sprocket

Abstract

A sprocket has a circumferentially spaced series of teeth bridging the peripheries of two axially spaced outer rings. An optional locking ring between the outer rings provides additional support to the teeth or the outer rings and helps lock the teeth into place. The sprocket can be a split sprocket for easy mounting to and removal from a shaft.

Description

Technical Field

[0001] This invention relates to toothed sprockets for conveyor belts. Background Technology

[0002] Modular plastic conveyor belts and sprockets are frequently used in the food industry to transport products. When operating at high speeds, such as exceeding 500 feet per minute, the plastic belt and its plastic sprockets experience wear on the drive side of the sprockets and the driven side of the belt. As these surfaces wear, the belt-sprocket engagement deteriorates, and the belt begins to skip teeth, resulting in uneven conveying speeds. Ultimately, the belt, sprockets, or both must be replaced. Summary of the Invention

[0003] One type of sprocket embodying the features of the present invention includes a first outer ring and a second outer ring, each having a radially outer periphery and a central hub defining an axial orifice. The axial orifices are aligned. A spacer between the first and second outer rings sets an axial separation distance between them. Teeth are attached to the outer peripheries of the first and second outer rings at circumferentially spaced tooth positions around the outer peripheries of the first and second outer rings, and extend across the outer peripheries of the first and second outer rings.

[0004] Another type of sprocket embodying the features of the invention includes outer rings, each having a radially outer periphery and a central hub defining an axial orifice. Spacers between the outer rings define the axial separation distance between them. Teeth are attached to the outer periphery of the outer rings at circumferentially spaced tooth positions around the outer periphery and span the outer periphery of the outer rings. A locking ring abuts the outer rings to reinforce them and has a radially outer periphery. The locking ring has a plurality of circumferentially spaced and extending protrusions on its radially outer periphery, and the teeth have holes that receive the protrusions to lock the teeth. Attached Figure Description

[0005] Figure 1 This is an isometric view of one type of sprocket that embodies the features of the present invention.

[0006] Figure 2 yes Figure 1 An enlarged view of a portion of the sprocket-driven conveyor belt.

[0007] Figure 3 yes Figure 1 An enlarged view of a portion of the sprocket, showing the attachment of the toothed plates to the outer ring.

[0008] Figure 4 yes Figure 1An enlarged view of a portion of the sprocket, showing the teeth locked by the locking ring.

[0009] Figure 5 This is an isometric view of one type of split sprocket embodying the features of the present invention, shown as being mounted on a shaft.

[0010] Figure 6 yes Figure 5 An isometric view of one half of a split sprocket.

[0011] Figure 7 This is an isometric view of the main part of another type of split sprocket.

[0012] Figure 8 yes Figure 7 An enlarged view of a portion of a split sprocket.

[0013] Figure 9 yes Figure 7 An isometric view of the wider type of split sprocket. Detailed Implementation

[0014] One type of sprocket embodying the features of the present invention is in Figures 1 to 4 As shown in the diagram, the sprocket 10 is constructed from a series of circumferentially spaced teeth 12 surrounding the periphery 14 of two outer rings 16, 17. The spacing between the teeth defines the pitch of the sprocket. Each outer ring 16, 17 has a central hub 18 that defines an axial bore 20 perpendicular to the axis of rotation 22 of the sprocket 10. Spokes 24 extend radially outward from the hub 18 to the outer periphery 14 of the outer rings 16, 17. Windows 26 formed between successive spokes 24 facilitate cleaning of the sprocket 10. Spacers 28 separate the outer rings 16, 17 from each other by an axial separation distance D. Fasteners 30, such as bolts and nuts, hold the sprocket together. Bolts extend through holes (not shown) in the outer rings 16, 17 and extend from one outer ring through the hollow spacer 28 to the other outer ring. Nuts are fastened to the ends of the bolts. Optional locking rings 32 help support the teeth 12 between the two radially spaced outer rings 16, 17. Similar to outer rings 16 and 17, locking ring 32 has a central hub 36, an aperture, and radial spokes 38 extending outward from the hub to the outer periphery 40. The outer diameter of outer rings 16 and 17 is larger than the outer diameter of locking ring 32. When locking ring 32 is used, spacers 28 are provided between the opposing sides 34 of outer ring 16 and locking ring, and between the opposite opposing sides 35 of outer ring 17 and locking ring. Figure 1As shown, spacer 28 and fastener 30 secure outer rings 16, 17 and locking ring 32 to their spokes 24, thereby axially aligning orifice 20. Orifice 20 shown in the example is square. When orifice 20 is aligned, its four sides are aligned to receive a drive shaft or idler shaft with a square cross-section. Other polygonal orifice shapes, as well as circular orifices with keyways for receiving keys on the shaft, can also be used.

[0015] like Figure 2 As shown, the toothed plate 12 defines a plane inclined relative to the radial direction 42 (i.e., the direction from the axis of rotation to the periphery of the outer ring 16). The inclination angle α is defined in... Figure 2 As shown in the diagram, the toothed sprocket 12 has a driving surface 44, which extends along the sprocket. Figure 1 or Figure 2 When rotated clockwise, it engages with the driven surface 46 on the inner side of the conveyor belt 48 to drive the conveyor belt along the conveying direction 50. The space 49 between the successive toothed sprockets 12 provides a passage for cleaning the sprocket.

[0016] Figure 3 A slot 52 is shown leading to the outer periphery 14 of the outer ring 16. The slot 52 mates with a slot 54 in the toothed plate 12 to hold the toothed plate 12 in a circumferentially spaced toothed position. When installed in place, the toothed plate 12 spans the outer rings 16, 17 and extends axially outward beyond the outer rings 16, 17. The outer edge 56 of the toothed plate 12 extends radially outward from the periphery 14 of the outer rings 16, 17.

[0017] like Figure 4 As shown, the toothed blade 12 is a rectangular blade with a height H and a width W, both of which are greater than its thickness T. The toothed blade 12 has a hole 58 passing through its thickness T, which receives a protrusion 60 extending circumferentially from a toothed seat 62 on the periphery 40 of the locking ring 32. The toothed seat 62 is spaced apart from the sprocket pitch P. The toothed seat 62 has a backing 64 against which the toothed blade 12 rests. The backing 64 defines a region relative to the radial direction 42. Figure 2 Angle α.

[0018] The sprocket 10 is assembled as follows: First, the two outer rings 16, 17 are aligned so that their orifices 20 are aligned. Then, some of the toothed pieces 12 are installed across the two outer rings 16, 17 at their tooth positions. Before installing most of the toothed pieces 12, a locking ring 32 is positioned between the two outer rings 16, 17. The locking ring 32 is rotated so that it is just disaligned from the outer rings 16, 17, so that the protrusion 60 on the toothed seat 62 does not obstruct the installation of the remaining toothed pieces 12. Once all the toothed pieces 12 are installed bridging the two outer rings 16, 17, the locking ring 32 is rotated so that the protrusion 60 passes through the hole 58 in the toothed piece 12 until the toothed piece is placed against the seat back 64. In this case, the locking ring 32 and the orifices of the two outer rings 16, 17 are aligned, and the fastener holes are also aligned. Subsequently, the spacer 28 and the fastener 30 are installed to lock the toothed pieces 12 into place together with the locking ring 32. The toothed plate 12 can be removed and replaced by reversing the process described above.

[0019] Alternatively, the toothed sprocket 12 can be welded to the outer rings 16, 17 and the locking ring 32. If the locking ring 32 is not required to support the toothed sprocket 12, it can be omitted from the sprocket 10. To extend wear life, the sprocket is made of a metal such as stainless steel or carbon steel, which can be laser-cut to ensure precision. Furthermore, if a wider sprocket is required, more than three rings can be used to provide sufficient support for the toothed sprocket. The large open area provided by the window and spaced toothed sprockets facilitates cleaning of the sprocket.

[0020] With Figure 1 A type of split sprocket with similar features to sprocket 10 and other features is described in Figure 5 and Figure 6 As shown in the diagram, the split sprocket 70 includes two sprocket halves 72, which can be bolted together via aligned attachment holes 74, 75 in each sprocket half. Figure 1 Unlike the sprocket 10, the split sprocket 70 can be mounted on or removed from the shaft 76 without removing the shaft from the bearing housing or gearbox in the conveyor frame. Instead, each sprocket half 72 is radially introduced onto the shaft 76. The two sprocket halves 72 are then bolted together through attachment holes 74, 75.

[0021] Each sprocket half 72 includes two outer half-rings 78, an optional locking half-ring 80 (locking half-ring), and peripheral teeth 12. Each outer half-ring 78 and locking half-ring 80 has two spokes 82, 83 extending radially from a central hub portion 84. The spokes 82 at the closed ends of the hub portions 84 of the outer half-rings 78 and locking half-rings 80 are aligned and spaced apart by spacers 28 to form the sprocket half 72, wherein the spacers 28 are secured together by bolts 30 and nuts. The hub portion 84 of each sprocket half 72 defines a circular semi-orifice 86 for mounting on a circular shaft 76, which has a keyway 88. However, this orifice can be as follows: Figure 1 The shape of a square or other opening. Similarly, Figure 1 The orifice in the sprocket can be round or other shapes. The toothed plate 12 is compatible with... Figures 1 to 4 The sprocket 10 is attached to the periphery of the sprocket half 72 in the same manner. In this example, the locking half-ring 80 of each sprocket half 72 is identical, and the outer half-ring 78 of each sprocket half is identical. However, the outer ring and the locking ring can be segmented along the line, such that each half-ring is different from the other half-rings, or each half-ring is not even an actual half-ring, but the two "half-rings" are, for example, "one-third ring" and "two-thirds ring".

[0022] The two sprocket halves 72 are mounted on the shaft 76 by first axially moving them onto the shaft 76. A keyway 88 in one of the sprocket halves 72 is positioned to receive a shaft key 92 extending from a shaft keyway 93. (The other sprocket half 72 may also have a keyway 88 for use with a shaft having two shaft keys 92). The two sprocket halves 72 are slightly offset axially. Attachment holes 75 in the spokes 83 at the open end of the hub portion 84 of each sprocket half 72 are aligned with attachment holes 74 in the overlapping spoke root 90 of the other sprocket half. The spoke root 90 extends radially inward toward the hub portion 84 from the periphery of the outer half-ring 78 and the locking half-ring 80 of the sprocket half 72. Bolts passing through the aligned attachment holes 74, 75 and through the spacer 28 into the nut secure the two sprocket halves 72 together to the shaft 76. The hub portion 84 of the fastened sprocket half 72 transforms the two half-holes 86 into circumferentially closed orifices for receiving the shaft 76. Aligned grooves 94 on the outer side of the hub portion 84 of each outer half-ring 78 and locking half-ring 80 receive optional axial reinforcement plates 96, which are bolted to the hub portion or otherwise secured to the hub portion to provide additional rigidity.

[0023] Another type of split sprocket is found in Figure 7 and Figure 8 As shown in the diagram. The split sprocket 98, illustrated by way of example, is composed of... Figure 5The split sprocket 70 is constructed from largely the same components, but with some differences. One difference is that the locking half-ring 100 axially abuts the axial inner surfaces 99 of the two outer half-rings 78 to overlap the outer half-rings. The second difference is that the locking half-ring 100 does not include... Figure 6 The locking half-ring 80 has a seat back 64. A third difference is that the number and length of the spacers are selected to accommodate different configurations. The locking half-ring 100 reinforces the outer half-ring by overlapping with the outer half-ring 78, which is helpful for sprockets with wide axial widths or heavy loads. Protrusions 101 on the periphery of the locking half-ring 100 are received in holes 58 in the toothed sprocket 12 to lock the toothed sprocket in place.

[0024] Figure 9 It shows Figure 7 The wider sprocket half 102 of the split sprocket. In this example, the sprocket half 102 includes four outer half-rings 78, each outer half-ring 78 adjacent to an overlapping locking half-ring 100. The wider sprocket half 102 also has axially elongated teeth 104 and a reinforcing plate 106 corresponding to the axially elongated sprocket half 102. It has a similar design to... Figure 9 The locking half-ring 80 and the full-circle locking rings around their periphery can be used in a similar manner. Figure 1 The sprocket 10 is connected to and reinforces the outer rings 16 and 17.

Claims

1. A sprocket, comprising: A first outer ring having a radially outer periphery and a central hub, the central hub of the first outer ring defining an axial orifice; A second outer ring having a radial outer periphery and a central hub, the central hub of the second outer ring defining an axial aperture aligned with the axial aperture of the first outer ring; A spacer is provided between the first outer ring and the second outer ring to set an axial separation distance between the first outer ring and the second outer ring; The toothed plate is attached to the outer periphery of the first outer ring and the outer periphery of the second outer ring at circumferentially spaced tooth positions around the outer periphery of the first outer ring and the outer periphery of the second outer ring, and spans across the outer periphery of the first outer ring and the outer periphery of the second outer ring.

2. The sprocket according to claim 1, characterized in that, The first outer ring and the second outer ring have spokes that extend radially from the central hub to the outer periphery to define a window between circumferentially successive spokes.

3. The sprocket according to claim 1, characterized in that, The openings of the first outer ring and the second outer ring are square.

4. The sprocket according to claim 1, characterized in that, The first outer ring and the second outer ring have slots leading to the outer periphery at the tooth position, and the tooth has a slot that mates with the slots of the first outer ring and the second outer ring to position the tooth at the tooth position.

5. The sprocket according to claim 1, characterized in that, The toothed plate defines a plane that is inclined relative to the radial direction.

6. The sprocket according to claim 1, characterized in that, The first outer ring and the second outer ring have axial outer surfaces, and the toothed plate extends axially outward from the axial outer surfaces.

7. The sprocket according to claim 1, characterized in that, The toothed plate is welded to the first outer ring and the second outer ring.

8. The sprocket according to claim 1, characterized in that, The toothed blade is a rectangular blade having a height, a width, and a thickness, wherein the thickness is less than the height and less than the width.

9. The sprocket according to claim 1, characterized in that, The sprocket includes a locking ring having a radially outer periphery and a central hub defining an axial orifice, the locking ring being positioned between a first outer ring and a second outer ring.

10. The sprocket according to claim 9, characterized in that, The locking ring has toothed seats at circumferentially spaced positions on its outer periphery, the toothed seats supporting the toothed piece between the first outer ring and the second outer ring.

11. The sprocket according to claim 10, characterized in that, The tooth holder has a backrest arranged at an angle relative to the radial direction, and the tooth plate is placed against the backrest at the tooth position at an angle inclined relative to the radial direction.

12. The sprocket according to claim 9, characterized in that, The locking ring has a circumferentially extending protrusion, and the toothed plate has a hole through which the hole passes to receive the protrusion when the axial opening of the locking ring is aligned with the axial openings of the first outer ring and the second outer ring, thereby locking the toothed plate in place.

13. The sprocket according to claim 9, characterized in that, The spacer is disposed between the first outer ring and the first side of the locking ring, and between the second outer ring and the opposite second side of the locking ring.

14. The sprocket according to claim 1, characterized in that, The sprocket includes a fastener extending from the first outer ring to the second outer ring, and the spacer is hollow to receive the fastener, the fastener holding the first outer ring and the second outer ring apart by the axial separation distance.

15. The sprocket according to claim 1, characterized in that, The sprocket includes one or more locking rings disposed between the first outer ring and the second outer ring.

16. The sprocket according to claim 15, characterized in that, Some of the spacers axially space the one or more locking rings from the first outer ring and the second outer ring.

17. The sprocket according to claim 15, characterized in that, The sprocket includes a first locking ring that overlaps the first outer ring and a second locking ring that overlaps the second outer ring.

18. The sprocket according to claim 15, characterized in that, The first outer ring and the second outer ring, the one or more locking rings and the toothed plate are made of steel.

19. The sprocket according to claim 1, characterized in that, The first outer ring and the second outer ring are each formed by the first outer half ring and the second outer half ring, respectively.

20. The sprocket according to claim 19, characterized in that, The first outer half-ring and the second outer half-ring are axially offset relative to each other.

21. The sprocket according to claim 19, characterized in that, The sprocket includes one or more locking rings disposed between the first outer half-ring and the second outer half-ring, the one or more locking rings being formed by the first locking half-ring and the second locking half-ring.

22. The sprocket according to claim 21, characterized in that, Some of the spacers axially space the one or more locking half-rings from the first outer half-ring and the second outer half-ring.

23. The sprocket according to claim 21, characterized in that, The sprocket includes a first locking half-ring that overlaps the first outer half-ring and a second locking half-ring that overlaps the second outer half-ring.

24. The sprocket according to claim 19, characterized in that, The sprocket includes a reinforcing plate that extends axially from the center hub of the first outer ring to the second outer ring.

25. The sprocket according to claim 1, characterized in that, The sprocket includes an additional outer ring and a plurality of locking rings adjacent to the first outer ring, the second outer ring, and the additional outer ring.

26. The sprocket according to claim 1, characterized in that, The sprocket consists of two identical sprocket halves.

27. The sprocket according to claim 1, characterized in that, Each of the toothed plates has an outer edge that extends radially outward from the outer periphery of the first outer ring and the second outer ring.

28. A sprocket, comprising: Multiple outer rings, each having a radial outer periphery and a central hub defining an axial orifice; Spacers between the outer rings to set an axial separation distance between the outer rings; A toothed plate, the toothed plate being attached to the outer periphery of the outer ring at toothed positions spaced circumferentially around the outer periphery of the outer ring, and spanning the outer periphery of the outer ring; Multiple locking rings, the multiple locking rings being adjacent to the outer ring to reinforce the outer ring, and having a radially outer periphery; The locking ring has a plurality of circumferentially spaced and circumferentially extended protrusions on its radially outer periphery, and the toothed plate has a hole that receives the protrusions to lock the toothed plate.

29. The sprocket according to claim 28, characterized in that, The sprocket consists of two identical sprocket halves.

30. The sprocket according to claim 28, characterized in that, Each of the outer rings includes two outer ring halves, and each of the locking rings includes two locking ring halves.

31. The sprocket according to claim 30, characterized in that, The two outer ring halves are identical, and the two locking ring halves are identical.

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