JPH0211516Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a mechanical seal as an external seal incorporated in a drilling drill used for underground excavation work such as boring.

[Conventional technology]

2. Description of the Related Art Conventionally, a drill shown in FIG. 4 has been known as a drilling drill used for underground excavation work such as boring. In the figure, 1 is a non-rotating housing, 2 is a fixed shaft fixed to the housing 1, and 3 is an umbrella-shaped shaft having a substantially conical outer shape with a large number of super-hard bits 4, 4, etc. protruding from the outer surface. It is a rotating body. The umbrella-shaped rotating body 3 is rotatably mounted on the fixed shaft 2 through bearings 6 and 7 in a shaft hole 5 bored in its back,
It is rotated by a drive source (not shown).
Furthermore, a gap 8 between the fixed shaft 2 and the shaft hole 5 is filled with lubricating oil for the purpose of preventing the bearings 6 and 7 from seizing. The fixed ring 10 is airtightly fitted and fixed to the umbrella-shaped rotating body 3 via an O-ring 11, and the fixed ring 10 is fixed to the umbrella-shaped rotating body 3 airtightly through an O-ring 11 at a sliding end surface 12' formed on the outer diameter side. It is sealed by a mechanical seal M consisting of a sliding end surface 10' of the rotary ring 12 that closely slides thereon.

[Problem that the invention attempts to solve]

The mechanical seal M not only seals lubricating oil as described above, but also functions to prevent the intrusion of foreign substances such as muddy water from the outside. When used in
There was a problem in that sand and mud entered between 0' and 12', causing surface roughness and deteriorating the sealing performance.

The present invention has been developed in view of the above-mentioned problems, with the purpose of preventing foreign matter such as muddy water from entering the sliding surface of a mechanical seal for an excavation drill, and improving the durability of the seal.

[Means for solving problems]

For the above purpose, the mechanical seal for an excavation drill of the present invention has a fixed shaft that is integrally fixed to a housing, and has a loosely fitted crown on the end protruding from the housing, and has a large number of ultra-hard bits on the outer surface. A protruding umbrella-shaped rotating body is fixed to the umbrella-shaped rotating body side in a mechanical seal interposed between the housing and the umbrella-shaped rotating body of a drilling drill that performs excavation by rotation of the umbrella-shaped rotating body. A required number of blade members are provided protruding from the outer surface of the rotating ring at equal intervals in the circumferential direction. It is configured to be inclined in the direction of discharging to the side.

[Effect]

In the above configuration, when the rotating ring rotates as the umbrella-shaped rotating body is driven, the fluid (muddy water, etc.) on the outside is caused to rotate and flow by each blade member integrally formed with the rotating ring, so that centrifugal force is generated. Since each blade member has an inclined portion that causes a pumping action in the outer diameter direction, in combination with the action of the centrifugal force, the fluid is forcibly discharged in the outer diameter direction. It will be done.

〔Example〕

Next, one embodiment of the present invention will be described in detail based on the drawings.

First of all, FIG. 1 is a front sectional view of the main parts of the drilling drill showing the installed state of this embodiment. In this figure, the same reference numerals as in the conventional example shown in FIG. In other words, 1 is a housing, 2 is a fixed shaft fixed to the housing 1, and 3 is an umbrella-shaped rotating body having a large number of super hard bits 4, 4, etc. protruding from its outer surface, and a shaft bored in the back thereof. It is rotatably fitted to the end of the fixed shaft 2 in the hole 5 via bearings 6 and 7, and is rotationally driven by a drive source (not shown). M' also prevents the lubricating oil filled in the gap 8 between the fixed shaft 2 and the shaft hole 5 to lubricate the bearings 6 and 7 from leaking out of the machine, and prevents muddy water etc. from outside the machine. The mechanical seal of this embodiment is interposed between the housing 1 and the umbrella-shaped rotating body 3 in order to prevent the intrusion of It is airtightly fixed to the umbrella-shaped rotating body 3 through a fixed fixed ring 10 and an O-ring 13 made of a metal material that can withstand high temperature and high pressure conditions. A rotary ring 14 made of durable, hard and dense cast material is constructed so as to slide closely against each other on both sliding surfaces 10' and 14'. As shown separately in FIGS. 2 and 3, the rotating ring 14 has a required number of blade members 15, 15, . In addition, each blade member 15 has an inclined portion 15' on the outer diameter side thereof which curves clockwise with respect to the outer diameter direction in its planar shape. For this reason,
The umbrella-shaped rotating body 3 rotates around the fixed shaft 2 by a drive source (not shown), and the rotating ring 14 rotates along with this.
When the mechanical seal rotates counterclockwise in Fig. 3, that is, in the direction of arrow A, the mechanical seal
The muddy water, etc. on the outside of M' is rotated in the direction of arrow A by the rotation of the blade members 15, 15, and flows in the outer radial direction due to the centrifugal force. Since the inclined portions 15', 15'... of... have a spiral shape, the muddy water, etc. is forcibly discharged in the outer radial direction, thereby preventing mechanical seals.
Muddy water and the like that try to enter between the sliding surfaces 10' and 14' of M' are removed.

[Effect of idea]

As described above, the mechanical seal for an excavation drill of the present invention uses the pumping action of the vane member integrally formed with the rotating ring to remove foreign matter such as muddy water that tries to enter the sliding surface, and prevents abnormalities on the sliding surface. It is possible to prevent wear and damage, eliminate sand clogging, etc., and improve seal durability, and its practical effects are extremely large.

[Brief explanation of the drawing]

Fig. 1 is a front sectional view showing an installed state of an embodiment of a mechanical seal for an excavation drill according to the present invention, Fig. 2 is a front sectional view of a rotary ring constituting the embodiment, and Fig. 3 is a plan view of the same. , FIG. 4 is a front sectional view showing a state in which a conventional mechanical seal for an excavation drill is installed. DESCRIPTION OF SYMBOLS 1...Housing, 2...Fixed shaft, 3...Umbrella-shaped rotating body, 4...Super hard bit, 5...Shaft hole, 6,
7... Bearing, 10... Fixed ring, 10', 1
4'...Sliding surface, 13...O ring, 14...Rotating ring, 15...Blade member, 15'...Slanted part,
M′...Mechanical seal.

Claims (1)

[Scope of utility model registration request] An umbrella-shaped rotating body, which is loosely fitted onto the end of a fixed shaft that is integrally fixed to the housing and protrudes from the housing, and has a large number of ultra-hard bits protruding from its outer surface, excavates by rotation. In a mechanical seal interposed between the housing and the umbrella-shaped rotating body of a drilling drill that performs The blade member is characterized in that it protrudes in a direction equidistant manner, and at least a part of the blade member is inclined with respect to the radial direction in a direction that discharges surrounding fluid, etc. to the outer diameter side by rotation thereof. Mechanical seal for drilling drills.