JP5042046B2 - Leak inspection method for hydraulic drive unit with reduction gear - Google Patents

Description

  The present invention relates to a leak inspection method for a hydraulic drive unit with a reduction gear for driving a crawler, for example.

As a hydraulic drive device provided with a reduction gear, the one shown in Patent Document 1 is conventionally known. This hydraulic drive device is used, for example, as a travel drive device for a crawler type vehicle, and outputs a high torque by linking a speed reduction mechanism to a motor mechanism.
This conventional hydraulic drive unit with a speed reducer will be described in detail with reference to FIGS.
A cylindrical rotary drive body 3 provided with a bottom plate is rotatably assembled to the motor housing 1 via a bearing 2 provided on the outer periphery of the motor housing 1, and the motor housing 1 and the rotary drive body 3 are combined to rotate. A reduction gear built-in chamber 3 a is defined in the body 3. A floating seal 6 comprising a pair of seal rings 4 and 4 and a pair of O-rings 5 and 5 is provided on the outside of the bearing 2, and oil leakage occurs from the assembly portion of the motor housing 1 and the rotary drive body 3. I am trying not to. The rotational drive body 3 thus configured is provided with a speed reducer built-in chamber 3a, and the speed reducer built-in chamber 3a incorporates a speed reducing mechanism 7 composed of a planetary gear provided with a rotating shaft 7a.

  The speed reducer built-in chamber 3a in which the speed reduction mechanism 7 is incorporated as described above is filled with lubricating oil to prevent the speed reduction mechanism 7 from being seized. The floating seal 6 described above prevents leakage of the lubricating oil. To do.

On the other hand, the motor housing 1 is provided with a motor built-in chamber 1a, and a motor mechanism 8 composed of an axial swash plate motor is built into the motor built-in chamber 1a. The motor housing 1 is provided with a bearing mounting hole 1b, and the bearing 9 provided in the bearing mounting hole 1b rotatably supports the tip of the motor shaft 8a of the motor mechanism 8. Further, the motor housing 1 is formed with a shaft projecting hole 1c, the rotating shaft 7a of the speed reduction mechanism 7 is projected from the shaft projecting hole 1c, and the rotating shaft 7a of the speed reducing mechanism 7 is provided at the tip of the motor shaft 8a. The motor shaft 8a and the rotating shaft 7a are integrally rotated.
In addition, the seal member 10 is mounted in the bearing mounting hole 1b and closer to the reduction gear incorporating chamber 3a than the bearing 9, and the lubricating oil filled in the reduction gear incorporating chamber 3a leaks to the motor incorporating chamber 1a. I am trying not to.

  Further, the opening part of the motor built-in chamber 1a on the side opposite to the rotary drive body 3 is blocked by a valve case 11 incorporating a valve for controlling the motor mechanism 8, and a motor shaft 8a is supported by a bearing 12 provided on the valve case 11. The base end of is supported rotatably.

Next, an assembling procedure of the hydraulic drive unit with a reduction gear will be described.
First, the speed reduction mechanism 7 is assembled in the speed reducer built-in chamber 3 a of the rotation drive body 3, and the motor housing 1 before the motor mechanism 8 is assembled is assembled to the rotation drive body 3. When the motor housing 1 and the rotary drive body 3 are assembled in this way, the bearing 2 and the floating seal 6 are also assembled as shown in FIG. Therefore, the motor housing 1 and the rotary drive body 3 are kept relatively rotatable, and their assembled portions are sealed in a liquid-tight manner by the floating seal 6.

When the rotary drive body 3 and the motor housing 1 before incorporating the motor mechanism 8 are assembled as described above, the opening of the motor assembly chamber 1a is closed with the sealing plate 13 as shown in FIG. Compressed air is supplied from the supply hole 14. Since this compressed air is guided to the reduction gear built-in chamber 3a via the bearing mounting hole 1b, if the floating seal 6 is not functioning sufficiently, air leakage occurs there. The air leakage at this time is detected and the sealing function is checked. If there is no problem, the lubricating oil is injected from the lubricating oil supply hole 15 provided in the motor housing 1 into the reduction gear built-in chamber 3a.
The method for checking the air leakage will be described in detail later.

  When lubricating oil is filled in the speed reducer built-in chamber 3a of the rotary drive body 3 as described above, the seal member 10 and the bearing 12 are installed in the bearing mounting hole 1b of the motor housing 1, and then the motor mechanism is installed in the motor built-in chamber 1a. 8 is incorporated. At this time, the motor shaft 8 a is supported by the bearing 12, and the periphery of the motor shaft 8 a is sealed by the seal member 10. In addition, in this state, the motor shaft 8a and the rotating shaft 7a are coupled so as to be integrally rotatable.

Finally, the opening of the motor built-in chamber 1a is sealed with the valve case 11 to complete the assembly of the hydraulic drive unit with a reduction gear. The hydraulic drive device with a reduction gear exhibits its driving force as follows. To do.
First, if the motor mechanism 8 rotates, the motor shaft 8a and the rotating shaft 7a rotate with it, and the reduction mechanism 7 rotates. Then, with the rotation of the speed reduction mechanism 7, the rotation drive body 3 rotates to drive, for example, an industrial machine crawler.

  On the other hand, as a leak inspection method for checking the sealing function of the floating seal 6, for example, the one disclosed in Patent Document 2 is conventionally known. An inspection method based on this conventional inspection method will be described below.

The leak tester 101 includes an air pump P, and an inspection passage 102 and a comparison passage 103 are connected to the air pump P in parallel. A regulator or the like (not shown) is provided in both the passages 102 and 103 so that a constant supply pressure is always supplied to both the passages 102 and 103.
Further, both the passages 102 and 103 are provided with electromagnetic valves 104 and 105, and both the passages 102 and 103 are opened and closed by controlling the switching of the electromagnetic valves 104 and 105.

The inspection passage 102 is connected to the air supply hole 14 of the sealing plate 13 and guides the compressed air supplied from the air pump P to the air supply hole 14. Therefore, when compressed air is supplied from the air pump P, the compressed air is guided to the motor built-in chamber 1a and the speed reducer built-in chamber 3a through the inspection passage 102 and the air supply hole 14.
On the other hand, the master M is connected to the comparison passage 103 in the same manner as described above. This master M is the same type as the hydraulic drive device with a reduction gear to be inspected, and is the hydraulic drive device with a reduction gear that has passed the leak inspection. Further, the leak tester 101 is provided with a differential pressure detecting means 106 for detecting a differential pressure between the inspection passage 102 and the comparison passage 103.

Then, the compressed air is continuously supplied from the air pump P for a predetermined time, and the inside of the hydraulic drive unit with a reduction gear, that is, the motor built-in chamber 1a and the reducer built-in chamber 3a to be inspected is pressurized.
Further, similarly to the above, the compressed air is continuously supplied to the master M to pressurize the inside of the master M.

After pressurizing the hydraulic drive unit with a speed reducer and the master M to be inspected for a predetermined time as described above, the solenoid valves 104 and 105 are switched to close both the passages 102 and 103. When a predetermined time elapses after both the passages 102 and 103 are closed, the differential pressure detecting means 106 detects the differential pressure in both the passages 102 and 103.
At this time, if there is an air leak from any of the rotary drive bodies 3 of the hydraulic drive unit with a reduction gear to be inspected, the pressure in the inspection passage 102 becomes lower than the pressure in the comparison passage 103, and the inspection passage 102. The differential pressure between the inside and the comparison passage 103 increases.
When the differential pressure detected by the differential pressure detection means 106 exceeds a preset allowable range, it is determined that there is a leak in the reduction gear built-in chamber 3a to be inspected, and parts are exchanged or assembled. Try again. On the other hand, if the differential pressure is within the allowable range, the inspection object is passed to the next step on the assumption that the leakage inspection has passed.

When the leak inspection of the rotary drive body 3 is completed as described above, the motor mechanism 8 is then incorporated into the motor built-in chamber 1a as described above, and the opening of the built-in chamber 1a is closed with the valve case 11. In this state, the motor built-in chamber 1a and the reducer built-in chamber 3a are completely partitioned by the seal member 10.
In this state, compressed air is supplied to the motor built-in chamber 1a to check whether there is a leak in the motor built-in chamber 1a. In this inspection method, the leak tester 101 shown in FIG. 3 is used, and the presence or absence of leak is determined by detecting the differential pressure with the master M.
If there is no leak in the motor housing 1 by the leak inspection, the motor built-in chamber 1a is filled with hydraulic oil.

The reason why the leak in the motor built-in chamber 1a is inspected as described above is as follows. For example, when there are a plurality of nests in the motor housing 1 and they are continuous, the hydraulic oil filled in the motor built-in chamber 1a leaks into the reducer built-in chamber 3a and mixes with the lubricating oil.
However, since the components and characteristics of the hydraulic oil and the lubricating oil are completely different, if the hydraulic oil flows into the reducer built-in chamber 3a, the hydraulic oil is mixed with the lubricating oil, and the lubricating oil is inherently present. Lubricating performance is impaired. On the other hand, if the lubricating oil flows from the reducer built-in chamber 3a into the motor built-in chamber 1a, the lubricating oil is mixed into the working oil, and the power transmission performance inherent in the working oil is impaired. . Therefore, a leak inspection of the motor built-in chamber 1a is executed to prevent mixing of hydraulic oil and lubricating oil.
Japanese Patent Laid-Open No. 7-305746 JP-A-8-313384

The conventional leak inspection method as described above has the following problems.
That is, in the conventional inspection method, when the leakage of the rotary drive body 3 is inspected, compressed air is supplied to the motor built-in chamber 1a and the pressure is guided to the reducer built-in chamber 3a. The pressure in 1a and the reducer built-in chamber 3a becomes the same. Therefore, even if the motor housing 1 has continuous bubbles due to the plurality of nests, it cannot be checked at the time of leak inspection of the rotary drive body 3.

Therefore, whether or not there is a leak in the motor housing 1 is found only in the leak inspection process that is performed after the motor mechanism 8 is built in the motor built-in chamber 1a and the opening of the motor built-in chamber 1a is closed with the valve case 11. Can not do it.
However, when a leak in the motor built-in chamber 1a is found after the motor mechanism 8 is completely incorporated into the motor built-in chamber 1a, the motor mechanism 8 is removed from the motor built-in chamber 1a, and the cause of the leak is determined. It must be repaired.

Therefore, when the above open bubbles are formed in the housing 1, not only the work of incorporating the motor mechanism 8 into the housing 1 or the attachment of the valve case 11 is wasted, but the work of removing it is necessary. There was a problem that work efficiency was extremely deteriorated.
An object of the present invention is to provide a leak inspection method capable of improving work efficiency by finding a leak in a motor housing in a stage before the assembly work of a hydraulic drive unit with a reduction gear is completed.

  In this invention, a cylindrical rotary drive body provided with a bottom plate is rotatably fitted to a motor housing, and the rotary drive body and the motor housing are combined to form a reduction gear built-in chamber in the rotary drive body, A motor mechanism is incorporated in the motor built-in chamber provided in the motor housing, a speed reducer is incorporated in the reducer built-in chamber, and both the built-in chambers communicate with each other through a bearing mounting hole formed in the motor housing. The motor shaft is supported by a bearing provided in the bearing mounting hole, and the rotational force of the motor shaft is transmitted to the rotary drive body via the speed reduction mechanism, while the assembly portion of the motor housing and the rotary drive body is sealed. This is based on the assumption that a reduction gear built-in chamber is liquid-tight and has a reduction gear-equipped hydraulic drive.

On the premise of the above-mentioned device, the first invention is that the rotary drive body incorporating the speed reduction mechanism in the speed reducer built-in chamber is assembled to the motor housing before the motor mechanism is incorporated, and then the air nozzle is closely attached to the bearing mounting hole. From this air nozzle, compressed air is supplied to the speed reducer built-in chamber to detect air leakage, and the liquid tightness of the speed reducer built-in chamber is inspected.
The second invention is characterized in that compressed air is supplied to the reduction gear built-in chamber, pressure change in the reduction gear built-in chamber is detected, and liquid tightness of the reduction gear built-in chamber is inspected.

According to the present invention, when the leak inspection of the reduction gear built-in chamber is performed, the air nozzle is brought into close contact with the bearing mounting hole and the compressed air is directly supplied to the reduction gear built-in chamber. Of course, it is also possible to detect a leak in the motor housing that defines the chamber for incorporating the reduction gear. In other words, the leak of the motor housing can be found before assembling the motor mechanism, the valve case, or the like to the motor housing. In addition, for example, when there is a material defect in the motor housing, such as when there are a plurality of nests in the motor housing and they continuously form a leak hole, it becomes easy to find it.
When a leak is detected in the motor housing as described above, the repair work can be started only by removing the motor housing from the rotary drive body, and the work efficiency can be improved.

  The best embodiment of the present invention will be described with reference to FIG. However, in this embodiment, the same hydraulic drive device with a reduction gear as that described above is assumed. The leak tester is the same leak tester as described above. Accordingly, the same reference numerals as those in the related art are assigned to the same configurations as in the prior art, and detailed descriptions of the hydraulic drive device with a reduction gear and the leak tester are omitted.

As shown in FIG. 1, a cylindrical air nozzle 16 is used in this inspection method. The air nozzle 16 has an opening 16a at its tip, and a seal member 17 is provided around the opening. An air supply port 16b is formed at the end opposite to the opening 16a, and the air supply port 16b is connected to the inspection passage 102 described above.
The cylindrical air nozzle 16 has an outer diameter smaller than the inner diameter of the bearing mounting hole 1b and larger than the shaft protruding hole 1c, and the opening 16a surrounds the shaft protruding hole 1c. When in close contact, the intimate portion is sealed with the seal member 17.

Then, the speed reduction mechanism 7 is assembled in the speed reducer built-in chamber 3 a of the rotation drive body 3, and the motor housing 1 before the motor mechanism 8 is assembled is fitted to the rotation drive body 3.
In the above state, the opening 16a of the air nozzle 16 is brought into close contact with the periphery of the shaft protruding hole 1c, and the compressed air from the air pump P is directly supplied to the reduction gear incorporating chamber 3a. In this state, the compressed air from the air pump P is directly supplied to the reducer built-in chamber 3a while the motor built-in chamber 1a of the motor housing 1 is opened to the atmosphere.

Therefore, when the compressed air from the air pump P is supplied to the speed reducer built-in chamber 3a, a differential pressure corresponding to the pressure of the compressed air is generated in the speed reducer built-in chamber 3a and the motor built-in chamber 1a.
At this time, if the motor housing 1 has a plurality of continuous nests, and if the reduction gear built-in chamber 3a and the motor built-in chamber 1a opened to the atmosphere communicate with each other through the nest, compressed air is generated from there. Leakage and the pressure in the reducer built-in chamber 3a are relatively lower than the pressure of the master M. If this relative difference in pressure is detected by the leak tester 101, it can be seen that a leak has occurred in at least one of the reduction gear built-in chambers 3a.

In any case, when the differential pressure with the master M exceeds the allowable range as described above, the cause is a structural leak of the floating seal 6 or the like, or the material of the motor housing 1 or the like. One of the leaks due to a flaw. Therefore, the cause of the leak is investigated and repaired. At this time, the motor housing 1 is removed from the rotary drive 3 and the repair work is performed. However, considering the trouble of removing the motor housing 1 after incorporating the motor mechanism 8 as in the prior art, it is clear that the repair work of this embodiment is more efficient.
When a plurality of nests are continuous with the motor housing 1 as described above, the nests are filled with a filler.

As described above, when there is no abnormality when the leak on the speed reducer built-in chamber 3a side is inspected, or after the repair is completed, the motor built-in chamber 1a is built in the motor built-in chamber 1a and the motor built-in chamber 1a is closed with the valve case 11. Complete the entire assembly.
When the entire assembly is completed, compressed air is again supplied from the air pump P to the motor built-in chamber 1a, and the leak is detected. The inspection target in this case is a cause of structural leakage such as a member for sealing the motor built-in chamber 1a and a defect in the assembly state.

  In any case, according to this embodiment, since the air nozzle 16 only needs to be brought into close contact with the existing bearing mounting hole 1b, the target leak inspection can be performed only by using a simple tool called the air nozzle 16.

It is a figure which shows the leak test | inspection method of this embodiment. It is sectional drawing of the hydraulic drive device with a reduction gear. It is a figure explaining a leak inspection method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor housing 1a Motor built-in chamber 1b Bearing mounting hole 3 Rotating drive body 3a Reducer built-in chamber 6 Floating seal 7 Deceleration mechanism 7a Rotating shaft 8 Motor mechanism 8a Motor shaft

Claims (2)

  A cylindrical rotary drive body provided with a bottom plate is rotatably fitted to the motor housing, and the rotary drive body and the motor housing combine to form a reduction gear built-in chamber in the rotary drive body. A motor mechanism is built in the provided motor built-in chamber, and a speed reducer built-in chamber is built in the above-described reduction gear built-in chamber. The motor shaft is supported by the bearing provided in the bearing mounting hole, and the rotational force of the motor shaft is transmitted to the rotary drive via the speed reduction mechanism. This is a hydraulic drive unit with a speed reducer that makes the chamber liquid-tight. Assembled in the previous motor housing, and then brought the air nozzle into close contact with the bearing mounting hole. From this air nozzle, compressed air is supplied to the reducer built-in chamber to detect air leaks and check the liquid tightness of the reducer built-in chamber Leak inspection method for hydraulic drive unit with speed reducer.   2. A leak inspection method for a hydraulic drive unit with a reduction gear according to claim 1, wherein compressed air is supplied to the reduction gear built-in chamber, pressure change in the reduction gear built-in chamber is detected, and liquid tightness of the reduction gear built-in chamber is checked. .

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