US3625441A

US3625441A - Counterrotating refiner

Info

Publication number: US3625441A
Application number: US861581A
Authority: US
Inventors: Martin O Saltarelli; Alexander D Cormack; Charles Ornstein
Original assignee: Beloit Corp
Current assignee: Beloit Corp
Priority date: 1969-09-29
Filing date: 1969-09-29
Publication date: 1971-12-07
Anticipated expiration: 1988-12-07

Abstract

A counterrotating refiner employs symmetrical construction of motors and the refining section to provide thermal and mechanical stability. The refiner includes a base section for fixedly mounting one portion, the feed portion, of the apparatus and a second base section for mounting another portion of the refiner for movement axially of the apparatus on controlled bearing surfaces for inspection and maintenance, and to provide for axial motion of one end of the refiner to eliminate stress concentrations upon expansion due to an increase in temperature. The refiner also employs structure for sealing nonparallel flanges of the refining chamber while maintaining the refining discs in a parallel relationship to prevent distortion of the frame of the refiner.

Description

United States Patent inventors Appl. No.

Filed Patented Assignee Martin 0. Saltarelli Lenox;

Alexander D. Cormack; Charles Ornstein, both of Pittsfield, all of Mass.

Sept. 29, 1969 Dec. 7, 1971 Belolt Corporation Beloit, Wis.

COUNTERROTATING REFINER 16 Claims, 19 Drawing Figs.

Primary E.taminer- Donald G. Kelly Auorney--Hill, Sherman, Meroni, Gross & Simpson ABSTRACT: A counterrotating refiner employs symmetrical construction of motors and the refining section to provide thermal and mechanical stability. The refiner includes a base section for fixedly mounting one portion, the feed portion, of the apparatus and a second base section for mounting another portion of the refiner for movement axially of the apparatus on controlled bearing surfaces for inspection and maintenance, and to provide for axial motion of one end of the refiner to eliminate stress concentrations upon expansion due to an increase in temperature. The refiner also employs structure for sealing nonparallel flanges of the refining chamber while maintaining the refining discs in a parallel relationship to prevent distortion of the frame of the refiner.

PATENTEDDEB nsn 3.625441 SHEET [MM 10 PATENTEDDEC Han 3.625441 SHEEN UBUF 10 PATENTEDUEB nan 3,525,441 sum ouur 10 j gj 56 m xlw 2 PATENTEDUEB Han 3525441 SHEET USUF 10 PATENTEDDEB 71921 3,6255441 SHEET 07UF 10 PATENTEI] DEC 7 I97! SHEEI DSUF 10 COUNTERROTATING REFINER BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to counterrotating refiner apparatus, and more particularly to the elimination of distortion in such apparatus due to temperature and/or mechanical forces which develop during operation thereof.

2. Description of the Prior Art Refiners which employ a pair of parallel rotating attrition surfaces are well known in the art and employed extensively in the attrition milling of various materials including wood chips, saw dust, corn, peanuts, and the like, to obtain fibers of optimum length for use in making paper. Generally speaking, any one, or a combination of the elements of thrust, torque and temperatures developed within refiners operate in a disadvantageous manner to cause misalignment of the rotating equipment. This misalignment negates the parallel relationship between the refining surfaces and causes a decrease in the quality of the end product.

It is then highly advantageous, and a primary object of the present invention, to provide a stable counterrotating refiner by eliminating distortion due to temperature and/or mechanical forces to insure optimum parallelism of the refining surfaces which in turn will provide optimum performance of the refiner and optimum quality of the product of the refiner.

SUMMARY OF THE INVENTION According to the invention, a counterrotating refiner is provided with a fixed feed end and a control end which is movable along controlled bearing surfaces axially with respect to the feed end. The rotating refining discs which carry the attrition surfaces are aligned for parallelism by shifting and/or shimming the control end refining disc with respect to the feed end refining disc. After alignment of the discs parallel to one another, and the refiners are bolted, the mating flanges of the feed end of the refiner and the control end of the refiner are generally not parallel to each other due to the normal buildup of manufacturing tolerances. Bolting these two flanges in this out of parallel condition, without the utilization of adjustment bushings or shims would strain and distort the frames and destroy the alignment of the refining discs. Since the refining cavity must be sealed with a compressible gasket between the flanges, there is no metal-to-metal contact between the flanges and the bolts will be subject to the the teeth loads. Therefore, an adjustment screw assembly including an adjustment bushing provides a metaI-to-metal contact.

A movable base assembly is provided in accordance with the principles of the present invention to facilitate maintenance and to absorb forces generated during refining. The control end of the refiner is movable axially of the apparatus with respect to the feed end to permit ample working space for changing refining discs and cleaning the refining chamber. The base assembly includes a plurality of bearings which movably support the control end of the refiner on a pair of cylindrical tracks while firmly holding the refiner against lateral forces. The refining thrust load and the adjustment bolts on the refiner flange hold the control end of the refiner against axial vibration. This permits the control end of the refiner to move axially with changes in length due to heat and thrust loads and prevents distortion of the refiner frames which cause misalignment of the refiner discs, as is found with refiner sections that are fixedly anchored with respect to one another.

According to the invention, a labyirnth seal is provided between the feeder spout and the rotating head which holds the refiner disc on the feed end of the machine to prevent unrefined stock from bypassing the refining discs. The seal has the particular advantages of easy installation, reduced maintenance and a longer labyirnth passage, than heretofore known in prior seal devices.

Oil leakage from the bearings to the driving motors due to a pressure differential caused by the fan action of the motors must, of course, be prevented. Prior refiners have customarily employed lip4ype oil seals at these locations, which seals have proved inadequate due to their rapid wear at the required high surface speeds of the associated shafts. These seals required frequent inspection and replacement. According to the present invention, a vacuum breaker arrangement is utilized in conjunction with a labyirnth seal to provide an effective and maintenance free seal which virtually eliminates the need for inspection.

Also, according to the invention, the antifriction bearings are insulated in constructions which employ motors of high horsepower rating, say 1,000 hp. or more, to prevent damage to the bearings due to stray currents in the refiner apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects, features and advantages of the invention, its organization, construction and operation will be readily apparent from the following description of a preferred embodiment thereof taken in conjunction with the accompanying drawings, although variations and modifications may be effected without departing from the spirit and scope of the novel concepts of the disclosure, and in which:

FIG. I is perspective pictorial representation of a counterrotating refiner constructed in accordance with the principles of the present invention and shown with the control end axially displaced from the feed end;

FIG. 2 is a side-elevational view of the refiner of FIG. I shown with the control end and feed end in operable relationship, and showing a portion of the refining section of the apparatus in fragmentary section;

FIG. 3 is an end-elevational view of the control end of the refiner illustrated in FIGS. 1 and 2;

FIG. 4 is an illustration of the motor and housing which may constitute a portion of either the feed end or the control end of the refiner, illustrating in a broken away and partially sectioned portion thereof the stator, rotor and shaft of the motor;

FIG. 5 is a sectional elevational view of a thrust bearing for use with the motor of the FIG. 4;

FIG. 6 is a sectional elevational view of a radial bearing for use with the motor illustrated in FIG. 4;

FIG. 7 is sectional view of the adjustment screw assembly for insuring a parallel relationship between the refining surfaces while providing for misalignment of the feed end and control end of the refiner;

FIG. 8 is a sectional elevational view of the refining section of the refiner illustrated in FIGS. I and 2;

FIG. 9 is a plan view of a base assembly constructed in accordance with the present invention;

FIG. 10 is a sectional view of the base assembly of FIG. 9 taken along the line XX;

FIG. II is a sectional view of the base assembly illustrated in FIG. 9 taken along the line XI-XI;

FIG. I2 is a sectional view of a portion of the apparatus illustrated in FIG. 9 taken along the line XII-XII;

FIG. I3 is a sectional view of the apparatus illustrated in FIG. 12 and taken along the line XIII-XIII;

FIG. M is a fragmentary end view of a portion of the apparatus illustrated in FIG. 9;

FIG. 15 is an elevational view of the motor end bell construction which is partially shown in FIG. 3;

FIG. I6 is a sectional view of the apparatus illustrated in FIG. I5 and taken along the line XVIXVI;

FIG. 17 is an elevational view of the opposite side of the apparatus illustrated in FIG. 15;

FIG. I8 is an end elevational view of the bell construction illustrated in FIG. I7; and

FIG. 19 is a sectional view of the ripe construction of the apparatus illustrated in FIGS. 15-18 taken along the line XIX XIX of FIG. I7.

DESCRIPTION OF THE PREFERRED EMBODIMENT General Description In the drawings, particularly in FIGS. 1-4, there is illustrated and generally referenced at 10 a counterrotating refiner comprising a feed end 11 and a control end 12 which are disposed on opposite sides of refining section 13 and mounted on a base assembly 14. The feed end 11 is fixedly mounted on a stationary raised portion of the base assembly 14, further referenced 14fs. The control end 12 is affixed to a portion of the base assembly 14, further referenced 14011, which, in turn, is mounted for movement axially of the refiner on a stationary portion of the base assembly, here referenced 14cs.

The feed end 11 and the control end 12 each carry a

rotatable refining disc

17 and 18, respectively, which form part of the refining section 13. The

refining discs

17 and 18 are respectively carried by shafts l and 16 of the feed end motor and the control end motor.

The control end motor and the feed end motor and their corresponding housing may be of similar construction as shown in the drawings. Referring in particular to FIG. 4, a motor for the control end or the feed end would comprise rotor 19 carried by a suitably journaled shaft and a stator 20 surrounding the rotor. The motor apparatus is contained in a housing 21 having a vent structure 22 with vent openings and deflecting loovers 23 and 24, respectively. The symmetrical construction of the motor and housing apparatus of the feed end 11 and the control end 12 are indicated by the corresponding reference numerals 21f-24f and 21c-24c, respectively.

The counterrotating refiner is provided with a feeder assembly 25 for feeding the raw stock into the refiner by way of a feed channel 26.

Mounted on the control end 12 of the refiner is a control console 37 for controlling and monitoring the operation of the refiner l0 and a lubricating apparatus for providing proper lubrication of the equipment.

DETAILED Description Feeder Assembly (FIGS. 1 and 2). The feeder assembly 25 comprises a feed channel 26 for feeding stock, such as wood chips, saw dust, corn, peanuts and the like received at a stock inlet 30 to the refiner section 13. The feed channel 26 includes a feed worm 27 therein which is drivingly connected to a motor or prime mover 28 through feed driving connections 29. The stock is moved by the feed worms 27 through the channel to the feeder spout 125 which connects the feeder assembly 25 in communication with the refining section 13 (FIG. 8).

Refining Section 13 (FIG. 8). The refining section 13 comprises a pair of oppositely

rotating refiner discs

17 and 18 respectively carried by shafts and 16 of the feed end and control end motor rotors 19. The

refiner discs

17 and 18 carry

respective attrition members

100 and 101 which are secured thereto by screws 102-106. The relationship between screw 106, refining disc 18 and attrition member 101 illustrates an alternate method of connecting the attrition member 101 to the refining disc 18 as opposed to that illustrated with respect to screws 102-105. Refining disc 18 also carries secured thereto by screws 99 a cap 97 having distribution surfaces thereon. Cap 97 covers a nut 95 which secures the refining disc 18 to shaft 16, disc 18 being radially secured to shaft 16 by a key (not shown) corresponding to keyway 108. An O-ring 109, a sleeve 110 and a packing ring 111 provide water tight seals between the chamber of the refining section defined by wall 76 and lining 86, and shaft 16.

The refining disc 17 is secured to the shaft 15 by a key (not shown) corresponding to keyway 107 and by a nut 94. A cap 96 with a distribution surface thereon is, secured to the refining disc 17 by screws 98. A sleeve 116 carrying an electrical insulator 120 and an O-ring 117 provide a water tight seal between the shaft 15 and the channels 112. The shaft 15 is further provided with a water tight relationship with respect to channel 113 by a compression ring 118 and a plurality of packing rings 119, the compression ring 118 being secured and tightened by an eye bolt 115 of a seal adjusting apparatus 114 on the exterior of the refiner section inlet apparatus 33.

The refiner section inlet apparatus 33 includes an annulartype chamber 113 which receives stock from an inlet channel 34 which is secured to the feed channel 26 of the feeder assembly 25 at flanges 31 and 32.

The refiner section inlet apparatus 33 is secured to the wall 75 of the refiner section by way of a plurality of screws 121. The refiner section inlet apparatus 33 has further attached thereto the stationary portions 123 of a labyimth seal 122 by means of a plurality of screws 128. The labyirnth seal 122 is preferably constructed of a pair of semicircular portions which constitute the seal portion 123 upon assembly. Although not particularly illustrated in the drawing seal portion 123 comprises a pair of semicircular seal portions, an upper portion and a lower portion, the joining lines of these portions lying in front of and behind the shaft 15 as viewed in FIG. 8. The rotating portion 124 of the seal 122 is attached to the refining disc 17 by way of a plurality of screws 129. The labyimth seal portions 123 and 129, as well as the

chambers

112 and 113, receive a water spray through a water spray connection 126 having an opening 127 therein. The water effects an increase in sealing at the seal 122 so that any leakage at this point would be clear water and operates as a cooling for the stock as it is processed between the attrition surfaces of the

attrition members

96, 97, 100 and 101.

The mass, after undergoing attrition between the aforementioned surfaces, leaves the periphery of the refining discs and may be taken off at any number of outlets of the refining section indicated at 130, however, due to the gravity, outlet 1300 is preferred through the base of the refiner.

Adjustment Screw Assembly 81 (FIGS. 1 2 and 7). A plurality of adjustment screw assemblies 81 at each of the four comers of the wall 76 of the refining section 13. The adjustment screw assemblies operate to lock the liner 86 of the wall 76 and the top plate of the refiner section 13 and its liner 86 together in a sealed engagement with a gasket 87 therebetween when the control end 12 is moved axially toward the feed end 11 and the

refining discs

17 and 18 are aligned in a parallel relationship. The refining discs are aligned for parallelism by shifting and/or shimming the control end 11 with respect to the feed end 12. After this initial alignment is made the apparatus is secured to the respective portions of the base assembly. Bolting of the top plate 83 of the refiner section 13 (feed end 11) to the flange or refiner housing end plate 76 in an out of parallel condition would strain and distort the frames of the apparatus and destroy the alignment of the

refining discs

17 and 18. Therefore, for use after alignment, the adjustment screw assemblies 81 are provided to compress the gasket 87 and to provide a metal-to-metal contact between the feed end 11 and the control end 12.

Each adjustment screw assembly 81 comprises a threaded adjustment bushing 88 to be received by a threaded bore 82 and hole 87a in gasket 87. A jamnut 89 is provided with a threaded bore 90 for receiving the threaded bushing 88, the threaded bushing 88 being advanced through plate 76 for abutment with the top plate 83 of the refining section 13 at a desired spacing between the top plate 83 and end plate 76. This spacing is sufficient for compression of the gasket 87 to provide a water tight seal. The jamnut 89 locks the adjustable bushing in place. The assembly 81 is further provided with an adjustment stud 91 including a threaded shank 92 and a head 93. The adjustment stud 91 extends through a bore in the adjustable bushing 88 and into a threaded bore 84 of the top plate 83. The adjustable stud may therefor be rotated to move the top plate 83 relative the end plate 76 to compress the gasket 87 in accordance with the permitted spacing set by the adjustable bushing 88.

Attention is invited that the refiner

section end plates

75 and 76 are rigidly secured to the feed end 11 and the control end 12 by way of a plurality of posts or rigid members, 77-66 of which are illustrated in the drawings, to further provide mechanical stability between the feed end 11 and the control end 12 when the two ends are mated in an operable relationship to form the refiner section 13.

Base Assembly 14 (FlGS. 1-3 and 9-14). Ashereinabove described, the refiner 10 is provided with a base assembly on which the feed end 11 is fixedly secured and the control end 12 is axially movable. The general configuration of the base assembly will be appreciated from FIGS. 1-3; however, attention is invited to FIGS. 9-14 for a more detailed description thereof.

FIG. 9, and F1GS. 10-14 illustrate the control end stationary portion of the base assembly 14cs and the control end movable portion of the base assembly 14cm, the feed end stationary portion 14fs being readily apparent to those skilled in the art by reference to the more general showing in FIGS. 1 and 2. The movable base assembly includes frame mounting members 131 extending longitudinally of the control end stationary portion Mar. The frame mounting members include a plurality of holes spaced longitudinally thereof for mounting the control end 12 of the apparatus Connecting the frame mounting members are a plurality of lateral frame members 133 spaced as required along the length of this portion of the base assembly. Also extending longitudinally of the mounting members 131, and affixed to the mounting members 131 and the lateral frame members 133 as shown in the drawing by welding, are a pair of longitudinal frame members 134. Each of the longitudinal members 134 have a seat milled on their upper and outer corners for receiving therein and having bolted thereto by means of screws 136 respective cylindrical carriage rails 135. Affixed thereto to the upper surfaces of longitudinal frame members 134 is a plate 137. A tubular cross member 138 aids in supporting the plate on the lateral frame member 133.

Mounted on the plate or floor 137 is a hydraulic ram or hydraulic cylinder 139 having an extensible piston 140 which is connected by way of a movable frame member 141 to the control end movable base portion 14cm. The hydraulic, or perhaps pneumatic, ram is mounted in the particular embodiment illustrated such that extension of the piston 140 thereof effects movement of the control end movable portion 14cm of the base assembly 14 in a direction to part the feed end 11 and the control end 12.

The frame portion 141 of the base assembly movable portion 14cm comprises a top plate 142 for supporting the control end apparatus 12 of the refiner 10. The base portion 14cm further includes an end wall 143 and a plurality of screws 144 for securing the top plate 142 and the end wall 143 to the frame portion 141.

The movable portion 14cm of the base assembly 14 further includes a pair of sidewall assemblies 145 comprising a longitudinally extending vertically oriented member 146 and a horizontally oriented longitudinally extending member 147 which are secured together by suitable means such as welding. The sidewall assembly 145 further includes a longitudinally extending angularly disposed member 148 and a longitudinally extending angularly disposed member 149 and a plurality of generally vertically oriented members 150 secured to the

members

147, 148 and 149. The members 147-150 are covered on their exterior by a cover skirt 151 and provide a longitudinally extending skirt type housing for bearings 152 which support the control end in the vertical direction and bearings 153 which stabilize the control end in the horizontal and vertical directions. The bearings 152 and 153 are provided with hearing seals 154.

End plates 155 are provided at the end of each bearing station, which can be seen in the drawing to include at least two sets of bearings on each side of the base assembly 14. Secured to the end or link plates 155 by screws 158 and flanges 157 are felt wipers 156 for maintaining the cylindrical carriage rails in a dirt-free condition.

As can be seen in FIG. 14, the stationary portion s is provided with a locking mechanism 186 to prevent movement of the movable portion 14cm. The locking mechanism comprises a locking pin 1811 having a plurality of projections 192 thereon which are rotatable with the pin 1 into a free or engaged condition with aperture 167 in plate 137 upon rotation of the L-shaped handle 139. Handle 189 is biased to a latch condition by wire spring 193. Movement of the wire spring 193 to release the latch permits rotation of a L-shaped plate 190 about a hinge 191 so as to overlie the rail 135 and place the L- shaped plate 191) in an interference relationship with the bearings which support the movable portion Mom. The movable portion 14cm may therefore be locked into position with respect to the stationary portion 14cs.

Motor End Bell 159, Thrust Bearings and Radial Bearings (F1GS. 4-6 and 15-19). Referring first to FIGS. 15-19, there is illustrated an end bell assembly 159 for supporting a bearing assembly for the shaft of the motor apparatus. The end bell assembly 159 comprises a bearing support plate 160 having a plurality of fan-shaped holes 161 therein to decrease the weight of the plate, provide for better air circulation and provide access to certain components of the motor. A bearing housing guide ring 162 is provided as an arcuate-shaped component having a bore 163 for receiving a bearing therein and a keyway 164 for locking the associated bearing against rotation.

The bearing support plate is also provided with a plurality of holes 165 for receiving screws or bolts for securing the bearing support plate 160 to the housing 21 of the motor assembly.

The end bell assembly 159 further comprises a plurality of rib assemblies 166 having a T cross section including members 167 and 168 which are welded together and in turn welded to a cover plate 169 which forms the exterior of the distal ends of the motor housings 21. The rib assemblies 166 are also welded to the bearing housing guide ring 162 and to a peripheral side plate 173.

The cover plate 169 includes a plurality of rectangularly shaped holes 170 therein having corresponding cover plates 171 which are attached to cover plate 169 by way of screws 172. Holes 170 provide access to the interior of the end bell assembly 159 and through the last-mentioned apparatus to the motor equipment through the fan-shaped holes 161.

The peripheral side plate 173 also includes at least one rectangular hole 174 therein, and an associated cover plate (not shown), for access to the bearing assembly and motor equipment.

Attention is particularly invited to the four mounting bars 176-179 including respective threaded bores 180-183 therein for receiving screws to secure the end bell assembly 159 to the stator frame in a manner which provides rigidity in the axial direction of the refiner immediately adjacent the

corresponding motor shafts

15 and 16.

The peripheral sidewall 173 is provided with a pipe coupling 175 for extending the vacuum breaker connection to the associated bearing over an intermediate conduit (not shown).

Referring now to FIG. 5 there is illustrated a thrust bearing which comprises an annular thrust bearing housing 39 which is connected to an end cover 43 by way of a plurality of capscrews and lockwashers 45 and 46, respectively. The end cover 43 includes a suitable bore for receiving the distal end of the motor shaft as illustrated in the drawing and a thrust bearing sleeve 40 is provided, also suitably bored to receive the end of the same shaft, the thrust bearing sleeve 40 being secured to the end of the shaft by way of capscrews 53 and a retaining wire 41 locking the screws 53 against accidental extraction.

The thrust bearing sleeve 40 is provided with two bearing

seats

49 and 50. The bearing seat 511 of an electrical insulator 52 receives bearing 48 and forces the bearing race thereof against the end wall of the thrust bearing housing 39. The electrically insulating bearing seat 51 receives a bearing 47, as does a bearing seat 49 which is provided in the end cover 43.

The thrust bearing housing 39 is provided with at least one oil outlet 54 and at least oil inlet 54a in communication with the bearings 47 and 48, the illustrated oil inlet obtaining this communication through an aligned hole in the end cover 43. The end cover 43 is provided with a vacuum breaker port 56 for communication with the pipe connection 175 of the peripheral sidewall of the above-discussed end bell assembly 159, and in combination with the labyimth grooves 56a provides an effective and maintenance free seal which virtually eliminates the need for inspection which is required with the prior employed lip-type oil seals.

Each of the bearings 47 and 48 are provided with endsensing-type thermal detectors 57 and 58, respectively, which, are in turn, connected to the control apparatus 37, or any other suitable alarm indicating apparatus, to provide an indication of bearing temperature The thrust bearing housing 39 is also provided with a key 44 secured thereto by means of a screw 55. The thrust bearing is inserted into the bore 163 of the bearing housing guide ring 162 with key 44 extending into keyway 164 to lock the thrust bearing against rotation.

A radial bearing for the other end of the motor apparatus for the feed end of the machine and the control end of the machine is illustrated in FIG. 6 as comprising a radial bearing housing 59 and an end cover 60 bored to receive different diameter portions of the motor shaft. Also, mounted on the shaft for rotation therewith is an oil flinger 61 and a bearing 65 which are held in place against an abutting surface of the shaft by means of a threaded bearing locknut 70, having a resilient insert 71, for engagement with a threaded shaft section 72. A water flinger 62 is mounted on the shaft for rotation therewith and includes a groove therein having an O-ring 73 for providing a watertight seal thereat.

The radial bearing further includes an end-sensing temperature detector 69 for providing a reading of bearing temperature as discussed above with respect to the thrust bearing.

The bearing is provided with oil inlets and outlets only one of which is shown and vacuum breaker ports 68 which in combination with labyimth grooves 74 provide an effective and maintenance-free oil seals, as discussed above with respect to the thrust bearing.

The radial bearing is also provided with a key 63 which is secured to the radial bearing housing 59 by means of a screw 64. As in the case with the thrust bearing, the radial bearing is positioned in a bearing housing guide ring and held against rotation by means of a cooperating keyway for the key 63.

The foregoing description has set forth a counterrotating refiner having parallel rotating attrition surfaces which are maintained in their parallel relationship under all operating conditions by the provision in the refiner of unifonn thrust, torque and temperature-absorbing members in a symmetrical manner around the refiner. The symmetrical distribution of forces is accomplished by distributing the forces through stress members of equal strength at all points in a plane per pendicular to the drive shafts of the refiner. The moveable frame of the refiner also permits an axial motion of one end of the refiner with respect to the other end thereof to eliminate stress concentrations due to thermal expansion. The symmetrical construction of the motors and refiner housing thereby provides thermal and mechanical stability for the refiner. Further, the mobility of one end of the refiner with respect to the other end along controlled bearing surfaces provides for ease of maintenance and inspection of the refiner.

What we claim is:

1. Apparatus for defibrating fibrous stock comprising a pair of prime movers each having a rotating shaft disposed in substantial axial alignment with the other, a first of said prime movers being fixed and the second of said prime movers being axially movable relative to said first prime mover,

first attrition means carried on the shaft of said first prime mover for rotation therewith,

second attrition means carried on the shaft of said second prime mover for rotation therewith parallel to said first attrition means,

means defining a refining chamber enclosing said first and second attrition means, and including a first portion fixed to said first prime mover and a second portion fixed to said second prime mover,

means for sealing said first and second portions together to form the refining chamber, said sealing means including a compressible gasket disposed between said portions, means for connecting said first and second portions to compress said gasket and provide a seal thereat, means for selectively adjusting the distance between said portions and the compression of said gasket, and

means for feeding fibrous stock to the refining chamber.

2. Apparatus according to claim 1, wherein said apparatus comprises a first plurality of rigid members spaced-apart about the shaft of said first prime mover and fixedly secured between said first prime mover and said first portion of said means which define said refining chamber, and a second plurality of rigid members spaced-apart about the shaft of said second prime mover and fixedly secured between said second prime mover and second portion of said means which defines said refining chamber whereby forces generated in the refining operation are evenly distributed axially of the defibrating apparatus.

3. Apparatus according to claim I, wherein said first portion of said refiner housing includes an aperture therein; said means for feeding stock including means forming a stock feed channel disposed in sealed engagement with said aperture of said first portion with the channel thereof in communication with said refining chamber, a bore in said stock channel-forming means receiving the rotating shaft of said first prime mover, and an annular labyrinth seal including a first seal section mounted on said first attrition means for rotation therewith and a second seal section mounted on said stock channel forming means in sealing engagement with said first seal section.

4 Apparatus according to claim 1, wherein one of said prime movers comprises a rotor mounted on the associated shaft, a stator mounted about said rotor and having a stator frame, and an end bell assembly having a central aperture, thrust bearing apparatus secured in said aperture and a plurality of rigid members extending from said end bell assembly immediately adjacent said central aperture and spaced-apart thereabout and secured to said stator frame to thereby provide a fixation of said shaft against thrust forces exerted thereon.

5. Apparatus according to claim 4, wherein said thrust bearing apparatus includes means defining a chamber, bearing means in said chamber, means providing lubricant within said chamber, an opening in said chamber defining means for receiving the end of said shaft, means mounting said bearing means on said shaft, labrynith-sealing means fonned adjacent the shaft-receiving opening and a vacuum port formed in said chamber-defining means in communication with said shaft adjacent said labrynith-sealing means, said sealing means and the application of a vacuum to said port minimizing lubricant leakage to the exterior of said thrust bearing.

6. Apparatus according to claim 5, wherein means are included for electrically insulating said shaft from said means defining said chamber.

7. Apparatus according to claim 1, comprising a base assembly including a fixed base portion mounting said first prime mover and a movable base portion mounting said second prime mover, said movable base portion being movably mounted on said fixed base portion.

8. Apparatus according to claim 7, comprising means secured to said base portions and operable to move said movable portion relative said fixed base portion.

9. Apparatus according to claim 8, wherein the last-named means is a fluid-operated ram device having a cylinder connected to one of said base portions and an extensible member connected to the other of said base portions.

10. Apparatus according to claim 7, wherein said fixed base portion comprises a plurality of spaced-apart elongate carriage rails and said movable portion includes bearing means for supporting said movable portion on said carriage rails.

11. Apparatus according to claim 10, wherein said carriage rails are cylindrical rods and said bearing means includes arcuate bearing surfaces at least partially embracing said cylindrical rods.

12. Apparatus according to claim 10, comprising means fixed to said movable base portion for wiping said carriage rails.

13. Apparatus according to claim 10, comprising releasable latching means mounted on one of said base portions and including means selectively movable in and out of an interference relationship with the other of said base portions.

M. Apparatus for defibrating fibrous stock, comprising a pair of parallel axially aligned facing refining members mounted for rotation,

a corresponding pair of prime movers for rotating said refining members in opposite directions,

means mounting said prime movers for relative axial movement,

means forming a refining chamber for enclosing said refining members and including first and second sections affixed to separate ones of said prime movers and having parallel mating portions,

compressible sealing means disposed between said first and second sections, and

means providing a gap of variable dimension about said refining chamber between said first and second sections to compensate for nonparallelism between said mating portions including means for compressing said sealing means as permitted by said gap.

15. The apparatus set forth in claim 14, wherein said means providing said gap comprises,

a plurality of apertures in said compressible sealing means spaced-apart about and adjacent the outer on one thereof,

a plurality of first threaded bores in said mating portion of said first section, v

a plurality of second threaded bores in the mating portion of said second section,

a plurality of adjustable bushing each including head,

a central bore and a threaded shank engaging a second threaded bore and extending through an aperture in said sealing means to abut said first section,

a nut carried on said threaded shank for adjustment against said second section, and

an adjustable stud including threaded shank extending through said central bore and engaging a first threaded bore, and a head for abutting said head of said bushing 16. Apparatus according to claim 7, comprising releasable latching means mounted on one of said base portions and including means selectively movable in and out of an interference relationship with the other of said base portions.

Pat N 3,625 ,441 Da'ted December 7; 1971 Inventor) Martin O. saltarelll et a1 It is certified tha t error appears in the abo and that said Letters Pa ve-identified patent tent are hereby corrected as shown below:

Claim 15, line 4, "on one" should read edge Claim 15, line 20, "threaded" should read a threaded Signed and sealed this 26th day of March 1974.

(SEAL) Attest:

EDWARD M.ELETCHER,JR.

C. MARSHALL DANN Attesting Officer Commissioner of Patents M PO-1050 (10-69) USCOMM'DC 50375-P69 Q U.5. GOVERNMENT PRINTVNG OFFICE 1965 D366-3!

Claims

2. Apparatus according to claim 1, wherein said apparatus comprises a first plurality of rigid members spaced-apart about the shaft of said first prime mover and fixedly secured between said first prime mover and said first portion of said means which define said refining chamber, and a second plurality of rigid members spaced-apart about the shaft of said second prime mover and fixedly secured between said second prime mover and second portion of said means which defines said refining chamber whereby forces generated in the refining operation are evenly distributed axially of the defibrating apparatus.
3. Apparatus according to claim 1, wherein said first portion of said refiner housing includes an aperture therein; said means for feeding stock including means forming a stock feed channel disposed in sealed engagement with said aperture of said first portion with the channel thereof in communication with said refining chamber, a bore in said stock channel-forming means receiving the rotating shaft of said first prime mover, and an annular labrynith seal including a first seal section mounted on said first attrition means for rotation therewith and a second seal section mounted on said stock channel forming means in sealing engagement with said first seal section. 4 ApparatUs according to claim 1, wherein one of said prime movers comprises a rotor mounted on the associated shaft, a stator mounted about said rotor and having a stator frame, and an end bell assembly having a central aperture, thrust bearing apparatus secured in said aperture and a plurality of rigid members extending from said end bell assembly immediately adjacent said central aperture and spaced-apart thereabout and secured to said stator frame to thereby provide a fixation of said shaft against thrust forces exerted thereon.
5. Apparatus according to claim 4, wherein said thrust bearing apparatus includes means defining a chamber, bearing means in said chamber, means providing a lubricant within said chamber, an opening in said chamber defining means for receiving the end of said shaft, means mounting said bearing means on said shaft, labrynith-sealing means formed adjacent the shaft-receiving opening and a vacuum port formed in said chamber-defining means in communication with said shaft adjacent said labrynith-sealing means, said sealing means and the application of a vacuum to said port minimizing lubricant leakage to the exterior of said thrust bearing.
6. Apparatus according to claim 5, wherein means are included for electrically insulating said shaft from said means defining said chamber.
7. Apparatus according to claim 1, comprising a base assembly including a fixed base portion mounting said first prime mover and a movable base portion mounting said second prime mover, said movable base portion being movably mounted on said fixed base portion.
8. Apparatus according to claim 7, comprising means secured to said base portions and operable to move said movable portion relative said fixed base portion.
9. Apparatus according to claim 8, wherein the last-named means is a fluid-operated ram device having a cylinder connected to one of said base portions and an extensible member connected to the other of said base portions.
10. Apparatus according to claim 7, wherein said fixed base portion comprises a plurality of spaced-apart elongate carriage rails and said movable portion includes bearing means for supporting said movable portion on said carriage rails.
11. Apparatus according to claim 10, wherein said carriage rails are cylindrical rods and said bearing means includes arcuate bearing surfaces at least partially embracing said cylindrical rods.
12. Apparatus according to claim 10, comprising means fixed to said movable base portion for wiping said carriage rails.
13. Apparatus according to claim 10, comprising releasable latching means mounted on one of said base portions and including means selectively movable in and out of an interference relationship with the other of said base portions.
14. Apparatus for defibrating fibrous stock, comprising a pair of parallel axially aligned facing refining members mounted for rotation, a corresponding pair of prime movers for rotating said refining members in opposite directions, means mounting said prime movers for relative axial movement, means forming a refining chamber for enclosing said refining members and including first and second sections affixed to separate ones of said prime movers and having parallel mating portions, compressible sealing means disposed between said first and second sections, and means providing a gap of variable dimension about said refining chamber between said first and second sections to compensate for nonparallelism between said mating portions including means for compressing said sealing means as permitted by said gap.
15. The apparatus set forth in claim 14, wherein said means providing said gap comprises, a plurality of apertures in said compressible sealing means spaced-apart about and adjacent the outer edge thereof, a plurality of first threaded bores in said mating portion of said first section, a plurality of second threaded bores in the mating portion of said second section, a plurality of adjustable bushings each including a head, a central bore and a threaded shank engaging a second threaded bore and extending through an aperture in said sealing means to abut said first section, a nut carried on said threaded shank for adjustment against said second section, and an adjustable stud including a threaded shank extending through said central bore and engaging a first threaded bore, and a head for abutting said head of said bushing
16. Apparatus according to claim 7, comprising releasable latching means mounted on one of said base portions and including means selectively movable in and out of an interference relationship with the other of said base portions.