JPH06337073A - Seal device for rotary shaft - Google Patents

Abstract

PURPOSE:To provide a non-contact type seal device capable of properly sealing the end of a rotary shaft. CONSTITUTION:Regarding a sealed section at the end of a rotary shaft 1, a plurality of rows of annular recess grooves 9, 11, 17 and 18 are engraved on the internal surface of a housing 6, and each one of compressed air supply holes 21 and 25, or air release (or air intake) holes 27 and 30 is communicated alternately with each groove, thereby effectuating an air sealing effect. Also, different types of fluid having different characteristics tending to leak from or enter the housing 6 can be separately collected without being mixed through fluid collection lines 39 and 41, as a result of providing at least two air release (air intake) holes 27 and 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary shaft sealing device for machine tools, general machines, ships, chemical equipment machines and the like.

[0002]

2. Description of the Related Art In a seal device for a shaft end portion of a rotary shaft device, fluids having different characteristics (in the present invention, fluids) inside and outside the housing of the rotary shaft, which are unfavorable or unfavorable to mix with each other, are used. When a fluid other than air is supplied and it is desired to collect them without mixing them, conventionally, a contact type seal member such as an O-ring is mounted between the housing and the peripheral surface of the rotary shaft. The method of isolating the fluids supplied inside and outside is generally used, but in such a sealing method, when the rotation speed of the shaft becomes high and the sliding speed of the sealing surface becomes large, the sealing material becomes Wear is often a problem.

Further, in Japanese Utility Model Laid-Open No. 64-38240, a jet lubrication spindle is referred to as an annular groove is provided between a housing and a rotary shaft, and compressed air is supplied to the central groove to form an air pocket. By using an annular groove adjacent to the groove, through which lubricating oil leaks, as an oil pocket, and connecting suction means for forcibly conveying the lubricating oil in the oil pocket groove to the outside of the device to the oil pocket. , A technique for simultaneously achieving the purpose of sealing the lubricating oil and preventing the intrusion of foreign matter from the outside to prevent atmospheric pollution due to the leakage of the lubricating oil has been proposed. There is no disclosure of the technical idea of separately collecting fluids having different characteristics supplied to each of them without mixing them.

[0004]

SUMMARY OF THE INVENTION In a rotary shaft device, the present invention separately supplies fluids having different characteristics (lubricating oil and cutting oil) supplied to the inside and outside of the device without mixing them. It is an object of the present invention to provide a sealing device that can be collected and recycled and that is extremely durable even when used under the condition of high speed operation.

[0005]

In order to achieve the above-mentioned object, the present invention has the respective constituents described below. (1) A seal device for a shaft end portion of a rotary shaft device, wherein a plurality of circumferential annular recessed grooves are formed at a predetermined interval in an axial direction on an inner cylindrical surface of the housing facing the rotary shaft peripheral surface. The plurality of annular recessed grooves are alternately communicated with one of the compressed air hole or the fluid recovery hole from the end portion, and at least two annular recessed grooves communicated with the fluid recovery hole are provided so as to exist inside and outside the housing. A rotary shaft seal device configured to collect fluids of different properties without mixing them.

[0006]

According to the seal device for the shaft end of the present invention, a circumferential annular groove is provided on the inner cylindrical surface of the housing, which faces the rotary shaft peripheral surface with a minute interval, and the annular groove is formed in the axial direction of the cylindrical surface. A plurality of strips that are independent of each other and are spaced apart from each other, and one of the compressed air holes and the fluid recovery hole are alternately communicated with each one of the concave grooves, and the fluid recovery hole is formed. Since at least two annular grooves that communicate with each other are provided,

(1) High-speed airflows ejected from the annular groove communicating with the compressed air holes into the minute gaps on the peripheral surface of the rotary shaft are directed toward the annular grooves communicating with the fluid recovery holes arranged adjacent to each other. Since it occurs evenly over the entire circumference, the inner cylindrical surface gap of the housing on both sides of the annular concave groove communicating with the compressed air hole is air-sealed. (2) The air flow flowing from the annular groove communicating with the compressed air hole is
At least two annular recessed grooves that communicate with the fluid recovery holes that are adjacent to the recessed grooves are housed, and are collected outside via the communication holes.

(3) Fluids having different characteristics, such as bearing lubricating oil and cutting oil, which intervene or enter the inner cylindrical surface gap of the housing on both sides of the annular groove communicating with the compressed air holes. Are respectively placed on the high-speed air flow, or blocked, blocked in the moving direction and accommodated in the adjacent annular recessed groove together with the air, without mixing with each other,
It is recovered from each fluid recovery hole. (4) Since there is no contact or friction between mechanical members in the above-mentioned air seal portion, it does not wear even when the shaft rotates at high speed, and therefore has a long service life and is easy to maintain.

(5) Fluids supplied to the inside and outside of the housing of the sealing device and having different characteristics from each other can be collected separately without being mixed and can be recycled. (6) With the configuration that guarantees the above-mentioned action, more reliable effects can be obtained by stacking them. (7) The fluid recovery hole may be either atmospheric pressure open or positive suction.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, one embodiment of the present invention will be described with reference to the drawings. The specific construction of each member for assembling the device of the present invention is appropriately designed within the technical level in the field at the time of this application. Considering that changes can be made, the gist of the present invention should not be limitedly interpreted based on only the structure and shape of the present embodiment without showing any special reason.

FIG. 1 shows a cross section of an embodiment of a rotary shaft seal device of the present invention. In the figure, a rotary shaft 1 is supported by a housing 5 by a bearing mechanism 7, and another housing 6 which serves as an outer ring retainer and a cover of the bearing mechanism 7 is provided on the front surface thereof. The inner cylindrical surface of the housing 6 and the outer peripheral surface of the rotating shaft 1 face each other with a minute gap. Four annular recessed grooves 9, 11, 17, 18 are formed on the inner cylindrical surface of the housing 6 at a predetermined interval in the axial direction. The annular grooves 9 and 17 communicate with the compressed air supply holes 21 and 25, respectively,
The annular concave grooves 11 and 18 communicate with the atmosphere opening holes 27 and 30, respectively.

That is, an annular groove for supplying compressed air,
The annular concave grooves open to the atmosphere for fluid recovery are alternately arranged. The compressed air supply holes 21 and 25 are arranged so that compressed air is supplied from a compressed air source 34 provided outside. Further, the atmosphere opening hole 27 is the first fluid recovery line.
39, and the atmosphere opening hole 30 is connected to the second fluid recovery pipe 41.
, Are connected independently of each other. Consider a case where the seal device for a rotating shaft configured as described above is used in an environment in which the first fluid (for example, cutting oil) floats.

The first fluid tries to enter the inside of the rotary shaft device through the gap between the front end of the rotary shaft 1 and the housing 6, but most of it is pushed back by the air flow ejected from the annular groove 9. . The first fluid that has not been pushed back and has entered the inside rides on the air flow from the annular groove 9 to the annular groove 11 that is open to atmospheric pressure, and reliably flows into the atmosphere opening hole 27 together with the air, and the first fluid recovery pipe Recovered via Route 39. Since the air flow from the annular groove 17 to the annular groove 11 is also generated, the first fluid cannot further penetrate into the rotary shaft device.

A second fluid (for example, lubricating oil for the bearing mechanism 7) exists inside the rotary shaft device, and the second fluid tries to flow out from the gap between the rotary shaft 1 and the housing 6 to the outside. . However, the second fluid flows into the atmosphere opening hole 30 from the annular groove 18 which is open to the atmosphere, and is recovered through the second fluid recovery conduit 41. Even if the second fluid gets over the annular groove 18 and tries to go further to the outside, it is pushed back by the air flow from the annular groove 17 toward the annular groove 18 and cannot flow out any more. Thus, the first fluid and the second fluid are collected separately without being mixed, the first fluid does not enter the inside of the rotary shaft device, and the second fluid does not flow out to the outside. It is surely sealed.

FIG. 2 shows a cross section of an embodiment in which the rotary shaft sealing device of the present invention is applied to a tool spindle of a machine tool. In the figure, parts having the same functions as those in FIG. 1 are designated by the same reference numerals. 1 is a rotary shaft, 3 is a taper shank receiving hole of a tool, 5 and 6 are hazing, 7 is a bearing mechanism for supporting the rotary shaft, and 9, 11, 13, 15, 17 and 19 are respectively on the peripheral surface of the rotary shaft. With the annular groove provided independently (in a non-released state) in the circumferential direction of the inner cylindrical surface of the housing facing each other with a minute gap, the annular groove 9 is arranged on the outermost side, and is directed toward the inner side of the rotation axis. Sequentially, multiple lines are provided adjacent to each other.

However, the annular groove 19 located on the innermost side of the housing is open toward the bearing mechanism 7 side. In addition, on the circumferential surface of the rotary shaft facing the annular groove 9, 11, 15 and 17, an annular groove having a sectional shape adapted to the function of the annular groove is formed. Reference numerals 21, 23 and 25 denote compressed air supply holes provided through the housing 6, respectively.
Is in communication with the annular groove 9, the hole 23 is in communication with the annular groove 13, and the hole 25 is in communication with the annular groove 17, and the space between the inner cylindrical surface of the housing and the peripheral surface of the rotary shaft is passed through the annular grooves. A high-speed air flow in the axial direction is generated in the minute gap based on the supply of the compressed air.

Numerals 27 and 29 are air opening holes provided in the housing 5, respectively. The hole 27 communicates with the annular groove 11 and the hole 29 communicates with the annular groove 15, respectively, and the adjacent compressed air. A high-speed air flow flowing out from the communicating annular groove is received, passed through the atmosphere opening hole, and recovered to the outside via the first fluid recovery conduit 39. Reference numeral 31 denotes a suction hole provided in the housing 6, which communicates with the annular recessed groove 19 and stores lubricating oil together with air and collects the lubricating oil to the outside via the second fluid recovery conduit 41. In other words, while the machinery is operating, there are many occasions when the cutting oil splashes outside the housing and enters the inside through the fine gap between the rotating shaft and the housing, and mixes with the bearing lubricating oil. It will not be blocked by the high-speed flow of the pressurized air flowing out from the groove 9 and flow into the inside.

Even if it intrudes, it cannot be penetrated further inward because it is housed in the atmosphere release annular groove 11 and is recovered to the outside through the atmosphere release hole 27. Further, it is blocked by the high-speed air flow from the compressed air communicating annular groove 13 provided inside thereof and flows into the atmosphere releasing annular groove 11 side,
Be recovered. The operation of the atmosphere releasing annular groove 15 is also the same as that described above, but this is mainly because when no tool is attached to the tool receiving hole 3, even if cutting oil enters from the air passage hole 33, the annular groove is formed. 15 and the air release hole 29 can be recovered. Since the cutting oil mist may penetrate into many places, the collecting means is provided in duplicate in this embodiment.

On the other hand, the leakage of the bearing lubricating oil is blocked by the high-speed air flow flowing out from the compressed air communicating annular groove 17 and does not seep out to the outside of the housing. Will be collected. In the case of the present embodiment, the cutting oil and the lubricating oil do not mix with each other with the compressed air communicating annular groove 19 as a boundary. In order to ensure this action, in the drawing, the cross section of the groove on the peripheral surface of the rotary shaft facing the compressed air communicating annular concave groove 19 is an isosceles triangular shape, and air of equal power is provided on both sides of the concave groove 19. The flow is designed to occur.

As described above, the fluid contained in the air collected from the atmosphere release holes 27, 29 is a cutting oil with no mixing, and is filtered through a filter to remove dust, cutting chips, iron dust, etc. If so, it can be reused as it is. Further, the fluid collected from the suction hole 31 is a lubricating oil that is not mixed and can be reused by separating iron powder, dust and the like. In the present embodiment, 27 and 29 are described as atmosphere release holes provided in the housing, but by connecting these to a negative pressure source, they can be made to function as air suction holes or forced exhaust holes. If so, the collection effect will be more reliable.

Even when the annular groove arranged at the outermost end of the housing is used for fluid recovery, the effect can be obtained by communicating the groove with the forced exhaust hole. it can. In the figure, 35 is a flow rate throttle valve provided in series in the air supply pipe line from the compressed air source 34 to the annular groove 13, 37 is an opening / closing valve of the bypass passage, usually through the flow rate throttle valve 35. Compressed air is supplied to the annular groove 13, but when the tool mounted on the rotary shaft 1 is replaced, the bypass valve 37 is opened and a large amount of air is supplied to the annular groove 13, so that the annular groove 13 The compressed air is supplied to the taper shank receiving hole 3 of the rotary shaft 1 through the air passage hole 33 provided in the circumferential surface of the rotary shaft 1 opposite to the inner surface of the rotary shaft 1. It is designed to be able to be cleaned.

In the present embodiment, the cutting fluid and the lubricating oil are exemplified as the fluids having different characteristics, but the device of the present invention is, for example, a cutting agent, a chemical, seawater, a polluted gas or a harmful gas. It can be used for machines and devices in a wide range of fields equipped with a high-speed rotating shaft, such as the case where a lubricating oil can be used.

[0023]

Since the device of the present invention is as described above, (1) the fluids supplied to the inside and outside of the housing of the seal device for the rotating shaft and having different characteristics are collected separately without being mixed. , Each can be recycled. (2) The working environment is well maintained without leaking the fluid supplied into the housing to the outside, and a reliable sealing effect that the outside fluid does not enter the rotary shaft device is obtained.

(3) Since there is no mechanical contact or friction in the air seal part, there are no members that wear even when the shaft rotates at high speed, therefore the seal characteristics are unchanged, the service life is long, and maintenance is not required. Is easy. And so on, it is possible to obtain special actions and effects that cannot be expected from conventional devices.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a rotary shaft seal device of the present invention.

FIG. 2 is a cross-sectional view of another embodiment of the rotary shaft seal device of the present invention.

[Explanation of symbols]

 1 rotary shaft 3 taper shank receiving hole 5, 6 housing 7 bearing 9, 11, 13, 15, 17, 17, 18, 19 annular groove 21, 23, 25 compressed air supply hole 27, 29, 30 atmosphere release hole 31 suction hole 33 Air through hole 34 Compressed air source 35 Flow rate throttle valve 37 Open / close valve 39 First fluid recovery pipeline 41 Second fluid recovery pipeline

Claims (1)

[Claims] 1. A seal device for a shaft end portion of a rotary shaft device, wherein a plurality of circumferential annular recessed grooves are formed at a predetermined interval in an axial direction on an inner cylindrical surface of a housing facing the rotary shaft peripheral surface. , The plurality of annular recessed grooves are alternately communicated from one end to one of the compressed air hole or the fluid recovery hole, and are present inside and outside the housing through at least two annular recessed grooves communicated with the fluid recovery hole. A sealing device for a rotary shaft, characterized in that fluids having different properties are collected separately without being mixed.