Simple device and method for determining breather leakage of lubricating oil

Abstract

To clarify how lubricant behaves in an engine or drive system by a simple device and method.MEANS FOR SOLVING THE PROBLEM: Provided is a chamber that can be filled with a sample of lubricant, and a see-through window is formed in at least one side surface of the chamber. A set of small bevel gears is arranged horizontally in the chamber that can be seen through the see-through window, and the rotation of the bevel gears is controlled to provide a simple determination device for behavior such as a breather leakage phenomenon of lubricant. A small amount of lubricant sample is filled up to a height where a part of the bevel gear is submerged in the chamber, and the bevel gear is rotated. The lubricant is raked up and bubbles are generated and retained in the lubricant, and such a state is determined with visually observation through the see-through window.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an apparatus and method for easily determining breather leakage caused by use of lubricating oil, particularly lubricating oil for engines and drive trains. [Background technology]

[0002] In recent years, fuel economy of automobiles has been improved, and low viscosity lubricating oils have been used in engine oils and drivetrain lubricating oils in order to further improve fuel economy. While lowering the viscosity of lubricating oils can improve fuel economy, it is known that this reduces wear resistance and seizure resistance, and increased foaming of the lubricating oil is also becoming a problem.

[0003] In particular, leakage of lubricating oil from breathers in drivetrain devices not only has a negative impact on the environment due to the leaked lubricating oil, but also leads to a decrease in the amount of oil in the drivetrain devices, which can cause damage to the device units. For these reasons, there is an increasing need to develop low-viscosity lubricating oils by easily determining the breather leakage phenomenon.

[0004] Conventionally, foaming in the lubricating oil has been considered to be one of the main causes of breather leakage. JIS K2518 is widely used to evaluate the foaming properties of lubricating oils (Non-Patent Document 1). In this JIS K2518 method, a lubricating oil sample is placed in a test container (measuring cylinder) and heated to 24°C or 93.5°C. Air is then introduced through a diffuser and blown in at a rate of 94±5 ml / min for 5 minutes, and the foam volume is measured.

[0005] That is, in Sequence I of JIS K2518, when the temperature of the lubricating oil sample reaches 24±0.5°C, dry air is blown in from the diffuser at a flow rate of 94±5ml / min for 5 minutes, and then the inside of the test container (capacity 1000ml) is immediately observed, the volume of the liquid is subtracted from the total volume, the volume of the foam powder is read in 10ml increments, and the foamability is measured. After that, the sample is left for 10 minutes, and the volume of the foam powder is read again in 10ml increments, and this is measured as foam stability.

[0006] In Sequence II, once the sample temperature reaches 93±1°C, measure the foaming degree and foam stability in the same manner as in Sequence I. In Sequence III, after the measurement in Sequence II, any remaining foam in the sample is gently stirred to completely eliminate it, then the sample is removed from the water bath and left in the air to cool to 43.5°C, and the foaming degree and foam stability are measured in the same way as in Sequence I.

[0007] As described above, the JIS method evaluates the amount of foam generated and its stability under static conditions after forcibly blowing dry air to generate foam, and there are many points that raise doubts as to whether this method accurately reflects the phenomena occurring in lubricating oil in actual equipment. [Prior art documents] [Patent documents]

[0008] [Non-Patent Document 1] JIS K2518 Summary of the Invention [Problem to be solved by the invention]

[0009] Therefore, it would be possible to measure the breather leakage phenomenon for lubricant samples using an actual machine, but it would be necessary to prepare an actual axle unit for each lubricant prototype.This type of actual machine requires a large amount of lubricant sample, making it unsuitable for testing prototypes, and it would also increase the amount of wasted oil and increase the environmental load, making it difficult to perform testing and measurement.

[0010] The present invention aims to clarify how a lubricating oil sample behaves and to make it possible to determine the breather leakage phenomenon using a relatively small number of prototypes with a simple device and method. [Means for solving the problem]

[0011] The present invention provides a chamber that can be filled with a lubricating oil sample, with a viewing window formed on at least one side of the chamber, and a pair of small bevel gears arranged laterally within the chamber that can be seen through the viewing window, with the bevel gears being able to be controlled to rotate, thereby providing a simple device for determining whether a lubricating oil breather leaks.

[0012] The chamber of the device is filled with a lubricating oil sample to a height that partially immerses the pair of bevel gears, and the bevel gears are rotated at the speed of the actual machine, causing the lubricating oil to be stirred up by the rotation of the bevel gears. This causes bubbles to be generated and retained in the lubricating oil, and this state can be judged by visual observation through the viewing window. [Effects of the Invention]

[0013] According to the present invention, a relatively simple device and method can be used to observe the continuous occurrence of lubricating oil being stirred up in a chamber, the generation of bubbles, the increase in the volume of the lubricating oil due to the entrapment of bubbles in the oil, the release of bubbles from the oil, etc. This allows for a wide range of applications of the foaming that causes breather leakage and the behavior of the lubricating oil to be developed and verified for high-performance lubricating oils that are less likely to cause breather leakage. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a front view showing an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view in which a part of FIG. 1 is omitted. [Figure 3] 1 is an explanatory photograph showing the state of the lubricant surface during testing of Sample 1. [Figure 4] 1 is an explanatory photograph showing the state of the lubricant surface during testing of Sample 2. DETAILED DESCRIPTION OF THE INVENTION

[0015] The simple determination device 1 has a chamber 2 formed of a steel plate or the like. The illustrated chamber 2 is formed in a rectangular cylindrical shape, and a lid (not shown) can be placed on the top surface 3. One side of this chamber 2 is provided with a see-through window 5 formed by fitting a transparent glass plate or acrylic plate.

[0016] Inside the chamber 2, which can be seen through the viewing window 5, a set of small bevel gears 6 facing laterally are provided. The bevel gear 6 is connected to a motor 8 provided outside the chamber 2 so that it can rotate at any speed.

[0017] When a judgment test is carried out using this device, the chamber 2 is filled with the lubricating oil sample 11 up to a height such that a part of the lower part of the bevel gear 6 is immersed. When the bevel gear 6 is rotated in this state, the lubricating oil sample 11 is scooped up by the bevel gear, and the entire bevel gear can be lubricated.

[0018] As the bevel gear 6 rotates, the lubricating oil sample 11 is stirred and mixed, and as a result, air bubbles are trapped in the sample. The lubricating oil sample with the trapped air bubbles is further stirred and mixed, and the air bubbles in the lubricating oil sample are further refined, the amount of air bubbles increases, and the volume of the lubricating oil sample increases.

[0019] Some of the bubbles in the lubricating oil sample turn into foam and either rise above the oil surface of the lubricating oil sample 11 and disappear, or remain on the oil surface without disappearing. These movements can be visually observed through the observation window 5, and the oil surface height of the lubricating oil sample before the start of the test, during the test, and immediately after the test, as well as the height to which the lubricating oil sample is scraped up, can be measured, and the extent of the scraping phenomenon, foaming phenomenon, and the defoaming phenomenon that occurs simultaneously with these can be grasped and measured. [Example]

[0020] The simplified breather leakage phenomenon determination device and evaluation method of the present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0021] The chamber 2 of the simple determination device 1 is a square steel container with an inner diameter of 50 mm on one side and a rectangular cylindrical shape with a height of 120 mm, and the top surface 3 can be covered with a lid (not shown). An opening measuring 90 mm in height and 25 mm in width is made on one side (front panel) of the chamber 2, 10 mm above the bottom, and this opening is covered with a transparent, durable glass or acrylic plate, forming a viewing window 5.

[0022] A gear box 7 (BE55L-001 manufactured by Kyouiku Gear Industry) equipped with a set of small bevel gears 6 whose axial centers are located 25 mm from the bottom surface is fixed inside the chamber 2, and these bevel gears 6 can be seen through the viewing window 5. This viewing window 5 is provided with a scale 9 (unit: mm) indicating the height from the inner bottom surface of the chamber 2 . One gear shaft of the pair of bevel gears 6 can be rotated at any desired rotation speed by a motor 8 disposed outside the chamber 2 .

[0023] The chamber 2 was filled with the lubricating oil sample 11 at room temperature (about 21° C.) to a height of 30 mm from the bottom (oil volume: 75 ml), and the bevel gear 6 was rotated at a rotation speed of 3000 rpm for 5 minutes. When the bevel gear 6 started to rotate, the lubricating oil sample 11 was repeatedly stirred up and dropped, and air bubbles were generated, so this state was observed through the observation window and judged.

[0024] 〔test〕 The following tests were carried out to determine the performance of the apparatus and method of the above embodiment. The following test samples were prepared:

[0025] Sample 1: Mineral oil-based differential lubricant (properties: kinematic viscosity at 40°C is 64.92 mm 2 / s, kinematic viscosity at 100°C is 9.33mm 2 / s, VI is 122) Sample 2: Mineral oil-based differential lubricant (properties: kinematic viscosity at 40°C is 336.6 mmHg) 2 / s, kinematic viscosity at 100°C is 25.80mm 2 / s, VI is 100)

[0026] (Exam contents) 75 ml of sample 1 was filled into the chamber of the simple evaluation device described in the above example, and the oil level was raised to 30 mm so that part of the bevel gear was immersed. The gear was rotated at 3000 rpm for 5 minutes, and the oil level of sample 1 and the jump height of sample 1 were measured during operation. Sample 2 was also measured in the same manner as Sample 1 above.

[0027] (Test results) The photographs in Figure 3 show the state of Sample 1 before the start of the test, during the test, and immediately after the test was stopped. The state of sample 2 before the start of the test, during the test, and immediately after the test was stopped are shown in the photographs in Figure 4.

[0028] The height of the oil surface in the state of Sample 1 shown in FIG. 3 and the state of Sample 2 shown in FIG. 4 is shown in Table 1 below, expressed as a numerical value (mm).

[0029] [Table 1]

[0030] (Test contents of comparative example) Samples 1 and 2 were tested for foaming power and foam stability for Sequence I, Sequence II, and Sequence III according to the method of JIS K2518.

[0031] (Test results for comparative examples) The test results for the comparative examples are shown in Table 2 below.

[0032] [Table 2]

[0033] (Discussion of test results) As shown in Figure 3 and Table 1, for sample 1 with low kinematic viscosity, the oil level was 30 mm before the start of the test, but the oil level rose to 23 mm during the test, reaching a height of 80 mm, and the oil level returned to 30 mm immediately after the test was stopped. On the other hand, for sample 2 with a high kinetic viscosity, the oil level before the test started was also 30 mm, but the oil level during the test was 25 mm, the oil level rose to 46 mm, and the oil level immediately after the test was stopped was 34 mm.

[0034] As such, it can be seen that the low viscosity sample 1 is stirred up higher during the stirring test than the high viscosity sample 2, posing a greater risk of breather leakage. Also, with sample 1, the oil level returned to the same level as before the test immediately after the test was completed, but with sample 2, the oil level is higher than before the test began, which suggests that the sample has trapped many air bubbles and the oil level has not yet returned to its original level.

[0035] On the other hand, according to the foaming test according to the JIS method in the comparative example, as shown in Table 2, there was no substantial difference between Sample 1 and Sample 2 in terms of foaming degree and foam stability for Sequence I, Sequence II, and Sequence III, and it is therefore impossible to evaluate whether there is a risk of breather leakage.

[0036] The results of these tests show that this simple evaluation device and method can easily predict the degree of air bubbles and the risk of breather leakage depending on the type of lubricating oil. In this way, it can be effectively used for performance testing of prototype oils. [Explanation of symbols]

[0037] 1 Simple determination device 2 chambers 3 Top surface 5. Viewing window 6 Bevel Gear 9 Scale 11 Lubricating oil samples

Claims

1. A simple device for determining breather leakage phenomena of lubricating oil, including the phenomenon of scraping up, foaming, and defoaming of a lubricating oil sample, comprising: A simple device for determining breather leakage of lubricating oil, which has a chamber that can be filled with a lubricating oil sample, a transparent window formed on one side of the chamber, a set of small bevel gears arranged horizontally within the chamber that can be seen through the transparent window, and a motor that can control the rotation of the bevel gears.

2. 2. A simplified device for determining breather leakage of lubricating oil according to claim 1, wherein the chamber is formed in a rectangular cylindrical container and has a see-through window formed on the front side, which corresponds to one side of the container.

3. 3. A simplified device for determining breather leakage of lubricating oil according to claim 1, wherein the observation window is provided with a gauge capable of measuring the liquid level of the lubricating oil sample filled in the chamber.

4. The device for easily determining breather leakage phenomena of lubricating oil, including the phenomenon of lubricating oil sample being scraped up, foamed, and defoamed, comprises a chamber filled with lubricating oil, a see-through window on one side of the chamber, a set of small bevel gears positioned within the chamber so that they can be seen through the see-through window, and a motor for controlling the rotation of the bevel gears. The chamber is filled with the lubricating oil sample so that part of the bevel gear is immersed, and the bevel gears are rotated to scrape up and mix the lubricating oil, and the behavior of the lubricating oil sample and the state of foam generation are observed and evaluated through the see-through window.

5. 5. The simple method for determining breather leakage of lubricating oil according to claim 4, wherein the height of the lubricating oil surface and the height of the lubricating oil scraped up when the bevel gear is rotated are evaluated.

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