BUSHING AND TOOTHED WHEEL ASSEMBLY WITH PREFERRED ROTATION
Technical Field This invention relates to an assembly consisting of a tapered bushing and a toothed wheel, with a preferred direction of rotation. More particularly, this invention relates to an assembly, which allows the bushing and the toothed wheel to be mated together, or separated, using a threaded rod inserted and tightened from either side of the assembly. Background Art Assemblies using conventional tapered bushings to fasten pulleys, sheaves, or gears to shafts are widely used. Tapered bushings use less space on an axial shaft than other types of bushings and are favored for this reason. For example, the QD bushing and wheel assembly requires additional axial space due to the flange area of the bushing that protrudes from the face of the wheel. Assemblies using tapered bushings have a female mating surface on the wheel and a male mating surface on the bushing. The tapered bushing is axially split and contractible about the shaft which it receives. As the male mating surface of the bushing is mated with the female mating surface of the wheel, the bushing contracts around the shaft. Thus, by mating the bushing and the wheel, the bushing becomes affixed to the shaft and the wheel affixed to the bushing. However, difficulty is often encountered in the process of mating the bushing and the wheel, and in separating the bushing from the wheel once mated.
Prior art improvements to these assemblies have focused on designs that aid in mating or separating the bushing and the wheel. In U.S. Patent No. 2,402,743 entitled "MOUNTING FOR SHEAVES, ETC.", granted June 7, 1944, the inventor used a plurality of screws parallel with the hub axis for effecting wedging of the bushing between the hub and the shaft. As the screws are tightened sufficiently their heads abut against the bushing shoulders and further entry of the screws into the hub wedges the bushing between the hub and the shaft. However, in this invention the screws are only inserted from one side of the assembly. As the use of the invention of U.S. Patent 2,402,743 became more widespread, difficulties arose when the assembly was to be mounted in close proximity to another item, such as a drive motor or another bushing wheel assembly. This problem became more apparent to the inventor with the use of assemblies with toothed wheels having a preferred direction of rotation, such as assemblies for use with the Eagle PD™ belt described in U.S. Patent 5,209,705. When affixing these assemblies to a shaft to rotate in the preferred direction, the face of the assembly containing the screws may be in close proximity to another
item. This results in great difficulty in tightening the screws.
U.S. Patent No. 3,682,505 entitled "MEANS FOR MOUNTING SHEAVES, ETC.," granted August 8, 1972, describes an attempt to overcome this problem. With the mounted- sheave system disclosed in this patent, a plurality of longitudinal bores are formed in the assembly. Each bore is aligned and in communication with a screw hole. Each screw for use in the assembly includes a socket or slotted portion at the end for engaging a driving tool which can be inserted into either the bore or the hole to tighten the screw from either side of the assembly. A disadvantageous limitation of this system is that the bolts can only be inserted from one face of the assembly. Access to insert or remove these bolts may be limited when the face of the assembly containing the holes is placed in close proximity to another item. Disclosure of Invention
The toothed wheel and tapered bushing assembly of the invention addresses the problem of the prior art that occurs when the prior art assembly is mounted in close proximity to another item. Since access to the screws, used to mate or separate the bushing and the wheel, may be limited, this invention allows the screws, or threaded rods, to be inserted and tightened from either face of the assembly. This invention allows assembly inventories to be half that needed in the past because the assembly can be used regardless of which side of the assembly is in close proximity to the other item. This invention relates to an assembly 10 of a toothed wheel 12 and a tapered bushing
14. The toothed wheel 12 has a tapered hole 16 forming at least one tapered surface 18 in the wheel 12. The tapered hole 16 also forms a first and a second opening, the first opening Wj being larger than the second opening W2. The tapered bushing 14 has at least one tapered surface 20. The bushing tapered surface 20 is capable of mating relationship with the wheel tapered surface 18. The assembly 10 has a first face 22 and a second face 24 spaced apart from one another along an axis. When the tapered surfaces of the bushing 14 and the wheel 12 are in mated relationship, the first opening Wj of the wheel hole 16 is in proximity to the first face 22 of the assembly 10 and the second opening W2 of the wheel hole 16 is in proximity to the second face 24 of the assembly 10. The assembly 10 also has a first hole or set of holes H1; respectively, for receiving a threaded rod 26. This hole or set of holes Hj extends at least partially along the mating surfaces from the first face 22 of the assembly 10 toward the second face 24 of the assembly 10. The holes Hj are formed in part by a groove 28 located in the toothed wheel 12 and in part by a groove 30 located in the bushing 14.
The toothed wheel 12 in the assembly of the invention has a preferred direction of
rotation about its axis. The assembly 10 also has a second hole or set of holes H2, respectively, for receiving a threaded rod 26. These holes H2 extend at least partially along the mating surfaces from the second face 24 of the assembly 10 toward the first face 22 of the assembly 10. The holes H2 are formed in part by a groove 32 located in the toothed wheel 12 and in part by a groove 34 located in the bushing 14. The threaded rod 26 is able to interact with surfaces in or adjacent to the wheel and the bushing grooves of each hole. This interaction can cause the toothed wheel 12 and the bushing 14 to be moved in an axial direction with respect to each other when the threaded rod 26 is threaded into either the first or second hole or sets of holes and is tightened. Definitions
For ease of understanding this disclosure, the following terms are disclosed.
"Axial" or "axially" means the lines or directions that are parallel to the axis of rotation of the toothed wheel and bushing assembly 10.
"Taper" or "tapered" means that an item gradually narrows toward one end. Brief Description of Drawings
Fig 1 is a view from the first face 22 of an assembly 10 embodying the invention and having a set of two holes Hj on the first face 22 and a set of two holes H2 on a second face 24.
Fig 2 is a longitudinal section of the assembly 10 taken on the line 2-2 of Fig 1.
Fig 3 is a longitudinal section of the assembly 10 taken on the line 3-3 of Fig 1. Fig 4 is a detailed view of one of the holes of the assembly 10 formed in part by a bushing groove and in part by a wheel groove.
Fig 5 is a detailed view of an embodiment of the invention where the threaded rod 26 is in threaded connection with the surface of one groove and where the bottom of the threaded rod 26 pushes on the surface forming a blind half-hole in the other groove. Fig 6 is a detailed view of an embodiment of the invention where the threaded rod 26 with a head 36 is shouldered on the surface adjacent one groove and is in threaded connection with the surface of the other groove.
Fig 7 is a detailed view of an embodiment of a hole used to separate the bushing 14 and the toothed wheel 12. Fig 7 shows a threaded rod 26 with a head 36 shouldered upon the surface adjacent one groove and in threaded connection with the surface of the other groove where the threaded groove also contains an open cavity 38 immediately below the threaded rod head 36.
Fig 8 shows an embodiment of the invention where the two sets of holes are interconnected by a passage 40 of smaller cross-sectional area than the interconnected holes.
Detailed Description of the Invention
Fig 1 shows a view of a mated assembly 10 of a tapered bushing 14 and a toothed wheel 12, having a preferred direction of rotation about an axis, in mated relationship with one another. This assembly 10 is viewed from the first face 22 which contains the larger opening Wj of the tapered hole 16 in the toothed wheel 12 and the wider end of the tapered bushing 14. The tapered bushing 14 contains a split 42 which is contractible around an inserted axial shaft 44. The bushing 14 may contain a keyway 46 for locking the bushing 14 onto the shaft 44. The first face 22 of the assembly 10 contains a hole or set of holes Hj, shown as two holes in Fig 1, which extend at least partially along the mating surfaces of the toothed wheel 12 and the tapered bushing 14 from the first face 22 of the assembly 10 toward the second face 24 of the assembly 10. Each of these holes Hj is formed in part by a groove 28 located in the toothed wheel 12 and in part by a groove 30 located in the bushing 14. The assembly 10 also has a second hole or set of holes H2, represented by two holes in Fig 1, which extend at least partially along the mating surfaces of the toothed wheel 12 and the tapered bushing 14 from the second face 24 of the assembly 10 toward the first face 22 of the assembly 10. These holes H2 are formed in part by a groove 32 located in the toothed wheel 12 and in part by a groove 34 located in the bushing 14. Each of the holes of the first and second sets contain surfaces in or adjacent to the wheel and the bushing grooves. When interacted with by a threaded rod 26, these surfaces allow the bushing 14 and toothed wheel 12 to be moved in an axial direction which respect to one another. Since the assembly 10 contains a hole or set of holes on both the first face 22 and the second face 24, the threaded rod 26 can be inserted and tightened from either face of the assembly 10.
In a preferred embodiment of the invention, each face of the assembly 10 will contain three holes, two for mating the bushing 14 and the wheel 12 and one for separating the bushing 14 from the wheel 12. This embodiment allows the assembly 10 to be both mated together and separated with access to only one of the two faces.
Fig 2 shows a longitudinal view of the assembly 10, taken along line 2-2 of Fig 1, with the bushing 14 and the wheel 12 mated together. The view shows the first set of holes H1 ; represented by two holes, on the first face 22 of the assembly 10. The holes Hj are formed, respectively, by aligning a groove 28 in the toothed wheel 12 and a groove 30 in the tapered bushing 14. The holes Hj shown are for mating the bushing 14 and the toothed wheel 12. In each hole Hl5 a blind half-hole is formed by a surface 48 in the groove 30 of the bushing 14. Each toothed wheel groove 28 extends at least as far along the mating surfaces as the blind half-hole; however, the toothed wheel groove 28 may extend beyond the blind half-hole and
may even extend completely through the assembly 10.
Fig 3 shows a longitudinal view of the assembly 10, taken along line 3-3 of Fig 1, with the bushing 14 and the wheel 12 mated together. This view shows the second set of holes H2, represented by two holes, on the second face 24 of the assembly 10. The holes H2 are formed, respectively, by aligning a groove 32 in the toothed wheel 12 and a groove 34 in the tapered bushing 14. The holes H2 are for mating the bushing 14 and the toothed wheel 12. In each hole H2, a blind half-hole is formed by a surface 50 in the groove 32 of the toothed wheel 12. Each bushing groove 34 extends at least as far along the mating surfaces as the blind half- hole; however, the bushing groove 34 may extend beyond the blind half-hole and may even extend completely through the assembly 10.
Fig 4 shows a detailed view of a hole Hx H2 formed in part by a bushing groove 30,34 and in part by a toothed wheel groove 28, 32. Each groove contains surfaces which can interact with a threaded rod. The figure shows a groove shorter in length than the other groove, which ends in a surface 48, 50 forming a blind half-hole. The other groove, at least as long or longer in length than the groove containing the half-blind hole, is threaded 52 to receive a threaded rod 26. Fig 4 can represent mating holes on either the first 22 or the second 24 face of the assembly 10. If Fig 4 represents a mating hole on the first face 22 of the assembly 10, the groove containing the surface 48 which forms the blind half-hole is a bushing groove 30 and the groove which contains the threads 52 is a toothed wheel groove 28. Conversely, if Fig 4 represents a mating hole on the second face 24 of the assembly 10, the groove containing the surface 50 which forms the blind half-hole is a toothed wheel groove 32 and the groove containing the threads 52 is a bushing groove 34. The grooves of the hole used to separate the bushing from the toothed wheel will be exactly opposite those used in mating the bushing 14 and the toothed wheel 12. A separating hole on the first face 22 of the assembly 10 will be formed by a toothed wheel groove containing a surface forming a blind half -hole and a bushing groove containing threads, for threaded connection with a threaded rod 26. A separation hole on the second face 24 of the assembly 10 will be formed by a bushing groove containing a surface forming blind half-hole and a toothed wheel groove containing threads. Although the hole shown is parallel to the axis of rotation, the hole can also be formed at an angle along the mating surfaces.
Fig 5 shows a threaded rod 26 inserted into a mating hole, either on the first face 22 or on the second face 24 of the assembly 10. If the mating hole is the first hole or set of holes Hj on the first face 22 of the assembly 10, then the threaded rod 26 is in threaded connection with the threads 52 located in the toothed wheel groove 28. The bottom of the threaded rod
26 is forced against the surface 48 forming the blind half-hole in the bushing groove 30. As the threaded rod 26 is tightened, the bushing 14 is forced into mated relationship with the toothed wheel 12. If the mating hole of Fig 5 depicts the second hole or set of holes H2 contained on the second face 24 of the assembly 10, then the threaded rod 26 is in threaded connection with the threads 52 located in the bushing groove 34. The end of the threaded rod
26 is forced against the surface 50 forming the blind half-hole in the toothed wheel groove 32.
As the threaded rod 26 is tightened, the toothed wheel 12 is forced into mated relationship with the tapered bushing 14. Although Fig. 5 depicts a threaded rod having a head, other variations of threaded rods are sufficient for this embodiment. Fig 6 shows another embodiment of the invention. Fig 6 shows mating holes on either the first face 22 or the second face 24 of the assembly 10. This embodiment requires the use of a threaded rod 26 having a head 36. The hole is formed by the bushing groove 30, 34 and the toothed wheel groove 28, 32 becoming aligned. One of the grooves having a shoulder 54 adjacent the groove on the face 22, 24 of the assembly 10. The other groove containing threads 52, to receive a threaded rod 26. The head 36 of the threaded rod 26 is forced against the shoulder 54 of the groove containing the shoulder. The threads of the threaded rod 26 are in threaded connection with the threads 52 of the groove containing the threads. As the threaded rod 26 is tightened, the threads 52 pull the part of the assembly 10 having the threads in the grooves toward the head 36 of the threaded rod 26 and into mated relationship with the other part of the assembly 10. With this embodiment of the invention, the head 36 of the threaded rod 26 can be shouldered upon either an area adjacent the bushing groove 34 or the toothed wheel groove 28, with the opposite groove containing the threads 52.
Fig 7 represents an embodiment of a separation hole for either face 22, 24 of the assembly 10. The separation hole is formed by a bushing groove 30, 34 and a toothed wheel groove 28, 32 becoming aligned. One of the two grooves has a shoulder 54 adjacent the groove on the face 22, 24 of the assembly 10 for shouldering the head 36 of the threaded rod 26. The other groove has an open cavity 38 beginning at the face 22, 24 of the assembly 10 and extending partially along the groove. The second groove also has threads 52, to receive a threaded rod 26, located in the groove adjacent the cavity 38. When the threaded rod 26 with a head 36 is shouldered against the shoulder 54 adjacent one of the grooves and in threaded connection with the threads 52 of the other groove and the threaded rod 26 is tightened, the head 36 of the threaded rod 26 will push on the shoulder 54 of one groove while travelling into the open cavity 38 of the other groove forcing the bushing 14 and the toothed wheel 12 to separate.
Fig 8 shows a detailed view of an embodiment of the invention where the first hole Ht is interconnected to the second hole H2 by a passage 40. The passage 40 has a smaller cross- sectional area than the intersected holes themselves. This passage 40 can be centered between the holes as shown or located nearer a groove surface which forms the holes. In one form, the passage 40 may be formed by a bore used to aid in drilling the interconnected holes.