Flow measurement system and flow measurement method

Abstract

The invention provides a flow measuring system and a flow measuring method, and relates to the field of motors, the flow measuring system comprises an oil collecting cover and a measuring device, the oil collecting cover is used for being arranged at the axial end of a rotor core of a rotor assembly to be measured, and the oil collecting cover is used for forming an oil cavity with the axial end face of the rotor core; the measuring device comprises a measuring cavity and a measuring structure, the measuring cavity is communicated with the oil cavity and provided with a measuring outlet, and the measuring structure is used for measuring the flow of the measuring outlet according to oil in the measuring cavity. Cooling lubricating oil sprayed out of the two ends of the rotor iron core is thrown to the oil collecting cover, falls into the oil cavity after speed reduction, then enters the measuring cavity of the corresponding measuring device and flows out of the measuring outlet, and the cooling lubricating oil flowing out of the measuring outlet basically overcomes the influence of the rotating speed of the rotor assembly on the flow of the rotor assembly. The flow distribution condition of the axial end part of the rotor assembly to be measured can be obtained by measuring the flow at the measuring outlet through a flow meter and other measuring structures.

Description

Technical Field

[0001] The present invention relates to the field of motors, and in particular to a flow measurement system and a flow measurement method. Background Art

[0002] In order to prevent the motor from overheating, the rotor core of the motor rotor assembly is usually provided with an oil path running axially therethrough, and cooling lubricating oil flows out from the axial end of the rotor core through the lubricating oil path to achieve lubrication and cooling of the rotor assembly.

[0003] Since whether the cooling lubricating oil flow rate in the motor rotor assembly meets the design requirements has an important impact on the performance of the motor rotor assembly, it is very important to study the cooling lubricating oil flow distribution at both ends of the motor rotor assembly. The following methods are generally used for research: First, by observing whether the operating temperature of the motor rotor assembly is within the design range and whether the lubrication of related components such as bearings is sufficient, the cooling lubricating oil flow distribution is judged. This indirect analysis method cannot accurately grasp the cooling lubricating oil flow distribution in the rotor core; second, the simulation method is used to calculate the flow rate. This method does not consider the influence of actual assembly and processing on the calculation results, and the error is large; third, a flow meter and other tools are set at the axial end of the rotor core, and the flow meter and other tools are used to directly measure the lubricating coolant flow at both ends of the rotor core. Since the rotor assembly works at a high-speed rotation state, the cooling lubricating oil has a higher speed when it flows out from the end of the rotor core, and the kinetic energy of the cooling lubricating oil is relatively large. Direct measurement using flow meters and other measuring tools will result in larger measurement results. Summary of the invention

[0004] The present invention aims to solve the technical problem that the prior art cannot accurately grasp the flow rate of cooling lubricating oil at the axial end of a motor rotor assembly.

[0005] On the one hand, the present invention provides a flow measurement system, including an oil collecting hood and a measuring device, wherein the oil collecting hood is used to be arranged at the axial end of the rotor core of the rotor assembly to be measured, and the oil collecting hood is used to form an oil cavity between the axial end surface of the rotor core, and the measuring device includes a measuring cavity and a measuring structure, the measuring cavity is connected to the oil cavity to receive the cooling lubricating oil flowing out of the oil cavity, and a measuring outlet is provided at the bottom of the measuring cavity, and the measuring structure is used to measure the flow of the measuring outlet according to the oil in the measuring cavity.

[0006] Optionally, the measuring structure includes scale lines arranged on the side wall of the measuring cavity for measuring the height of the liquid level therein.

[0007] Optionally, the measuring structure comprises a flow meter, and the flow meter is used to measure the cooling lubricating oil flow rate of the measuring outlet when the liquid level of the measuring chamber is in dynamic equilibrium.

[0008] Optionally, the measuring device further has a buffer chamber, which is located on one side of the measuring chamber and is provided with an overflow hole connected to the measuring chamber. The buffer chamber is connected to the oil chamber to receive the cooling lubricating oil flowing out of the oil chamber.

[0009] Optionally, the buffer chamber is located below the oil chamber, the buffer chamber is open toward one end of the oil chamber, a second oil outlet connected to the oil chamber is provided on the oil collecting cover, and the second oil outlet is open toward the buffer chamber.

[0010] Optionally, the bottom wall of the buffer cavity is higher than the bottom wall of the measuring cavity, and the overflow hole has a preset height from the bottom wall of the buffer cavity;

[0011] And / or, the measuring cavity is cylindrical, and the radius of the measuring outlet is less than or equal to one tenth of the radius of the measuring cavity.

[0012] Optionally, the flow measurement system includes two oil collecting hoods and two measuring devices, the two oil collecting hoods are respectively used to be arranged at the axial ends of the rotor core, and the two oil collecting hoods are respectively used to form the oil chamber between the corresponding axial end faces of the rotor core, and the measuring chambers of the two measuring devices are respectively connected to the two oil chambers one by one.

[0013] Optionally, the flow measurement system further comprises an oil storage tank, which is respectively connected to the measurement outlets of the two measurement devices so as to receive the cooling lubricating oil flowing out of the measurement outlets of the two measurement devices.

[0014] Optionally, the flow measurement system further comprises a circulation pump, wherein the circulation pump is used to transport the cooling lubricating oil in the oil storage tank to the oil passage of the rotor shaft of the rotor assembly to be measured, and the oil passage of the rotor shaft is respectively connected with each oil passage of the rotor core;

[0015] And / or, the flow measurement system further comprises a driving device, wherein the driving device is used to be drivingly connected to the rotor assembly to be measured.

[0016] On the other hand, the present invention provides a flow measurement method, using the above-mentioned flow measurement system, the process of measuring the cooling lubricating oil flow at the axial end of the rotor core of the rotor assembly to be measured by the flow measurement method includes the following steps:

[0017] Obtaining the liquid level h when the liquid level in the measuring chamber is in dynamic equilibrium;

[0018] Calculation of the cooling oil flow rate at the measuring outlet based on the Bernoulli equation Where g is the acceleration due to gravity;

[0019] The cooling lubricating oil flow rate of the measuring outlet is calculated according to the cooling lubricating oil flow rate of the measuring outlet, and the cooling lubricating oil flow rate of the measuring outlet is q=ρ*π*r 2 *v, where ρ is the density of the cooling lubricating oil and r is the radius of the measuring outlet.

[0020] The flow measurement system and flow measurement method of the present invention have at least the following advantages compared to the prior art:

[0021] An oil collecting hood is arranged at the axial end of the rotor core of the rotor assembly to be measured, and an oil cavity is formed between the oil collecting hood and the axial end face of the rotor core. The cooling lubricating oil sprayed from the end of the rotor core is thrown toward the oil collecting hood, falls into the oil cavity after being decelerated, and then enters the measuring cavity of the measuring device. After being further decelerated in the measuring cavity, it flows out from the measuring outlet at the bottom. The cooling lubricating oil flowing out from the measuring outlet basically overcomes the influence of the rotation speed of the rotor assembly on its flow rate. The flow rate at the measuring outlet is measured by a measuring structure such as a flowmeter, and the flow distribution at the axial end of the rotor assembly to be measured can be obtained. The measurement result is relatively accurate, which is conducive to studying the influence of the structural change of the rotor assembly on the flow distribution. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic diagram of a flow measurement system according to an embodiment of the present invention;

[0023] Figure 2 Another schematic diagram of a flow measurement system according to an embodiment of the present invention;

[0024] Figure 3 It is a schematic diagram of the external structure of the oil collecting hood according to an embodiment of the present invention;

[0025] Figure 4 is a cross-sectional view of an oil collecting hood according to an embodiment of the present invention;

[0026] Figure 5 Schematic diagram of the structure of a measuring device according to an embodiment of the present invention.

[0027] Description of reference numerals:

[0028] 1. Oil collecting cover; 11. Second oil outlet; 12. Opening; 13. End face; 14. Through hole; 2. Measuring device; 21. Measuring chamber; 211. Measuring outlet; 22. Buffer chamber; 221. Overflow hole; 23. Flow meter; 3. Oil chamber; 4. Oil storage tank; 5. Circulating pump; 6. Driving device; 7. Rotor assembly to be measured; 71. Rotor core; 72. Rotor shaft. DETAILED DESCRIPTION

[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0030] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "matched" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] In addition, it should be noted that in the description of the present invention, it should be noted that the terminology nouns in the various embodiments, such as "upper", "lower", "front", "back" and other words indicating directions, are only for simplifying the description of the positional relationship based on the drawings in the specification, and do not mean that the referred elements and devices must be operated in accordance with the specific directions and defined operations and methods and structures in the specification. Such directional nouns do not constitute limitations on the present invention.

[0032] Herein, an XZ coordinate system is established, wherein the X axis represents the left-right direction, the positive direction of the X axis represents the left, and the reverse direction of the X axis represents the right, and the Z axis represents the up-down direction, the positive direction of the Z axis represents the top, and the reverse direction of the Z axis represents the bottom. It should be noted that the aforementioned X axis and Z axis are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0033] like Figure 1-Figure 2 As shown, a flow measurement system of an embodiment of the present invention includes an oil collecting hood 1 and a measuring device 2, wherein the oil collecting hood 1 is used to be arranged at the axial end of the rotor core 71 of the rotor assembly 7 to be measured, and the oil collecting hood 1 is used to form an oil chamber 3 between the axial end surface of the rotor core 71, and the measuring device 2 includes a measuring chamber 21 and a measuring structure, the measuring chamber 21 is connected to the corresponding oil chamber 3 to receive the cooling lubricating oil flowing out of the oil chamber 3, and a measuring outlet 211 is provided at the bottom of the measuring chamber 21, and the measuring structure is used to measure the flow of the measuring outlet 211 according to the oil in the measuring chamber 21.

[0034] Specifically, Figure 3-Figure 4 As shown, the oil collecting cover 1 is hollow inside, and one end of the oil collecting cover 1 facing the rotor core 71 is provided with an opening 12 communicating with the inside thereof, and the open end of the oil collecting cover 1 cooperates with the axial end surface of the rotor core 71 to form an oil chamber 3 between the oil collecting cover 1 and the rotor core 71. The oil collecting cover 1 also has an end surface 13 arranged opposite to the opening 12, and the end surface 13 can be provided with a through hole 14 for the rotor shaft 72 of the rotor assembly 7 to be tested to pass through.

[0035] A plurality of oil passages are arranged inside the rotor core 71. After the cooling lubricating oil entering the rotor assembly 7 to be tested is divided, it flows to different oil passages of the rotor core 71 respectively, and finally sprays out from the axial end of the rotor core 71. It should be noted that when the oil cavity 3 at the end of the rotor core 71 is connected to only one of the oil passages, the cooling lubricating oil flow rate at the end of the rotor core 71 is the cooling lubricating oil flow rate of the oil passage; when the oil cavity 3 at the end of the rotor core 71 is connected to the corresponding plurality of oil passages, the cooling lubricating oil flow rate at the end of the rotor core 71 is the sum of the cooling lubricating oil flow rates of the plurality of oil passages connected to the oil cavity 3 at the end.

[0036] The measuring device 2 is arranged vertically, and a measuring outlet 211 is arranged at the bottom of the measuring cavity 21 . The cooling lubricating oil from the oil cavity 3 can enter from the upper opening of the measuring cavity 21 and flow out from the measuring outlet 211 at the bottom.

[0037] In this embodiment, an oil collecting cover 1 is provided at the axial end of the rotor core 71 of the rotor assembly 7 to be tested, and an oil chamber 3 is formed between the oil collecting cover 1 and the axial end surface of the rotor core 71. The cooling lubricating oil sprayed from the end of the rotor core 71 is thrown toward the oil collecting cover 1, falls into the oil chamber 3 after being decelerated, and then enters the measuring chamber 21 of the measuring device 2. After being further decelerated in the measuring chamber 21, it flows out from the measuring outlet 211. The cooling lubricating oil flowing out from the measuring outlet 211 basically overcomes the influence of the rotation speed of the rotor assembly on its flow rate. By measuring the flow rate at the measuring outlet 211 through a measuring structure such as a flowmeter 23, the flow distribution of the cooling lubricating oil at the axial end of the rotor assembly 7 to be tested can be obtained. The measurement result is relatively accurate, which is conducive to studying the influence of the structural changes of the rotor assembly on the flow distribution.

[0038] Optionally, the measuring structure includes scale lines arranged on the side wall of the measuring cavity 21 for measuring the height of the liquid level therein.

[0039] In this embodiment, at least part of the side wall of the measuring cavity 21 is made of a transparent material, and a plurality of scale lines are provided along the vertical direction, so that the operator can conveniently observe the scale lines corresponding to the liquid level in the measuring cavity 21 and read the liquid level height data, and the liquid level height measurement method is simple. A corresponding relationship between the scale lines and the flow rate at the end of the rotor assembly 7 to be measured can be established, and the flow rate can be quickly analyzed by observing the scale lines; or, the corresponding flow rate value at the end of the rotor assembly 7 to be measured can be directly marked at the scale lines.

[0040] like Figure 2 As shown, optionally, the measuring structure includes a flow meter 23, and the flow meter 23 is used to measure the cooling lubricating oil flow rate of the measuring outlet 211 when the liquid level of the measuring chamber 21 is in dynamic equilibrium.

[0041] It should be noted that when the cooling lubricating oil first enters the measuring chamber 21 from the oil chamber 3, the flow rate of the measuring outlet 211 is slow and the flow rate is small. As the cooling lubricating oil liquid level in the measuring chamber 21 gradually rises, the total gravitational potential energy of the cooling lubricating oil in the measuring chamber 21 increases, the oil outlet speed of the measuring outlet 211 will increase, and the flow rate will increase. When the flow rate of the cooling lubricating oil entering the measuring chamber 21 is equal to the flow rate of the cooling lubricating oil flowing out of the measuring outlet 211, the cooling lubricating oil in the measuring chamber 21 will be in a dynamic equilibrium state, that is, the liquid level of the cooling lubricating oil in the measuring chamber 21 remains basically unchanged. At this time, the cooling lubricating oil flow rate of the measuring outlet 211 is equal to the cooling lubricating oil flow rate at the axial end of the rotor core 71. In this way, the cooling lubricating oil flow rate at the axial end of the rotor core 71 is converted into the cooling lubricating oil flow rate measured at the measuring outlet 211.

[0042] By setting a flow meter 23 at the measuring outlet 211 and measuring the cooling lubricating oil flow rate of the measuring outlet 211 during dynamic balancing, the cooling lubricating oil flow rate at the axial end of the rotor core 71 can be obtained. The flow measurement method is relatively simple and intuitive. The flow meter 23 can be selected to have a higher measurement accuracy.

[0043] like Figure 1 and Figure 5 As shown, optionally, the measuring device 2 further has a buffer chamber 22, which is located on one side of the measuring chamber 21, and the buffer chamber 22 is provided with an overflow hole 221 connected to the measuring chamber 21, and the buffer chamber 22 is connected to the oil chamber 3 to receive the cooling lubricating oil flowing out of the oil chamber 3.

[0044] Specifically, the interior of the measuring device 2 can be divided into a measuring chamber 21 and a buffer chamber 22 by a vertically arranged partition. The two opposite surfaces of the partition constitute the side walls of the measuring chamber 21 and the buffer chamber 22 respectively. An overflow hole 221 can be arranged on the partition, and the shape of the overflow hole 221 is not limited.

[0045] In this embodiment, a buffer chamber 22 is provided on one side of the measuring chamber 21, and the buffer chamber 22 is connected to the oil chamber 3, so that the cooling lubricating oil coming out of the oil chamber 3 can first enter the buffer chamber 22 for buffering, and after reducing the influence of factors such as the rotation speed of the rotor assembly 7 to be measured and the gravity of the cooling lubricating oil, enter the measuring chamber 21 from the overflow hole 221, and flow out from the measuring outlet 211. In this way, the liquid level of the measuring chamber 21 can more easily reach a dynamic equilibrium state, which is beneficial to further improve the accuracy of flow measurement.

[0046] like Figure 1-Figure 2As shown, optionally, the buffer chamber 22 is located below the oil chamber 3, and the buffer chamber 22 is open toward one end of the oil chamber 3. The oil collecting hood 1 is provided with a second oil outlet 11 connected to the oil chamber 3, and the second oil outlet 11 is open toward the buffer chamber 22.

[0047] Specifically, the axis of the rotor assembly 7 to be measured is arranged horizontally, that is, it is arranged along the direction indicated by the X-axis. Measuring devices 2 are respectively arranged at both axial ends of the rotor assembly 7 to be measured, and the measuring devices 2 are located below the corresponding oil collecting hood 1. The upper end of the buffer cavity 22 of the measuring device 2 is open, and a second oil outlet 11 is arranged on the annular side wall of the oil collecting hood 1. The second oil outlet 11 is located at the bottom of the oil collecting hood 1 and is arranged toward the open end of the buffer cavity 22.

[0048] In this embodiment, the oil chamber 3 and the buffer chamber 22 are arranged up and down so that the cooling lubricating oil in the oil chamber 3 can automatically flow out from the second oil outlet 11 under the action of gravity and enter the buffer chamber 22 from the open end of the buffer chamber 22. The way in which the cooling lubricating oil in the oil chamber 3 enters the buffer chamber 22 is relatively simple, and there is no need to set up additional pipelines and other related structures, thereby reducing the influence of external environmental factors on the oil flow rate.

[0049] When the oil height in the measuring chamber 21 is in dynamic balance, the oil flow at the axial end of the rotor core 71, the oil flow at the second oil outlet 11, the oil flow at the overflow hole 221 and the oil flow at the measuring outlet 211 are all equal.

[0050] like Figure 1 and Figure 5 As shown, optionally, the bottom wall of the buffer chamber 22 is higher than the bottom wall of the measuring chamber 21 , and the overflow hole 221 has a preset height from the bottom wall of the buffer chamber 22 .

[0051] In this embodiment, the measuring device 2 is located below the oil chamber 3, and the bottom wall of the buffer chamber 22 is higher than the bottom wall of the measuring chamber 21, that is, the height difference between the bottom wall of the buffer chamber 22 and the oil chamber 3 is small. The oil is first buffered in the buffer chamber 22 and then enters the measuring chamber 21, and flows out from the measuring outlet 211 under the action of gravity, which is conducive to the step-by-step buffering of the oil and reduces the influence of gravity on the measurement of its flow rate.

[0052] Among them, the overflow hole 221 is at a preset height from the bottom wall of the buffer chamber 22, so that the oil entering the buffer chamber 22 can be stored in the buffer chamber 22 for a period of time, and only flows to the measuring chamber 21 after the oil volume reaches a certain height, which can improve the oil buffering effect.

[0053] Optionally, the measuring cavity 21 is cylindrical, and the radius of the measuring outlet 211 is less than or equal to one tenth of the radius of the measuring cavity 21. Since the flow velocity calculation formula of the measuring outlet 211 involves the liquid level of the measuring cavity 21, a smaller radius of the measuring outlet 211, i.e., a smaller caliber, has less influence on the height of the liquid level, which is beneficial to improving the accuracy of the flow velocity measurement; at the same time, the flow calculation formula of the measuring outlet 211 also involves the radius of the measuring outlet 211, and the smaller the radius of the measuring outlet 211, the smaller the proportion of the flow calculation, and the higher the flow measurement accuracy.

[0054] Optionally, the flow measurement system includes two oil collecting covers 1 and two measuring devices 2, the two oil collecting covers 1 are respectively used to be arranged at the axial ends of the rotor core 71, and the two oil collecting covers 1 are respectively used to form the oil chamber 3 between the corresponding axial end faces of the rotor core 71, and the measuring chambers 21 of the two measuring devices 2 are respectively connected to the two oil chambers 3 in a one-to-one correspondence. The cooling lubricating oil flowing out from the axial ends of the rotor core 71 enters the corresponding oil chamber 3 and then flows into the corresponding measuring device 2, which can realize the convenient measurement of the cooling lubricating oil flow at the axial ends of the rotor core 71 and better grasp the flow distribution.

[0055] like Figure 1-Figure 2 As shown, optionally, the flow measurement system further includes an oil storage tank 4 , which is respectively connected to the measurement outlets 211 of the two measurement devices 2 to receive the cooling lubricating oil flowing out of the measurement outlets 211 of the two measurement devices 2 .

[0056] In this embodiment, the lower parts of the measuring cavities 21 of the two measuring devices 2 can extend into the oil storage tank 4, or the measuring outlets 211 of the measuring devices 2 are connected to the oil storage tank 4 through pipelines, so that the oil flowing out of the measuring outlets 211 of the two measuring devices 2 can be collected in the oil storage tank 4, thereby realizing the recycling of the oil, reducing waste, and avoiding pollution to surrounding related structures.

[0057] like Figure 1-Figure 2 As shown, optionally, the flow measurement system also includes a circulation pump 5, which is used to transport the cooling lubricating oil in the oil storage tank 4 to the oil channel of the rotor shaft 72 of the rotor assembly 7 to be measured, and the oil channel of the rotor shaft 72 is respectively connected to each oil channel of the rotor core 71.

[0058] In this embodiment, an oil passage extending axially is provided inside the rotor shaft 72. One end of the oil passage of the rotor core 71 is connected to the oil passage of the rotor shaft 72, and the other end is connected to the corresponding oil chamber 3. One end of the circulating pump 5 is connected to the oil storage tank 4 through a pipeline, and the other end is connected to the oil passage of the rotor shaft 72 through a pipeline.

[0059] The circulation pump 5 draws the cooling lubricating oil in the oil storage tank 4 to the oil channel of the rotor shaft 72. During the rotation of the rotor assembly, the oil in the oil channel of the rotor shaft 72 flows to the corresponding oil chamber 3 through the corresponding oil channel of the rotor core 71. The oil in the oil chamber 3 enters the measuring device 2 and flows out from the measuring outlet 211 to the oil storage tank 4, thereby realizing the circulation of the cooling lubricating oil.

[0060] like Figure 1-Figure 2 As shown, optionally, the flow measurement system further includes a driving device 6, and the driving device 6 is used for driving connection with the rotor assembly 7 to be measured.

[0061] In this embodiment, the driving device 6 can be a driving motor, which is driven and connected to the rotor shaft 72 of the rotor assembly 7 to be tested. The driving device 6 can drive the rotor assembly 7 to be tested to rotate to simulate the high-speed rotation condition of the rotor assembly 7 to be tested during actual operation. The driving device 6 can also control the rotor assembly 7 to be tested to rotate at different speeds to measure the flow distribution at different speeds, thereby accumulating more data for the later research and development of the motor rotor assembly.

[0062] Another embodiment of the present invention provides a flow measurement method, using the above-mentioned flow measurement system, the process of measuring the cooling lubricating oil flow at the axial end of the rotor core 71 of the rotor assembly 7 to be measured by the flow measurement method includes the following steps:

[0063] Obtaining the liquid level h when the liquid level in the measuring chamber 21 is in dynamic equilibrium;

[0064] Calculate the cooling lubricating oil flow rate at the measuring outlet 211 according to the Bernoulli equation Where g is the acceleration due to gravity;

[0065] The cooling lubricating oil flow rate of the measuring outlet 211 is calculated according to the cooling lubricating oil flow rate of the measuring outlet 211. The cooling lubricating oil flow rate of the measuring outlet 211 is q=ρ*π*r 2 *v, where ρ is the density of the cooling lubricating oil and r is the radius of the measuring outlet 211.

[0066] In this embodiment, according to the above analysis, when the liquid level in the measuring chamber 21 is in dynamic equilibrium, the cooling lubricating oil flow rate at the measuring outlet 211 is equal to the cooling lubricating oil flow rate at the axial end of the rotor core 71, that is, it is only necessary to measure the cooling lubricating oil flow rate at the measuring outlet 211 when in dynamic equilibrium.

[0067] According to the Bernoulli equation, the fluid obeys the law of conservation of energy during the flow process, and the cooling lubricating oil flow rate at the measuring outlet 211 can be calculated. Substituting the liquid level h and gravity acceleration g of the measuring chamber 21 in dynamic equilibrium into the above formula, the specific value of the cooling lubricating oil flow rate v at the measuring outlet 211 can be obtained. The liquid level h can be directly read from the liquid level scale on the side wall of the measuring chamber 21.

[0068] The cooling oil flow mentioned in this article refers to the mass flow, according to mass flow = liquid density * flow area * flow velocity, that is, q = ρ * π * r 2 *v, by substituting the flow velocity v of the measuring outlet 211, the density ρ of the cooling lubricating oil and the radius r of the measuring outlet 211 into the above formula, the specific value of the lubricating cooling oil flow q of the measuring outlet 211 can be obtained, that is, the specific value of the cooling lubricating oil flow at the axial end of the rotor core 71 can be obtained.

[0069] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A flow measurement system, characterized in that: The invention comprises an oil collecting hood (1) and a measuring device (2), wherein the oil collecting hood (1) is used to be arranged at the axial end of a rotor core (71) of a rotor assembly (7) to be measured, and the oil collecting hood (1) is used to form an oil cavity (3) between the axial end surface of the rotor core (71), and the measuring device (2) comprises a measuring cavity (21) and a measuring structure, wherein the measuring cavity (21) is connected to the oil cavity (3) to receive cooling lubricating oil flowing out of the oil cavity (3), and a measuring outlet (211) is provided at the bottom of the measuring cavity (21), and the measuring structure is used to measure the flow rate of the measuring outlet (211) according to the oil in the measuring cavity (21).

2. The flow measurement system according to claim 1, characterized in that: The measuring structure comprises a scale line arranged on a side wall of the measuring cavity (21) for measuring the height of the liquid level therein.

3. The flow measurement system according to claim 1, characterized in that: The measuring structure comprises a flow meter (23), and the flow meter (23) is used to measure the cooling lubricating oil flow rate of the measuring outlet (211) when the liquid level of the measuring chamber (21) is in dynamic equilibrium.

4. The flow measurement system according to claim 1, characterized in that: The measuring device (2) further comprises a buffer chamber (22), the buffer chamber (22) being located on one side of the measuring chamber (21), and the buffer chamber (22) being provided with an overflow hole (221) communicating with the measuring chamber (21), and the buffer chamber (22) being communicated with the oil chamber (3) to receive the cooling lubricating oil flowing out of the oil chamber (3).

5. The flow measurement system according to claim 4, characterized in that: The buffer chamber (22) is located below the oil chamber (3), and one end of the buffer chamber (22) is open toward the oil chamber (3). The oil collecting cover (1) is provided with a second oil outlet (11) connected to the oil chamber (3), and the second oil outlet (11) is open toward the buffer chamber (22).

6. The flow measurement system according to claim 4, characterized in that: The bottom wall of the buffer cavity (22) is higher than the bottom wall of the measuring cavity (21), and the overflow hole (221) has a preset height from the bottom wall of the buffer cavity (22); And / or, the measuring cavity (21) is cylindrical, and the radius of the measuring outlet (211) is less than or equal to one tenth of the radius of the measuring cavity (21).

7. The flow measurement system according to any one of claims 1 to 6, characterized in that: It comprises two oil collecting covers (1) and two measuring devices (2), the two oil collecting covers (1) are respectively used to be arranged at the two axial ends of the rotor core (71), and the two oil collecting covers (1) are respectively used to form the oil chamber (3) between the corresponding axial end faces of the rotor core (71), and the measuring chambers (21) of the two measuring devices (2) are respectively connected to the two oil chambers (3) in a one-to-one correspondence.

8. The flow measurement system according to claim 7, characterized in that: It also comprises an oil storage tank (4), which is respectively connected to the measurement outlets (211) of the two measurement devices (2) to receive the cooling lubricating oil flowing out of the measurement outlets (211) of the two measurement devices (2).

9. The flow measurement system according to claim 8, characterized in that: It also includes a circulation pump (5), the circulation pump (5) being used to transport the cooling lubricating oil in the oil storage tank (4) to the oil passage of the rotor shaft (72) of the rotor assembly (7) to be tested, the oil passage of the rotor shaft (72) being respectively connected to each oil passage of the rotor core (71); And / or, it also includes a driving device (6), wherein the driving device (6) is used to be drivingly connected to the rotor assembly (7) to be tested.

10. A flow measurement method, characterized in that: A flow measurement system as claimed in any one of claims 1 to 9 is used to measure the cooling lubricating oil flow at the axial end of the rotor core (71) of the rotor assembly (7) to be measured, the method comprising the following steps: Obtaining a liquid level height h when the liquid level in the measuring chamber (21) is in dynamic equilibrium; The cooling lubricating oil flow rate at the measuring outlet (211) is calculated according to the Bernoulli equation Where g is the acceleration due to gravity; The cooling lubricating oil flow rate of the measuring outlet (211) is calculated according to the cooling lubricating oil flow rate of the measuring outlet (211), and the cooling lubricating oil flow rate of the measuring outlet (211) is q=ρ*π*r 2 *v, wherein ρ is the density of the cooling lubricating oil and r is the radius of the measuring outlet (211).

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