Flow rate measuring device

Abstract

To provide a flow rate measuring device that has a simple configuration.SOLUTION: A flow rate measuring device includes: a first acquisition part for acquiring a level of liquid in a bearing installed to a shaft; a second acquisition part for acquiring the number of revolutions of the shaft; and a third acquisition part for acquiring a flow rate of the liquid to the bearing on the basis of the level and the number of revolutions.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a flow measurement device. [Background technology]

[0002] 2. Description of the Related Art A positive displacement flowmeter that measures the flow rate of a fluid is known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-296809 Summary of the Invention [Problem to be solved by the invention]

[0004] A positive displacement flowmeter has a path for introducing a liquid such as oil and a path for discharging the liquid, and the paths must be filled with the liquid to be measured. When mounting a positive displacement flowmeter, processing is required to provide the paths. Also, when measuring the flow rate of lubricating oil in multiple bearings, multiple positive displacement flowmeters occupy space. Therefore, the objective of the present invention is to provide a flow rate measuring device with a simple configuration. [Means for solving the problem]

[0005] The above objective can be achieved by a flow measuring device comprising a first acquisition unit that acquires the height of a liquid surface in a bearing provided on a shaft, a second acquisition unit that acquires the rotation speed of the shaft, and a third acquisition unit that acquires the flow rate of the liquid into the bearing based on the height of the surface and the rotation speed. Effect of the Invention

[0006] A flow rate measuring device having a simple configuration can be provided. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic view illustrating a flow rate measurement device according to an embodiment. [Diagram 2] Fig. 2(a) is a block diagram illustrating a hardware configuration of a flow measurement device, and Fig. 2(b) is a flowchart illustrating a process according to an embodiment. [Diagram 3] FIG. 3 is a diagram showing an example of the flow rate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, the flow rate measuring device of the present embodiment will be described with reference to the drawings. However, in the drawings, the dimensions, ratios, etc. of each part may not be illustrated to be completely consistent with the actual ones. Also, in some drawings, some details may be omitted.

[0009] 1 is a schematic diagram illustrating a flow rate measurement device 10 according to an embodiment. The flow rate measurement device 10 has a first acquisition unit 12, a second acquisition unit 14, and a third acquisition unit 16. The flow rate measurement device 10 measures the flow rate of a liquid (e.g., oil) supplied to a bearing of a transmission 20, for example.

[0010] The transmission 20 has a shaft 22, a part 24, and a bearing 26, and is mounted on, for example, an electric vehicle. The shaft 22 rotates when power is transmitted from a power source (not shown). The part 24 is attached to the shaft 22 and rotates together with the shaft 22.

[0011] The bearing 26 is provided outside the shaft 22 and faces the outer circumferential surface of the shaft 22. The transmission 20 has, for example, two bearings 26. One of the two bearings 26 is designated as bearing 26a, and the other is designated as bearing 26b. The bearing 26a is located near one end of the shaft 22. The bearing 26b is located near the other end of the shaft 22.

[0012] A liquid is supplied to bearing 26 for lubrication, cooling, and the like. The liquid is, for example, oil. An oil chamber 27 is provided near bearing 26a. An oil chamber 28 is provided near bearing 26b. One end of an oil passage 30 is connected to oil chamber 27. One end of an oil passage 32 is connected to oil chamber 28.

[0013] Oil is stored in a storage section (not shown). An oil supply device 34 scoops up the oil in the storage section and supplies the oil to the oil chambers 27 and 28 through the oil passages 30 and 32. Because the oil is scooped up, the oil is supplied in a gas-liquid mixed state. In other words, the oil passages 30 and 32 may not be filled with oil and may contain air. Oil accumulates in the oil chambers 27 and 28. The oil lubricates and cools the bearings 26a and 26b. The oil is discharged from the oil chambers 27 and 28. The oil level in the oil chamber 27 is referred to as oil level 29a. The oil level in the oil chamber 28 is referred to as oil level 29b.

[0014] The flow rate measuring device 10 includes a computer and the like, and measures the flow rate of oil supplied to the bearings. The flow rate measuring device 10 is connected to oil level sensors 40 and 42 and a rotation speed sensor 44.

[0015] The oil level sensors 40 and 42 are, for example, float-type liquid level sensors or capacitor-type liquid level sensors. The oil level sensor 40 measures the height of the oil level 29a in the oil chamber 27. The oil level sensor 42 measures the height of the oil level 29b in the oil chamber 28. The rotation speed sensor 44 includes, for example, an encoder, and measures the rotation speed of the shaft 22.

[0016] 2(a) is a block diagram illustrating a hardware configuration of the flow measurement device 10. The flow measurement device 10 includes a CPU (Central Processing Unit) 50, a RAM (Random Access Memory) 52, a ROM (Read Only Memory) 53, a storage device 54, and an interface 56. The CPU 50, the RAM 52, the ROM 53, the storage device 54, and the interface 56 are connected to one another via a bus or the like. The RAM 52 is a volatile memory that temporarily stores programs, data, and the like. The storage device 54 is a solid state drive (SSD) such as a flash memory, a hard disk drive (HHD), or the like. The storage device 54 stores programs and the like.

[0017] The CPU 50 executes a program stored in the RAM 52, thereby realizing a first acquisition unit 12, a second acquisition unit 14, and a third acquisition unit 16 in the flow measurement device 10. Each unit of the flow measurement device 10 may be hardware such as a circuit.

[0018] The first acquisition unit 12 acquires the height of the oil level 29a in the oil chamber 27 from the oil level sensor 40, and acquires the height of the oil level 29b in the oil chamber 28 from the oil level sensor 42. The second acquisition unit 14 acquires the rotation speed of the shaft 22 from the rotation speed sensor 44. The third acquisition unit 16 acquires the flow rate of oil to the bearing 26a based on the height of the oil level 29a and the rotation speed of the shaft 22. The third acquisition unit 16 acquires the flow rate of oil to the bearing 26b based on the height of the oil level 29b and the rotation speed of the shaft 22.

[0019] Fig. 2(b) is a flow chart illustrating the process in the embodiment. The second acquisition unit 14 acquires the rotation speed of the shaft 22 (step S10). The first acquisition unit 12 acquires the height of the oil level 29a and the height of the oil level 29b (step S12). The third acquisition unit 16 acquires the oil flow rate (step S14). This completes the process in Fig. 2(b).

[0020] FIG. 3 is a diagram showing an example of a flow rate, and the third acquisition unit 16 estimates the flow rate using a map such as that shown in FIG. 3. The horizontal axis represents the rotation speed of the shaft 22. The vertical axis represents the height of the oil surface. The solid line, dotted line, and dashed line are equal flow rate lines. The solid line corresponds to the flow rate F1. The dotted line corresponds to the flow rate F2. The dashed line corresponds to the flow rate F3. Of the flow rates F1, F2, and F3, the flow rate F1 is the largest, and the flow rate F3 is the smallest. The flow rate F2 is smaller than the flow rate F1 and larger than the flow rate F3.

[0021] When the rotation speed is R1 and the oil level is H1, the flow rate is F1. When the rotation speed is R2 and the oil level is H2, the flow rate is F2. When the rotation speed is R3 and the oil level is H3, the flow rate is F3.

[0022] According to this embodiment, the first acquisition unit 12 acquires the height of the oil level 29a and the height of the oil level 29b. The second acquisition unit 14 acquires the rotation speed of the shaft 22. The third acquisition unit 16 acquires the flow rate of the liquid to the bearings based on the oil level height and the rotation speed. It is not necessary to provide an oil path separate from the supply path to the bearings (oil passages 30 and 32). It is only necessary to know the oil level height and the rotation speed of the shaft 22. This simplifies the configuration.

[0023] By acquiring the height of the oil level 29a in the bearing 26a and the height of the oil level 29b in the bearing 26b, the flow rate of oil to the bearing 26a and the flow rate to the bearing 26b can be acquired. That is, the flow rates to a plurality of bearings can be estimated at once by the process of FIG. 2(b). Since it is not necessary to provide a flow meter for each bearing, the configuration is simplified. The oil path of the positive displacement flow meter is filled with oil. Since the oil supply device 34 supplies oil by scooping, air may be included in the oil. It is difficult to use a positive displacement flow meter. In this embodiment, since it is based on the oil level height, the flow rate can be acquired even if air is included in the oil. A scooping-up type oil supply device 34 can be used.

[0024] In the example of Fig. 1, two bearings 26a and 26b are provided on one shaft 22, and the oil flow rates for the two bearings are obtained. Three or more bearings may be provided, and the oil flow rates for three or more bearings may be obtained. The oil flow rates for bearings provided on two or more shafts may be obtained. Since the flow rates for multiple bearings are obtained at one time, processing is simplified.

[0025] By providing one oil level sensor for each bearing, the oil level for each bearing can be obtained. The oil chambers 27 and 28 may be configured so that the inside can be seen, such as a clear case. The oil level can be measured visually. A gauge may be provided on the case. In addition to the oil level sensor, the oil level may be obtained by non-destructive testing such as X-ray CT (Computed Tomography) or MRI (Magnetic Resonance Imaging). The oil level may be obtained by combining the above methods.

[0026] The second acquisition unit 14 may acquire the rotation speed of another shaft that meshes with the shaft 22 via a gear, and calculate the rotation speed of the shaft 22 from the acquired rotation speed. The second acquisition unit 14 may acquire the rotation speed of the shaft 22 based on the vehicle speed, the rotation speed of the wheels, etc. The rotation speed of the shaft 22 may be acquired by combining a plurality of methods.

[0027] The flow rate measurement device 10 may be mounted on a vehicle or may be disposed outside the vehicle. For example, the flow rate is measured using the flow rate measurement device 10 during vehicle inspection.

[0028] Although a preferred embodiment of the present invention has been described in detail above, the present invention is not limited to such a specific embodiment, and various modifications and variations are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0029] 10 flow rate measuring device, 12 first acquisition unit, 14 second acquisition unit, 16 third acquisition unit, 20 transmission, 22 shaft, 24 parts, 26, 26a, 26b bearings, 27, 28 oil chamber, 29a, 29b oil level, 30, 32 oil passage, 34 oil supply device, 50 CPU, 52 RAM, 53 ROM, 54 storage device, 56 interface

Claims

[Claim 1] A first acquisition unit that acquires a height of a liquid surface in a bearing provided on the shaft; A second acquisition unit that acquires a rotation speed of the shaft; A flow rate measuring device comprising: a third acquisition unit that acquires a flow rate of the liquid to the bearing based on the height of the surface and the rotation speed.

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