US2881903A

US2881903A - Bearing arrangement for slender cross members in wide conveyors

Info

Publication number: US2881903A
Application number: US612194A
Authority: US
Inventors: Tore P Ahlen
Original assignee: Individual
Current assignee: Individual
Priority date: 1956-09-26
Filing date: 1956-09-26
Publication date: 1959-04-14
Anticipated expiration: 1976-04-14

Description

April 14, 1959 MEMBERS IN vWIDE CQNVEYORS 4 Sheets-Sheet 1 Filed Sept. 26, 1956 awf- N m mm H MR/ m O T .o I? y. K V. Y Y. v v; v

April 14, 1959 T P, HL

BEARING ARRANGEMENT FOR SLENDER CROSS MEMBERS IN WIDE CONVEYORS 4 Sheets-Sheet 2 Filed Sept. 26, 1956 TORE P. AHLEN 8) April 14, 1959 T:\ -P. AHLEN BEARING ARRANGEMENT FOR SLENDER CROSS MEMBERS IN WIDE CONVEYORS 4 Sheets-Sheet 5 Filed Sept. 26, 1956 awn/ml? TORE P. AHLEN arromvsr:

April 14, 1959 T. P. AHLEN BEARING ARRANGEMENT FOR SLENDER CROSS MEMBERS IN WIDE CONVEYORS 4 Sheets-Sheet 4 Filed Sept. 26, 1956 bi l/F A fi I L i. m. mm. mfl 3T 1 62 4 W y m- E MN. f b. m2 NE Nu o- B No. 3 M9 mo AHLEN United States Patent 2,881,903 BEARING-ARRANGEMENT FOR SLENDER CRGSS MEMBERS IN WIDE "C-ONVEYORS Tore P. Amen, Vancouver, British Columbia, Canada Application September 26, 1956, serial No. 612,194 17 Claims. (Cl. 198-183 This invention relates to improved cross members for relatively wide conveyors. I v 7 There are wide conveyors in use having very long and slender cross members. For example, pulp dryers include a pair of endless chains running around sprockets at opposite ends of the machine, and spaced cross members extending between the chains and carried thereby. -For the sake of convenience, this invention will be described in connection with a pulp dryer conveyor, but it is to be understood that it may be used in any conveyor system in which the same or similar problems exist.

In order to understand the difiiculties involved, it is necessary to have an idea'of the dimensions of the main elements of the conveyor. For example, a pulp dryer may be 100 ft. long and 14 ft. wide, each cross-member extending between the conveyor thereof being a little under 14 ft. long and approximately 1.25 to 1.75 inches in diameter. These long and very slender cross members prevent the conveyors from being operated at high speeds because of whipping as they travel around the comparatively small sprocketsat the ends of the machine. As soon as a cross member'starts to move around the sprockets, its speed in -a horizontal direction is greatly reduced at the ends thereof secured to the chains so that the member tends to bow-outwardly, thus setting up bending and whipping action.

The long cross members now "in general use consist of a tube which extends between the side chains ofthe conveyor with its ends spaced 'a little from the 'chains. Each end of this tube slidably fits over a tube sleeve, and the latter is mounted on a short shaft, the axis of which coincides with that of the tube. This shaft usually projects through the adjacent'conveyor chain and is secured thereto in any convenient manner. The outside diameter of the tube sleeve is usually slightly less than the inside diameter of the conveyor tube and the length of the sleeve is usually in the neighbourhood of four inches, and the tube sleeve forms a bearing for the tube end. Theoretically, the tube 'end slides back and forth on the sleeve as the tube sags or bows outwardly. However, there must be a comparatively "large tolerance between these elements so that the tube is never truly aligned with the sleeve. This results in binding so'that vibrations set up by the whipping o'f the tube are'transmitted tothe chain and the rest of the equipment.

The present "invention overcomes or greatly reduces 60 these disadvantages by providing-means "for connecting each end of the cross member'tube-to the shaft which requires only' very small tolerances and which permits 'r'ela'tive movement between the tube and shaft while cushio'ning this movement to absorb a great nan of the vibration.

As stated 'above, when the cross-member reaches the sprockets atanrend ofithe machine, the speed of its-'ho'rizontal movement is suddenly reduced. With the stand M 2,881,903 Ce Patented Apr. 14, 1959 2 of those that are created, thereby protecting both the cross members and the rest of the equipment.

According to the present invention, every dynamic force set up as a cross member moves around the sprockets .at each end of the machine is cushion-resisted by meansof springs, allowing a certain amount of turning and/or deflection to take place in and by the cross member-over a longer interval of time than is the case with standard cross members, thereby eliminating or at least substantially reducing jarring and vibration.

A cross member according to the present invention includes along tube of relatively small diameter. As the construction is the same at bothends of the tube, one end only will now be referred to. A shaft of considerably smaller diameter than the tube projects freely into the end of the latter. The outer end of the shaft is connected to the adjacent conveyor side chain in any suitable manner :as is customary with conveyors of this type. Bearing means are provided within the tube for rotatably and concentrically mounting it on the shaft. The bearing means includes spaced bearings through which the shaft rotatably extends. These bearings are slidable longitudinally of the shaft, and spring means is provided for resiliently retaining the bearings in normal positions on the shaft, but the spring meanspermits the bearings to slide in either direction along the shaft. Means is also provided for resiliently retaining the circumferential surface of the tube in a given desired .position but in such a Way as to permit the tube torota-te in either direction without damage to the equipment under conditions which may occasionally occur.

It is desirable to keep the cross member tubes from rotating during the operation of the paper making machine. This leaves the same portion of each tube -exposed to the pulp. The tubes tend to rotate aroundt-heir longitudinal axes, but as this would take place irregularly, parts of the tube surfaces that have become dirty, would be rotated into contact with the pulp, thereby marking it and lowering the pulp grade. The :pres'ent apparatus normally prevents this rotation of the tubes, but it will permit rotation thereof if sufiicient force is applied "to them. This might take place when the pulp web breaks, and rather than resistthe rotation of the tubes at this time, the apparatus will permit the rotation.

The present invention contemplates a bearing ='arrangement at each end of a cross member, each bearing-arrangement comprising a shaft connected to a conveyor side chain and extending inwardly therefrom within the adjacent end of a cross member tube, said shaft beingof considerably smaller diameter than the tube and concentric therewith, spaced bearing means within and connected to the tube and slidably mounted on the shaft, said bearing meansmaintaining thetube andshaft-in their concentric'relationship, and springmeans within the-tube connected thereto and to the shaft permitting limited back and forth movement of the tube along the shaft and cushioning said movement.

Examples of this invention are illustrated in the'accompanying drawings, in which,

Figure 1 is a plan view of a pulp conveyor showing the long slender cross members thereof,

Figure 2 is a side elevation of this machine,

Figure 5 is an end'elevatio'n of the machine,

Figure 4 is an enlarged sectional view through one end of a cross member illustrating the preferred formofibeating arrangement therefor,

Figures 5, '6 and 7 are vertical sections taken respec tively on the lines 55, 6-6 and 7-7 of Figure '4,

Figure 8 is a sectional view similar to Figure '6', but illustrating a-variationof the apparatus of the latter. figure,

Figure 9 is a view similar to Figure 4 illustratingta-n alternative form of bearing arrangement,

cushioning said movement.

- shaft 30 between

bearings

35 and 36.

of a pulp conveyor to provide the necessary back- 7 ground for this invention. This conveyor includes spaced side chains 12 running around

sprockets

13 and 14 mounted on common shafts 15 and 16 at opposite ends of the machine. The upper and lower runs of each chain 12 'slide through supporting

troughs

18 and 19 at the sides Either of the shafts 15 or 16 is rotated of the machine. by a suitable source of power, not shown.

The conveyor includes a plurality of spaced long, slender cross members 22. These cross members are 12 to which they are connected as hereinafter described. As previously stated, a conveyor of this type may be about 100 feet long and around 14 feet wide. Each cross member 22 may be a little under 14 feet long and its diaineter may range anywhere from 1.25 to 1.75 inches.

Figures 4 to 7 illustrate a preferred form of bearing means or arrangement 25. The cross member 22 consists of a long slender tube 27. This tube extends across the space between the two side chains 12, and terminates adjacent the inner edges thereof. A shaft 30 is connected to the side chain 12 in the conventional manner, and extends inwardly therefrom into the adjacent end of cross member tube 27. In practice, the shaft extends through the pivotal joint of two adjacent chain links so that when it moves around each sprocket it moves on the pitch-line circle thereof. Instead of the chain 12 riding on the bottom of trough 18, each shaft 30 may extend through the chain and have a roller 32 mounted on its outer end which moves over the trough surface. It will be noted that shaft 30 is of considerably smaller diameter than tube 27, and that the axis of the shaft coincides with that of the tube.

Spaced bearing means are provided within and connected to the tube and are slidably mounted on the shaft.

The spaced bearing means are indicated at 35 and 36 in, Figure 4. As these are preferably identical, only bearing means 35 will be described in detail. This bearing means includes a sleeve bearing 40 slidably mounted on shaft 30 within the tube. A rigid radial web 41 is connected to the sleeve bearing and to the tube. made up of a pair of

annular discs

43 and 44 placed side by side and having laterally projecting

sleeves

45 and 46 centrally thereof. These sleeves have flanges 47 and 48 extending towards shaft 30, and these flanges along with the

sleeves

45 and 46 form an annular receptacle for the sleeve bearing 40. The outer edges of the annular discs 'are held together by a plurality of inwardly-projecting

lugs

50 and 51 punched out of tube 27.

1 Suitable spring means is provided within the tube conand forth movement of the tube along the shaft and One form of such spring means is illustrated in Figure 4. A stop is provided on In this example, the stop is in the form of a tube 55 mounted on the shaft and having a flat spot 56 in the surface thereof bearing against a corresponding fiat spot 57 on the shaft, see Figure 7. This prevents longitudinal movement of the tube on the shaft.

Radial flanges

60 and 61 are formed on the ends of this tube. Coil springs 64 and 65 are freely mounted on the shaft between flange 60 and hearing 35, and flange 61 and bearing 36, respectively. These are equalizing springs which permit limited movement of the bearings back and forth on the shaft while cushioning said movement. I

\ Suitable spring means is provided which engages the shaftand the tube to permit circumferential oscillatory parallel to each other and extend between the side chains This web may be nected thereto and to shaft 30 permitting limited back movement of the latter around the former while cushioning this movement. In the preferred form, this spring means is in the form of a radial flat spring 68 connected at its ends to the tube in any convenient manner and normally bearing against a flat surface 70formed on shaft 30, see Figure 6. For ease of mounting, the ends of this spring may extend through diametrically

opposite slots

72 and 73 formed in the tube 27 and which are just large enough to accommodate the ends of the spring. This spring may also have

lugs

75 and 76 pressed outwardly therefrom just inside the tube surface, as clearly shown in Figure 6. If desired, spring 68 may be formed with a shallow transverse dish 77, see Figure 4, which prevents the edges of the spring from biting into the shaft.

Spring 68 permits a certain amount of circumferential oscillatory movement of tube 27 around shaft 30, and the resiliency of this spring cushions this movement. However, if sufiicient force is applied to the tube, it can force the spring off the flat surface 70 of the shaft on to the opposite curved surface thereof, see Figure 6. As the tube tends to rotate around its longitudinal axis as conveyor 10 operates, the flat spring will soon roll off the curved surface 79 back on to the flat surface 70 of the shaft.

The operation of bearing arrangement 25 is very simple. As the cross member tube 27 moves around one of the sets of

sprockets

13 and 14, it tends to bow outwardly towards the centre thereof, since said centre is not supported, whereas the tube ends are connected to the side chains 12 of the conveyor. As

bearings

35 and 36 are slidably mounted on shaft 30, the end of the tube may slide back and forth on the shaft, such movement being cushioned by the

springs

64 and 65. These springs, therefore, absorb a'great deal of the vibration which would otherwise be transmitted to the side chains and the rest of the equipment. The tolerance between the sleeves of

bearings

35 and 36 may be so limited that there is practically no danger of the sleeves binding on the shaft.

Furthermore, as the tube 27 moves around the sprocket, it tends to rotate around its own axis, and spring 68 permits this to take place to a limited degree, slowing up the action and cushioning the turning movement. However, the spring also retains the tube in a set position relative to shaft 30 so that the tube always presents the same surface to the pulp being transported by the conveyor. As previously stated, if the tube is subjected to a violent turning motion as sometimes happens, spring 68 will allow it to turn rather than cause damage to some part of the equipment.

Figure 8 illustrates a variation of the spring arrangement of Figure 6. In this example, shaft 30 is provided with flat surfaces 80 and 81 on opposite sides thereof at its inner end.

Springs

82 and 83, similar to spring 68, extend across tube 27 and through slots in the latter, said springs respectively bearing against flat surfaces 80 and 81. These springs normally prevent the tube from rotating around the shaft, cushioning any tendency of the tube to move, but they will allow the relative rotation if sufiicient force is exerted on the tube.

Figures 9 and 10 illustrate an alternative form of hearing means or arrangement 85. This arrangement includes a shaft 87 connected to the side chain 12 at the pivotal joint of a pair of links thereof and extending inwardly therefrom into the adjacent end of cross member tube 27. This shaft is concentric with the tube, as shown. Spaced bearing means 90 and 91 are provided between the shaft and the tube, and as these are identical, only bearing 90 will be described in detail. This bearing means includes a sleeve bearing 93 slidably mounted on shaft 87, said sleeve being connected to a rigid radial disc 94 which extends outwardly to the tube 27. This disc is held in place by a plurality of lugs 95 punched inwardly of the tube on opposite sides of the disc. A compara- 75 tively large ing or boss 96 may be pressed inwardly from the tube to fit into a corresponding notch 97 in thedisc to prevent the latter from turning. I A stop sleeve 100 is mounted on shaft -87 between the bearings 90 and 91 in the same manner as sleeve 55 in Figure 4. Sleeve 100 has radial flanges 102 and 103 at its opposite ends. Coil springs 107 and 108 extend between flange 102 and bearing 90, and flange 103 and bearing 91, respectively. Spring 107 has ends 110 and 111 which extend through flange 102 and disc 94 to connect the spring thereto. Similarly, spring 108 has ends 113 and 114 extending through flange 103 and the disc of bearing 91 in order to connect said spring thereto.

The bearing arrangement 85 of Figures 9 and opcrates in somewhat the same manner as the previouslydescribed bearing arrangement.

Springs

107 and 108 act as compensating springs and permit the bearings 90 and 91 to slide back and forth to a limited degree along shaft 87. This permits the cross member tube 27 to move back and forth relative to said shaft, and this action is cushioned by the springs.

Springs

107 and 108 are so connected to the stop 100 and the bearings 90 and 91 that they permit circumferential oscillatory movement of the tube around the shaft to a limited degree and cushion said movement.

Figures 11 and 12 disclose bearing arrangement 120 which includes a shaft 122 connected to the side chain 12 and extending inwardly therefrom into the adjacent end of cross member tube 27. This bearing arrangement includes

bearings

125 and 126 which are the same as

bearings

35 and 36 of Figure 4. A stop tube 129 isfixedly connected to shaft 122 in the same manner as tube 55 is on shaft 30, and a pair of spiral springs 132 and 133 exfeud between the

bearings

125 and 126 and the ends of the stop tube. The inner ends of these springs are connected to the stop tube at 135 and 136 while the outer ends thereof are connected to the tube 27 at 138 and 139.

By referring to Figure 11, it will be seen that these springs spiral away from each other.

During operation, the springs 132 and 133 of Figures 11 and 12 permit the cross member tube 27 to move back and forth to a limited degree along shaft 122, While cushioning said movement. These springs also permit circumferential oscillatory movement of the member tube around the shaft while cushioning the latter movement.

What I claim as my invention is:

1. In a conveyor having cross members made up of very long slender tubes extending between endless side chains which extend around comparatively small sprockets, said tubes having a bearing arrangement at each end thereof, each bearing arrangement comprising a shaft connected to a conveyor side chain and extending inwardly therefrom into the adjacent end of a cross member tube, said shaft being of considerably smaller diameter than the tube and concentric therewith, spaced bearing means within and connected to the tube and slidably mounted on the shaft, said bearing means maintaining the tube and shaft in their concentric relationship, and spring means within the tube between the spaced bearing means and connected to the tube and to the shaft permitting limited back and forth movement of the tube along the shaft and cushioning both of the back and forth movements.

2. In a conveyor having cross members made up of very long slender tubes extending between endless side chains which extend around comparatively small sprokets, said tubes having a bearing arrangement at each end thereof, each bearing arrangement comprising a shaft connected to a conveyor side chain and extending inwardly therefrom into the adjacent end of a cross member tube, said shaft being of considerably smaller diameter than the tube and concentric therewith, spaced bearing means within and connected to the tube and slidably mounted on the shaft, said bearing means maintaining the tube and shaft in their concentric relationship, and spring means within the tube connected thereto and 6 to "the shaft permitting limited back'andfor'th movement of the tube along the shaft and circumferential oscillatory movement of the former around the latter, said spring means cushioning both of said movements.

3. In a conveyor having cross members made up 'of very long slender tubes extending between endless side chains which extend around comparatively small sprockets, said tubes having a bearing arrangementat'each end thereof each bearing arrangement comprising :a shaft connected to a conveyor side chain and extending inwardly therefrom into the adjacent end of a cross member tube, said shaft being of considerably smaller diameter than the tube and concentric therewith, spaced bearing means within and connected to the tube and slidably mounted on the shaft, longitudinal spring means within the tube connected thereto and to the shaft Spermitting limited back and forth movement of the tube along the shaft, and lateral spring means engaging the shaft and connected to the tube permitting circumferential oscillatory movement of the latter around the former, both said spring means cushioning their respective movements.

4. In a conveyor having cross members made up of very long slender tubes extending between endless side chains which extend around comparatively small sprockets, said tubes having -a bearing arrangement at each end thereof, each bearing arrangement comprising a shaft connected to 'a conveyor side chain and extending inwardly therefrom into the adjacent-end of a cross member tube, said shaft being of considerably small diameter than the tube and concentric therewith, spaced bearing means within and connected to the tube and slidably mounted 'on the shaft, and equalizing spring means connected to the shaft between the bearing means and extending outwardly to bear against each of their latter,

spring means permitting limited back and forth movement of the tube along "the shaft and cushioning both of the back and forth movements.

5. A bearing arrangement as claimed in claim 4 including radial spring means connected to the tube and engaging the shaft permitting circumferential oscillatory movement of the former around the latter, said radial spring means cushioning the oscillatory movement.

6. A bearing arrangement as *clamed in claim 4 in which the radial spring means is a flat spring connected at its ends to the tube and normally bearing against a flat surface formed on the shaft.

7. A bearing arrangement as claimed in claim 6 in which the shaft is curved in cross section opposite the flat surface thereof.

8. A bearing arrangement as claimed in claim 4 in which the radial means comprises two flat springs connected at their ends to the tube and normally bearing against flat surfaces formed on opposite'sides of the shaft.

9. In a conveyor having cross members made up of very long slender tubes extending between endless side chains which extend around comparatively small sprockets, said tubes having a bearing arrangement 'at each end thereof, each bearing arrangement comprising a shaft connected to a conveyor side chain and extending inwardly therefrom into the adjacent end of a cross member tube, said shaft being of considerably smaller diameter than the tube and concentric therewith, spaced hearing means within and connected to the tube and slidably mounted on the shaft, a stop on the shaft between the bearing means, and a coil spring around the shaft between each bearing means and the stop, said springs permitting limited back and forth movement of the tube along the shaft and cushioning both of the back and forth movements.

10. A bearing arrangement as claimed in claim 9 including a flat spring connected at its ends to the tube and normally bearing against a flat surface formed on the shaft.

11. In a conveyor having cross members made up of 7 very long slender tubes extending between endless side chains which extend around comparatively small sprockets, said tubes having a bearing arrangement at each end thereof, each bearing arrangement comprising a spring around the shaft between each bearing and the stop, said springs permitting limited back and forth movement of the tube along the shaft and cushioning both of the back and forth movements.

12. In a conveyor having cross members made up of verylong slender tubes extending between endless side chains which extend around comparatively small sprockets, said tubes having a bearing arrangement at each end thereof, each bearing arrangement comprising a shaft connected to a conveyor side chain and extending inwardly therefrom into the adjacent end of a cross member tube, said shaft being of considerably smaller diameter than the tube and concentric therewith, spaced sleeve bearings slidably mounted on the shaft within the tube, a

stilf radial web connected to each bearing and to the 1 tube, avstop on the shaft between the bearings, a coil spring around the shaft between each bearing and the stop, said springs permitting limited back and forth movement of the tube along the shaft and cushioning said movement, and a flat radial spring connected at its ends to the tube and normally bearing against a fiat surface formed on the shaft, said radial spring permitting circumferential oscillatory movement of the tube around the shaft and cushioning said movement.

13. In a conveyor having cross members made up of very long slender tubes extending between endless side chains which extend around comparatively small sprockets, said tubes having a bearing arrangement at each end thereof, each bearing arrangement comprising a shaft connected to a conveyor side chain and extending inwardly therefrom into the adjacent end of the cross member tube, said shaft being of considerably smaller diameter than the tube and concentric therewith, spaced bearing means within and connected to the tube and slidably mounted on the shaft, said bearing means maintaining the tube and shaft in their concentric relationship, and a coil spring connected at one end of each bearing means and at its opposite end to the shaft, said springs permitting limited back and forth movement of the tube along the shaft and circumferential oscillatory movement of the former around the latter, said springs cushioning both said movements.

14. In a conveyor having cross members made up of very long slender tubes extending between endless side chains which extend around comparatively small sprockets, said tubes having a bearing arrangement at each end thereof, each bearing arrangement comprising a shaft connected to a conveyor side chain and extending inwardly therefrom into the adjacent end of a cross member tube, said shaft being of considerably smaller diameter than the tube and concentric therewith, spaced bearing means within and connected to the tube and slidably mounted on the shaft, said bearing means maintaining the tube and shaft in their concentric relationship, and a pair of spiral springs between the bearing means connected at their inner ends to the shaft and at their outer ends to the tube, said springs spiralling away from each other and permitting limited back and forthmovement of the tube along the shaft and circumferential oscillatory movement of the former around the latter, said springs cushioning both said movments.

15. In a conveyor having cross members made up of very long slender tubes extending between endless side chains which extend around comparatively small sprockets, said tubes having a bearing arrangement at each end thereof, each bearing arrangement comprising a shaft connected to a conveyor side chain and extending inward- 1y therefrom into the adjacent end of a cross member tube concentrically of said tube, bearing means between the shaft and the tube within the latter and connected to one and slidably connected to the other, said bearing means retaining the tube and shaft in their concentric relationship, and spring means within the tube connected thereto and to the shaft permitting limited back and forth movement of the tube along the shaft and circumferential oscillatory movement of the former around the latter, said spring means cushioning both of said movements.

16. In a conveyor having cross members made up of very long slender tubes extending between endless side chains which extend around comparatively small sprockets, said tubes having a bearing arrangement at each end thereof, each bearing arrangement comprising a shaft connected to a conveyor side chain and extending inwardly therefrom into the adjacent end of a cross member tube concentrically of said tube, bearing means between the shaft and the tube within the latter and connected to one and slidably connected to the other, said bearing means retaining the tube and shaft in their concentric relationship, longitudinal spring means within the tube connected thereto and to the shaft permitting limited back and forth movement of the tube along the shaft and cushioning both of said movements, and lateral spring means engaging the shaft and connected to the tube permitting circumferential oscillatory movement of the latter around the former and cushioning said oscillatory movement.

17. In a conveyor having cross members made up of Very long slender tubes extending between endless side chains which extend around comparatively small sprockets, said tubes having a bearing arrangement at each end thereof, each bearing arrangement comprising a shaft connected to a conveyor side chain and extending in wardly therefrom into the adjacent end of a cross member tube concentrically of said tube, bearing means between the shaft and the tube within the latter and connected to one and slidably connected to the other, said bearing means retaining the tube and shaft in their concentric relationship, spring means within the tube connected thereto and to the shaft permitting limited back and forth movement of the tube along the shaft and cushioning both of said movements, and radial spring means connected to the tube and engaging the shaft permitting circumferential oscillatory movement of the former around; the latter, said radial spring means cushioning the oscillatory movement.

References Cited in the file of this patent UNITED STATES PATENTS