JP3454782B2 - Rotary joint with shear pin - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to the field of rotary joints such as those used with drying or cooling drums such as dryer drums employed in the manufacture of paper.

[0002]

2. Description of the Prior Art Self-supporting rotary joints have the advantage of being relatively simple in configuration, as compared to trunnion mounted rotary joints, supported by a rotating drum structure associated with the self-supporting rotary joint. However, it is easy to install and maintain. However, the self-supporting rotary joint is supported by a bearing housing fixed to the rotating drum structure, supports the siphon, and is prevented from rotating by the use of torque lugs, thus "fixing" the bearing within the bearing housing. (freezing) causes the rotary joint nipple that is immobile and supports the rotary joint body head to rotate. Rotation of the rotary joint nipple causes the rotary joint body head to rotate, breaking the hose conduits for supplying steam or water and the hose conduit for removing condensate that are attached to the rotary joint body head. The hose conduit attached to the rotary joint body head is usually a flexible hose reinforced with wire such that when the rotary joint body head rotates, the torque lug and the anchor associated with this torque lug are destroyed and the joint hose is Breaks, turns, torn edges and turning wires turn around, creating a very dangerous situation for people in the surrounding area.
Steam is discharged into the area and considerable damage is experienced and humans are threatened until attention is paid to this situation.

[0003]

Because of the advent of higher speed, heavier dryer drums and larger rotary joints, it is possible to support the rotary joint and its associated nipples with roller bearings rather than carbon bushings. desirable. However, roller bearings require regular lubrication and are easier to "stick" and seize than carbon bushings, thus compromising the design of desirable rotary joints for large or high speed equipment in the past, and making them self-supporting. The use of roller bearings in type rotary joints was limited.

It is an object of the present invention that the joint body head is attached to a stationary nipple supported by a bearing, and the joint body head is prevented from rotating when the bearing is fixed to cause rotation of the nipple. The object is to provide a self-supporting rotary joint that is automatically released from the nipple.

Another object of the present invention is to provide a fragile means,
An object is to provide a self-supporting rotary joint that supports the joint body so as to protect the joint body from rotation.

A further object of the present invention is to provide a self-supporting rotary joint which is supported on rolling bearings and which uses adiabatic nipples to reduce the operating temperature of the bearing as steam is moved through the rotary joint. is there.

Another object of the present invention is to provide a self-supporting rotary joint which is supported by roller bearings and which is subjected to axial biasing forces to keep the roller bearings in place during thermal expansion of the roller bearings. It is in.

A further object of the present invention is to support an immovable siphon, the horizontal portion of the siphon support tube serving two purposes, namely in addition to supporting the siphon, to insulate the bearing structure from steam. It is to provide a self-supporting rotary joint that functions as a steam sleeve to assist.

[0009]

In a self-supporting rotary joint for a rotating drum, a bearing housing is mounted concentrically with the drum structure and rotatably with the drum structure. Rolling bearings are arranged in the bearing housing, which form a support for the outer end of a tubular nipple that extends through the journal of the drum for introducing steam into the drum, which tubular nipple normally , A support for the siphon structure located in the drum.

The joint body head is attached to the outermost end of the nipple by a shear pin, and the torque lug formed on the joint body head engages with the torque anchor to prevent the joint body head from rotating and to be connected to the joint body head. Prevents possible damage to heat transfer medium hoses such as steam, water and condensate.

If one or more rolling bearings in the bearing housing become stuck or seized due to corrosion or damage to another bearing, the rotation of the bearing housing is transmitted to the nipple, causing it to rotate. This high torque applied to the nipple is transmitted to the joint body head and rotation of the joint body head is limited by the torque lug associated with the joint body head. The resistance to rotation of the nipple and rotation of the body head causes the pair of shear pins interposed between the nipple and the body head to break, continuing to rotate the nipple but not transmitting this rotation to the body head.

Upon rupture of the shear pin, steam will begin to leak through the O-ring seal, which was previously static and now dynamic, so that maintenance personnel will be aware of this steam leak and be aware of bearing seizure. Become. An electrical alarm is also provided adjacent the bearing structure to sense the rotation of the nipple and electrically indicates the seizure of the bearing.

For large size self-supporting rotary joints, the use of tapered roller bearings to support the rotary joint is desirable due to its ability to carry greater loads than ball bearings. However, tapered roller bearings require lubrication and the high temperatures to which the bearings are exposed due to steam temperature make proper lubrication of the roller bearings difficult. To improve the life of the roller bearing, the present invention employs a steam sleeve inside the nipple, which is fixed to the nipple for accurate rotation with the nipple. The nipple has recesses or spaces that retard heat transfer between the nipple and the siphon support tube / steam sleeve, allowing the bearing to operate cooler than other methods and prolong bearing life. A further improvement in extending the bearing life is achieved by the use of spring means interposed between the roller bearings in order to achieve an exact axial alignment of the roller bearings in the bearing housing, which utilization of all the bearings Allows for accurate axial positioning of roller bearings at temperatures of and to accommodate thermal expansion of bearings.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A typical rotatable heat exchange drum 10 is shown in phantom in the drawings. Such heat exchange drums are commonly used in paper mills for drying purposes, and in some circumstances, similar drums are used for cooling purposes. When dry, the drum 10 contains hot steam, and the rotary joint 1 generally indicates at 12 this hot steam.
2 is introduced into the drum 10 and the condensate is supplied to the rotary joint 12
Remove from drum 10 by. When removing the condensate from the drum, the rotary joint, as is well known, has a siphon device 14 arranged in the drum and for removing the condensate or condensate from the drum.

The drum 10 has a support shaft structure 16 to which an annular bearing housing 18 is fixed by bolts 20. The bearing housing 18 has an annular shape and accommodates and supports a bearing structure described later. The bearing structure supports a tubular nipple 66 and a siphon support tube 22.
2 is typically arranged horizontally and has an outer end located outside the drum and an inner end 26 extending inside the drum (see FIG. 1).
(See) and the steam is attached to this siphon support tube 22
Introduced into the drum by. The inner end 26 of the siphon support tube comprises a siphon pipe support 28 and the outer end of the nipple is supported inside the rotary joint nipple. The nipple 66 supports the rotary joint body head 30, which has a steam inlet port 32 to which a steam supply hose is connected. The rotary joint body head 30 has an axial opening in which a cylindrical siphon bushing 34 is mounted, and a horizontal siphon pipe 36.
Extends through the center of the siphon support tube 22 and has a vertical siphon portion 38 attached to the outer end of the siphon pipe 36 (see FIG. 1). The end of this vertical siphon section 38 has a common siphon shoe or foot 4
0, this siphon shoe or foot 40 is secured to the end of the vertical siphon portion 38 and is positioned adjacent the inner surface of the drum for withdrawing condensate or condensate from the bottom portion of the drum 10. In the structure shown, the siphon 38 is of the “immovable” type, the siphon structure does not rotate with the drum, and the siphon foot 40 is always adjacent to the bottom of the drum to remove condensate from the drum. Are arranged.

A siphon fitting 42 is bolted to the body head 30 and communicates with the siphon pipe 36. The body head has a radially extending torque lug 48 (see FIG. 3) which cooperates with a stationary torque anchor 50. The cooperation of the torque lug 48 and the torque anchor 50 prevents the body head 30 from rotating about the rotation axis of the drum.

Steam is supplied to the body head 30 and its inlet 32 by an enhanced steam hose 44 and condensate is withdrawn from the rotary joint by a siphon hose 46 (see FIG. 3) in communication with the siphon fitting 42.

Bearing housing 18 houses a pair of axially spaced tapered roller bearings 52 and 54. The annular collar 56 has bearings 52 and 5
4 and is engaged with the stop ring 58,
The stop ring 58 is located in an annular groove configured in the steam sleeve for axially positioning the roller bearing 54. An annular disc spring 60 interposed between the end of the collar 56 and the inner ring of the bearing 52 imparts an axial biasing force on the bearing 52, accommodating axial expansion of the bearing due to increased temperature of the bearing components. The roller bearings 52 and 54 are held within the bearing housing 18 by an annular bearing cap 62, which is held in place by screws 64 threaded into the bearing housing 18.

An annular air space 74 is provided between the nipple and the siphon support tube to reduce heat transfer from the outer end 24 of the siphon support tube to the bearings 52, 54. The nipple 66 has a tapered bore 68, which cooperates with a tapered surface 70 configured on the outer end of the siphon support tube 22 to accurately position the siphon support tube within the nipple and the siphon support tube and nipple. An O-ring seal 72 between and prevents steam from entering an annular air space 74 configured in a bore inside the nipple. Therefore, the air space 74
Is the hot siphon support tube 22 and bearing 5
An annular space is formed between the inner rings of the two and 54 to reduce the amount of heat transferred between the siphon support tube and the bearing due to the low heat transfer characteristics of the chamber defined by the air space 74.

The outer end of the siphon support tube 22 is fixed to the nipple with a placement key pin 76 (see FIG. 2) and a threaded hollow nut fastener 92 which attaches the tapered portion 70 of the support tube 22 to the nipple. It is pulled into the inner tapered portion 68. The outer end of the nipple 66 has a flange 78 extending in the radial direction.
8 is in contact with the annular carbon bushing 80. An axial shoulder 82 is configured on the body head 30, which cooperates with an O-ring seal 84 to statically prevent vapor leakage between the body head or nipple and the atmosphere. An axially extending hole 86 is formed in the flange 78 which is aligned with the axially extending hole 88 formed in the body head to be in spaced relationship with the axis of the nipple and a pair of diametrically opposed shear pins 90.
Are located in holes 86, 88 to form a torque-resistant connection between the nipple and support tube and body head 30. During normal operation of the rotary joint, the shear pin 90
Prevents relative rotation between the siphon support tube / steam sleeve and nipple assembly and the body head.

The lubrication of the roller bearings 52 and 54 is
As can be seen in FIG. 2, this is accomplished by a grease fitting neck 94 in communication with a suitable passageway to the roller bearing.

If it is desired to utilize an electrical alarm switch which senses the rotation of the nipple, an electrical switch 96, such as that shown schematically in FIG.
4 is provided adjacent to a structure fixed to the outer end of the nipple.

Normal operation will be described. Steam hose 44
Is introduced into the rotary joint 12 by means of the tube 22 and is introduced into the drum 10 through the tube 22. The bearing housing 18 rotates with the drum 10 and supports the nipple, which is the rotary joint body head 30 and the outer end 2 of the siphon support tube 22.
Supports 4. This type of rotary joint arrangement is considered "self-supporting" because the entire rotary joint structure is supported by the drum structure.

Due to the engagement of the torque lug 48 and the torque anchor 50 of the body head, the rotary joint head 30 is held against rotation by the small rotational frictional forces of the bearings and siphon support tube 22 and associated siphon support structure. 28 is immovable. When the rotary joint operates in the normal manner, the shear pin 90 prevents rotation of the nipple and the structure associated with the nipple.

One or both roller bearings 5
If 2, 54 fails, sticks or seizes, a very large torque force is suddenly applied to the nipple 66 and siphon support tube 22. Such torque forces also tend to rotate the rotary joint body head 30, and the shear pin 90 is designed to shear in such situations,
Unless large torque forces are applied to the body head 30 by the rotating nipple 66, flange 78, and siphon support tube 22, the torque lug 48 or torque anchor 50 will break. The acceptance of the pilot portion 82 of the body head into the now rotating nipple bore acts as a guide to maintain the position of the body head and rotation of the siphon pipe 36 within the siphon bushing 34 relative to the body head 30. The siphon pipes are kept aligned.

When the pin 90 is sheared, rotation occurs between the flange 78 and the body head pilot shoulder 82, causing the previously static seal 84 to become a dynamic seal, immediately beginning to leak steam and shear pin 90. Notify maintenance personnel that the was broken. In addition, if the electrical switch 96 is used, the electrical switch 96 also signals the rotation of the steam sleeve and nipple assembly to signal bearing seizure.

From the above description, the shear pin 9 which is easily broken
It will be appreciated that the use of 0 protects the body head 30 against rotation and prevents breakage of the hoses 44, 46 and the dangerous incidental conditions that occur when these hoses break. Thus, the practice of the present invention allows for the use of roller bearings with large self-supporting rotary joints, eliminating previously existing problems with such use of roller bearings.

It should be appreciated that various modifications to the inventive concept will be apparent to those skilled in the art without departing from the spirit and scope of the invention.

[Brief description of drawings]

FIG. 1 is a front partial cross-sectional view showing a self-supporting rotary joint and a typical siphon structure utilizing the concepts of the present invention, the rotary drum being shown in phantom.

FIG. 2 is an enlarged front sectional view of a rotary joint.

FIG. 3 is a perspective view of a self-supporting rotary joint constructed according to the present invention showing the structure of the supply hose, siphon hose and torque lug.

[Explanation of symbols]

10 drums 12 Self-supporting rotary joint 18 Bearing housing 22 Support tube 30 Rotary joint body head 32 entrance 34 Siphon fitting 36 Siphon pipe 52 bearing 54 bearing 60 disc spring 66 nipples 78 Flange 86 holes 90 shear pins

Continuation of the front page (56) Reference JP-A-1-1249898 (JP, A) JP-A-61-266694 (JP, A) JP-A-4-262024 (JP, A) JP-A-60-148797 (JP , A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16D 9/08 D21F 5/02 F16L 39/04

Claims (8)

(57) [Claims] 1. A self-supporting rotary joint for introducing steam into a heat exchange drum rotating about a rotation axis, comprising:
An elongated tubular bearing housing fixed to the drum concentrically with the axis of rotation of the drum and rotatably with the drum; and a tubular nipple concentric with the axis of rotation of the drum in the tubular bearing housing.
Bearing means mounted within the tubular bearing housing and interposed between the tubular bearing housing and the tubular nipple for supporting the tubular nipple;
A rotary joint body head, a frangible means for connecting the rotary joint body head to the tubular nipple, a steam tube having an outer end extending through the tubular nipple and an inner end located in the drum. Non-rotating means formed in the rotary joint body head, which is in communication with each other, and which blocks rotation of the steam inlet formed in the rotary joint body head and the rotary joint body head about the rotation axis of the drum. A self-supporting rotary joint in which, when the torque force applied to the rotary joint body head by the tubular nipple exceeds a predetermined value, the breakable means is broken. 2. Further extending through the steam tube,
An immovable siphon pipe having an inner end arranged in the drum and an outer end extending through the rotary joint body head, a siphon connected to an inner end of the siphon pipe, and a siphon pipe of the siphon pipe. The self-supporting rotary joint according to claim 1, further comprising a siphon fitting that is connected to the outer end portion and is attached to the rotary joint main body head. 3. The self-supporting rotary joint of claim 1, wherein the bearing means comprises a roller bearing. 4. A set of two roller bearings axially spaced from each other disposed within the tubular bearing housing and the set of roller bearings are adapted to thermal expansion and have a minimum internal clearance. 4. A self-supporting rotary joint according to claim 3, comprising spring means axially positioned for maintaining. 5. The self-supporting rotary joint of claim 1, further comprising thermal insulation means configured on said tubular nipple, said bearing means engaging and supporting said tubular nipple. 6. The radius of the heat insulating means having an annular recess formed in the tubular nipple, creating an air space between the bearing means and the outer end of the steam tube, and passing through the tubular nipple. A self-supporting rotary joint as claimed in claim 5 which forms a thermal barrier against directional heat transfer. 7. The tubular nipple further comprises a radially extending flange disposed adjacent to the rotary joint body head, wherein the fragile means is provided on the flange and the rotary joint body head. 6. The self-supporting rotary joint of claim 5 having at least one shearable pin snugly fitted within the constructed bore and spaced from the axis of rotation of the drum. 8. The self-supporting rotary joint of claim 5, wherein the frangible means comprises at least two shearable pins diametrically associated with each other with respect to the axis of rotation of the drum.