JP6542745B2 - Sealing device for housing end and torque limiter with sealing device - Google Patents

Description

  The present invention relates to a sealing device at a housing end and a torque limiter provided with the same.

  In various machine parts, a sealing device is used which seals the open end of a cylindrical housing in which a space having a circular cross section extending in the axial direction is formed by a disk-like shield plate.

  A torque limiter is an example of a mechanical component using such a sealing device. As disclosed in Patent Document 1, the torque limiter is incorporated in a sheet feeding device of a printer or a copying machine and used, and a plurality of sheets are fed to the main body of the printer or copying machine in a multi-layered state. Avoid that. The torque limiter includes a cylindrical outer ring (corresponding to a housing) and a shaft-shaped inner ring located concentrically with the inner side of the outer ring, and the end of the coil spring wound around the inner ring is fixed to the outer ring, In many cases, the inner ring and the outer ring rotate relative to each other when a rotational torque larger than the frictional force between the inner ring and the coil spring acts. In such a torque limiter, a sealing device is used in which the inner ring and the coil spring are accommodated in a space formed inside the outer ring, and the open end of the space is sealed by a shield plate press-fitted therein.

The torque limiter is not limited to the sheet feeding device, and is also used as a component that cuts off the load and protects the motor when an overload (excessive rotational torque) is applied to the motor or the like of the drive source. Further, as a friction type torque limiter, there is one using a roller described in Patent Document 2, which will be described with reference to FIG.
The torque limiter shown in FIG. 8 includes a cylindrical outer ring O, a shaft-shaped inner ring I concentrically located inside the outer ring O, and a spherical roller R positioned between the outer ring O and the inner ring I, The inner ring I is provided with a coil spring B, a washer C, and a shield plate S. On the inner surface of the outer ring O, a female screw F located at the open end on one side in the axial direction, and a frusto-conical shape whose inner diameter gradually decreases toward the other axial side adjacent to the female screw F in the axial direction A tapered portion T is formed. A plurality of axially extending grooves G are formed in the tapered portion T at equal angular intervals in the circumferential direction. The rollers R are rotatably fitted in the respective grooves G. The coil spring B is held in a state in which both ends thereof are held between the shield plate S and the washer C and have an elastic force. Then, the roller R receives the elastic force of the coil spring B via the washer C, and is pressed against the outer surface of the tapered portion T and the inner ring I.
An external thread M is formed on the outer peripheral surface of the shield plate S, and the shield plate S and the outer ring O are screwed together. Therefore, by rotating the shield plate S with respect to the outer ring O, the shield plate S can move in the axial direction with respect to the outer ring O, whereby the elastic force applied to the roller R by the coil spring B ( The magnitude of the spring force of the coil spring B can be changed.

  The torque limiter shown in FIG. 8 works as follows. That is, when a torque smaller than a predetermined value is applied from the outer ring O to the inner ring I, the friction between the roller R pressed by the spring force of the coil spring B and the outer ring O and the inner ring I And the inner ring I rotate together. On the other hand, when the rotational torque applied from the outer ring O to the inner ring I is larger than a predetermined value, the rotational torque exceeds the resistance torque due to the frictional force between the roller R and the outer ring O and the inner ring I. O will rotate relative to the inner ring I. At this time, in the torque limiter provided with the sealing device shown in FIG. 8, adjustment of the spring force of the coil spring B by rotating the shield plate S with respect to the outer ring O even in the assembled state. That is, the frictional force between the roller R and the outer ring O and the inner ring I can be adjusted. Thereby, it becomes possible to change the above-mentioned rotation torque according to a use application or to finely adjust the predetermined value of the above-mentioned rotation torque for every individual.

  By the way, the sealing device by the shield plate is a general means for closing the opening of the housing and is not provided only with the torque limiter, and as shown in FIG. 7 described later, the rotating body is disposed inside And may be provided on machine parts filled with a lubricant such as grease or oil. In this case, after the housing is filled with oil such as grease, the open end of the housing is sealed with an oil seal such as rubber by a shield plate for supporting and fixing the oil seal.

JP 2008-274979 A JP, 2009-192061, A

  In the torque limiter sealing device shown in FIG. 8, since the shield plate S and the outer ring O are screwed together, due to vibration during rotation of the torque limiter, unexpected external force, etc., along with long-term use Loosening may occur in the screwing portion, and the shield plate S may move in the axial direction unintentionally with respect to the outer ring O. When the shield plate S moves in the axial direction with respect to the outer ring O, the spring force of the coil spring B in contact with the shield plate S also changes, and accordingly the outer peripheral surfaces of the roller R and the tapered portion T of the outer ring O and the inner ring I The friction between them changes. As a result, a predetermined value of rotational torque set in advance fluctuates, and the function as a torque limiter is lost.

Further, in the case of the above-described sealing device provided with a shield plate used together with an oil seal in a machine component in which oil such as grease is filled in the housing, the following problems occur.
Since the oil seal is a product that is usually manufactured by an elastic body such as rubber, its manufacturing tolerance is relatively large and it expands and contracts depending on temperature, so if the oil seal is not properly disposed in the housing, The oil leaks to the outside from the gap between the oil seal and the housing and the inner ring (rotary body), causing an unexpected malfunction such as seizing of mechanical parts. Therefore, the position of the shield plate that presses the oil seal is adjusted in the axial direction, and the amount of change in the outer diameter and inner diameter of the oil seal is made an appropriate value, and the oil from the gap between the oil seal and the housing and inner ring to the outside At the same time as preventing leakage, it is necessary to prevent deterioration due to excessive deformation of the oil seal.

  The present invention provides a sealing device capable of changing the axial position of the shield plate relative to the housing and preventing the axial position from being unintentionally changed, and the sealing device An object of the present invention is to provide a provided torque limiter.

In view of the above-described problems, the present invention provides a thickness change region in which an outer peripheral edge of the shield plate has a locking edge portion whose axial thickness differs stepwise in the circumferential direction. One is to engage a locking projection provided at the open end of the cylindrical housing so that the axial position of the shield plate can be adjusted. That is, the present invention
“A sealing device for sealing the open end of a cylindrical housing in which a space having a circular cross section extending in the axial direction is formed by a disk-shaped shield plate,
The inner circumferential surface of the open end of the housing is provided with a plurality of locking projections spaced in the circumferential direction,
At the outer end of the shield plate, thickness changing regions in which a plurality of locking edges whose axial thickness differs stepwise in the circumferential direction are provided by the number corresponding to the locking projections.
Opposing surfaces orthogonal to the axial direction are respectively formed on the locking projection of the housing and the locking edge of the shield plate,
The axial position of the shield plate can be adjusted by rotating the shield plate and changing the opposite surface of the locking edge against which the opposing surface of the locking projection of the housing abuts. "
It is a sealing device characterized by

  In the sealing device of the present invention, it is preferable that in the wall thickness change area of the shield plate, "a projection that protrudes in the axial direction is formed at both circumferential ends of each of the locking edges." Further, it is preferable that the shield plate be provided with a rotation assisting means for rotating it with respect to the housing.

  When applying the sealing device of the present invention to a mechanical part capable of adjusting the spring force of a spring accommodated in the inside of a housing, "the end portion of the spring is in contact with the shield plate, the shield The spring force of the spring can be changed by adjusting the axial position of the plate. The torque limiter is one of the mechanical parts that accommodates the spring inside the housing, but the sealing device according to the invention is particularly advantageous in that: A spring, one of the outer ring and the inner ring being non-rotatably connected to the inner ring and the other being non-rotatably connected to the housing.

The sealing device of the present invention basically comprises a cylindrical housing in which a space having a circular cross section extending in the axial direction is formed, and a disk-shaped shield plate for closing the open end. In the present invention, the outer end portion of the shield plate is provided with a thickness variation area in which a plurality of locking edges whose axial thickness is stepwise different in the circumferential direction are provided, The axial position of the shield plate can be adjusted by selecting the fastening edge and engaging with the plurality of locking projections provided on the inner circumferential surface of the open end of the housing.
In other words, opposite faces are respectively formed on the locking projections of the housing and the locking edge of the shield plate, and when the shield plate is installed at the open end of the housing, the facing surfaces abut each other. If the thickness is different, the axial position of the shield plate (the position of the opposite surface to the opposite surface) will change. In the present invention, since the shield plate is provided with a plurality of locking edges whose thickness gradually differs in the circumferential direction, the shield plate can be formed even after the opening facing end of the housing is closed by the shield plate. The axial position of the shield plate can be adjusted by rotating and changing the locking edge on which the locking projection of the housing abuts.

  And in this invention, the opposing surface respectively formed in the latching protrusion of a housing, and the latching edge of a shield board is a surface orthogonal to the axial direction. Since it is not the contact between the faces that intersect in the axial direction in plan view, such as screwing of the screw, the axial direction is obtained even if the housing and shield plate receive an external force that relatively rotates due to vibration etc. There is no component force, and there is no loosening of the shield plate and no change in its axial position.

Since the sealing device of the present invention can adjust the axial position of the shield plate, it can be applied to, for example, a torque limiter shown in FIG. 1 that adjusts the spring force of a coil spring to change the set value of rotational torque. At that time, it is possible to prevent the change of the unintended setting value due to the change of the position of the shield plate due to the vibration during the operation of the torque limiter.
By the way, the applicant of the present application uses a very large spring constant spring such as a so-called ring spring to obtain a torque limiter having a small and compact structure but having an increased frictional force and an increased setting value of rotational torque. Are proposed (see Japanese Patent Application No. 2016-178191). In this torque limiter, an outer ring and an inner ring formed with conical surfaces abutting each other are used, and the rotational torque acting between the outer ring and the inner ring exceeds the frictional force acting on the abutting conical surfaces. , Both rings start to rotate relatively. Then, the friction force of this torque limiter is proportional to the pressure of the surface where the inner ring and the outer ring abut, and when the axial distance between the two rings slightly changes, the pressure and the friction change significantly (spring constant Is very big). When the sealing device of the present invention is applied to such a torque limiter, it is possible to significantly change the setting value of the rotational torque only by slightly changing the thickness of the locking edge of the shield plate, Moreover, since it is possible to prevent an unintended change in the set value, it is obvious that an excellent effect can be obtained.

It is a figure which shows the whole structure of the Example which applied the sealing device of this invention to the torque limiter. It is a figure which shows the housing of the torque limiter shown in FIG. It is a figure which shows the inner ring of the torque limiter shown in FIG. It is a figure which shows the outer ring of the torque limiter shown in FIG. It is a figure which shows the inner ring of the torque limiter shown in FIG. It is a figure which shows the shield board of the torque limiter shown in FIG. It is a figure which shows the example which applied the sealing device of this invention to the machine component with which oil was filled. It is a figure which shows an example of the friction type torque limiter using the conventional roller.

  Hereinafter, a sealing device of the present invention will be described by way of an example of a torque limiter to which the sealing device is applied, with reference to the attached drawings. FIG. 1 shows the overall structure of a torque limiter to which the embodiment of the sealing device of the present invention is applied, and FIGS. 2 to 6 show single parts of each component.

  As shown in FIG. 1, the torque limiter of the present embodiment comprises a housing 1, in which an inner ring 2 having a common central axis o, an outer ring 3, an inner ring 4, a shield plate 5, and a wave form A spring 6 is provided. In the illustrated embodiment, the outer ring 3 and the inner ring 4 are provided in pairs. That is, the torque limiter of the present embodiment has a ring spring consisting of the outer ring 3 and the inner ring 4 in which the conical surfaces are in contact with each other. And the inner ring 2 relative to each other is determined.

Referring to FIGS. 1 and 2, the housing 1 is a generally cylindrical member made of synthetic resin or metal. An opening 11 is provided and opened on one side in the axial direction of the housing 1 and this open end is closed by the shield plate 5 to which the sealing device of the present invention is applied (detailed structure will be described later).
The other side of the housing 1 in the axial direction is closed by an end plate 12 which is a part of the housing 1, and inside the housing 1 is formed a space 13 having a circular cross section extending in the axial direction. A through hole 14 is formed at the center of the end plate 12 and a circular recess 15 concentric with and surrounding the through hole 14 is formed, and the end of the inner ring 2 is supported by the circular recess 15. Further, a pair of substantially rectangular protrusions 16 are formed on the outer surface of the end plate 12, and the torque limiter of the present embodiment overloads a power transmission system that opens and closes a lid of a notebook computer by a motor, for example. When being interposed as a time blocking means, a motor as a driving member is connected to the inner ring 2, and a shaft or the like for pivoting a lid as a driven member is connected to the projection 16 of the housing 1.

  1 and 3, the inner ring 2 is a substantially cylindrical shaft-like member, and has a large diameter portion 21 having a relatively large outer diameter and a small diameter portion 22 having a relatively small outer diameter. . A cylindrical outer peripheral surface 23 is formed at one end of the large diameter portion 21 (right end in the center cross section in FIG. 3), and a pair of drive members such as a motor are connected to one end of the small diameter portion 22. A U-shaped notch 25 is formed.

The structure of the ring spring provided in the torque limiter of this embodiment and the basic operation of the torque limiter of this embodiment will be described with reference to FIGS. 1, 4 and 5. FIG.
The outer ring 3, which is one element of the ring spring, is formed by pressing a plate-like metal and is formed into a radially inward flat portion 31 in which a through hole of the inner ring 2 is formed, and this plane And a conical surface portion 32 connected to the outer periphery of the portion 31. The conical surface portion 32 extends obliquely in the direction away from the central axis o at the outer peripheral edge of the outer flat portion 31. Four U-shaped notches 33 are formed in the flat portion 31 to engage with the projections 24 (FIG. 3) provided on the cylindrical outer peripheral surface 23 of the inner ring 2. The outer ring 3 is relatively rotated. Impossible to be fitted into the inner ring 2.
The inner ring 4 which is the other element of the ring spring is made of a plate-like metal like the outer ring 3 and has a facing conical surface portion 42 through which the inner ring 2 penetrates and a radial outer surface provided at its end. And the flat portion 41 of the direction. The opposing conical surface portion 42 is inclined and extends in a direction approaching the central axis o at the inner peripheral edge of the flat surface portion 41 and, as shown in FIG. 1, abuts on the conical surface portion 32 of the outer ring 3 when the torque limiter is assembled. . Two U-shaped notches 43 are formed in the flat portion 41 to engage with a pair of ridges 17 (FIG. 2) formed on the inner peripheral surface of the housing 1, and the inner ring 4 is a housing Relative rotation to 1 is not possible. The flat portion 41 is also provided with four notches 44 for avoiding interference with the locking projections 18 of the housing 1 when the inner ring 4 is inserted into the housing 1.

The basic operation of the torque limiter of this embodiment is as follows.
When rotational torque is applied from the drive member to the inner ring 2 and the rotational torque is less than a predetermined value (that is, when the load torque acting on the housing 1 is less than the predetermined value with the driven member normal) The friction between the inner surface of the conical surface 32 of the outer ring 3 engaged nonrotatably with the inner ring 2 and the outer surface of the opposite conical surface 42 of the inner ring 4 engaged nonrotatably with the housing 1 By the force, the inner ring 2 and the housing 1 rotate integrally. In the torque limiter of this embodiment, as described above, the outer ring 3 and the inner ring 4 form a structure of a spring device known as a so-called "ring spring", and are elastically deformed by the load in the axial direction As the conical surface portion 32 of the ring 3 expands, the diameter of the opposing conical surface portion 42 of the inner ring 4 decreases. The frictional force acting between the conical surface portions of both rings generated as a result of this elastic deformation has a very large value even if the relative axial displacement of the outer ring 3 and the inner ring 4 is very small. Become. Therefore, even if the torque limiter according to the present embodiment is small, large torque can be transmitted between the inner ring 2 and the housing 1. For example, in various power transmission systems, for protecting the drive motor Space required for the torque limiter can be reduced.

On the other hand, when the driven member becomes abnormal and the load torque acting on the housing 1 becomes excessive and the rotational torque of the inner ring 2 becomes larger than a predetermined value, the conical surface portion 32 of the outer ring 3 and the inner ring 4 The inner ring 2 and the housing 1 rotate relative to each other by overcoming the frictional force between the opposing conical surface portion 42. As a result, the inner ring 2 can be rotated while the housing 1 is stopped, and burning of the motor connected to the inner ring 2 can be prevented.
By the way, in the torque limiter of this embodiment, the wave spring 6 installed at the center of the two outer rings 3 is not necessarily essential, but the friction force acting on the respective ring springs installed on both sides is It makes uniform and plays the role which stabilizes the setting torque in which inner ring 2 and housing 1 start rotation relatively.

Here, the sealing device of the present invention applied to the above torque limiter will be described. In the torque limiter shown in FIG. 1, the sealing device of the present invention is applied as the configuration of the opening 11 of the cylindrical housing 1 and the configuration of the shield plate 5 for closing the opening. For convenience of explanation, in the following description, the right side in the axial direction of the cross section A-A in which the opening 11 is provided may be referred to as "rear" and the left side on the opposite side as "front".
On the inner peripheral surface of the opening 11 of the housing 1, as shown in FIG. 2, four claw-shaped locking projections 18 engaged with the outer end of the shield plate 5 are provided at intervals in the circumferential direction. ing. Preferably, the locking projections 18 are provided at equal angular intervals in the circumferential direction. Each of the locking projections 18 has a relatively small height from the inner circumferential surface as shown in the center cross-sectional view in FIG. 2 and opens on both sides in the axial direction of the housing 1 toward the outside of the open end. An outer inclined surface 18a inclined to the inner surface and an inner rising surface 18b vertically rising from the inner circumferential surface so as to be perpendicular to the axial direction, and the inner rising surface 18b engages with the outer end of the shield plate 5; It becomes.

The shield plate 5 is a disk-shaped synthetic resin member, and as shown in FIG. 6, is divided into a central circular main portion 5a and an outer end portion 5b surrounding the same. A circular through hole 51 for bearing the inner ring 2 is formed at the center of the main portion 5a, and four cylindrical bottoms are provided at equal angular intervals in the circumferential direction on one side of the main portion 5a. A recessed portion 52 is provided, and this bottomed recessed portion 52 is a rotation assisting means for rotating the shield plate 5 by inserting an appropriate tool.
Then, at the outer end 5 b of the shield plate 5, four thickness change regions 53 are provided corresponding to the number of the locking projections 18 of the housing 1. In the illustrated embodiment, each thickness change area 53 extends in the circumferential direction over 90 °, and the entire circumference of the outer end 5 b of the shield plate 5 constitutes the thickness change area 53.

In each thickness change region 53, as shown in a cross section A-A, a cross section B-B, a cross section C-C, and a circumferential development enlarged view of FIG. A locking edge portion 54 is formed, and a rear surface of the locking edge portion 54 is an inner rising surface 18 b which is a front surface of the locking projection 18 (two-dot chain line in the circumferential development enlarged view) of the housing 1. Abut. Therefore, the rear surface of the locking edge 54 is also a surface orthogonal to the axial direction of the housing 1 similarly to the inner rising surface 18 b.
In the illustrated embodiment, in each thickness change area 53, three locking edges 54-1, 54-2, 54 in which the thickness is slightly different in a step-like manner (about 1/20 mm). -3 is formed, and the thickness of each is set to t1, t2, and t3 (t1 <t2 <t3). The three locking edges 54-1, 54-2, 54-3 have the same length in the circumferential direction and, between each locking edge, they are directed axially backwards. A slightly projecting protrusion 55 is formed.

Then, the specific aspect which applies the sealing apparatus of this invention to the torque limiter of FIG. 1 is demonstrated.
When assembling the torque limiter of FIG. 1, after the end of the inner ring 2 is inserted into the recess 15 of the housing 1 and the inner ring 2 is installed in the space portion 13, the front outer ring 3 and the inner ring 4 sequentially and the wave spring 6. Insert the rear outer ring 3 and the inner ring 4. In this state, the shield plate 5 is attached to the opening end of the housing 1 to close the opening 11. In this case, the small diameter portion 22 of the inner ring 2 is inserted into the through hole 51 of the shield plate 5 5. Push 5 in the axial direction toward the front. Thereby, the outer end 5b of the shield plate 5 elastically rides over the outer inclined surface 18a (FIG. 2) of the locking projection 18 of the housing 1, and the front surface 5f (FIG. 6) of the shield plate 5 is on the rear side. It abuts on the rear face of the inner ring 4. Then, the inner rising surface 18b of the locking projection 18 of the housing 1 and one of the locking edges 54 of the shield plate 5 abut each other in such a manner as to receive the reaction force of the ring spring consisting of the outer ring 3 and the inner ring 4. As shown in FIG. 1, the shield plate 5 is attached to the opening 11.

At this time, the distance from the rear surface of the end plate 12, which is the axial length of the space portion 13 of the housing 1, to the front surface 5 f of the shield plate 5 is the locking edge of the shield plate 5 that contacts the locking projection 18 of the housing 1. It changes with the thickness of the part 54. That is, depending on which of the three locking edges 54-1, 54-2, 54-3 is engaged with the locking projection 18, the position of the front surface 5f of the shield plate 5 is equal to the difference in thickness. It can be adjusted.
The torque limiter in the embodiment of FIG. 1 generates a frictional force between the conical surface portions of both rings by utilizing the principle of a ring spring by the elastic deformation of the outer ring 3 and the inner ring 4. Even if the distance between the two rings, that is, the change in the axial length of the space 13 of the housing 1 is small, the change is large (the spring constant is large). Thus, even if the difference in thickness of the three locking edges 54-1, 54-2, 54-3 is small, by changing the locking edge that engages the locking projection 18, It becomes possible to adjust the set value of the rotational torque at which the torque limiter starts to slip and rotation transmission becomes impossible.

  In order to change the locking edge engaged with the locking projection 18, it is necessary to rotate the shield plate 5, but in one side surface of the main portion 5a of the shield plate 5 of this embodiment, four cylinders A bottomed recess 52 of shape is provided. The bottomed recess 52 serves as a rotation assisting means for rotating the shield plate 5, into which an appropriate tool is inserted, which is axially pressed against the elastic force of the ring spring by both rings. In the displaced state, the shield plate 5 is rotated in the circumferential direction. By changing the locking edge 54, in the manufacturing process of the torque limiter, it is possible to correct the variation etc. of the set value of the rotational torque, and at the same time correct the fluctuation of the set value due to the secular change of the torque limiter. You can also.

  In the sealing device of the present invention, the opposing surfaces respectively formed on the locking projection 18 of the housing 1 and the locking edge 54 of the shield plate 5 are both surfaces orthogonal to the axial direction, and the opposing surfaces abut The shield plate 5 is attached to the housing 1. Since the contact surface is not an oblique surface such as screwing, even if an external force is applied due to vibration or the like generated during operation of the torque limiter, the connection of the shield plate is loosened or the axial position thereof Does not change. Since a small amount of axially extending projection 55 is formed between the three locking edges 54-1, 54-2, 54-3, the locking is performed by the vibration or the like generated during operation of the torque limiter. The unpredicted situation in which the projection 18 engages with the other locking edge from the initially set locking edge is prevented.

Next, an embodiment in which the sealing device of the present invention is applied to an oil-filled machine part will be described with reference to FIG.
In the machine part shown in FIG. 7, a shaft (inner ring) 2 'is rotatably inserted into the housing 1' in a cylindrical housing 1 'filled with oil. The shaft 2 'has a large diameter portion 2a' and a reduced diameter portion 2b ', and the large diameter portion 2a' is not shown, for example, a roller of a roller type one-way clutch or a gear of a reduction gear. The rotating member of is attached. An oil seal OS and a shield plate 5 'for supporting and fixing the oil seal OS are disposed on the reduced diameter portion 2b'.
The oil seal OS is an annular member made of rubber, the inner diameter of which corresponds to the outer diameter of the shaft 2 ′ and the outer diameter of which corresponds to the inner diameter of the open end of the housing 1. The shield plate 5 'is the same as that of the embodiment described above, that is, as shown in FIG. 6, and its locking edge 54' and the locking projection 18 'of the housing 1' abut on opposite surfaces orthogonal to the axial direction. ing. An annular spacer W is disposed between the oil seal and the shield plate 5 '. The spacer W is axially stuck between the oil seal OS and the shield plate 5 '.

The machine part filled with oil operates in a state where the oil O filled inside the housing 1 ′ is sealed by the oil seal OS. At this time, since the oil seal OS is a product which is usually manufactured by an elastic body such as rubber, the manufacturing tolerance is relatively large and the oil seal OS also expands and contracts depending on the temperature. If not properly disposed inside, oil O leaks from the gap between the oil seal OS and the housing 1 'and the inner ring 2' to the outside, causing an unexpected malfunction such as burning of the mechanical parts.
In order to prevent such a situation, in the mechanical component shown in FIG. 7, the shield plate 5 'is provided with a plurality of locking edges 54' of different thicknesses as in the case shown in FIG. By rotating the shield plate 5 ', the locking edge 54' engaged with the locking projection 18 'of the housing 1' can be changed. Thereby, the position of the shield plate 5 'pressing the oil seal OS is adjusted in the axial direction, and the change amount of the outer diameter and the inner diameter of the oil seal OS is made an appropriate value, and the gap between the housing 1' and the inner ring 2 ' As a result, it is possible to prevent the oil O from leaking and to prevent the deterioration due to the excessive deformation of the oil seal OS.

  The sealing device of the present invention and the torque limiter to which the sealing device is applied have been described above in detail. In the above embodiment, the ring spring is composed of a pair of outer rings and a pair of inner rings, but instead the ring spring is a combination of one outer ring and one inner ring. It can also be configured. Further, it is apparent that it is within the scope of the present invention to appropriately adjust the number and positional relationship of the locking projections and the circumferential change area as well as the number of locking edges in the respective circumferential change areas.

1: Housing 18: engagement projection 2: inner ring 3: outer ring 4: inner ring 5: shield plate 52: recessed portion with bottom (rotation assisting means)
53: Thickness change area 54: Locking edge 55: Protrusion

Claims (6)

A sealing device for sealing an open end of a cylindrical housing in which a space having a circular cross section extending in the axial direction is formed by a disk-shaped shield plate,
The inner circumferential surface of the open end of the housing is provided with a plurality of locking projections spaced in the circumferential direction,
At the outer end of the shield plate, thickness changing regions in which a plurality of locking edges whose axial thickness differs stepwise in the circumferential direction are provided by the number corresponding to the locking projections.
Opposing surfaces orthogonal to the axial direction are respectively formed on the locking projection of the housing and the locking edge of the shield plate,
The axial direction position of the shield plate can be adjusted by rotating the shield plate and changing the opposing surface of the locking edge against which the opposing surface of the locking projection of the housing abuts. Sealing device.   The sealing device according to claim 1, wherein axially protruding protrusions are formed on both circumferential ends of each of the locking edges.   The sealing device according to claim 1 or 2, wherein the shield plate is provided with a rotation assisting means for rotating the shield plate relative to the housing.   A spring is accommodated in a space of the housing, an end of the spring is in contact with the shield plate, and the spring force of the spring can be changed by adjusting the axial position of the shield plate. The sealing apparatus in any one of claim 1 to 3. It is a torque limiter provided with the sealing device of Claim 4, Comprising:
An inner ring rotatable relative to the housing is installed in a space portion of the housing, and a frictional force by the spring is applied to the inner ring,
The torque limiter in which the inner ring relatively rotates when the magnitude of the torque acting on the inner ring exceeds the torque due to the frictional force of the spring.   The spring is a ring spring having an outer ring and an inner ring formed with conical surfaces abutting each other, one of the outer ring and the inner ring being non-rotatably connected to the inner ring and the other being the housing The torque limiter according to claim 5, wherein the torque limiter is non-rotatably coupled thereto.