connecting shaft. This connection method is simple, extremely convenient to install and disassemble, and has a good power transmission effect;

[0019] 4. The present invention supports the connecting shaft through the support seat. The connecting shaft is rotatably arranged in the ring sleeve of the support seat, which has good stability. The torque of the load dynamometer can be stably transmitted to the input shaft of the reduction gearbox to be tested through the connecting shaft, and the torque transmission effect is excellent.

[0020] 5. The present invention connects the connecting flange and the coupling, and the connecting shaft and the coupling by means of a flat key groove. The connection method is extremely simple, can stably transmit torque, and is also extremely convenient for disassembly.

[0021] 6. The method of installing and arranging the bearings of the present invention is extremely simple. By arranging the bearings in the slide grooves, the connecting shaft can be stably supported.

[0022] 7. The present invention provides two sets of bearings in the ring sleeve, and the two sets of bearings are spaced apart along the axial direction, which provides a better supporting effect on the connecting shaft.

[0023] The testing method of the present invention is very simple. By connecting a load dynamometer to the input shaft of the reduction gearbox to be tested, various modes of testing experiments can be completed. This solves the problem of the parking mechanism pawl being prone to early failure due to collision in the existing testing method, improves the test accuracy, and has great promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 : Schematic diagram of the connection between the load dynamometer of the present invention and the reduction gearbox to be tested (side view);

[0025] Figure 2 : Schematic diagram of the connection between the load dynamometer of the present invention and the reduction gearbox to be tested (axis view);

[0026] Figure 3 : Schematic diagram of the connection between the load dynamometer of the present invention and the reduction gearbox to be tested (top view);

[0027] Figure 4 : Schematic diagram of the connection structure between the load dynamometer of the present invention and the reduction gearbox to be tested;

[0028] Among them: 1—base; 2—support plate; 3—bracket; 4—connecting shaft; 5—connecting flange; 6—support seat; 7—ring sleeve; 8—bearing; 9—first shaft sleeve; 10—second shaft sleeve; 11—first flat key; 12—second flat key; 13—slide groove; 14—limiting groove; 15—retaining ring; 111—load dynamometer; 112—reduction gearbox to be tested. DETAILED DESCRIPTION

[0029] The embodiments of the present invention are described in detail below, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but are not to be construed as limiting the present invention.

[0030] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] This application relates to a load test method for the parking mechanism of an electric drive reduction gearbox. The test method of this application is to test the electric drive reduction gearbox with load, which is a bench test. Figures 1 to 3 As shown, the reduction gearbox 112 to be tested is fixed on the base 1 , and a torque is applied to the input shaft of the reduction gearbox 112 to be tested via a load dynamometer 111 to conduct an experiment.

[0034] Specifically, the following steps may be followed: S1, fixing the reduction gearbox 112 to be tested and the load dynamometer 111 on the base 1;

[0035] This application is provided with a dedicated base 1, such as Figure 2 and 3 As shown, the base 1 is provided with a plurality of groove-shaped structures, and the reduction gearbox 112 to be tested and the load dynamometer 111 are both mounted and fixed on the base 1, and can be adjusted in position as needed to accommodate reduction gearboxes and load dynamometers of different specifications to be tested;

[0036] S2. Connect one end of the input shaft of the reduction gearbox 112 to be tested to the load dynamometer 111 through a coupling;

[0037] The load dynamometer 111 is connected to the input shaft of the reduction gearbox 112 to be tested via a coupling, that is, the load dynamometer torque is directly transmitted to the input shaft of the reduction gearbox to be tested. The reduction gearbox to be tested includes an input shaft, an output shaft drivingly connected to the input shaft, and a differential drivingly connected to the output shaft. The input shaft of the reduction gearbox to be tested is drivingly connected to the output shaft via gears. The transmission ratio between the input shaft and the output shaft is greater than 1, that is, the rotation speed of the input shaft is higher than the rotation speed of the output shaft. The present application applies torque to the input shaft. Even if the output shaft rotates, after the torque is unloaded, the output shaft can quickly stop rotating, and the parking mechanism connected together can also quickly stop rotating, and the problem of early failure caused by pawl collision due to the parking mechanism being unable to stop quickly under the action of inertia will not occur;

[0038] Moreover, this application can realize various experiments on the gearbox to be tested using only one set of load dynamometers;

[0039] S3, the reduction gearbox 112 to be tested is put into the parking gear, and the load dynamometer 111 is started to load the set torque on the input shaft of the reduction gearbox 112 to be tested. After the set torque is reached, the torque is unloaded and the parking gear is disengaged at the same time. When the speed of the load dynamometer 111 reaches 0, one test cycle is completed;

[0040] The load dynamometer 111 applies torque to the input shaft of the gearbox 112 to simulate the actual vehicle usage. The gearbox 112 to be tested is put into parking gear, and torque is applied to the input shaft of the gearbox 112 to simulate the actual vehicle parking condition on a slope. This simulation experiment can be used to test the durability of the parking mechanism and the input shaft.

[0041] S4, repeat the set number of cycles according to step S3;

[0042] By performing a set number of cycles according to step S3, for example, 1000 times, and observing the damage of the part to be inspected, the durability of the inspected part can be evaluated.

[0043] In some embodiments of the present application, the method of fixing the reduction gearbox 112 to be tested on the base 1 in the above step S1 is optimized. Figures 1 to 3 As shown, in this embodiment, a support plate 2 is installed on the base 1. The support plate 2 is an L-shaped plate structure, including a bottom plate fixed on the base 1 and side plates located on the bottom plate. The side plates are arranged vertically, and two groups of brackets 3 spaced axially are provided on the side plates.

[0044] During use, the bottom plate is fixed to the base 1. Similarly, the bottom plate can be adjusted on the base 1 to the appropriate position as needed. The two sets of brackets 3 on the side panels are placed on both sides of the differential of the gearbox to be tested. The gearbox to be tested 112 is fixed to the base 1 through the brackets 3 and the differential. The end of the bracket 3 away from the side panel is fixedly connected to the two ends of the differential of the gearbox to be tested 112 by bolts, which is equivalent to the gearbox to be tested 112 being fixed to the support plate 2 through the brackets 3. This fixing method can completely expose the input shaft portion, facilitating connection with the load dynamometer 111, and the overall disassembly and installation are extremely simple.

[0045] In some other embodiments of the present application, this embodiment optimizes the method of connecting one end of the input shaft of the reduction gearbox 112 to be tested to the load dynamometer 111 through a coupling in the above-mentioned step S2. Specifically, this embodiment arranges a connecting shaft 4, a coupling and a connecting flange 5 between the reduction gearbox 112 to be tested and the load dynamometer 111, and transmits one end of the connecting shaft 4 to the input shaft end of the reduction gearbox 112 to be tested, fixes the connecting flange 5 to the power output part of the load dynamometer 111, and fixes the connecting flange 5 to the other end of the connecting shaft 4 through a coupling to support the connecting shaft 4, thereby completing the transmission connection between the reduction gearbox 112 to be tested and the load dynamometer 111.

[0046] The connecting shaft 4, the coupling and the connecting flange 5 are all coaxially arranged and also coaxial with the input shaft, so that the torque of the load dynamometer 111 can be stably and efficiently transmitted to the input shaft, and the measurement accuracy is higher.

[0047] In a further embodiment of the present application, this embodiment optimizes the above-mentioned method of supporting the connecting shaft 4. Specifically, a support seat 6 is installed on the base 1, and the support seat 6 is fixed to the base 1 by a pin. Similarly, the support seat 6 can also be adjusted in position on the base 1 to adapt to the load dynamometer and the reducer to be tested. The upper end of the support seat 6 is an annular ring sleeve 7, which is sleeved on the connecting shaft 4. Several groups of bearings 8 are arranged on the inner side of the ring sleeve 7, and the bearings 8 are sleeved on the connecting shaft 4 to support the connecting shaft 4.

[0048] The collar 7 supports the connecting shaft 4 via bearings 8, preventing axial misalignment caused by the connecting shaft 4 falling due to gravity, thereby making the torque transmission of the load dynamometer more efficient and stable. The bearings 8 within the collar 7 enable the connecting shaft 4 to rotate stably about the axial direction. In this embodiment, two sets of bearings 8 are provided within the collar 7, spaced axially and located near the axial ends of the collar 7.

[0049] In a preferred embodiment of the present application, this embodiment optimizes the above-mentioned method of fixing the connecting flange 5 to the other end of the connecting shaft 4 through a coupling. Specifically, Figure 4 As shown, the coupling includes a first sleeve 9 and a second sleeve 10. A first groove is provided on the inner side of the first sleeve 9, and a second groove is provided on the inner side of the second sleeve 10. A protruding first flat key 11 is provided at the end of the connecting shaft 4, and a second flat key 12 is provided at the end of the connecting flange 5.

[0050] During installation, insert the connecting shaft 4 into the first sleeve 9, so that the first flat key 11 enters the first groove along the axial direction, and the first flat key 11 is clamped in the first groove, so that the connecting shaft 4 and the first sleeve 9 are fixed as one in the direction of rotation around the axis; insert the end of the connecting flange 5 into the second sleeve 10, so that the second flat key 12 enters the second groove along the axial direction, and the second flat key 12 is clamped in the second groove, so that the connecting flange 5 and the second sleeve 10 are fixed as one in the direction of rotation around the axis, and then the first sleeve 9 and the second sleeve 10 are connected and fixed as one by bolts to complete the transmission connection between the connecting flange 5 and the connecting shaft 4.

[0051] This connection method is extremely simple, and is extremely convenient to disassemble and install. The connection can be released by pulling it outward, and the assembly efficiency is extremely high.

[0052] In some embodiments of the present application, the method of arranging several groups of bearings 8 inside the ring sleeve 7 is optimized. Specifically, Figure 4 As shown, several groups (two groups in this embodiment) of sliding grooves 13 arranged at intervals along the axial direction are opened on the inner side of the ring sleeve 7, the outer ring of the bearing 8 is arranged in the sliding groove 13, and the inner ring of the bearing 8 is set on the outer side of the circumference of the connecting shaft 4.

[0053] In addition, a circle of limiting grooves 14 is provided on the outer circumferential end face of the connecting shaft 4, and an annular retaining ring 15 is provided on the inner side of the ring sleeve 7. The outer circumferential end face of the retaining ring 15 is fixed between the two sets of bearings 8, and the inner side of the retaining ring 15 is clamped in the limiting groove 14, which is used to limit the relative displacement of the connecting shaft 4 and the ring sleeve 7 in the axial direction.

[0054] The outer ring of the bearing 8 is clamped in the slide groove 13. The connecting shaft 4 and the ring sleeve 7 are fixed together except for the rotation direction around the axis. The ring sleeve 7 provides stable support for the connecting shaft 4, so that the torque of the load dynamometer can be stably and efficiently transmitted to the input shaft of the reduction gearbox to be tested.

[0055] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for testing the parking mechanism of an electric drive reduction gearbox under load, characterized by: Follow the steps below: S1. Fix the reduction gearbox to be tested and the load dynamometer on the base (1); S2. Connect one end of the input shaft of the gearbox to be tested to the load dynamometer through a coupling; S3. Put the gearbox under test into the parking gear, start the load dynamometer and load the set torque on the input shaft of the gearbox under test. After reaching the set torque, unload the torque and simultaneously disengage the parking gear. When the speed of the load dynamometer reaches 0, one test cycle is completed. S4, repeat the set number of cycles according to step S3; In step S1, the method for fixing the reduction gearbox to be tested on the base (1) comprises: fixing an L-shaped support plate (2) comprising a bottom plate and a side plate on the base (1), placing two sets of brackets (3) on the side plate on both sides of the differential of the reduction gearbox to be tested, and fixing the reduction gearbox to be tested on the base (1) by fixing the brackets (3) to the differential; In step S2, the method for connecting one end of the input shaft of the reduction gearbox to be tested to the load dynamometer via a coupling comprises: arranging a connecting shaft (4), a coupling, and a connecting flange (5) between the reduction gearbox to be tested and the load dynamometer, drivingly connecting one end of the connecting shaft (4) to the end of the input shaft of the reduction gearbox to be tested, fixing the connecting flange (5) to the power output part of the load dynamometer, fixing the connecting flange (5) to the other end of the connecting shaft (4) via the coupling, supporting the connecting shaft (4), and completing the transmission connection between the reduction gearbox to be tested and the load dynamometer; The method for supporting the connecting shaft (4) comprises: installing a support seat (6) on the base (1), fixing the support seat (6) on the base (1) by means of a latch, wherein the upper end of the support seat (6) is a ring sleeve (7) sleeved on the connecting shaft (4), arranging a plurality of groups of bearings (8) on the inner side of the ring sleeve (7), and sleeve-mounting the bearings (8) on the connecting shaft (4) to support the connecting shaft (4); The base (1) is provided with a plurality of groove-shaped structures. The reduction gearbox (112) to be tested and the load dynamometer (111) are both mounted and fixed on the base (1). The positions can be adjusted as needed to adapt to reduction gearboxes to be tested and load dynamometers of different specifications. The bottom plate can be adjusted in position on the base (1). The support base (6) can also be adjusted in position on the base (1) to adapt to the load dynamometer and the reduction gearbox to be tested.

2. The method for testing the parking mechanism of an electric drive reduction gearbox under load according to claim 1, characterized in that: The method for fixedly connecting the connecting flange (5) and the other end of the connecting shaft (4) through a coupling comprises: the coupling comprises a first sleeve (9) and a second sleeve (10), the first sleeve (9) having a first groove formed on its inner side, and the second sleeve (10) having a second groove formed on its inner side; the end of the connecting shaft (4) is provided with a protruding first flat key (11), and the end of the connecting flange (5) is provided with a second flat key (12); the connecting shaft (4) is inserted into the first sleeve (9), so that the first flat key (11) enters the first groove in the axial direction; the end of the connecting flange (5) is inserted into the second sleeve (10), so that the second flat key (12) enters the second groove in the axial direction; the first sleeve (9) and the second sleeve (10) are connected and fixed as a whole by bolts, thereby completing the transmission connection between the connecting flange (5) and the connecting shaft (4).

3. The method for testing the parking mechanism of an electric drive reduction gearbox under load according to claim 1, wherein: The method for arranging a plurality of groups of bearings (8) on the inner side of the ring sleeve (7) comprises: providing a plurality of groups of sliding grooves (13) spaced apart along the axial direction on the inner side of the ring sleeve (7), arranging the outer rings of the bearings (8) in the sliding grooves (13), and sleeve-arranging the inner rings of the bearings (8) on the outer side of the circumference of the connecting shaft (4).

4. The method for testing the parking mechanism of an electric drive reduction gearbox under load according to claim 3, characterized in that: Two sets of bearings (8) are arranged in the ring sleeve (7).

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