Oil leakage prevention structure

Abstract

To provide an oil leak prevention structure which can post-fit a box body of an existing reduction gear without modifying the box body at all, and can surely prevent a contamination of its circumference by oil which leaks out of an air breather.SOLUTION: An oil leak prevention structure 1 for preventing a contamination of a box body 51 caused by a lubricant 54 when alleviating a rise of pressure in the box body 51 of a reduction gear 7 comprises: a pipe body 2 detachably connected to a connection part 56 arranged on an outside face of the box body 51; an air breather 57 arranged at an end part 2a not being the box body 51 side of the pipe body 2; and a leaked oil receiving part 3 which is composed of a vessel body 4 having an opening part 4a at an upper part, and in which the pipe body 2 is arranged while penetrating through a bottom face 4b of the vessel body, and the vessel body 4 is integrated to a peripheral side face of the pipe body 2. An altitude difference from the lowest position of a ceiling face 55 of the box body 51 up to a vertical lower-side end part of the air breather 57 is equal to or larger than 15 cm.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an oil leakage prevention structure for preventing the surface of a housing of a reducer from being soiled by leaked lubricating oil when a pressure increase inside the housing is alleviated.

[0002] First, an overview of a conventional reducer equipped with an air breather will be described with reference to Figs. 4 and 5. Fig. 4 is a vertical sectional view of a reducer equipped with an air breather according to a conventional technique, and Fig. 5 is a vertical sectional view showing an enlarged main part for explaining the operation of the air breather. As shown in FIG. 4, the reducer 50 is typically configured such that gears 53a-53f with different numbers of teeth are journalled by shafts 52a-52d within a housing 51, and these gears 53a-53f are combined to reduce the rotational speed input to a desired shaft and output it. In such a reducer 50, the gears 53a to 53f and the shafts 52a to 52d are housed in the housing 51 in a state where they are partially immersed in lubricating oil 54 in order to reduce friction when the individual gears 53a to 53f mesh with each other. In such a reduction gear 50, the temperature of the lubricating oil 54 rises depending on the outside air temperature and the operating conditions of the reduction gear 50. Then, as the temperature of the lubricating oil 54 rises, the lubricating oil 54 volatilizes, causing an increase in pressure inside the housing 51, which may hinder safe operation of the reduction gear 50. For this reason, the reducer 50 is usually provided with an air breather 57 in the housing 51 in order to keep the pressure inside the housing 51 close to atmospheric pressure.

[0003] More specifically, as shown in Figures 4 and 5, reducer 50 normally has a connection part 56 for attaching air breather 57 on the upper side of its top surface 55 or side surface, and air breather 57 is installed in a detachable or non-detachable state via a connection pipe 58 that is, for example, screwed to this connection part 56. Moreover, as shown in FIG. 5, for example, the air breather 57 has an air outlet portion 59 screwed onto the upper end side of a connecting pipe 58 provided at the connecting portion 56, and the air inside the housing 51 can be discharged to the outside from an air outlet hole 60 formed in the air outlet portion 59. That is, when the pressure rises in the housing 51 of the reducer 50 shown in Fig. 4, the air P in the housing 51 is discharged to the outside through the connecting pipe 58 and the air outlet part 59 of the air breather 57 as shown in Fig. 5. As a result, the pressure in the housing 51 of the reducer 50 is maintained close to atmospheric pressure.

[0004] On the other hand, the air discharged to the outside from the housing 51 of the reducer 50 usually contains lubricating oil 54, and if such air is discharged directly from the air outlet hole 60 of the air outlet section 59, the area around the air breather 57 will be contaminated by the lubricating oil 54. For this reason, the air breather 57 is provided in the air outlet portion 59 as shown in FIG. 5, for example, and has a cap 62 that covers the air outlet hole 60 without closing it. However, even if the air outlet portion 59 is provided with the cap 62, a portion of the lubricating oil 54 contained in the housing 51 is released together with the air from the air outlet hole 60, so that there remains a problem that the area around the air breather 57 is contaminated by the leaked lubricating oil 54. In consideration of such circumstances, the air outlet portion 59 constituting the air breather 57 further includes a filter receiving portion 59a surrounding the air outlet hole 60, and a short cylindrical filter 61 is provided on the filter receiving portion 59a. As a result, when air containing lubricating oil 54 is discharged from air discharge hole 60 in air discharge portion 59, a part or all of lubricating oil 54 can be adsorbed and removed by filter 61.

[0005] However, depending on the operating conditions of the reducer 50 and the properties of the lubricating oil 54 used, a sudden rise in the liquid level of the lubricating oil 54 inside the housing 51 may occur, and when the air inside the housing 51 is released, a large amount of the lubricating oil 54 may be released along with the air. In this case, as shown in FIG. 5, there is a problem in that lubricating oil Q that has not been completely removed by filter 61 housed in air breather 57 leaks onto top surface 55 of housing 51 around air breather 57, thereby contaminating these surfaces. As prior applications for addressing the above-mentioned problems, for example, the following are known.

[0006] Patent Document 1 discloses an invention entitled "Structure for Suppressing Internal Pressure Increase in a Reducer" which relates to a structure for suppressing an increase in internal pressure in a reducer. 11 of Patent Document 1 discloses a tray 85 that is provided in a communication hole 13 penetrating a housing 6, which is the housing of the reducer, and is attached to the base of a valve 70 that releases air inside the housing to the atmosphere. This tray 85 is also for receiving lubricating oil leaking from the valve 70. Furthermore, when the invention disclosed in Patent Document 1 is provided with the above-mentioned tray 85, even if the lubricating oil received by cover 80C shown in Figure 11 of the same document drips from cover 80C, the dripping lubricating oil can be received by tray 85, thereby preventing the lubricating oil from leaking out.

[0007] Patent Document 2 discloses an invention entitled "Oil Leak Prevention Structure for Power Divider" that relates to an oil leakage prevention structure for a power divider that connects an engine and a hydraulic pump installed in a construction machine. The oil leakage prevention structure for a power divider, which is an invention disclosed in Patent Document 2, is characterized in that a lubricating oil for a gear driven by an internal combustion engine is stored in a housing that accommodates a gear, and a substantially L-shaped conduit is provided in the upper part of the housing to supply the lubricating oil and open the space within the housing to the atmosphere, the conduit has a horizontal pipe that is inserted into the internal space of the housing from one side wall of the housing and has one axial end that faces the internal space and opens, and a riser pipe that is bent upward and continues from the other axial end of the horizontal pipe that protrudes outside the housing, and an air breather is attached to the upper end of the riser pipe, the horizontal pipe has one axial end that fits into a recess formed in the other side wall that faces the one side wall across the internal space, and a through hole that opens downward is formed in the one axial end, and is inclined at a predetermined angle with respect to an axis perpendicular to the inner wall surface of the one side wall so that the one axial end is lower than the other axial end. According to the invention disclosed in Patent Document 2 as described above, even when the work machine equipped with the power divider is inclined to the maximum extent, the horizontal or axial end of the horizontal pipe is lower than the other axial end, so that the lubricating oil in the pipe flows down from the through hole into the internal space of the housing, and the lubricating oil does not accumulate in the pipe. In addition, even if the lubricating oil enters the pipe from the through hole by increasing the distance from the through hole of the pipe to the air breather, it is difficult for the lubricating oil to be pushed out from the air breather to the outside. Furthermore, since the axis of the horizontal pipe does not face the gear, the lubricating oil that is splashed up does not penetrate deep into the through hole of the horizontal pipe. In this way, according to the invention disclosed in Patent Document 2, it is possible to reliably prevent the lubricating oil from leaking out to the outside through the pipe by using one pipe.

[0008] Patent Document 3, entitled "Bearing Device for Vertical Rotating Machine," discloses an idea related to a bearing device for a vertical rotating machine that is equipped with a seal mechanism for preventing oil leakage from the shaft through-hole of the bearing. The bearing device for a vertical rotating machine, which is an idea disclosed in Patent Document 3, is provided with an oil tank containing a bearing mechanism that supports a rotating shaft, a seal air introduction mechanism for preventing oil leakage from the through-hole of the rotating shaft, and a seal air discharge mechanism that discharges the introduced seal air back to the outside and has an air breather that captures the oil contained in the seal air, and is characterized in that it is provided with an oil trap that captures oil contained in the seal air that reaches the air breather, and an oil return pipe that returns the oil captured by this oil trap and the air breather to the oil tank separately from the seal air discharge pipe. According to the device disclosed in Patent Document 3 as described above, oil droplets contained in the sealing air are captured by an oil trap installed in front of the air breather and returned to the oil tank through an oil return pipe. This prevents the air breather from clogging and increases the ventilation resistance of the air breather pipe, thereby achieving a sufficient sealing effect with stable operation. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2020-190317 A [Patent Document 2] Japanese Patent Application Publication No. 10-169760 [Patent Document 3] Publication No. 60-121528 Summary of the Invention [Problem to be solved by the invention]

[0010] In the case of the invention disclosed in the above-mentioned Patent Document 1, the provision of drip pan 85 (see Figure 11 of Patent Document 1) is thought to prevent the area around valve 70 from being soiled by oil dripping from cover 80C. However, if the oil level inside the housing rises significantly, even the provision of drip pan 85 may not completely prevent oil leakage.

[0011] In the case of the invention disclosed in Patent Document 2, it is believed that the leakage of oil from the air breather can be effectively prevented. However, when trying to implement the invention in an existing reducer 50 as shown in Figures 4 and 5, for example, it is necessary to modify even the internal structure of the casing, which is an extremely complicated task and involves high costs for modifying reducer 50. Furthermore, when replacing the existing reducer 50 as shown in FIGS. 4 and 5 with a reducer equipped with the invention disclosed in Patent Document 2, there is a problem in that the cost required for capital investment increases further.

[0012] The device disclosed in Patent Document 3 is also considered to be able to effectively prevent oil leakage from the air breather, but has the same problems as the device disclosed in Patent Document 2 mentioned above. Furthermore, in the case of the device disclosed in Patent Document 3, the oil leakage prevention structure including the air breather is complicated, which causes the problem of the time-consuming maintenance. Furthermore, with the device disclosed in Patent Document 3, it is not easy to determine whether the reason leakage from the air breather does not occur is because the oil trap is functioning normally or because the oil trap is unintentionally clogged. In the latter case in particular, there is a concern that a fatal problem may occur, such that the bearing device cannot be operated safely.

[0013] The present invention has been made in response to such conventional circumstances, and its purpose is to provide an oil leakage prevention structure that can be retrofitted to an existing reducer housing without any modification, that can make it difficult for oil to leak from the air breather, and that can prevent the reducer housing and its surroundings from being soiled even if oil does leak from the air breather. [Means for solving the problem]

[0014] The oil leakage prevention structure, which is a first invention for solving the above-mentioned problems, is an oil leakage prevention structure that prevents the housing of a reducer from being contaminated by lubricating oil when alleviating the pressure rise inside the housing of the reducer, and is characterized in that it comprises a tube body that is detachably connected to a connection portion provided on the outer surface of the housing, an air breather provided at the end of the tube body that is not on the housing side, and an oil leakage receiving portion consisting of a container body having an opening at the top, with the tube body disposed penetrating its bottom surface and the container body fixed integrally to the peripheral surface of the tube, and the height difference from the lowest point of the top surface of the housing to the vertically lower end of the air breather is 15 cm or more. In the first invention having the above configuration, the pipe body has the effect of holding the air breather vertically above the housing of the reducer, and in addition, by setting the height difference from the lowest position of the top surface of the housing of the reducer to the vertically lower end of the air breather to 15 cm or more, the pipe body has the effect of suitably suppressing the lubricating oil from overflowing from the air breather even if a significant rise in the liquid level of the lubricating oil occurs in the housing of the reducer. In addition, the air breather has the effect of guiding some of the air inside the housing to the outside when the pressure inside the housing of the reducer increases, thereby maintaining the air pressure inside the housing at a level close to atmospheric pressure. Furthermore, the container body constituting the oil leakage receiving portion has the function of receiving and storing the lubricating oil leaking from the air breather. Also, by integrally fixing the above-mentioned container body to the tube body arranged penetrating the bottom surface of the container body, the lubricating oil stored in the container body is prevented from leaking from the joint between the tube body and the container body. In addition, since the tube body and the container body are integrated, when the tube body is attached to or detached from the housing of the reducer, the container body can also be attached to or detached from the housing, which has the effect of facilitating the handling of the oil leakage receiving portion.

[0015] A second invention is the above-mentioned first invention, characterized in that the tube body and the container body are made of metal, and the container body is welded to the tube body. The second invention having the above configuration has the same effect as the first invention. Furthermore, in the second invention, the tube body and the container body are both made of metal, and the tube body is integrated with the container body by welding, which increases the strength, heat resistance, and durability of each component, and also increases the strength of the joints between them. In this case, even if the housing is continuously subjected to vibrations as the reducer is operating, it has the effect of preventing malfunctions such as damage to the tube body or container body, or gaps occurring at the joints between them.

[0016] The third invention is the first or second invention described above, characterized in that when the oil leakage prevention structure is viewed in a plane, there is a gap between the periphery of the air breather and the opening of the oil leakage receiving portion (however, the opening of the oil leakage receiving portion is arranged outside the periphery of the air breather), and the size of this gap has an area greater than or equal to the radius of the air breather. The third invention having the above configuration has the same effect as the first or second invention. In addition, in the third invention, when the oil leakage prevention structure is viewed from above, a gap is formed between the periphery of the air breather and the opening of the oil leakage receiving portion, which means that the entire air breather is disposed on the container body constituting the oil leakage receiving portion. In this case, when lubricating oil leaks out of the air breather together with air, all of the leaked lubricating oil can be received by the container body. Furthermore, in the third invention, when the oil leakage prevention structure is viewed in a plane, there is an area in which the size of the gap between the periphery of the air breather and the opening of the oil leakage receiving portion is greater than or equal to the radius of the air breather, so that by looking into the bottom side of the container body from this area, the condition of the inside (bottom side) can be visually confirmed. In other words, since the third invention has the above-mentioned gap, the bottom side of the container body can be seen, making it possible to easily check whether or not oil is leaking from the air breather.

[0017] The fourth invention is any one of the first to third inventions described above, characterized in that the connection part is cylindrical and has a female threaded portion on its inner surface, the outer surface of the end side of the tube body that is connected to the connection part has a male threaded portion, and a sealing material is provided between the connection part and the tube body. The fourth invention having the above configuration has the same effect as the first to third inventions. In addition, in the fourth invention, a pipe body having an air breather on the upper end side and an oil leakage receiver on the body can be screwed to a connection part provided on the housing side. In this case, it is possible to prevent the lubricating oil contained in the housing from leaking out from the screwed part of the connection part and the pipe body. Furthermore, in the fourth invention, a sealing material is interposed between the connection part on the housing side and the screw-threaded part of the tube body, which has the effect of preventing lubricating oil from leaking out of the housing from the screw-threaded part between the connection part on the housing side and the tube body, even if the housing is continuously subjected to vibrations due to operation of the reducer.

[0018] The fifth invention is any one of the first to fourth inventions described above, characterized in that the oil leakage receiving portion is provided with an oil leakage absorbing material housed within its hollow portion. The fifth invention having the above configuration has the same effect as each of the first to fourth inventions. Furthermore, in the fifth invention, the oil leakage receiving portion has an oil leakage absorbent material in its hollow portion, so that the lubricating oil leaking from the air breather and contained in the container body constituting the oil leakage receiving portion can be absorbed and held in the oil leakage absorbent material. In this case, the cleaning work of the oil leakage receiving portion is the replacement work of the oil leakage absorbent material housed in the oil leakage receiving portion. Effect of the Invention

[0019] According to the first invention as described above, by ensuring a height difference of 15 cm or more from the lowest point of the top surface of the reducer housing to the vertically lower end of the air breather, it is possible to make it difficult for the lubricating oil to leak from the air breather even if the liquid level of the lubricating oil contained in the housing rises significantly. In other words, according to the first invention, the risk of lubricating oil leaking from the air breather can be reliably reduced without modifying the internal structure of the reducer housing or providing an oil trap downstream of the air breather. Furthermore, by fixing the oil leakage receiving portion integrally to the tube supporting the air breather, the lubricating oil leaking from the air breather and contained in the oil leakage receiving portion can be prevented from leaking out from the joint between the tube and the oil leakage receiving portion. In this case, the top surface of the reducer and the periphery of the air breather can be reliably prevented from being soiled by lubricating oil leaking from the air breather.

[0020] The second invention has the same effects as those of the first invention. Furthermore, according to the second invention, the container body and the tube body constituting the oil leakage receiving portion are both made of metal and are integrated by welding, so that the strength, heat resistance, and durability of the oil leakage prevention structure according to the second invention can be improved. Therefore, according to the second invention, even if the oil leakage prevention structure of the second invention is continuously subjected to vibrations due to the operation of the reducer, there is no risk of a gap occurring at the joint between the tube body and the oil leakage receiving portion, and therefore the lubricating oil contained in the oil leakage receiving portion will not leak to the outside from these joints. As a result, according to the second aspect of the present invention, it is possible to more reliably prevent the top surface of the reducer and the periphery of the air breather from being soiled by lubricating oil leaking from the air breather.

[0021] The third invention has the same effect as the first or second invention. Furthermore, according to the third invention, the bottom edge side of the oil leakage receiving portion can be visually confirmed by looking into the gap between the periphery of the air breather and the opening of the oil leakage receiving portion. In this case, it is easy to check whether or not lubricating oil is leaking from the air breather, and the amount of leakage. Furthermore, since it is easy to check whether or not lubricating oil is leaking from the air breather, as well as the amount of leakage, any abnormal condition occurring within the reducer can be easily detected. In other words, if the amount of lubricating oil leaking is less than normal or there is no lubricating oil leaking even when the reducer is operating normally, there is a possibility that there is a shortage of lubricating oil inside the housing. On the other hand, if the amount of lubricating oil leaking is greater than normal even though the reducer is operating normally, there may be an excess of lubricating oil in the casing, or abnormal heat may be being generated inside the reducer casing due to an abnormality in the gears or the like. Therefore, according to the third aspect of the invention, it is possible to indirectly monitor the state inside the reducer while reliably preventing the housing and the area around the air breather from being contaminated by lubricating oil overflowing from inside the reducer housing.

[0022] The fourth invention has the same effects as those of the first to third inventions described above. Furthermore, according to the fourth invention, even if vibrations are continuously applied to the tube constituting the oil leakage prevention structure due to the operation of the reducer, it is possible to prevent loosening of the screwed portion of the connection part between the tube and the housing side. In this case, it is possible to effectively prevent the lubricating oil inside the housing from leaking from the screwed portion of the connection between the tube and the housing side of the reducer.

[0023] The fifth invention has the same effects as those of the first to fourth inventions. Furthermore, according to the fifth invention, when the lubricating oil in the housing of the reducer overflows from the air breather and is received in the oil leakage receiving section, the lubricating oil in the oil leakage receiving section can be absorbed and held in the oil leakage absorbent. In this case, the cleaning work of the leaked oil receiving portion according to the fifth aspect of the present invention can be completed simply by replacing the leaked oil absorbent that has absorbed the lubricating oil. Therefore, according to the fifth aspect of the present invention, the maintenance work can be simplified. [Brief description of the drawings]

[0024] [Figure 1] 1 is a vertical cross-sectional view of a reducer equipped with an oil leakage prevention structure according to an embodiment of the present invention. [Diagram 2] 2 is an enlarged vertical cross-sectional view showing a main part of the oil leakage prevention structure according to the embodiment of the present invention. FIG. [Diagram 3] 4 is an enlarged vertical cross-sectional view showing a main part of an oil leakage prevention structure according to a modified example of an embodiment of the present invention. FIG. [Figure 4] FIG. 1 is a vertical sectional view of a reducer equipped with an air breather according to a conventional technology. [Diagram 5] FIG. 4 is an enlarged vertical cross-sectional view showing a main part for explaining the operation of the air breather. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] An oil leakage prevention structure and a reducer equipped with the same according to an embodiment of the present invention will be described in detail with reference to Figs. 1 to 3.

[0026] [1-1: Basic configuration of the present invention] First, an oil leakage prevention structure according to an embodiment of the present invention and a reducer including the same will be described with reference to Figs. Fig. 1 is a vertical cross-sectional view of a reducer equipped with an oil leakage prevention structure according to an embodiment of the present invention. Fig. 2 is a vertical cross-sectional view showing an enlarged view of a main part of the oil leakage prevention structure according to an embodiment of the present invention. Note that the same parts as those shown in Figs. 4 and 5 above are given the same reference numerals, and description of their configurations will be omitted. The reducer 7 according to this embodiment is obtained by replacing the air breather 57 and the connecting pipe 58 in the reducer 50 shown in Figs. 4 and 5 with the oil leakage prevention structure 1 according to this embodiment.

[0027] Moreover, the oil leakage prevention structure 1 according to this embodiment includes an air breather 57 that is provided to reduce a pressure rise inside the housing 51 of the reducer 7 . More specifically, the oil leakage prevention structure 1 of this embodiment comprises a pipe body 2 that is detachably connected to a connection portion 56 protruding from the outer surface of the housing 51 of the reducer 7, an air breather 57 that is detachably or non-detachably provided on the upper end 2a of the pipe body 2 that is not on the housing 51 side, and an oil leakage receiving portion 3 that is fixed integrally to the body of the pipe body 2. In the oil leakage prevention structure 1 as described above, the oil leakage receiving portion 3 has a through hole 4c formed in the bottom surface 4b of a container body 4 having an opening 4a at the top, a pipe body 2 is inserted into this through hole 4c, and the bottom surface 4b of the container body 4 is fixed integrally to the peripheral side surface of the pipe body 2. Furthermore, in the oil leakage prevention structure 1 as described above, as shown in FIG. 2, the height difference H from the lowest position of the housing 51 of the reducer 7 to the vertically lower end 57a of the air breather 57 is set to 15 cm or more.

[0028] In the reducer 7 according to this embodiment, the oil leakage prevention structure 1 is provided on the top surface 55 side of the housing 51, but the oil leakage prevention structure 1 may be provided to protrude from a side surface of the housing 51 closer to the top surface 55. In this case, too, the length of the pipe body 2 may be set so that the height difference H from the lowest position of the housing 51 of the reducer 7 to the vertically lower end of the air breather 57 is 15 cm or more. Furthermore, in the reducer 7 of this embodiment, no particular upper limit is set for the height difference H from the lowest position of the housing 51 to the vertically lower end of the air breather 57, but there is no particular advantage to setting it significantly larger than 15 cm.

[0029] [1-2: About the action and effect of the basic configuration of this invention] According to the oil leakage prevention structure 1 according to this embodiment as described above, the air breather 57 can be held vertically above the top surface 55 of the housing 51 of the reducer 7 in a spaced-apart state. In this case, even if the temperature of the lubricating oil rises inside the housing 51 of the reducer 7 and the liquid level rises significantly, the lubricating oil 54 can be effectively prevented from overflowing from the air outlet hole 60 of the air breather 57. Furthermore, in the oil leakage prevention structure 1 according to this embodiment, even if the lubricating oil 54 overflows from the air breather 57, the overflowing lubricating oil 54 can be received and held by the oil leakage receiving portion 3. Furthermore, in the oil leakage prevention structure 1 of this embodiment, the container body 4 constituting the oil leakage receiving portion 3 is fixed integrally onto the peripheral surface of the pipe body 2, so there is no need to worry about the lubricating oil 54 contained in the oil leakage receiving portion 3 leaking out to the outside from the joint between the pipe body 2 and the container body 4. As a result, the oil leakage prevention structure 1 of this embodiment can reliably prevent the top surface 55 of the housing 51 of the reducer 7 and the area around the air breather 57 from being soiled by the lubricating oil 54 overflowing from the air breather 57.

[0030] In addition, according to the oil leakage prevention structure 1 of this embodiment, since the oil leakage receiving portion 3 is fixed to the pipe body 2, when the pipe body 2 is removed from the housing 51 of the reducer 7, the oil leakage receiving portion 3 can also be removed together. This makes it possible to simplify the attachment and detachment work of the oil leakage prevention structure 1 of this embodiment to the housing 51. Furthermore, the oil-leakage prevention structure 1 according to the present embodiment as described above can be easily installed in the housing 51 of an existing reducer 7. In other words, the oil-leakage prevention structure 1 according to the present embodiment can be installed without making any changes to the housing 51 of the reducer 7 according to the conventional technology shown in Figs. 4 and 5 above. Therefore, according to the oil leakage prevention structure 1 of this embodiment, it is possible to reliably prevent the top surface 55 of the housing 51 and the periphery of the air breather 57 from being soiled by the lubricating oil 54 while using the existing reducer 50 as is.

[0031] [1-3: Detailed structure of the present invention] In the oil leakage prevention structure 1 of this embodiment, the container body 4 and the pipe body 2 that constitute the oil leakage receiving portion 3 are both made of metal, and the container body 4 may be welded to the peripheral side surface of the pipe body 2 (optional component). In this case, a weld mark 4d as shown in Figs. 1 and 2 is formed at the joint between the pipe body 2 and the container body 4 in the oil leakage prevention structure 1 according to this embodiment. In this case, the strength, heat resistance, and durability of the pipe body 2 and the container body 4 in the oil leakage prevention structure 1 according to the embodiment can be improved compared to when they are made of, for example, synthetic resin. Also, by using welding as the joining method, the joining strength of these can be significantly increased. More specifically, it is possible to screw the container body 4 onto the peripheral surface of the tube body 2 to integrate them together; however, in this case, there is a concern that the joint between the tube body 2 and the container body 4 may become loose when vibrations generated by the operation of the reducer 7 continuously act on the joint between the tube body 2 and the container body 4. Furthermore, if loosening occurs at the joint between the tube body 2 and the container body 4, there is a concern that the lubricating oil 54 contained in the oil leakage receiving section 3 will leak to the outside through a gap that occurs at the joint between the tube body 2 and the container body 4. On the other hand, in the oil leakage prevention structure 1 according to this embodiment, when the container body 4 is welded to the pipe body 2, the above-mentioned problem does not occur. Therefore, when the container body 4 is welded to the tube body 2 to form an integrated unit, it is possible to reliably prevent the lubricating oil 54 held in the oil leakage receiving portion 3 from leaking out of the oil leakage receiving portion 3 and causing damage to the top surface 55 of the housing 51 or the area around the base of the tube body 2.

[0032] However, when the container body 4 is screwed onto the peripheral surface of the tube body 2 and a sealing material made of, for example, synthetic resin is interposed at the joint between them, it may be possible to prevent the joint between the tube body 2 and the container body 4 from loosening. Therefore, when a sealant as described above is interposed between the joint between the pipe body 2 and the container body 4, the container body 4 may be screwed onto the peripheral side surface of the pipe body 2.

[0033] In the oil leakage prevention structure 1 according to this embodiment, when the oil leakage prevention structure 1 is viewed in plan, as shown in Fig. 2, a gap X may be formed between the periphery 57b of the air breather 57 and the opening 4a of the oil leakage receiving portion 3, and the size of this gap X may be set to be equal to or larger than the radius of the air breather (optional component). However, the periphery 57b of the air breather 57 is disposed inside the position of the opening 4a of the oil leakage receiving portion 3. In this case, the inside of the oil leakage receiving portion 3 can be seen through a gap X formed between the peripheral edge 57b of the air breather 57 and the opening 4a of the oil leakage receiving portion 3 and having a size equal to or larger than the radius of the air breather 57. In this case, it is possible to easily check whether the lubricating oil 54 is leaking from the air breather 57 and the amount of the lubricating oil 54 that has leaked.

[0034] By checking whether or not lubricating oil 54 is leaking from air breather 57 and the amount of lubricating oil 54 leaking, it is also possible to indirectly monitor whether or not there is a blockage inside air breather 57 of tube body 2 or 7, and the condition inside housing 51 of reducer 7. In other words, from the fact that the lubricating oil 54 is leaking from the air breather 57, it can be confirmed that the air breather 57 of the tubes 2 and 7 is not clogged. Furthermore, when the oil leakage receiving portion 3 in the oil leakage prevention structure 1 of this embodiment is periodically observed, for example, if a constant leakage of a certain amount of lubricating oil 54 is found, and if the leakage of lubricating oil 54 from the air breather 57 stops or decreases suddenly even though there is no significant change in the operating conditions of the reducer 7, the amount of lubricating oil 54 in the housing 51 may be insufficient. Furthermore, for example, if a certain amount of lubricating oil 54 is constantly leaking and the amount of lubricating oil 54 increases even though there is no significant change in the operating conditions of the reducer 7, some kind of malfunction may have occurred inside the housing 51, causing a sudden rise in temperature of the lubricating oil 54. In this way, by closely checking for the presence or absence of oil leakage from the air breather 57 and the amount of oil leakage, it may be possible to carry out inspection and maintenance before a malfunction in the reducer 7 reaches a fatal situation.

[0035] Therefore, in the oil leakage prevention structure 1 of this embodiment, by configuring the inside of the oil leakage receiving portion 3 to be visually inspected, it is possible to easily determine whether or not the oil leakage receiving portion 3 needs to be cleaned, and it also becomes easier to detect abnormalities in the reducer 7. As a result, there is an advantage that the reducer 7 equipped with the oil leakage prevention structure 1 according to this embodiment can be operated continuously in a stable state.

[0036] As an attachment structure for attaching the oil leakage prevention structure 1 according to this embodiment to the housing 51 of the reducer 7, for example, the configurations shown in Figs. That is, as shown in Figures 1 and 2, the connection part 56 protruding from the housing 51 of the reducer 7 is a cylindrical body 56a having a female threaded part 56b on its inside, and a male threaded part 2c on the outer surface of the lower end 2b side of the tube body 2, and a sealing material 5 made of, for example, synthetic resin may be interposed between these threaded parts (optional component). In this case, even if continuous vibrations act on the connection portion between the tube body 2 of the oil leakage prevention structure 1 of this embodiment and the connection portion 56 on the housing 51 side as the reducer 7 is operated, loosening between them can be effectively prevented. As a result, it is possible to prevent the lubricating oil 54 contained within the housing 51 from leaking out from the joint between the connection part 56 on the housing 51 side and the pipe body 2. Therefore, by screwing the tube body 2 to the connection part 56 on the housing 51 side and placing a sealing material 5 between them, it is possible to reliably prevent the lubricating oil 54 from leaking from the connection part between the connection part 56 and the tube body 2 and causing damage to the top surface 55 of the housing 51 and the area around the base of the tube body 2.

[0037] [2: Variations of the present invention] Finally, an oil leakage prevention structure according to a modified example of this embodiment will be described with reference to FIG. Fig. 3 is an enlarged vertical cross-sectional view showing a main part of an oil leakage prevention structure according to a modified embodiment of the present invention. Note that the same parts as those shown in Figs. 1 and 2, and Figs. 4 and 5 are given the same reference numerals, and the description of their configurations is omitted. An oil leakage prevention structure 1' according to a modified example of this embodiment is an oil leakage prevention structure 1 shown in Figs. 1 and 2, in which an oil leakage absorbent material 6 is provided in the hollow portion of the oil leakage receiving portion 3. The oil leakage absorbent 6 used in the modified oil leakage prevention structure 1' may be, for example, a sheet material made of oil-absorbent natural fibers, synthetic fibers, polymers, etc. In addition, such oil leakage absorbent 6 may be an inexpensive rag, since it is discarded after use.

[0038] In this way, when the oil leakage prevention structure 1' relating to the modified example of this embodiment is provided with an oil leakage absorbent 6 in the hollow portion of the oil leakage receiving portion 3, the lubricating oil 54 leaked from the oil leakage receiving portion 3 can be absorbed and retained by the oil leakage absorbent 6. In this case, the cleaning work of the lubricating oil 54 accumulated in the leaked oil receiving portion 3 can be simplified since it is only necessary to replace the leaked oil absorbent 6 impregnated with the lubricating oil 54.

[0039] Furthermore, the connection structure between the oil leakage prevention structure 1' (or the oil leakage prevention structure 1) in this embodiment and the connection portion 56 on the housing 51 side does not require a sealing material 5 to be interposed between the pipe body 2 and the cylindrical body 56a as shown in Figure 3 (optional component). More specifically, by making the threaded engagement area between the male threaded portion 2c formed on the lower end 2b side of the tube body 2 and the female threaded portion 56b formed on the inner surface of the cylindrical body 56a that constitutes the connection portion 56 sufficiently large, it is possible to effectively prevent loosening of these threaded portions even if continuous vibrations are applied as the reducer 7 is operated. [Industrial Applicability]

[0040] As described above, the present invention is an oil leakage prevention structure that can be easily retrofitted to an existing reducer housing without making any modifications, that can make it less likely for oil to leak from the air breather, and that can prevent the reducer housing and its surroundings from being soiled even if oil does leak from the air breather, and can be used in technical fields related to power generation equipment, etc. [Explanation of symbols]

[0041] 1,1'...oil leakage prevention structure 2...tube body 2a...upper end 2b...lower end 2c...male threaded portion 3...oil leakage receiver 4...container body 4a...opening 4b...bottom surface 4c...through hole 4d...welding mark 5...sealing material 6...oil leakage absorber 7...reduction gear 50...reduction gear 51...housing 52a-52d...shaft 53a-53f...gear 54...lubricating oil 55...top surface 56...connection portion 56a...tubular body 56b...female threaded portion 57...air breather 57a...vertical lower end 57b...periphery 58...connection pipe 59...air outlet portion 59a...filter receiver 60...air outlet hole 61...filter 62...cap P...air Q...lubricating oil (oil leakage)

Claims

1. An oil leakage prevention structure for preventing the housing of a reducer from being contaminated by lubricating oil when alleviating a pressure increase in the housing, A pipe body detachably connected to a connection part provided on an outer surface of the housing; an air breather provided at an end of the pipe not on the housing side; a leakage oil receiving portion comprising a container body having an opening at an upper portion, the pipe body being disposed so as to penetrate the bottom surface of the container body, and the container body being fixed integrally to a peripheral surface of the pipe body; The height difference from the lowest position of the top surface of the housing to the vertically lower end of the air breather is 15 cm or more, An oil leakage prevention structure characterized in that the oil leakage receiving portion is provided with an oil leakage absorbing material housed within its hollow portion.

2. The tube body and the container body are made of metal, 2. The oil leakage prevention structure according to claim 1, wherein the container body is welded to the pipe body.

3. When the oil leakage prevention structure is viewed in plan, a gap is provided between a periphery of the air breather and the opening of the oil leakage receiving portion, 3. The oil leakage prevention structure according to claim 1, further comprising an area in which the size of the gap is equal to or larger than the radius of the air breather.

4. The connecting portion is cylindrical and has a female screw portion on its inner surface. The outer surface of the pipe at the end portion connected to the connecting portion is provided with a male thread portion, 4. The oil leakage prevention structure according to claim 1, further comprising a seal material provided between the connecting portion and the pipe body.

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