JP7481599B1 - Covers, seal structures and industrial machinery - Google Patents

Abstract

This cover releasably closes the space around a grease drain port for discharging lubricant from a sealed lubricated part of the main body of an industrial machine, and when attached to the main body of the industrial machine, the cover comprises: a through hole exposing the grease drain port; a first mating surface provided around the entire circumference of the through hole and facing a first seating surface provided around the entire circumference of the grease drain port; and a second mating surface disposed facing a second seating surface provided at a position surrounding the outside of the first seating surface all around, and the first mating surface is capable of sealing the entire circumference of the through hole by a first seal member compressed between the first seating surface and the first mating surface.

Description

The present disclosure relates to covers, sealing structures and industrial machinery.

Conventionally, a lubricant discharge structure has been known in which a lubricant such as grease is injected into a sealed lubricated part such as a reducer, and the used lubricant is discharged from a grease drain port (see, for example, Patent Document 1).
This lubricant discharge structure includes a tube connected to a grease drain port, a plug that releasably closes the end of the tube, and a cover that houses the tube while it is connected to the grease drain port when the lubricant is not being replaced. By providing a hole in the cover and leaving the plug at the end of the tube exposed from the cover, the plug can be removed to discharge the lubricant from the open end of the tube without removing the cover.

JP 2005-177914 A

However, this structure requires the work of attaching a tube, a connecting part for connecting the tube to the grease drain port, a fitting for removably attaching the plug to the end of the tube, and the tube. Therefore, it is desirable to keep the number of parts, processing labor, and assembly labor low, and to perform the replacement work easily at low cost and without contaminating the inside with lubricant discharged during replacement.

One aspect of the present disclosure is a cover that releasably closes a space around a grease drain port for discharging lubricant from a sealed lubricated part of an industrial machine body, and when attached to the industrial machine body, the cover includes a through hole that exposes the grease drain port, a first mating surface that is provided around the entire circumference of the through hole and faces a first seating surface that is provided around the entire circumference of the grease drain port, and a second mating surface that is disposed around the entire circumference facing a second seating surface that is provided in a position that completely surrounds the outside of the first seating surface, and the first mating surface is capable of sealing the entire circumference of the through hole with a first seal member that is compressed between the first seating surface.

Another aspect of the present disclosure is a seal structure that uses a cover to releasably close the space around a grease drain port for discharging lubricant from a sealed lubricated part of an industrial machine body, the seal structure comprising: a first seating surface that is provided on the industrial machine body and is provided around the entire periphery of the grease drain port, and a second seating surface that is provided in a position that completely surrounds the outside of the first seating surface; a through hole that is provided on the cover and exposes the grease drain port when the cover is attached to the industrial machine body; a first mating surface that is arranged opposite the first seating surface around the entire periphery and a second mating surface that is arranged opposite the second seating surface around the entire periphery; and a first seal member that is compressed between the first mating surface and the first seating surface to completely seal the periphery of the through hole.

Another aspect of the present disclosure is an industrial machine comprising an industrial machine body, a cover attached to the industrial machine body, and a first seal member sandwiched between the cover and the industrial machine body, the industrial machine body comprising a first seating surface provided around a grease drain port for discharging lubricant from a sealed lubricated part, and a second seating surface provided in a position surrounding the outside of the first seating surface around the entire circumference, the cover, when attached to the industrial machine body, comprising a through hole exposing the grease drain port, a first mating surface arranged opposite the first seating surface around the entire circumference, and a second mating surface arranged opposite the second seating surface around the entire circumference, and the first seal member is compressed between the first mating surface and the first seating surface to seal the periphery of the through hole around the entire circumference.

1 is a partial vertical cross-sectional view illustrating a cover, a seal structure, and an industrial machine according to an embodiment of the present disclosure. FIG. 2 is a partial side view of the cover and industrial machine of FIG. 1 . FIG. 2 is a partial side view of the industrial machine body with the cover of FIG. 1 attached. FIG. 3 is a rear view of the cover of FIG. 2 . FIG. 2 is a partial exploded vertical cross-sectional view illustrating the cover, the seal structure, and the industrial machine of FIG. 1. FIG. 2 is a partial vertical cross-sectional view illustrating a grease draining operation in the industrial machine of FIG. 1 .

A cover 12, a seal structure 30, and an industrial machine according to one embodiment of the present disclosure will be described below with reference to the drawings.
In this embodiment, a robot 1 will be described as an example of industrial machinery.

Any type of robot can be used as the robot 1, but here, the description will be given using a robot that has at least one rotary joint that is driven to rotate around a horizontal axis, such as a vertical six-axis articulated robot.
The industrial machinery may be any industrial machinery such as a robot 1, a machine tool, or an injection molding machine that has a sealed lubricated part 4 such as a reducer 3 and a grease drain port 5a for discharging used lubricant from the lubricated part 4.

1, the robot 1 includes a rotating body (industrial machine body) 2 supported rotatably about a vertical axis with respect to a base (not shown) fixed to an installation surface such as a floor. The robot 1 also includes a first arm (not shown) supported rotatably about a horizontal axis A with respect to the rotating body 2.

Between the rotating body 2 and the first arm, there is provided a reduction gear 3 that reduces the rotation of a motor (not shown) and rotates the first arm about the horizontal axis A relative to the rotating body 2. The reduction gear 3 has an internal reduction mechanism (not shown) and is filled with a lubricant such as grease to lubricate the reduction mechanism. As a result, the reduction gear 3 constitutes a lubricated part 4 that is sealed by its case, the rotating body 2, and the first arm.

The rotating body 2 is provided with a grease drain hole 5 that connects the inside of the reduction gear 3 with the outside of the robot 1. The grease drain port 5a at the tip of the grease drain hole 5 opens to the vertical side of the rotating body 2 and is normally blocked by a removable plug 6. The grease drain hole 5 is provided inside the radial outer shape of the reduction gear 3 and at a position higher than the horizontal axis A, for example as shown in Figures 1 and 2. This position corresponds to the recommended lubricant filling level in the reduction gear 3.

In this embodiment, the rotating body 2 and the reduction gear 3 are provided with central openings 2a, 3a that penetrate along the horizontal axis A in a region including the horizontal axis A. As shown in FIG. 1, the central openings 2a, 3a allow, for example, a filament 7 rising from the base side to pass through.

1 shows only one wire 7, but multiple wires may be provided, such as a cable for driving a motor disposed at the tip of the first arm, or a tube for supplying water or air. The wire 7 is fixed to the rotating body 2 at a midpoint in the longitudinal direction by a fastener such as a nylon band (not shown) and then wired to pass through the central openings 2a and 3a.

The rotating body 2 has seats (first and second seats) 8, 9 for mounting a cover 12 described later. As shown in Fig. 3, the first seat 8 is a machined flat surface that is provided in a position that completely surrounds the grease drain port 5a and extends in the vertical direction. The second seat 9 is also a machined flat surface that extends in the vertical direction and is formed in an annular shape, with its inner edge forming an opening 10 that opens the internal space M of the rotating body 2 to the outside.

When the cover 12 is removed, the opening 10 contains a space leading to the base, mounting bolts 11 for mounting the reducer 3 to the rotating body 2, and a central opening 2a. In other words, when the cover 12 is removed from the rotating body 2, the installation of the reducer 3 to the rotating body 2 and wiring of the wire body 7 can be performed through the opening 10 that opens to the inside of the second seat surface 9.

In this embodiment, the first seating surface 8 and the second seating surface 9 are provided on the same plane and are continuous with each other as shown in Figure 3. The second seating surface 9 has a plurality of screw holes 13 for attaching the cover 12, spaced apart in the circumferential direction.

The robot 1 further includes a cover 12 according to this embodiment that is attached to the rotating body 2 , and a first seal member 14 and a second seal member 15 that seal between the cover 12 and the rotating body 2 .
4, when the cover 12 is attached to the rotating body 2, the cover 12 includes a through hole 16 that exposes the grease drain port 5a, a first mating surface 17 that is disposed opposite the first seating surface 8 over the entire circumference, and a second mating surface 18 that is disposed opposite the second seating surface 9 over the entire circumference. Specifically, the first mating surface 17 and the second mating surface 18 may be unmachined surfaces obtained by manufacturing the cover 12 by die casting, or machined surfaces formed by machining the cover 12 may be used.

As shown in Figure 1, the through hole 16 has a shape that gradually widens from the first mating surface 17 side toward the outer surface side of the cover 12. In this embodiment, the first mating surface 17 and the second mating surface 18 are separate but provided on the same plane.

The first mating surface 17 is provided with a first annular seal groove 19 that completely surrounds the periphery of the through hole 16. The second mating surface 18 is provided with a plurality of bolt holes 21 that are provided at positions corresponding to the screw holes 13 of the second mating surface 9 when the second mating surface 18 is disposed opposite the second mating surface 9. The second mating surface 18 is also provided with a second annular seal groove 20 that is formed along the inner edge of the second mating surface 18 closer to the inner edge of the second mating surface 18 than all of the bolt holes 21.

The first seal member 14 is a rubber O-ring housed in the first seal groove 19 .
The second seal member 15 is an annular seal member that has the same cross section and is made of the same material as the O-ring received in the second seal groove 20 and is pre-formed to fit the shape of the second seal groove 20 .

As described above, the sealing structure 30 of this embodiment comprises a first seating surface 8 and a second seating surface 9 provided on the rotating body 2, a through hole 16, a first mating surface 17 and a second mating surface 18 provided in the cover 12, and a first seal member 14 and a second seal member 15.

The operation of the cover 12, the seal structure 30, and the industrial machine according to this embodiment will be described below.
According to this embodiment, by removing the cover 12 from the rotating body 2, the internal space M of the rotating body 2 is opened by the opening 10, so that installation and removal of the reducer 3, wiring work of the wire body 7, etc. can be performed through the opening 10.
Furthermore, by attaching the cover 12 of this embodiment to the rotating body 2, the opening 10 can be blocked to define the internal space M in an airtight state, and the space continuing to the base placed within the opening 10 and the internal structure such as the filament 7 can be hidden.

To attach the cover 12 to the rotating body 2, as shown in FIG. 5, the first seal member 14 is accommodated in the first seal groove 19 provided in the cover 12, and the second seal member 15 is accommodated in the second seal groove 20. The first seal member 14 and the second seal member 15 are held in the first seal groove 19 and the second seal groove 20, respectively, by their elasticity or by the adhesiveness of grease or the like that is additionally used.

In this state, the first mating surface 17 and the second mating surface 18 of the cover 12 are placed opposite the first seating surface 8 and the second seating surface 9 of the rotating body 2, respectively, and the bolts 22 that pass through the bolt holes 21 of the cover 12 are fastened to the corresponding screw holes 13. This brings the first mating surface 17 closer to the first seating surface 8, and the second mating surface 18 closer to the second seating surface 9. As a result, the first seal member 14 is compressed between the first seal groove 19 and the first seating surface 8, and the second seal member 15 is compressed between the second seal groove 20 and the second seating surface 9.

That is, according to this embodiment, as shown in Figures 1 and 2, when the cover 12 is attached to the rotating body 2, the grease drain port 5a provided on the rotating body 2 is disposed inside the through hole 16 of the cover 12 and is exposed to the outside. In addition, the gap between the rotating body 2 and the cover 12 is sealed around the entire circumference by the first seal member 14 and the second seal member 15.

To drain grease from the lubricated parts 4 such as the reduction gear 3, as shown in Figure 6, with the cover 12 still attached to the rotating body 2, the plug 6 is removed from the grease drain port 5a via the through hole 16, and new lubricant is filled through the grease supply port (not shown). As a result, the used old lubricant filled in the lubricated parts 4 is pushed out from the grease drain port 5a and discharged outside the robot 1 via the through hole 16 of the cover 12. In other words, the lubricant in the lubricated parts 4 is replaced with new lubricant, and the lubricant is filled up to the specified filling level.

In this case, according to this embodiment, the gap between the rotating body 2 and the cover 12 around the grease drain port 5a is sealed all around by the first seal member 14. Therefore, the lubricant pushed out from the grease drain port 5a does not enter the internal space M of the rotating body 2 through the gap between the rotating body 2 and the cover 12, but is all discharged to the outside through the through hole 16, as shown by the arrow.

That is, according to the cover 12, seal structure, and industrial machine of this embodiment, the periphery of the grease drain port 5a is directly sealed by the first seal member 14 disposed between the first seat surface 8 of the rotating body 2 and the first mating surface 17 of the cover 12. This eliminates the need for the tube, the connection parts for connecting the tube to the grease drain port 5a, and the fittings for removably attaching the plug 6 to the tip of the tube, as was previously required, and the installation work for the tube, etc.

This has the advantage of reducing the number of parts, processing steps, and assembly steps, thereby reducing costs. Furthermore, even without using tubes or the like, the lubricant can be easily replaced without contaminating the inside of the rotating body 2, such as the wire body 7, with the lubricant discharged during replacement.

Because the first seal member 14 that seals the grease drain port 5a and the second seal member 15 that seals the entire opening 10 are provided separately, the second seal member 15 can be omitted in applications that do not require high sealing of the internal space M of the rotating body 2. For example, in a robot used in an environment with little mist or dust, the second seal member 15 is unnecessary, and costs due to excessive protection can be suppressed.

According to this embodiment, the first and second bearing surfaces 8 and 9 of the rotating body 2 are disposed in the same plane, which facilitates machining. The first and second mating surfaces 17 and 18 of the cover 12 are also disposed in the same plane, which facilitates machining.
In addition, since the through hole 16 of the cover 12 has a shape that widens outward, the plug 6 can be easily removed from the outside, and the lubricant discharged from the grease drain port 5a can be easily discharged and wiped off.

The first and second seating surfaces 8 and 9 of the rotating body 2 and the first and second mating surfaces 17 and 18 of the cover 12 do not have to be arranged in the same plane. As long as the cover 12 is arranged in a position where the first mating surface 17 is in close contact with the first seating surface 8 and the second mating surface 18 is in close contact with the second seating surface 9 when the cover 12 is attached to the rotating body 2, they do not have to be arranged in the same plane.

In addition, in this embodiment, a cover 12 having both the first seal groove 19 and the second seal groove 20 is used, but instead, only the first seal groove 19 may be provided. As described above, in applications where it is not required to seal the internal space M of the rotating body 2, the second seal groove 20 for mounting the second seal member 15 may not be provided at all.

In addition, in this embodiment, an O-ring or an equivalent sealing member is used as the first sealing member 14 and the second sealing member 15, but a flat gasket may be used instead. When an O-ring is used as the first sealing member 14 and a gasket is used as the second sealing member 15, as described above, the second sealing groove 20 of the cover 12 may be omitted. Furthermore, when gaskets are used as both the first sealing member 14 and the second sealing member 15, both the first sealing groove 19 and the second sealing groove 20 may be omitted.

In addition, an example has been given of providing a first seal groove 19 on the first mating surface 17 of the cover 12 and a second seal groove 20 on the second mating surface 18, but instead, the first seal groove 19 may be provided on the first seating surface 8 of the rotating body 2 and the second seal groove 20 on the second seating surface 9.

Although the grease drain port 5a in the reduction gear 3 between the rotating body 2 and the first arm has been given as an example, it may be applied to the reduction gear in other joints, the gear box, and other lubricated parts. Also, although a vertical six-axis articulated robot has been given as an example of industrial machinery, it may be applied to other types of robots, machine tools, injection molding machines, and other industrial machinery.

Although each embodiment of the present disclosure has been described above in detail, the present disclosure is not limited to the above-mentioned individual embodiments. Various additions, substitutions, modifications, partial deletions, etc. are possible to these embodiments without departing from the gist of the invention, or without departing from the idea and intent of the present invention derived from the contents described in the claims and their equivalents. For example, in the above-mentioned embodiments, the order of each operation and the order of each process are shown as examples, and are not limited to these.

The following supplementary notes are further disclosed regarding the above-described embodiment and modified examples.
(Appendix 1)
A cover that releasably closes a space around a grease drain port for discharging a lubricant from a sealed lubricated part of an industrial machine body,
a through hole for exposing the grease drain port when the bearing is attached to the industrial machine body, a first mating surface provided around the entire circumference of the through hole and opposed to a first seating surface provided around the entire circumference of the grease drain port, and a second mating surface disposed opposite to a second seating surface provided at a position surrounding the outer side of the first seating surface over the entire circumference,
The cover is capable of sealing the entire periphery of the through hole by a first seal member compressed between the first mating surface and the first seating surface.

(Appendix 2)
The cover according to claim 1, wherein the first mating surface is provided with a first seal groove that completely surrounds the through hole and is capable of accommodating the first seal member.

(Appendix 3)
The cover of claim 2, wherein the second mating surface is provided with a second seal groove that extends around the entire circumference and accommodates a second seal member that is compressed between the second seat surface.

(Appendix 4)
The second seating surface is provided with a plurality of screw holes spaced apart in a circumferential direction,
The cover according to any one of claims 1 to 3, wherein the second mating surface is provided with a plurality of bolt holes that are provided at positions corresponding to the screw holes and through which bolts are passed.

(Appendix 5)
5. The cover according to claim 1, wherein the first sealing member is an O-ring.

(Appendix 6)
6. The cover of claim 1, wherein the first mating surface and the second mating surface are arranged on the same plane.

(Appendix 7)
A seal structure in which a space around a grease drain port for discharging a lubricant from a sealed lubricated part of an industrial machine body is releasably closed by a cover,
a first seating surface provided on the industrial machine body and entirely around the grease drain port, and a second seating surface provided at a position surrounding the outside of the first seating surface entirely;
a through hole that is provided in the cover and exposes the grease drain port in a state where the cover is attached to the industrial machine body, a first mating surface that is arranged to face the first seating surface over an entire circumference, and a second mating surface that is arranged to face the second seating surface over an entire circumference;
a first seal member that is compressed between the first mating surface and the first seating surface to seal the entire periphery of the through hole.

(Appendix 8)
The seal structure according to claim 7, wherein a first seal groove is provided on the first mating surface or the first seating surface, the first seal groove surrounding the entire periphery of the grease drain port and capable of accommodating the first seal member.

(Appendix 9)
9. The seal structure of claim 8, wherein the second mating surface or the second seating surface is provided with a second seal groove that extends around the entire circumference and accommodates a second seal member that is compressed between the second seating surface.

(Appendix 10)
The second seating surface is provided with a plurality of screw holes spaced apart in a circumferential direction,
10. The seal structure according to claim 7, wherein the second mating surface is provided with a plurality of bolt holes at positions corresponding to the screw holes through which bolts are passed.

(Appendix 11)
11. The seal structure according to claim 7, wherein the first seal member is an O-ring.

(Appendix 12)
12. The seal structure according to claim 7, wherein the first seating surface and the second seating surface are arranged on the same plane.

(Appendix 13)
The industrial machine includes an industrial machine body, a cover attached to the industrial machine body, and a first seal member sandwiched between the cover and the industrial machine body,
the industrial machine body comprises a first seating surface provided around an entire periphery of a grease drain port for discharging a lubricant from a sealed lubricated part, and a second seating surface provided at a position surrounding an outer side of the first seating surface over the entire periphery,
the cover includes, when attached to the industrial machine body, a through hole for exposing the grease drain port, a first mating surface disposed opposite the first seating surface over an entire periphery, and a second mating surface disposed opposite the second seating surface over an entire periphery,
The first seal member is compressed between the first mating surface and the first seating surface, thereby sealing the entire periphery of the through hole.

1. Robot (industrial machinery)
2. Swivel body (industrial machine body)
4: Lubricated part 5a: Grease drain port 8: Seat surface (first seat surface)
9 Seat (second seat)
REFERENCE SIGNS LIST 12 cover 13 screw hole 14 first seal member 15 second seal member 16 through hole 17 first mating surface 18 second mating surface 19 first seal groove 20 second seal groove 21 bolt hole 22 bolt

Claims (13)

A cover that releasably closes a space around a grease drain port for discharging a lubricant from a sealed lubricated part of an industrial machine body,
a through hole for exposing the grease drain port when the bearing is attached to the industrial machine body, a first mating surface provided around the entire circumference of the through hole and opposed to a first seating surface provided around the entire circumference of the grease drain port, and a second mating surface disposed opposite to a second seating surface provided at a position surrounding the outer side of the first seating surface over the entire circumference,
The cover is capable of sealing the entire periphery of the through hole by a first seal member compressed between the first mating surface and the first seating surface. The cover according to claim 1, wherein the first mating surface is provided with a first seal groove that completely surrounds the through hole and is capable of accommodating the first seal member. The cover according to claim 2, wherein the second mating surface is provided with a second seal groove that extends around the entire circumference and accommodates a second seal member that is compressed between the second seat surface. The second seating surface is provided with a plurality of screw holes spaced apart in a circumferential direction,
The cover according to claim 1 , wherein the second mating surface is provided with a plurality of bolt holes that are provided at positions corresponding to the screw holes and through which bolts are passed. The cover according to claim 1 , wherein the first seal member is an O-ring. The cover according to claim 1 , wherein the first mating surface and the second mating surface are disposed on the same plane. A seal structure in which a space around a grease drain port for discharging a lubricant from a sealed lubricated part of an industrial machine body is releasably closed by a cover,
a first seating surface provided on the industrial machine body and entirely around the grease drain port, and a second seating surface provided at a position surrounding the outside of the first seating surface entirely;
a through hole that is provided in the cover and exposes the grease drain port in a state where the cover is attached to the industrial machine body, a first mating surface that is arranged to face the first seating surface over an entire circumference, and a second mating surface that is arranged to face the second seating surface over an entire circumference;
a first seal member that is compressed between the first mating surface and the first seating surface to seal the entire periphery of the through hole. The seal structure according to claim 7, wherein the first mating surface or the first seating surface is provided with a first seal groove that completely surrounds the grease drain port and is capable of accommodating the first seal member. The seal structure according to claim 8, wherein the second mating surface or the second seating surface is provided with a second seal groove that extends around the entire circumference and accommodates a second seal member that is compressed between the second seating surface. The second seating surface is provided with a plurality of screw holes spaced apart in a circumferential direction,
The seal structure according to claim 7 , wherein the second mating surface is provided with a plurality of bolt holes that are provided at positions corresponding to the screw holes and through which bolts are passed. The seal structure according to any one of claims 7 to 9 , wherein the first seal member is an O-ring. The seal structure according to any one of claims 7 to 9 , wherein the first seating surface and the second seating surface are disposed on the same plane. The industrial machine includes an industrial machine body, a cover attached to the industrial machine body, and a first seal member sandwiched between the cover and the industrial machine body,
the industrial machine body includes a first seating surface provided around a grease drain port for discharging lubricant from a sealed lubricated part, and a second seating surface provided at a position surrounding the outside of the first seating surface over the entire circumference,
the cover includes, when attached to the industrial machine body, a through hole for exposing the grease drain port, a first mating surface disposed opposite the first seating surface over an entire periphery, and a second mating surface disposed opposite the second seating surface over an entire periphery,
The first seal member is compressed between the first mating surface and the first seating surface, thereby sealing the entire periphery of the through hole.

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