KR20090117985A - Seal structure - Google Patents

Abstract

PURPOSE: A seal structure is provided to reduce the axial length of a device by accepting a peripheral member of oil seal in the axial direction although two or more oil seals are arranged. CONSTITUTION: A seal structure comprises a main speed reducer casing(30), first and second oil seals(50,52), a pre-speed reducer casing(27), and an inner pin member. The outer circumference of a cylinder part(30A) of the main speed reducer casing is contacted with an external space. The first and the second oil seals are arranged in the inner circumference of the cylinder part of the casing. The pre-speed reducer casing is contacted with the inner circumference of the first oil seal. The inner pin member is contacted with the inner circumference of the second oil seal. The inner pin member is contacted with the pre-speed reducer casing. A part of the inner pin member is contacted with the internal space of the main speed reducer. The external space and the internal space are sealed by the first and the second oil seals.

Description

Seal structure

The present invention relates to a seal structure such as a lubricant.

As shown in FIG. 3 and FIG. 4, for example, Patent Document 1 discloses a first oil seal between the first link member 4 and the second link member 6 of the robot arm R. 8) and a seal structure in which the second oil seal 10 is arranged side by side is disclosed. The 1st, 2nd oil seals 8 and 10 are arrange | positioned with some clearance SL, and the vacuum grease 12 is filled in the space containing this clearance SL. A passive body 14 having a cylinder portion 14A is connected and fixed to the second link member 6. The cylinder portion 14A of the passive body 14 ensures the member strength of the passive body 14 itself and secures the installation space of the bearing 16. The bearing 16 is disposed between the cylindrical portion 14A of the passive body 14 and the first link member 4, whereby the first link member 4 and the second link member 6 are , It is possible to rotate relative to each other around the axis CL.

According to this seal structure, the air and an inert gas or the like are formed between the space SP1 of the substantially vacuum and the space SP2 of the inert gas in the robot arm R by the first and second oil seals 8 and 10. Can be sealed to prevent the fluids from coming and going to each other.

[Patent Document 1] Japanese Patent Application Laid-Open No. 05-305596

However, in the case of the seal structure which arranges and arranges oil seals in this way (especially in the case of the structure which arrange | positions these two oil seals 8 and 10 with gap SL as the structure disclosed by the said patent document 1). Naturally, the length L1 (refer FIG. 4) from the axial end to the end of the oil seals 8 and 10 tends to be long.

Moreover, in many cases, the oil seal is provided in the vicinity of the connection portion between the member and the member, for example, as shown in Figs. 3 and 4 above. Therefore, in the vicinity of the oil seal, a bending part for securing the strength of these members exists, or a bearing for rotatably supporting the members, or a bolt for connecting and fixing the members must be disposed. There is a lot. Accordingly, there is a tendency that the length of the peripheral member in the axial direction tends to be longer in relation to the bending portion, the bearing space, or the arrangement position of the bolt. As an example of the apparatus of Patent Document 1, this is, for example, the bending start portion P1 of the first link member 4 to the bending start portion P2 of the second link member 6 (the first link member ( 4) and the axial dimension L2 of the part which is needed for the connection of the 2nd link member 6 becomes easy to become large.

The present invention has been made to solve such a problem, and in a seal structure in which two oil seals are arranged side by side, in particular, it is possible to more reasonably shorten the axial length of the member around the oil seal. The subject is that.

In the seal structure which prevents the leakage of the fluid between a 1st space and a 2nd space, this invention has a cylindrical part, The 1st member whose outer periphery of the said cylindrical part faces the said 1st space, Two oil seals arranged in the inner circumference of the tubular portion of one member, a second member in contact with the inner circumference of one oil seal among the two oil seals, and the other of the two oil seals. And a third member that is in contact with the inner circumference of the oil seal and is in contact with the second member and faces a part of the second space, and between the first member and the second and third members. The above-mentioned problem is solved by sealing the said 1st space and the 2nd space by the said two oil seals arrange | positioned at.

In addition, the present invention provides a seal structure that prevents leakage of fluid between a first space and a second space, wherein the first member has a cylindrical portion, and an outer circumference of the cylindrical portion faces the first space. , Two oil seals arranged along the outer periphery of the tubular portion of the first member, a second member in contact with the outer periphery of one oil seal among the two oil seals, and the two oil seals, And a third member which is in contact with the outer circumference of the other oil seal and in contact with the second member and faces a part of the second space, wherein the first member and the second and second The said subject is solved similarly by sealing the said 1st space and the 2nd space by the said two oil seals arrange | positioned between three members.

Conventionally, in the case where two oil seals are arranged side by side, a single member is brought into contact with each of the outer circumferential side and the inner circumferential side of each of the two oil seals. With respect to the inner circumferential side or the outer circumferential side), each oil seal is in contact with a separate member. As a result, when further joining the third member to the member on the inner circumferential side (or the member on the outer circumferential side), the third member can be brought into the axial intermediate position of the two oil seals. ) To contribute to shortening of the axial direction.

Here, the present invention is also applicable to the case where three or more oil seals are arranged side by side. In this case, if the structure concerning this invention is established about two specific oil seals, the original effect | action of this invention can be acquired as it is.

Even in the case of arranging two (or two or more) oil seals, it is possible to rationalize the storage in the axial direction of the member around the oil seal, so that the axial length of the entire device in which the oil seal is fitted It can be shortened.

EMBODIMENT OF THE INVENTION Below, an example of embodiment of this invention is described in detail based on drawing.

1 shows a geared motor to which a seal structure according to an embodiment of the present invention is applied. 2 is an enlarged view of main parts thereof.

This geared motor 20 is for driving a tool magazine (not shown), and is composed of a motor 24, a pre reduction gear 26, and a main reduction gear 28. As described later, in this embodiment, the seal near the connection portion of the main reducer casing 30 corresponding to the output shaft of the pre reducer casing 27 of the pre reducer 26 and the main reducer 28 is removed. As the structure for carrying out, the present invention is applied.

The pre reducer 26 is a one-stage reducer having a bevel pinion 34 and a bevel gear 36. The main reducer 28 is a reduction gear of a so-called internally engaged planetary gear structure, and includes an input shaft 38 on which the bevel gear 36 is mounted. The eccentric bodies 40A to 40C are integrally formed on the input shaft 38. Outer gears 42A to 42C are fitted on the outer circumference of the eccentric bodies 40A to 40C so as to swing and rotate. The external gears 42A to 42C are internally engaged with the internal gear 44 while swinging and rotating.

In this embodiment, the rotation of the outer gears 42A to 42C is constrained by the inner pin member 46. By this structure, this internal gear 44 rotates and the said main reducer casing 30 integrated with this internal gear 44 rotates. The main reducer casing 30 is provided with the mounting flange 32, and the rotating disk part of the tool magazine which is not shown in figure is connectable.

This geared motor 20 is used in the environment in which a coolant exists. Therefore, the seal structure requires two functions. The first function does not allow the coolant (fluid) of the outer space (first space) SPo of the geared motor 20 to leak into the inner space (second space) SPi of the main reducer 28. Is a function. The second function "does not leak the lubricant (fluid) of the internal space SPi to the external space SPo. Is a function.

Therefore, as a structure for preventing the coolant of the outer space SPo of the geared motor 20 and the lubricant of the inner space SPi of the main reducer 28 from entering and exiting each other (in both directions), The seal structure which concerns on this invention is applied.

A detailed structure will be described with reference to FIGS. 1 and 2.

In this seal structure, the outer periphery of the cylindrical portion 30A of the main reducer casing (first member) 30 faces the outer space (first space) SPo. On the inner circumference of the cylindrical portion 30A of the main reducer casing 30, the first and second oil seals 50 and 52 are arranged side by side in the axial direction of the main reducer 28.

Among the first and second oil seals 50 and 52, the inner circumference of the first oil seal 50 is in contact with the pre reducer casing (second member) 27 of the pre reducer 26. However, of the first and second oil seals 50 and 52, the inner circumference of the second oil seal 52 is in contact with the inner pin member (third member) 46 of the main reducer 28. In other words, the inner circumferences of the first and second oil seals 50 and 52 are in contact with the separate members, respectively. As shown in FIG. 1, the inner side pin member 46 becomes a shape where the cylindrical pin part 46p protrudes and extends in the axial direction from the position of the circumferential equal interval of the disk-shaped flange part 46f. (In FIG. 1, only one of the pin portions is depicted), a part of which faces the internal space SPi of the main reducer 28 which is the second space.

The effective seal directions of the first and second oil seals 50 and 52 are reversed. The first oil seal 50 effectively prevents the intrusion (leakage) of the coolant from the outer space SPo to the inner space SPi, and the second oil seal 52 is external from the inner space SPi. Effectively prevent leakage of lubricant into the space (SPo). That is, between the main reducer casing (first member) 30, the pre reducer casing (second member) 27 and the inner pin member (third member) 46, the first and second oil seals 50, 52 is arranged so that the outer space (first space) SPo and the inner space (second space) SPi of the main reducer 28 are sealed.

As is clear from Figs. 1 and 2, the pre-decelerator casing 27 and the inner pin member 46 are in contact with the respective fitting surfaces 27B and 46B, so that the first and second oil seals 50 and 52 come into contact with each other. It is connected by the bolt 60 arrange | positioned in parallel with this listed direction, ie, the axis | shaft Om of the main reducer 28. As shown in FIG. The axial position of the head contacting surface 27A of the bolt 60 of the pre reducer casing 27 is substantially the same as the axial position of the end 50A of the first oil seal 50. However, since the fitting surface 27B of the pre-reduction casing 27 is located at the axial intermediate position of the first and second oil seals 50 and 52, the pressing thickness D1 of the bolt 60 is secured. .

An O-ring 64 is disposed between the pre-reduction casing (second member) 27 and the respective mating surfaces 27B and 46B of the inner pin (third member) 46. The O-ring 64 maintains the airtightness of the mating surfaces 27B and 46B, and as a result, the space SPs in which the first and second oil seals 50 and 52 exist and the internal space SPp of the pre-reduction gear. To block.

In this embodiment, the pre reducer casing 27 and the main reducer casing 30 are replaced with a predetermined gap δ1. This ensures the relative rotation of the pre reducer casing 27 and the main reducer casing 30 due to the presence of this gap δ1, making it difficult to flow the fluid between the outer space SPo and the inner space SPi. For sake.

Here, reference numeral 68 in the drawing denotes an oil seal for sealing between the internal space SPi of the main reducer 28 and the internal space SPp of the pre reducer 26.

Next, the operation of this seal structure will be described.

The outer space SPo of the geared motor 20 is effectively blocked from the inner space SPi by the gap δ1 and the first oil seal 50 (with an effective seal direction). In addition, although the effective sealing direction is different, the 2nd oil seal 52 exists in a line with the 1st oil seal 50. As shown in FIG. Therefore, it is more reliably prevented that coolant, foreign matter, and the like in the outer space SPo enter the inner space SPi.

On the other hand, the internal space SPi of the main reducer 28 is effectively blocked from the external space SPo by the second oil seal 52 (the effective sealing direction is appropriate). In addition, although the effective sealing direction is different, the 1st oil seal 50 exists in a line with the 2nd oil seal 52. As shown in FIG. Therefore, the leakage of the lubricant in the inner space SPi into the outer space SPo is certainly prevented.

In the axially intermediate positions of the first and second oil seals 50 and 52, the fitting surfaces 27B and 46B of the pre-reduction casing 27 and the inner pin 46 are located, but both members 27 and 46 are disposed. Is firmly connected by the bolt 60, and the O-ring 64 is interposed between the fitting surfaces 27B and 46B, so that the first and second oil seals 50 and 52 are Even if there is a coolant or a lubricant that has escaped, it does not enter the internal space SPp side of the pre reducer 26 via the fitting surfaces 27B and 46B.

Here, the axial position of the head abutting surface 27A of the bolt 60 connecting the pre reducer casing 27 and the inner pin 46 is the axial direction of the end portion 50A of the first oil seal 50. It's almost like a location. However, since the fitting face 27B of the pre-reduction casing 27 is positioned at the position where the first and second oil seals 50, 52 enter the axially intermediate position, sufficient pressing thickness D1 is secured. have. As a result, the axial position of the end face 46A of the inner side pin 46 from the axial position P1 of the head pressing surface 60A of the bolt 60 of the pre reducer casing 27 by the length entered. It is possible to shorten the axial length L3 of P2).

Here, in the present invention, it is not necessarily necessary that the directions of the effective seals are in the opposite directions, for example, the two seals are arranged side by side in the same state, so that only one seal is more strictly realized. A configuration may be made. However, when it is desired to effectively seal in both directions as in the above embodiment, it is preferable to make the effective seal directions of the first and second oil seals opposite.

On the other hand, in the said embodiment, although the example which the 1st member (single) and the 2nd and 3rd members contacted on the outer peripheral side of the 1st, 2nd oil seal was shown, but wants to connect Depending on the configuration of the member, it may be advantageous that the first member and the second and third members are in contact with the inner circumferential side of the first and second oil seals, and the second and third members contact with the outer circumferential side. . That is, this invention is the sealing structure which prevents the flow of fluid between a 1st space and a 2nd space, WHEREIN: The 1st member which has a cylindrical part, and the inner periphery of this cylindrical part faces the said 1st space, Two oil seals which are arranged along the outer periphery of the cylindrical part of the first member, a second member in contact with the outer periphery of one oil seal among the two oil seals, and the other of the two oil seals. And a third member which is in contact with the outer circumference of the oil seal and which is in contact with the second member and faces a part of the second space, wherein the first member and the second and third parts are provided. The two oil seals disposed between the members can be adapted even in a situation where the first space and the second space are sealed, and the same effect can be obtained.

It can be applied to a structure or a device in which two (or two or more) oil seals are arranged in a line.

BRIEF DESCRIPTION OF THE DRAWINGS The expanded sectional drawing which shows the principal part of the seal structure which concerns on an example of the Example of this invention.

2 is a sectional view of a gear magazine drive for driving a tool magazine to which the seal structure is applied.

3 is a cross-sectional view showing an example of a conventional seal structure.

4 is a partially enlarged cross-sectional view showing the main portion of FIG. 3.

* Description of the sign *

20: geared motor

24: motor

26: pre reduction gear

27: pre-reduction casing (second member)

27A: Tofu contact surface

27B: custom face

28: main reducer

30: main reducer casing (first member)

30A: barrel

38: input shaft

40A-40C: Eccentric Body

42A ~ 42C: Shout gear

44: Pinch

46: inner pin member (third member)

46B: custom face

50, 52: 1st, 2nd oil seal

60: bolt

64: O ring

66: Bearing

68: oil seal

SPo: Outer space (first space)

SPi: Internal space (second space)

δ: gap

Claims (5)

In the seal structure which prevents the leakage of the fluid between a 1st space and a 2nd space, A first member having a cylindrical portion and having an outer circumference of the cylindrical portion facing the first space, Two oil seals arranged in an inner circumference of the tubular portion of the first member, A second member in contact with the inner circumference of one of the two oil seals, Among the two oil seals, a third member is in contact with the inner circumference of the other oil seal, and in contact with the second member and facing a part of the second space. And the first space and the second space are sealed by the two oil seals disposed between the first member and the second and third members. The method according to claim 1, And the second member and the third member are joined by bolts arranged parallel to the direction in which the oil seals are arranged. The method according to claim 1 or 2, The O-ring is arrange | positioned between the fitting surface which the said 2nd member and the 3rd member contact, The seal structure characterized by the above-mentioned. The method according to any one of claims 1 to 3, And the effective sealing directions of the oil seals are opposite to each other so as to prevent leakage of fluid between the first space and the second space in both directions. In the seal structure for preventing the leakage of fluid between the first space and the second space, A first member having a tubular portion, the inner circumference of the tubular portion facing the first space, Two oil seals arranged side by side on the outer circumference of the tubular portion of the first member, A second member in contact with the outer periphery of one of the two oil seals, A third member which is in contact with the outer circumference of the other oil seal and abuts the second member, and partially faces the second space, of the two oil seals, And the first space and the second space are sealed by the two oil seals disposed between the first member and the second and third members.

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