JP2001021022A - Oil filter plug for gear casing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil filler plug for gear casings, capable of effectively preventing a lubricating oil from spouting out from an air vent while the original function of the air vent is maintained. SOLUTION: With this oil filler plug 10, in a gear casing 1 where the oil filler plug 10 provided with an air vent 15 is removably installed to an oil filler port 9 provided at the upper part of the gear casing 1 in which transmission gears 2, 3 are arranged-installed, a space part connected to the air vent 15 is provided inside the oil filler plug 10, and a spouting-out preventing body 16 consisting of a cylindrical body 17 having air-gap connected to the space part in the outer periphery is fitted into the space part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubrication plug for a gear casing in which a transmission gear is disposed, such as a worm speed reducer.

[0002]

2. Description of the Related Art In a gear casing of this type, an oil tap provided with an air vent hole is detachably attached to an oil inlet provided in an upper portion thereof, and lubricating oil injected into the gear casing from the oil inlet is transmitted. It is scraped up by the rotation of the gear,
The lubrication is performed by flowing into the rotation mechanism portion in the gear casing, and at the same time, the air in the gear casing expanded due to the temperature rise is discharged to the outside through the air vent hole of the lubrication plug. However, there has been a problem of oil leakage that a part of the lubricating oil which has been scraped up and scattered in the gear casing blows out from the air vent hole of the lubrication plug. on the other hand,
Various proposals have been made for lubrication stoppers for the purpose of preventing such lubricating oil from blowing out (for example,
See JP-A-4-71853 and JP-A-7-16056. However, there are few lubricating plugs that can obtain a sufficient blowing prevention effect.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to effectively prevent the lubricating oil from blowing out from an air vent hole while maintaining the original air vent function. An object of the present invention is to provide a lubrication plug for a gear casing.

[0004]

In order to achieve the above object, the present invention provides a lubrication plug provided with an air vent hole at a lubrication port provided at an upper portion of a gear casing in which a transmission gear is provided. In the gear casing which is detachably attached, a space portion communicating with the air vent hole is provided inside the lubrication plug, and the space portion has a void portion communicating with the space portion on an outer periphery. A lubrication plug for a gear casing, wherein a blowing prevention body of a cylindrical body is fitted and inserted.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment in which a lubrication plug according to the present invention is provided on a gear casing 1 of a worm reduction gear.
A worm 2 and the worm 2 are provided inside the gear casing 1.
The worm wheel 3 meshing with the worm wheel 3 is provided. The worm 2 is disposed at an upper portion inside the gear casing 1, and support shafts 2 a, 2 a projecting from both ends are provided on opposite side walls 1 a, 1 a of the gear casing 1 by tapered roller bearings 4.
4, an input shaft 5 connected to one of the support shafts 2 a protrudes from the gear casing 1. The support shaft 6 of the worm wheel 3 is mounted on the gear casing 1.
Are supported by bearings (not shown) on the front wall 1b and the rear wall 1c, and one end of the support shaft 6 projects from the gear casing 1 to form an output shaft. A storage chamber 7 for lubricating oil 8 is provided below the worm wheel 3 in the gear casing 1. On the other hand, a lubrication port 9 is provided on the upper wall 1d of the gear casing 1, and a lubrication plug 10 is removably attached to the lubrication port 9 by screw fitting with an O-ring 11 interposed therebetween.

As shown in FIG. 2, the lubrication plug 10 has a cylindrical body 12 screwed into the lubrication port 9 and a head 13 connected to the upper end of the body 12. An O-ring 11 is interposed below the neck of the head 13. The head 13 is provided with an air vent hole 15 which communicates with the cavity 14 of the body 12 and opens to the side of the head 13.
The lubricating oil blow-out preventing body 16 is fitted and fixed to the lubricating oil.

The blow-out preventing body 16 is a cylindrical body 17 which is inserted into the cavity 14 with nylon or other plastic material.
In the outer peripheral surface of the cylindrical body 17, a plurality of gap grooves 18 extending in the longitudinal direction and communicating with the cavity portion 14 are provided radially (see FIG. 3). Each gap groove 18 is deepest at the upper end, and the lower end is converged on the outer peripheral surface of the cylindrical body 17. A tapered surface 19 extending downward is formed on the inner peripheral surface of the cylindrical hole of the cylindrical body 17.

In the above-described configuration, the rotation of the worm 2 and the worm wheel 3 causes the lubricating oil 8 in the storage chamber 7 to be lifted up, thereby lubricating the rotating mechanism in the gear casing 1 and, in particular, vigorously splashing toward the worm 2. At the same time, part of the lubricating oil is scattered and atomized. On the other hand, the air in the gear casing 1 which has expanded due to the temperature rise is blown out by the blow-out preventing body 16.
Through the cylindrical hole of the cylindrical body 17 and the void groove 18 on the outer peripheral surface,
It is discharged to the outside through the air vent hole 15. At this time,
The lubricating oil scattered to the upper part in the gear casing 1 comes into contact with the side surface of the cylindrical body 17, rises through the gap groove 18, flows into the cavity 14 of the lubrication plug 10, but descends through the cylindrical hole of the cylindrical body 17. Since it is returned into the gear casing 1, it does not blow out from the air vent hole 15 to the outside. In particular, since the inner peripheral surface of the cylindrical hole of the cylindrical body 17 is formed on the tapered surface 19 that expands downward, the lubricating oil that has flowed into the cavity 14 of the lubrication plug 10 reliably descends through the cylindrical hole of the cylindrical body 17. Then, it is returned into the gear casing 1.

FIG. 4 shows another embodiment of the present invention, in which the blow-out preventing body 16 is formed by a coil spring 20 having a lower constriction inserted into the cavity 14. The air in the gear casing 1 flows into the cavity 14 through the gap between the coils of the coil spring 20, and the air vent hole 15
Is discharged to the outside. On the other hand, when the lubricating oil scattered in the gear casing 1 flows into the cavity 14 through the gap between the coils of the coil spring 20, the lubricating oil contacts the coil and is attenuated. 20
Or descends through the central hole thereof and is returned into the gear casing 1. Therefore, it does not blow out from the air vent hole 15.

[0011]

As described above, according to the lubrication plug of the present invention, it is possible to effectively prevent the lubricating oil from being blown out from the air vent hole while maintaining the original air vent function. In addition, since the blow-out preventing member formed of a cylindrical body having a void groove on the outer periphery is simply inserted into the space provided inside the lubrication plug, the structure is simple and the manufacturing cost is low.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view of a main part showing a worm speed reducer provided with an oil tap according to the present invention.

FIG. 2 is an enlarged cross-sectional view of the oil plug mounting portion.

FIG. 3 is a plan view of the blowout prevention body.

FIG. 4 is an enlarged sectional view showing another embodiment of the lubrication tap according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 gear casing 2 worm 3 worm wheel 9 lubrication port 10 lubrication plug 11 O-ring 12 body 13 head 14 vacant space 15 air vent hole 16 blow-out prevention body 17 cylindrical body 18 void groove 19 tapered surface 20 coil spring

Claims (5)

[Claims] 1. A gear casing provided on an upper portion of a gear casing in which a transmission gear is disposed, wherein an oil filler plug penetrating an air vent hole is detachably attached to the oil filler port. A hollow portion communicating with the air vent hole is provided inside the inside, and a blow-out preventing member of a cylindrical body having a void portion communicating with the void portion on the outer periphery is fitted into the hollow portion. A lubrication plug for a gear casing, characterized in that: 2. The lubrication plug of a gear casing according to claim 1, wherein the blow-out preventing body is a cylindrical body provided with a plurality of gap grooves extending in a longitudinal direction on an outer peripheral surface. 3. The lubrication plug according to claim 2, wherein the gap groove is deepest at an upper end of the cylindrical body, and a lower end thereof converges on an outer peripheral surface of the cylindrical body. 4. The lubrication plug according to claim 2, wherein the inner peripheral surface of the cylindrical body is formed as a tapered surface that extends downward. 5. The lubrication plug according to claim 1, wherein the blow-out preventing member is a coil spring having a narrowed bottom.