JP4020237B2 - Sealing device for vacuum equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sealing device for vacuum equipment that partitions an annular space between an outer cylinder and a rotary shaft that is rotatably inserted into the center thereof into two in the axial direction.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a power transmission device is used when rotating power such as a motor disposed in an atmospheric pressure space is input to equipment in a vacuum vessel such as a semiconductor manufacturing apparatus.
[0003]
As the power transmission device, for example, a rotary shaft arranged across the vacuum vessel and the atmospheric pressure space, a case that supports the rotary shaft so as to be rotatable around the rotary shaft, and an annular shape between the case and the rotary shaft It has at least a sealing device that partitions the space into two in the axial direction and shuts off the vacuum vessel and the atmospheric pressure space.
[0004]
The sealing device is configured such that a plurality of seal rings are installed adjacent to each other in the axial direction in the annular space. These plurality of seal rings are all used under the condition that the sealing ability is the same.
[0005]
[Problems to be solved by the invention]
In the above conventional example, all of the plurality of seal rings reach the end of their life almost at the same time, so when these seal rings reach the end of their life, the pressure in the vacuum vessel suddenly rises and instantaneously adversely affects the vacuum system. As a result, recovery takes a lot of time and cost.
[0006]
For this reason, the applicant of the present application has dealt with replacing the seal ring at a time considerably earlier than its original life, but there is room for improvement, such as shortening the replacement period and increasing running costs. .
[0007]
In view of such circumstances, an object of the present invention is to avoid an abrupt atmosphere destruction of a space to be sealed in a sealing device having a plurality of seal rings. In addition to the above object, the present invention makes it possible to make the replacement period of the seal ring as long as possible, and to automatically recognize the replacement time of the seal ring, thereby reducing the burden on the operator. It is an object.
[0008]
[Means for Solving the Problems]
The first sealing device of the present invention is a sealing device for vacuum equipment that shuts off a vacuum vessel and an atmospheric pressure space, and an annular space between an outer cylinder and a rotating shaft that is rotatably inserted in the center thereof. A vacuum device sealing device that divides a vacuum side into an atmospheric pressure side in a direction, and is arranged adjacent to one another in the axial direction with respect to either the outer cylinder or the rotating shaft, and the other is fixed A plurality of seals that are brought into contact with each other, and the plurality of seals have multiple sealing functions in the axial direction, and any one of the seals has a shorter life than the other seals. It is characterized by that.
[0011]
The vacuum device sealing apparatus according to the first aspect of the present invention is the vacuum device sealing device according to claim 1 , wherein the one space is a vacuum space and the other space is an atmospheric pressure space, set seal to the said vacuum space wherein is disposed the atmospheric pressure space nearer, it is characterized by.
[0012]
The sealing device for the present invention the third vacuum device, the sealing device for a vacuum apparatus according to claim 1 or 2, must be replaced every seal recognizes said set seal to a short life life It further has a monitoring device that performs a notification operation indicating that the
[0013]
The sealing device for the present invention the fourth vacuum device, the sealing device for a vacuum apparatus according to claim 3, wherein the monitoring device includes a sensing element for sensing the wear condition of the seal, which is set to a short life, all a notification element to perform a notification operation to indicate that the there is a need for replacement of the seal, with the seal to determine whether led to life on the basis of the output of said sensing element, said when it is determined that the service life And a control element that drives the notification element.
[0019]
In short, in the present invention, among the plurality of seal, by setting at least any one the short life, all seals are so to prevent life at the same time. Thus, as in the prior art, the sealing performance of all seal is substantially reduced at the same time, avoids a problem that the atmosphere of a sealed target space is rapidly destroyed.
[0020]
In particular, the third, the fourth configuration, monitoring the presence or absence of the arrival of the lifetime associated with the state of wear of seal which is set to the short life, all when the seal has reached its life and to perform the notification operation for requesting replacement of the seal. Thus, before any seal is life, all the need to replace the seal will allow the operator to reliably recognize, so can perform actions such as exchange reliably and correctly. Moreover, it is possible to use the life for seal that is set to a short life, by setting slightly longer than the seal that is set on the short life for the life of the other seal, all seals The replacement period can be made longer than that of the conventional example, which can contribute to a reduction in running cost.
[0021]
Therefore, when any work is performed in the sealed space, the operator can intentionally manage the stop time of the work, so that the work is unexpectedly interrupted and recovered as in the past. This does not lead to a situation where it takes a lot of time and cost.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
The details of the present invention will be described based on embodiments shown in the drawings.
[0023]
1 to 3 show an embodiment of the present invention. 1 is a cross-sectional view showing a power transmission device including a sealing device, FIG. 2 is a cross-sectional view taken along line (2)-(2) in FIG. 1, and FIG. 3 is an enlarged view of the sealing device in FIG. FIG.
[0024]
In the figure, 1 is a vacuum chamber, 2 is a power source such as a motor, and 3 is a power transmission device.
[0025]
The power transmission device 3 is for decelerating and transmitting the rotational power of the motor 2 to a device (not shown) in the vacuum chamber 1, and includes a cylindrical case 4, an input shaft 5, an output shaft 6, A planetary roller type speed reducer 7 and a sealing device 8 are provided.
[0026]
The case 4 is attached to the wall surface of the vacuum chamber 1 in a lateral orientation, and the input shaft 5 and the output shaft 6 are coaxially supported in the case 4 via two rolling bearings 9A to 9D. Has been.
[0027]
The outer end of the input shaft 5 protrudes from the one opening of the case 4 to the atmospheric pressure space, and the protruding portion and the output shaft of the motor 2 are interlocked and connected via gears 10A and 10B.
[0028]
The output shaft 6 has an outer end protruding into the vacuum chamber 1 from the other opening of the case 4, and this protruding portion is connected to a device (not shown) in the vacuum chamber 1.
[0029]
The planetary roller type speed reducer 7 decelerates the rotational power of the input shaft 5 and transmits it to the output rotary shaft 6. The speed reducer 7 includes a fixed wheel 15 fitted and fixed to the case 4, a sun roller 16 integrally formed with the input shaft 5 and inserted concentrically with the fixed wheel 15, and the fixed wheel 15 and the sun roller 16. A plurality of planetary rollers 17 interposed at several circumferential positions between them, and a radial direction in which one end is formed at the inner end of the output shaft 6 and inserted into the center of each planetary roller 17 via a needle roller 19 And a plurality of planetary shafts 18 supported in a cantilever manner with respect to the outward flange 6a.
[0030]
The fixed wheel 15 of the speed reducer 7 is positioned and mounted on the case 4 while being sandwiched between the two rings 11A and 11B. Further, the input shaft 5, the output shaft 6, and the speed reducer 7 are arranged between the nuts 12A and 12B that are screwed to the input shaft 5 and the output shaft 6 one by one, the rolling bearings 9A and 9B, and the rolling bearing 9C. And 9D are positioned in the axial direction by spacers 13A and 13B.
[0031]
The sealing device 8 divides the annular space between the case 4 and the output 6 into two in the axial direction, and includes two seal rings 20 and 30 as seals disposed adjacent to each other in the axial direction. Yes.
[0032]
These seal rings 20 and 30 have a configuration in which main lips 22 and 32 made of rubber or the like and auxiliary lips 23 and 33 are attached to the inner circumferences of the annular core bars 21 and 31, respectively. In the case 4, the lip 22, 23, 32, 33 is brought into contact with the outer peripheral surface of the output shaft 6 by being fitted and fixed to a region near the vacuum chamber 1. The main lips 22 and 32 are brought into contact with the outer peripheral surface of the output shaft 6 with a required pressure by the tightening force of the garter springs 24 and 34 attached to the outer periphery thereof. The seal rings 20 and 30 here preferably have a pressure-resistant structure as shown in, for example, Japanese Patent Application No. 11-272196 filed by the applicant of the present application.
[0033]
Here, the conditions are set such that the two seal rings 20 and 30 have different lifetimes.
[0034]
That is, the outer diameter dimensions of both the seal rings 20 and 30 are set to be the same, but the inner diameter dimension of the first seal ring 20 disposed closer to the vacuum chamber 1 is disposed closer to the atmospheric pressure space. The inner diameter dimension of the seal ring 30 is set smaller.
[0035]
The output shaft 6 also has a small diameter portion near the vacuum chamber 1, and the lips 22, 23 of the first seal ring 20 are brought into contact with the outer peripheral surface of the small diameter portion 6b. On the other hand, the lips 32 and 33 of the second seal ring 30 are brought into contact with the outer peripheral surface of the large-diameter main body portion of the output shaft 6.
[0036]
Under such conditions, the peripheral speed on the outer surface of the large-diameter main body portion of the output shaft 6 becomes faster than the peripheral speed on the outer surface of the small-diameter portion 6b. 23, the total slip distance at each lip 32, 33 of the second seal ring 30 is longer than the total slip distance at 23, resulting in differences in heat generation, wear, etc. The two seal rings 30 have a short life.
[0037]
If the sealing performance of the sealing device 8 is deteriorated, the pressure in the vacuum chamber 1 is not preferable. For example, the power transmission device 3 described above includes the second seal ring that has a short life as described above. A monitoring device 40 that performs a notification operation for monitoring whether or not 30 has reached the end of life and requesting replacement of both seal rings 20 and 30 is provided.
[0038]
The monitoring device 40 includes a detection unit 41, a notification unit 42, and a control unit 43.
[0039]
The detector 41 measures the wear state of the lips 32 and 33 of the second seal ring 30, and here, a strain gauge is used and is attached to the annular core 31 of the second seal ring 30. Used in the form of The reason why the detection portion 41 is a strain gauge is that the strain in the circumferential direction of the seal rings 20 and 30 increases as wear of the lips 22, 23, 32, and 33 of the seal rings 20 and 30 progresses. Based on.
[0040]
The notification unit 42 includes a display panel, a buzzer, and the like, and performs a notification operation for requesting replacement of both seal rings 20 and 30 when a drive signal is input from the control unit 43.
[0041]
The control unit 43 is composed of a microcomputer or the like, and recognizes the wear state of each of the lips 32 and 33 by comparing the output data of the detection unit 41 formed of a strain gauge with the reference data stored in advance in the internal memory. Then, it is determined whether or not the second seal ring 30 has a lifetime, and when it is determined that the second seal ring 30 has a lifetime, a drive signal is output to the notification unit 42.
[0042]
The reference data stored in the internal memory of the control unit 43 is created based on various experimental results, and the data measured by the detection unit 41 made of a strain gauge is associated with the lifetime. Has been.
[0043]
Next, the operation will be described. When the operation time of the power transmission device 3 described above exceeds the required time and the second seal ring 30 reaches the end of its life, the control unit 43 of the monitoring device 40 recognizes this based on the output from the detection unit 41, Driving the notification unit 42 performs a notification operation indicating that the sealing device 8 needs to be replaced. This notification operation enables the operator to recognize that the sealing device 8 needs to be replaced with a new one.
[0044]
Moreover, even if the second seal ring 30 has reached the end of its life as described above, the first seal ring 20 has not reached its end of life, so that the sealing performance of the sealing device 8 only needs to be slightly reduced. The pressure in 1 will only need to increase slightly. In other words, the pressure in the vacuum chamber 1 can be maintained almost unchanged.
[0045]
By the way, an operator who recognizes that the sealing device 8 needs to be replaced stops the operation of equipment (not shown) in the vacuum chamber 1 before replacing the sealing device 8 and then opens the vacuum chamber 1 to atmospheric pressure. Can be managed so that the preparation to do is performed at the optimal timing, so that the work of the equipment is unexpectedly interrupted and the recovery takes a lot of time and cost That's it.
[0046]
Moreover, since the service life of the second seal ring 30 is set slightly shorter than the service life of the first seal ring 20, when the replacement time of all seal rings is set earlier with a margin than the service life as in the conventional example. Compared to this, it is possible to lengthen the replacement cycle, which contributes to a reduction in running cost.
[0047]
In addition, this invention is not limited only to embodiment mentioned above, Various application and deformation | transformation can be considered.
[0048]
(1) In the above embodiment, the sealing device 8 is provided with the first seal ring 20 set to have a long life near the vacuum chamber 1 and the second seal ring 30 set to have a short life near the atmospheric pressure space. As shown in FIG. 4, the arrangement is reversed, and the portion of the output shaft 6 near the vacuum chamber 1 is made large in diameter, and the second seal ring 30 is also attached to the large diameter portion 6c. The first seal ring 20 may be disposed on the small-diameter main body portion of the output shaft 6. Even in this case, the same operation and effect as the above embodiment can be obtained. In addition, the number of seal rings used may be further increased. In that case, at least one of them may be set to have a shorter life than the other.
[0049]
(2) In the above embodiment, the detection unit 41 of the monitoring device 40 is configured to measure the strain of the second seal ring 30 using a strain gauge, but the second seal using a temperature sensor such as a thermocouple. A form in which the temperature of the ring 30 is measured or a form in which the vibration of the second seal ring 30 is measured using a vibrometer pickup or the like can be used.
[0050]
When the detection unit 41 is a temperature sensor, it is preferably attached to the case 4 so as to face the garter spring 34 attached to the second seal ring 30 in a non-contact manner, as shown in FIG. In this case, since the temperature rises according to the wear progress of the lips 32 and 33 of the second seal ring 30, the temperature change may be determined by the control unit 43.
[0051]
Further, when the detection unit 41 is a vibration meter pickup, as shown in FIG. 6, a recess 4a is provided on the outer periphery of the case 4 where the second seal ring 30 is fitted and fixed. Preferably it is attached to the bottom. In this case, since the vibration increases according to the wear progress of the lips 32 and 33 of the second seal ring 30, the change in the vibration may be determined by the control unit 43.
[0052]
In addition, the detection unit 41 can be a current measuring device that measures the output current of the motor 2 that drives the input shaft 5 as shown in FIG. 7, and the vacuum chamber 1 as shown in FIG. It can be set as the pressure sensor which measures the pressure rise in the inside. In the former case, the output current of the motor 2 increases in accordance with the progress of wear of the lips 32 and 33 of the second seal ring 30. Therefore, the change in the current may be determined by the control unit 43. In the latter case, the pressure in the vacuum chamber 1 increases in accordance with the progress of wear of the lips 32 and 33 of the second seal ring 30. Therefore, the change in the pressure may be determined by the control unit 43.
[0053]
Moreover, about the detection part 41, you may make it combine two or more forms mentioned above. In that case, since the detection accuracy is improved, the reliability of the life determination is enhanced.
[0054]
(3) For at least one of the first seal ring 20 and the second seal ring 30 in the above embodiment, the atmospheric gas in the vacuum chamber 1 is prevented from permeating and leaking from the outer surface of the rubber portion. The film may be coated. For example, in the case of the form shown in FIG. 3, as shown in FIG. 9, the outer surface of the rubber including the lips 22 and 23 of the first seal ring 20 disposed near the vacuum chamber 1 is silver, aluminum or copper. By coating the soft metal film 50 such as, the atmospheric gas in the vacuum chamber 1 may be prevented from permeating and leaking from the rubber portion. In this case, in addition to preventing the gas permeation as described above, the lubricity of the sliding portions of the lips 22 and 23 is improved, and when the lips 22 and 23 generate heat during the sliding operation, the heat dissipation is improved. Be able to.
[0055]
【The invention's effect】
In the invention of claims 1 to 4, among the plurality of seal, by setting at least any one the short life, because all seal is so to prevent the life time, as in the prior art , reduced sealing performance of all of the seal is almost at the same time, avoided the problem that the atmosphere of the sealed space is suddenly destroyed.
[0056]
Particularly, in the invention of claim 3 or 4, to monitor the presence or absence of the arrival of the lifetime associated with the state of wear of seal which is set to the short life, all sea when the seal has reached its life because they to perform the notification operation for requesting the exchange of Le, before any seal is life, all the need to replace the seal operator will be able to reliably recognize, exchange etc. Can be dealt with reliably and accurately. Moreover, it is possible to use the life for seal that is set to a short life, by setting slightly longer than the seal that is set on the short life for the life of the other seal, all seals The replacement period can be made longer than that of the conventional example, which can contribute to a reduction in running cost.
[0057]
Thus, in the present invention, when any work is performed in the sealed space, the operator can systematically manage the stop time of the work, so that the work is unexpectedly interrupted as in the past. Therefore, it does not lead to the situation that it takes a lot of time and cost for recovery.
[Brief description of the drawings]
1 is a cross-sectional view showing a power transmission device including a sealing device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line (2)-(2) of FIG. FIG. 4 is a cross-sectional view showing an enlargement of the sealing device of FIG. 4. FIG. 4 is a cross-sectional view showing a modification of the sealing device of FIG. 6 is a partially enlarged view showing a modification 2 of the detection unit in the monitoring device of FIG. 3 or FIG. 4. FIG. 7 is a partially enlarged view showing a modification 3 of the detection unit in the monitoring device of FIG. 8 is a partially enlarged view showing a modification 4 of the detection unit in the monitoring device of FIG. 3 or FIG. 4. FIG. 9 is a cross-sectional view of the upper half showing a modification of the seal ring of FIG.
DESCRIPTION OF SYMBOLS 1 Vacuum chamber 2 Motor 3 Power transmission device 4 Power transmission device case 6 Power transmission device output shaft 8 Power transmission device sealing device 20 Sealing device first seal rings 22 and 23 First seal ring lip 30 Sealing device Second seal ring 32, 33 Second seal ring lip 40 Monitoring device 41 Monitoring device detection unit 42 Monitoring device notification unit 43 Monitoring device control unit

Claims (4)

It is a sealing device for vacuum equipment that shuts off the vacuum vessel and the atmospheric pressure space, and the annular space between the outer cylinder and the rotation shaft that is rotatably inserted in the center of the vacuum vessel and the atmospheric pressure side in the axial direction. A vacuum device sealing device that divides into two, and is arranged adjacent to one another in the axial direction with respect to either the outer cylinder or the rotating shaft, and is fitted and fixed, and is in contact with the other. has a seal, has a multiple sealing function in the axial direction by the plurality of seals, said one of seal, than other seal is set to short-lived, and wherein the vacuum Equipment sealing device. In the vacuum device sealing device according to claim 1,
The one space is a vacuum space, the other space is an atmospheric pressure space, and the seal set to have a short life is disposed closer to the atmospheric pressure space than the vacuum space. A sealing device for vacuum equipment. The sealing device for vacuum equipment according to claim 1 or 2,
A sealing device for vacuum equipment, further comprising a monitoring device that recognizes the life of the seal set to the short life and performs a notification operation indicating that all seals need to be replaced. In the sealing device for vacuum equipment according to claim 3,
The monitoring device is based on a detection element that detects a wear state of the seal set to the short life, a notification element that performs a notification operation indicating that all seals need to be replaced, and an output of the detection element And a control element that drives the notification element when it is determined that the seal has reached the end of its life.

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