JPH0679789U - Sealing device for vertical shaft that reciprocates in the axial direction - Google Patents

Abstract

(57) [Abstract] [Purpose] To extend the oil seal life of the needle beam guide shaft that reciprocates in the vertical direction of the non-woven fabric manufacturing machine and enable it to support higher speeds. [Structure] An upper oil seal 5 and a lower oil seal 8 are provided below a cylindrical bearing 2 of a guide cylinder 1 which projects vertically from the lower surface of a crank box, and compressed air is supplied to an air chamber 4a between the two oil seals. Then, the sealing effect of the lip portion 8a of the lower oil seal is enhanced, air is jetted from the nozzle 17 to the upper oil seal to open the lip 5a to make a minute gap, and an air seal is constituted by the air flowing out above this gap. The exhaust oil that drops through the oil discharge space 13 is discharged to the outside of the machine by the air flow flowing out of the main oil discharge port 14. The felt ring 9 supplies a minimum amount of lubricating oil to the lower oil seal to prevent dust from entering.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention prevents leakage of lubricating oil from a vertical shaft that is supported by a guide tube that projects downward in the lower portion of a box body such as a gear box in which lubricating oil stays in the lower portion so that it can reciprocate in the axial direction. Sealing device.

[0002]

[Prior art]

 Conventionally, for example, as a seal structure of a vertical shaft for vertically moving a needle plate of a non-woven fabric manufacturing machine, there is a technique known in Japanese Utility Model Publication No. 4-5808. As shown in FIG. 2, one of the oil seals 103 prevents the lubricating oil accumulated in the oil sump 101a of the crank box 101 from lubricating the bearings and descending along the vertical shaft 102. The material is discharged from the discharge port 104. Reference numeral 105 is an air inlet for increasing the internal pressure of the cloth cover 106 to prevent invasion of cotton dust or the like.

[0003]

[Problems to be solved by the device]

 The method of preventing the falling lubricating oil of JP-B-4-5808 with a single oil seal as described in the prior art is difficult to predict the service life, and if oil leakage occurs, the product becomes dirty and loses its commercial value. However, there is a problem that this is a factor that prevents the speeding up of machines. The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a vertical shaft seal device which can improve the main seal life and can easily predict the seal replacement time. Is what you are trying to do.

[0004]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, in the axial shaft reciprocating vertical shaft seal device according to the present invention, a guide tube protruding downward to the lower surface of the box body such as a gear box in which lubricating oil is retained in the lower portion. A vertical shaft seal device that is axially reciprocally supported by an upper oil seal and a lower oil seal provided below the cylindrical bearing of the guide cylinder; A means for opening a lip portion of the upper oil seal by compressed air supplied between the upper oil seal and the lower oil seal to form an air seal in a minute gap with the outer circumference of the vertical shaft, and air discharged from the air seal. Further, it comprises means for discharging the oil drained from the cylindrical bearing to the outside, and the upper oil seal functions as a contact type seal only when stopped.

Further, it is possible to provide means for closing the lip portion of the lower oil seal by the compressed air supplied between the upper oil seal and the lower oil seal. Further, a felt ring may be provided at the lower end of the guide cylinder to prevent oil from entering the sealing surface of the lower oil seal and intrusion of dust.

[0006]

[Action]

 During operation, compressed air is sent between the upper and lower oil seals, and the lip of the lower oil seal is closed by compressed air to enhance the sealing effect and prevent the air from flowing out to the lower side. Blows out the air toward the upper oil seal. This jet of air opens the lip portion of the upper oil seal to create a minute gap, and the air that flows upward forms an air seal, and opens in the middle of the flow path that discharges the air that has flowed out of the lip portion to the outside. The waste oil that drops from the waste oil space is placed on the air flow and discharged to the outside.

[0007]

【Example】

 An example will be described based on FIG. A hollow needle beam guide shaft 3 is supported by a guide cylinder 1 vertically provided integrally with the lower surface of the crank box of the non-woven fabric manufacturing machine via a cylindrical bearing 2 so as to be vertically reciprocable by rotation of a crank shaft (not shown). The sealing device of the present invention is incorporated under the cylindrical bearing 2 of the guide cylinder 1. An upper oil seal 5 is incorporated on the upper side of an upper seal holder 4 which is inserted and fitted from below into a hole 1a at the lower end of the guide cylinder 1. The upper oil seal 5 is fixed to the upper end of the upper seal holder 4 and is an oil draining guide. The vertical position is regulated by 6, and the oil cutting guide 6 has a slight gap a between the outer periphery of the guide shaft 3 and the outer circumference.

Further, an outer peripheral groove serving as an air chamber 4a is formed in the upper seal holder 4, and a lower seal holder 7 is fitted in a large-diameter center hole 4b below the air chamber 4a. A lower oil seal 8 is inserted on the upper side of the lower seal holder 7, and a felt ring 9 is inserted in the large diameter center hole 8a on the lower side. The felt ring 9 is axially restricted by a lid 11. Reference numeral 10 is an oil supply port for supplying lubricating oil to the felt ring. The upper oil seal 5 does not have to press the lip portion 5a against the guide shaft, and the lower oil seal 8 has a spring. The guide shaft 3 reciprocates in the oil drain space 13 above the sealing device. An oil draining ring 12 is provided.

A main oil discharge port 14 communicating with the oil discharge space 13 is formed at a position corresponding to the seal device below the guide cylinder 1, and further penetrates the guide cylinder 1 and the upper seal holder 4 to form an upper oil seal. A seal oil discharge port 15 reaching the outer peripheral portion of 5 is provided. The upper oil seal 5 is provided with a small hole for oil discharge which communicates with the seal oil discharge port. Further, the guide cylinder 1 is provided with an air port 16 for supplying compressed air to the air chamber 4a of the upper seal holder 4, and the compressed air is supplied from this air port 16 only during machine operation. ing. The compressed air sent from the supply port 16 into the air chamber 4a is ejected from the nozzle 17 that is directed almost obliquely upward and acts on the lip portion 5a of the upper oil seal 5 to form a minute gap to form an air seal. Most of the oil flows out of the main oil discharge port 14 through the gap a of the oil draining guide 6, and partially flows out of the seal discharge port.

Further, the small-diameter central hole of the upper seal holder 4 corresponding to the air chamber 4a has a slight gap (b) between the upper seal holder 4 and the guide shaft 3, and an inner circumferential groove serving as the air chamber 4c is formed on the inner circumferential surface. Has been done. Then, a small hole communicating the two air chambers 4a, 4c and a downwardly sloping oblique hole opening above the air chamber 4a and the lower oil seal 7 are formed, and the upper chamber of the lower oil seal 8 is opened through the oblique hole. Since the compressed air supplied to the air chambers 4a and 4c has almost the same pressure, it acts as an air pressure that presses the seal portion 8a against the outer circumference of the guide shaft 3, and the air supplied from the small holes to the air chamber 4c has a gap (b). ) To the upper seal side.

Next, the operation of this embodiment will be described. The needle beam guide shaft 3 guided by the cylindrical bearing 2 to reciprocate has a high stroke S of 40 to 70 mm and a stroke number of 1000 to 2000 times / min. Therefore, the waste oil flowing out from the cylindrical bearing portion is almost mist. However, a part of it falls along the outer edge of the oil draining ring 12 provided on the guide shaft 2 and falls outside the protruding portion of the oil draining guide 6. During the rotation of the crankshaft, compressed air with a constant pressure P is supplied to the air chamber 4a from the air port 16, and the compressed air in the air chamber 4a goes to the upper chamber of the lower oil seal through the diagonal hole that descends to the right and to the small hole. It is supplied to the air chamber 4c through it, and the supply pressure P acts on the lower oil seal 8 to close the lip portion and urge it freely, and the downward flow is blocked, so most of the air is discharged to the nozzle. It spouts from 17 toward the upper oil seal 5.

Then, the lip portion 5a having no backup spring acts in the direction of weakening the pressing load to form a minute gap in the seal surface, and flows upward to form an air seal. The air flow flowing out from the seal surface is partially discharged through the main oil discharge port 14 through the gap a, and guides the mist-like oil or the oil dropped on the oil-cutting guide 6 to the outside. The felt ring 9 retains the lubricating oil supplied from the oil supply port 10 and prevents the minimum oil supply and dust from entering the sealing surface of the lower oil seal 8. When the crankshaft stops, the supply of compressed air is also stopped, and the lip portion 5a of the upper oil seal 5 adheres to the outer periphery of the guide shaft 3 due to the elasticity to exert a sealing effect, and gradually the upper oil seal 5 becomes closer to the gap a. A small amount of oil that has dropped upward is discharged from the seal oil discharge port 15.

As described above, the upper oil seal 5 exerts the air sealing effect in a substantially non-contact state during operation, and the lower oil seal 8 obtains the sealing effect by the contact of the lip portion. Although the life is short, even if the lower oil seal 8 is damaged and oil starts to leak, the felt ring 9 absorbs it and reuses it as lubricating oil so that it does not drop directly onto the product while the leak amount is small. Therefore, it is not necessary to make an emergency stop and replace the seals during operation, but it is sufficient to wait for the completion of one section of work before replacing. Also, for replacement work, the lower oil seal 8 can be easily taken out by removing the lower seal holder, and the seal can be easily replaced.

[0014]

[Effect of device]

 Since the present invention is configured as described above, it has the following effects. Since the upper oil seal functions as a non-contact air seal during operation, the life of the main upper seal is extended, the maintenance time for seal replacement is reduced, and the machine operating rate is improved. Furthermore, since the upper oil seal and the lower oil seal have a double structure, even if the function of one of the oil seals deteriorates, oil will not immediately leak. Even if an oil leak occurs, it can be stored in the felt ring and used as lubricating oil.By checking the amount of oil in the felt ring, the degree of deterioration of the oil seal can be predicted. Since the time for replacement can be scheduled, the inconvenience of replacing the seal by emergency stop during operation is eliminated.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a needle beam guide shaft sealing device of the present embodiment.

FIG. 2 is a sectional view of a seal portion of a needle beam guide shaft according to a conventional technique.

[Explanation of symbols]

1 Guide Tube 2 Cylindrical Bearing 3 Needle Beam Guide Shaft 4 Upper Seal Holder 4a, 4b Air Chamber 5 Upper Oil Seal 7 Lower Seal Holder 8 Lower Oil Seal 9 Felt Ring 14 Main Oil Discharge Port 15 Seal Oil Discharge Port 16 Air Port 17 Nozzle

Claims (3)

[Scope of utility model registration request] 1. A vertical shaft sealing device supported axially reciprocally in a downwardly projecting guide cylinder on the lower surface of a box body such as a gear box in which lubricating oil is retained in a lower portion, An upper oil seal and a lower oil seal provided below the cylindrical bearing of the guide cylinder, and a lip portion of the upper oil seal by compressed air supplied between the upper oil seal and the lower oil seal only during the reciprocating motion. Opening means for forming an air seal in a minute gap between the outer circumference of the vertical shaft and means for discharging oil discharged from the cylindrical bearing to the outside together with air discharged from the air seal. A vertical shaft reciprocating shaft seal device characterized in that an oil seal functions as a contact type seal. 2. The axial reciprocating means according to claim 1, further comprising means for closing the lip portion of the lower oil seal by the compressed air supplied between the upper oil seal and the lower oil seal. Sealing device for moving vertical shaft. 3. The axially reciprocating motion according to claim 1 or 2, wherein a lower end of the guide cylinder is provided with a felt ring for preventing oil supply and dust from entering the sealing surface of the lower oil seal. Shaft sealing device.