A brake wear particle testing device and method with high coaxiality and sealing performance

Abstract

The present invention relates to the field of vehicle testing technology, and in particular to a brake wear particle testing device and method with high coaxiality and sealing. The device includes a test hub and an absorption assembly; the test hub includes a rotating assembly, a rolling bearing and a stator spoke; the rotating assembly includes a spoke and a rim fixedly connected by bolts; the stator spoke includes a first center hole, and the rim includes a second center hole; the two ends of the rolling bearing are respectively mounted on the first center hole and the second center hole; the absorption assembly includes a collecting cover, and the stator spoke is fixedly connected and sealed to the collecting cover; the test hub replaces the original vehicle hub to perform a brake wear particle test, and during the rotation of the test hub, the stator spoke and the collecting cover are stationary; and under the connection of the rolling bearing, the collecting cover is coaxial with the test hub.

Description

Technical Field

[0001] The invention relates to the technical field of vehicle testing, and in particular to a brake wear particle testing device and method with high coaxiality and sealing performance. Background Art

[0002] With the continuous development of the economy and society, environmental protection has received more and more attention from people. Nowadays, with the popularization of new energy vehicles, the proportion of non-exhaust emissions in automobile pollution emissions will gradually increase. How to monitor and control non-exhaust particulate matter emissions has become an environmental problem that needs to be solved urgently.

[0003] Brake wear is considered to be the main source of non-exhaust emissions, and researchers have developed a number of devices to collect brake wear particulate matter. Most of the existing particulate matter collection devices currently connect the collection hood and the wheel hub together. This connection method allows the collection hood to rotate at high speed when the wheel hub rotates at high speed. This may cause deformation between the collection hood and the wheel hub. This deformation may cause the connecting bolts between the two to be damaged, causing the collection hood to detach from the wheel hub. This may not only lead to insufficient collection, but also may cause safety problems. In order to avoid this problem, some existing equipment will separate the collection hood from the wheel hub. Although this method avoids the problem of the collection hood detaching from the wheel hub, the gap between the two may still lead to insufficient collection.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The purpose of the present invention is to provide a brake wear particle testing device and method with high coaxiality and sealing performance, and to design a standardized testing wheel hub to solve the problems in the background technology.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a brake wear particle testing device with high coaxiality and sealing performance, comprising:

[0008] Test hub and absorber assembly;

[0009] The test wheel hub comprises a rotating assembly, a rolling bearing and a stator spoke; the rotating assembly comprises a wheel spoke and a wheel rim connected by bolts;

[0010] The stator spokes include a first center hole, and the wheel rim includes a second center hole; both ends of the rolling bearing are respectively mounted on the first center hole and the second center hole;

[0011] The absorption assembly includes a collection cover, and the stator spokes are fixedly and sealedly connected to the collection cover;

[0012] The test wheel hub replaces the original wheel hub of the vehicle to carry out the brake wear particle test. During the rotation of the test wheel hub, the stator spokes and the collecting cover are stationary; and under the connection of the rolling bearing, the collecting cover is coaxial with the test wheel hub.

[0013] Optionally, the absorption component includes a sampling pipeline and an absorption fan; the sampling pipeline is connected to the collection cover and the absorption fan respectively;

[0014] The collecting hood has a transition angle;

[0015] The edge of the collecting cover is provided with a third bolt hole, and the edge of the stator spoke is provided with a fourth bolt hole; bolts are passed through the third bolt hole and the fourth bolt hole to fix the collecting cover and the stator spoke in connection.

[0016] Optionally, the range of the transition angle a is 15°≤a≤30°;

[0017] Collection hood length I A1 Should meet 600mm≤I A1 ≤700mm.

[0018] Optionally, a sampling plane is provided on the internal cross section of the sampling pipe, and a plurality of sampling probes are evenly arranged on the sampling plane;

[0019] The sampling pipeline uses an elbow downstream of the collection hood and upstream of the sampling plane.

[0020] Optionally, the device further comprises:

[0021] Brake disc temperature sensor, installed on disc brakes or drum brakes.

[0022] Optionally, the device further comprises:

[0023] The blower is installed on the inner side of the test wheel hub and is used to blow the airflow from the inner side of the test wheel hub to one side of the collecting cover to adjust the temperature and humidity of the airflow.

[0024] Optionally, the spokes of the stator spokes are hollow structures with a hollow center and distributed along the shape of the spokes, the hollow structures adopt a conical collecting chamber, each hollow structure includes a plurality of air inlets and an air outlet, and gradually shrinks from each air inlet to the air outlet;

[0025] The spokes and the circular extension of the stator spokes have an included angle and are inclined toward the inner side of the collecting cover.

[0026] Optionally, the air inlets are distributed on the spokes, and the air outlets are located inside the center of the stator spokes;

[0027] The gas containing particulate matter is pumped by the blower, enters the hollow structure from the air inlet, and finally leaves the hollow structure from the air outlet and enters the collection hood.

[0028] In a second aspect, the present invention provides a method for testing brake wear particles with high coaxiality and sealing performance, using any brake wear particle testing device with high coaxiality and sealing performance, the method comprising:

[0029] Remove the original wheel hub of the vehicle and replace it with the test wheel hub;

[0030] Fixing the vehicle on a chassis dynamometer and fitting the drag coefficient on the test wheel hub;

[0031] The control vehicle is tested for emissions according to the specified cycle and the emission results are calculated.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention designs a brake wear particle collection device with high coaxiality and good sealing performance, taking into account the coaxiality, sealing performance and safety of the device. The present invention solves the problem of centering between the collection cover and the original wheel hub by using a rolling bearing to connect the standard test wheel hub and the collection cover, reduces disturbances during the collection process, and can ensure that the collection cover does not rotate while the wheel hub rotates, thereby ensuring the collection efficiency and avoiding safety problems caused by the separation of the collection cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 1 is a schematic structural diagram of a brake wear particle testing device with high coaxiality and sealing performance provided by an embodiment of the present invention;

[0036] Figure 2 is a schematic structural diagram of an absorption assembly provided by an embodiment of the present invention;

[0037] Figure 3 is a schematic diagram of a transition angle of a collection hood provided in an embodiment of the present invention;

[0038] Figure 4 is a schematic diagram of the position of the sampling probe provided by an embodiment of the present invention;

[0039] Figure 5is a schematic diagram of a bent pipe provided in an embodiment of the present invention;

[0040] Figure 6 is a schematic diagram of the installation position of the disc brake provided by an embodiment of the present invention;

[0041] Figure 7 is a schematic diagram of the installation position of the drum brake provided by an embodiment of the present invention;

[0042] Figure 8 is a schematic diagram of the position of a hair dryer provided in an embodiment of the present invention;

[0043] Fig. 9 is a schematic structural diagram of a stator spoke provided by an embodiment of the present invention;

[0044] Fig.10 is a side view of a stator spoke provided by an embodiment of the present invention;

[0045] Fig.11 It is a flow chart of a method for testing brake wear particles with high coaxiality and sealing performance provided by an embodiment of the present invention;

[0046] Among them, there are a test hub 100, a rolling bearing 1, a stator spoke 2, a first center hole 21, a fourth bolt hole 22, a spoke 3, a first bolt hole 31, a rim 4, a second bolt hole 41, a second center hole 42, a sampling pipe 5, a straight pipe 51, an absorption fan 6, a particle outlet 61, a collecting cover 7, a third bolt hole 71, a sampling plane 8, a sampling probe 9, a bent pipe 10, a brake disc temperature sensor 11, a blower 12, a fixing bracket 13, an air inlet 14, an air outlet 15, and a hollow structure 16. DETAILED DESCRIPTION

[0047] The following is a description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, including various details of the embodiments of the present invention to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, for clarity and conciseness, the description of well-known functions and structures is omitted in the following description.

[0048] Example 1

[0049] This embodiment provides a brake wear particle testing device with high coaxiality and sealing performance. Figure 1 As shown, the device comprises a test hub 100 and an absorption assembly. The structure and function of each component are described in detail below.

[0050] The test hub 100 includes a rotating assembly, a rolling bearing 1 and a stator spoke 2. The rotating assembly includes a spoke 3 and a rim 4 fixedly connected by bolts; specifically, the spoke 3 is in the shape of a ring, and a plurality of first bolt holes 31 are evenly distributed on the ring. The rim 4 is a cylindrical structure with a second center hole 42, and a plurality of second bolt holes 41 are evenly distributed on the edge of the cylinder, and the number of the first bolt holes 31 and the second bolt holes 41 are the same, and the positions correspond; the first bolt holes 31 and the second bolt holes 41 are fixed by bolts, so that the rim 4 and the spoke 3 are fixedly connected.

[0051] The stator spoke 2 is a sheet-like structure having a first central hole 21 , and the first central hole 21 is connected to the edge of the stator spoke 2 through a plurality of spokes. Figure 1 Five spokes are shown, but the number of spokes is not limited in this embodiment.

[0052] The rolling bearing 1 is a precision mechanical component that converts the sliding friction between the running shaft and the shaft seat into rolling friction, thereby reducing the friction loss, and includes an inner ring, an outer ring, a rolling element and a cage 4. The two ends of the rolling bearing 1 are respectively mounted on the first center hole 21 and the second center hole 42.

[0053] The absorption assembly includes a collection cover 7, and the stator spokes 2 are fixedly and sealedly connected to the collection cover 7. The edge of the collection cover 7 has a third bolt hole 71, and the edge of the stator spokes 2 also has a fourth bolt hole 22; bolts are passed through the third bolt holes 71 and the fourth bolt holes 22 to fix the collection cover 7 and the stator spokes 2. This connection method allows the collection cover 7 to be tightly connected to the test hub 100 without gaps, thereby ensuring sealing.

[0054] The test wheel hub 100 replaces the original wheel hub of the vehicle to carry out the brake wear particle test. During the rotation of the test wheel hub 100, the rim 4 rotates with the axle, driving the inner ring of the rolling bearing 1 to rotate through the second center hole 42, and the outer ring of the rolling bearing 1 is connected to the first center hole 21, so that the stator spokes 2 and the collection cover 7 remain stationary, so that the safety and stability of the collection cover 7 can still be guaranteed during the high-speed rotation of the wheel. Under the connection of the rolling bearing 1, the collection cover 7 is coaxial with the test wheel hub 100, solving the centering problem.

[0055] The present invention designs a brake wear particle collection device with high coaxiality and good sealing performance, taking into account the coaxiality, sealing performance and safety of the device. The present invention solves the problem of centering between the collection cover 7 and the original wheel hub by using a rolling bearing 1 to connect the standard test wheel hub 100 and the collection cover 7, reduces disturbances during the collection process, and can ensure that the collection cover 7 does not rotate while the wheel hub rotates, thereby ensuring the collection efficiency and avoiding the safety problems caused by the separation of the collection cover 7.

[0056] Example 2

[0057] Figure 2 Schematic diagram of the structure of the absorption assembly provided by the embodiment of the present invention. Figure 2 The absorption component includes a collection cover 7, a sampling pipeline 5 and an absorption fan 6, and the sampling pipeline 5 is respectively connected to the collection cover 7 and the absorption fan 6. The structure and function of each part are described in detail below.

[0058] Figure 3 Schematic diagram of the transition angle of the collection hood 7 provided in an embodiment of the present invention. The collection hood 7 has a transition angle a. In order to ensure the stability of the airflow, the transition angle a of the collection hood 7 is stable and in the range of 15°≤a≤30°. The inner and outer surfaces of the collection hood 7 must be smooth. Fasteners can be used at the transition point, but they must not protrude from the surface of the collection hood 7. The length of the collection hood 7 is I A1 Should meet 600mm≤I A1 ≤700mm.

[0059] The outer shell surface of the collecting hood 7 in contact with the aerosol (i.e., liquid particles or solid particles uniformly dispersed in the gas) should be a seamless structure, and stainless steel with an electroplated polished (or equivalent material) surface should be used. An airflow test device (not shown) is installed at the entrance of the collecting hood 7. By real-time monitoring and analysis of the airflow state at the entrance, the test parameters (such as airflow velocity, temperature, humidity and other parameters) are adjusted in time to ensure that the airflow remains in a turbulent state, and the Reynolds number is at least 4000 to ensure that the airflow is fully mixed. The Reynolds number Re of a given brake emission test is calculated using the following formula:

[0060] ;

[0061] In the above formula, U is the average cooling airspeed, unit is km / h; d i is the diameter of the sampling pipe 5, in mm; v is the kinematic viscosity of air (the default value is 1.48×10 -5 m² / s).

[0062] In some embodiments of the present invention, the sampling pipe 5 has a constant inner diameter d i , and should meet 175mm≤d i ≤225mm, the surface of the sampling pipe 5 in contact with the aerosol (i.e., liquid particles or solid particles uniformly dispersed in the gas) should be made of electro-polished stainless steel or equivalent material. At least one cross section is set inside the sampling pipe 5, a sampling plane 8 is set on the cross section, and multiple sampling probes 9 are evenly set on the same sampling plane 8. Figure 4 Schematic diagram of the arrangement of the sampling plane 8 and the sampling probe 9 provided in the embodiment of the present invention. The sampling probe 9 includes but is not limited to TPN10 sampling probe 9, SPN10 sampling probe 9, PM2.5 Sampling probe 9 and PM 10 Sampling probe 9. All sampling probes 9 are placed equidistantly from the central longitudinal axis of the sampling pipe 5. The spacing a1 of the outer diameter of the sampling probe 9 is required to be a1 ≥ 47.5 mm. The minimum radial distance requirement from the sampling probe 9 to the inner wall of the sampling plane 8 is a2 ≥ 47.5 mm. When the number of sampling probes 9 is 4, the inner diameter range of the sampling pipe 5 is required to be 190 mm ≤ d i ≤225mm. It should be noted that Figure 4 The diagram shows one end of the sampling probe 9 inside the sampling pipe 5, and the other end of the sampling probe 9 is located outside the sampling pipe 5, see Figure 2 shown.

[0063] Figure 5 Schematic diagram of the elbow 10 provided in the embodiment of the present invention. The sampling pipe 5 can be a straight pipe 51 or an elbow 10 downstream of the collecting hood 7 and upstream of the sampling plane 8. At most, an elbow 10 with a radius of ≤90° can be used. The bending radius r of the elbow 10 is b Should be at least the inner diameter of the pipe d i 2 times (2×d i The length of the area in front of the sampling plane 8 (close to the test hub 100, also in the upstream direction) should be at least the inner diameter d of the pipe. i Six times (6×d i ) and the diameter of the pipe after the sampling plane 8 (away from the test hub 100, also the downstream direction) should be at least d i Twice (2×d i ) of the straight pipe 51.

[0064] In some embodiments of the present invention, the absorption fan 6 is provided with a particle outlet 61, which is connected to the sampling pipe 5. The minimum operating flow rate of the absorption fan 6 should be determined to be 100-300 m 3 / h, the maximum operating flow rate is at least 5 times the minimum operating flow rate, and the maximum operating flow rate should be at least 1000 m greater than the minimum operating flow rate 3 / h. A fixing bracket 13 can be installed at any position of the absorption component to further avoid disturbance of the absorption component and ensure the absorption effect.

[0065] Example 3

[0066] In some embodiments of the present invention, the high coaxiality and sealing brake wear particle testing device further includes a brake disc temperature sensor 11. Optionally, the brake disc temperature sensor 11 uses an embedded thermocouple, and uses a commercially available temperature sensor 11 containing nickel chromium and chrome aluminum conductors, and the measurement temperature range is between 0°C and at least 800°C, and the maximum allowable error (tolerance) is +2.2°C or ±0.75% of the measured value. Figure 6The figure is a schematic diagram of the installation position of the disc brake provided by the embodiment of the present invention. The brake disc temperature sensor 11 can be installed on the disc brake, positioned 10 mm outward from the center of the friction path, and embedded 0.5±0.1 mm below the disc surface (i.e. the outer surface of the brake disc). On the ventilated disc, the brake disc temperature sensor 11 is placed in the center between the two fins of the disc plate. See Figure 6 Assuming that the width of the brake pad is x, the brake disc temperature sensor 11 is installed 10 mm outward from the center point x / 2 of x, that is, at x / 2-10 mm. Figure 7 Schematic diagram of the installation position of the drum brake provided by an embodiment of the present invention. The brake disc temperature sensor 11 can be installed on the drum brake and positioned at the center of the friction path recessed (0.5±0.1) mm below the inner surface of the brake drum. The center of the friction path is the center of the contact and friction part between the brake pad and the brake drum during braking. Assuming that the brake pad is 2x wide, the temperature sensor 11 is installed at the center point of 2x.

[0067] Figure 8 Schematic diagram of the position of the blower 12 provided in an embodiment of the present invention. The blower 12 is installed inside the test hub 100 and is used to blow the airflow from the inside of the test hub 100 to the side of the collection cover 7 to adjust the temperature and humidity of the airflow. During the test, by controlling the temperature and humidity of the airflow, the blower 12 blows the airflow from the inside of the hub to the side of the collection cover 7, so that as many particles as possible are absorbed by the collection cover 7, thereby improving the collection efficiency.

[0068] Example 4

[0069] In this embodiment, the structure of the stator spokes 2 is optimized on the basis of the above embodiments. Fig. 9 is a schematic structural diagram of a stator spoke 2 provided in an embodiment of the present invention, Fig.10 It is a side view of the stator spoke 2 provided in an embodiment of the present invention.

[0070] See also Fig. 9 and Fig.10 The spokes of the stator spokes 2 are hollow structures 16 which are distributed along the shape of the spokes. The hollow structure 16 adopts a conical collecting chamber (in Fig. 9 Each hollow structure 16 includes a plurality of air inlets 14 and an air outlet 15, and gradually contracts from each air inlet 14 to the air outlet 15. Fig. 9 , four air inlets and one air outlet 15 (towards the hub) are provided on each spoke, the air inlets 14 are distributed on the spokes, and the air outlet 15 is located inside the center of the stator spoke 2. Fig.10, the spokes and the outer extension of the stator spokes 2 are not on the same horizontal plane, and the spokes and the circular extension of the stator spokes 2 have an angle, which is inclined to the inside of the collection cover 7, for example, 10°. Such a shape and design makes the air flow rate gradually increase after entering, and the particles are more difficult to deposit near the wall under the entrainment of the air flow, but gather to the outlet with the high-speed air flow.

[0071] The gas containing particles is pumped by the blower 12, enters the hollow structure 16 from the air inlet 14, and finally leaves the hollow structure 16 from the air outlet 15 and enters the collection cover 7. This structure helps to reduce the impact of particles when passing through the stator spokes 2, which leads to the deposition of particles. The flow of gas in the stator spokes 2 can drive the air and the rolling bearing 1 to exchange heat, reduce the high temperature generated by the rolling bearing 1 during operation, and extend the service life of the rolling bearing 1, achieving an unexpected technical effect. In addition, the stator spokes 2 are made of electroplated stainless steel, and the surface is not easy to adsorb particles, which reduces the deposition of particles.

[0072] Example 5

[0073] The present invention also provides a method for testing brake wear particles with high coaxiality and sealing performance. The brake wear particles testing device with high coaxiality and sealing performance of any of the above embodiments is used. Fig.11 , the method provided in this embodiment includes the following operations:

[0074] S110. Remove the original wheel hub of the vehicle and replace it with the test wheel hub.

[0075] Before the actual test, the vehicle needs to be cleaned and dried to prevent dust on the vehicle body from affecting the test results. The original wheel hub of the vehicle is removed and replaced with a standard test wheel hub.

[0076] S120, fixing the vehicle on a chassis dynamometer, and fitting the drag coefficient on the test wheel hub.

[0077] The drag that needs to be simulated by the chassis dynamometer can be regarded as the sum of the speed-related drag and the acceleration-related inertial drag acting on the vehicle. The speed-related drag is usually expressed by the drag coefficient. In addition, the temperature and humidity of the test environment need to be set.

[0078] Before the emissions test, five WLTP-Brake cycles are run; no hot soak is applied between the 10 strokes (i.e. stopping and waiting for the brake disc temperature to drop to 40°C), but a hot soak is applied between the five repeated cycles.

[0079] Measure the background particle concentration before and after the emission test to confirm that the background particle concentration is less than 20# / Ncm 3; Weigh the brake friction materials (brake pads / brake shoes) and brake discs / brake drums.

[0080] S130: Control the vehicle to perform an emission test according to a specified cycle and calculate the emission results.

[0081] Optionally, run 1 WLTP-Brake cycle for emission testing; apply hot soak sections between 10 strokes. Test result analysis combines the Aps sampling flow and pipeline flow to calculate the emission results. Since the vehicle has a total of 4 tires, the final emission result = (emission result of the front brake × 2 + emission result of the rear brake × 2). The emission result includes the quality and quantity of the emissions.

[0082] Specifically, Aps is an aerodynamic particle size spectrometer that can measure the mass concentration data M and number concentration data N of particles in the air every second. Figure 2 When the device is working, the particles generated by braking are mixed with air and enter the sampling pipe 5, and then enter the APS through the sampling probe 9 to obtain the particle mass concentration data M (unit: mg / m 3 ) and number concentration data N (unit # / m 3 ), combined with the flow rate F in sampling pipeline 5 (unit: m 3 / s), and integrate the time to calculate the total particulate matter emissions during the test. One set of equipment can only measure the emission results of one wheel. When testing the front wheel, the rear wheel can also be tested with one set of equipment.

[0083] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and this document does not limit this.

[0084] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A brake wear particle testing device with high coaxiality and sealing performance, characterized in that: include: Test hub and absorber assembly; The test wheel hub comprises a rotating assembly, a rolling bearing and a stator spoke; the rotating assembly comprises a wheel spoke and a wheel rim connected by bolts; The stator spokes include a first center hole, and the wheel rim includes a second center hole; both ends of the rolling bearing are respectively mounted on the first center hole and the second center hole; The absorption assembly includes a collection cover, and the stator spokes are fixedly and sealedly connected to the collection cover; The test wheel hub replaces the original wheel hub of the vehicle to perform the brake wear particle test. During the rotation of the test wheel hub, the stator spokes and the collection cover are stationary; and under the connection of the rolling bearing, the collection cover is coaxial with the test wheel hub; The spokes of the stator spokes are hollow structures with a hollow center and distributed along the shape of the spokes. The hollow structures adopt a conical collecting chamber. Each hollow structure includes a plurality of air inlets and an air outlet, and gradually shrinks from each air inlet to the air outlet. The spokes have an angle with the circular extension of the stator spokes and are inclined toward the inner side of the collecting cover. The air inlets are distributed on the spokes, and the air outlets are located on the inner side of the center of the stator spokes; the gas containing particulate matter is pumped by the blower, enters the hollow structure from the air inlet, and finally leaves the hollow structure from the air outlet and enters the collection cover.

2. The brake wear particle testing device with high coaxiality and sealing performance according to claim 1 is characterized in that: The absorption component includes a sampling pipeline and an absorption fan; the sampling pipeline is connected to the collection cover and the absorption fan respectively; The collecting hood has a transition angle; The edge of the collecting cover is provided with a third bolt hole, and the edge of the stator spoke is provided with a fourth bolt hole; bolts are passed through the third bolt hole and the fourth bolt hole to fix the collecting cover and the stator spoke in connection.

3. The brake wear particle testing device with high coaxiality and sealing performance according to claim 2 is characterized in that: The range of the transition angle a is 15°≤a≤30°; Collection hood length I A1 Should meet 600mm≤I A1 ≤700mm.

4. The brake wear particle testing device with high coaxiality and sealing performance according to claim 3 is characterized in that: A sampling plane is arranged on the cross section of the interior of the sampling pipe, and a plurality of sampling probes are evenly arranged on the sampling plane; The sampling pipeline uses an elbow downstream of the collection hood and upstream of the sampling plane.

5. The brake wear particle testing device with high coaxiality and sealing performance according to claim 4, characterized in that: Also includes: Brake disc temperature sensor, installed on disc brakes or drum brakes.

6. The brake wear particle testing device with high coaxiality and sealing performance according to claim 5, characterized in that: Also includes: The blower is installed on the inner side of the test wheel hub and is used to blow the airflow from the inner side of the test wheel hub to one side of the collecting cover to adjust the temperature and humidity of the airflow.

7. A method for testing brake wear particles with high coaxiality and sealing performance, characterized in that: Using the high coaxiality and sealing brake wear particle testing device according to any one of claims 1 to 6, the method comprises: Remove the original wheel hub of the vehicle and replace it with the test wheel hub; Fixing the vehicle on a chassis dynamometer and fitting the drag coefficient on the test wheel hub; The control vehicle is tested for emissions according to the specified cycle and the emission results are calculated.

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