JP2002331974A - Cantilever tooth sprocket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sprocket assembly reduced in noise level by using two or more segments having two or more cantilever tooth so as to absorb the impact of a crawler component and reduce noise. SOLUTION: The drive sprocket assembly is rotated around an axis. The drive sprocket assembly comprises a circular hub part concentrically arranged around the axis. The circular hub part has a peripheral part. The drive sprocket assembly comprises two or more arch-shaped segments arranged around the peripheral part of the hub part. Each of the arch-shaped segments comprises a first end part, a second end part, and a middle part. The arch-shaped segment comprises two ore more cantilever teeth and minute cross webs extending outward.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates generally to drive sprockets and, more particularly, to drive sprockets formed by segments having cantilevered teeth to reduce noise during operation.

[0002]

BACKGROUND OF THE INVENTION Earthmoving and construction machines with a self-propelled endless track chain assembly for support and propulsion generally utilize a sprocket wheel that engages and drives the track chain. Several different types of sprocket wheels have been used so far, including a single wheel member with a plurality of integral teeth, or supporting multiple wheel segments, each segment having a plurality of teeth. And a circular support member having However, many conventional drive sprocket configurations have been ineffective or practically limited with respect to their ability to reduce noise levels during drive operation on endless track chain assemblies.

[0003] One attempt to reduce the noise of sprocket assemblies has been by Thomas Oer, the inventor of the present invention.
U.S. Pat. No. 4,881,93, issued Nov. 21, 1989, and assigned to the assignee of the present invention.
No. 0, "Sprocket Assembly". The sprocket assembly described in the cited Oertley patent lowers noise levels by using a support housing and individually replaceable full width tooth structures that are resiliently separated from adjacent tooth structures. are doing. The arrangement requires many components, including resilient pads between adjacently located teeth, retaining members and pins for supporting the resilient pads in place, and the hub portion of the drive sprocket. An elastic cushion band disposed between the elastic cushion band and the tooth structure.

[0004]

SUMMARY OF THE INVENTION The present invention is directed to overcoming one or more of the problems set forth above.

[0005]

SUMMARY OF THE INVENTION In one form of the invention, a drive sprocket assembly is adapted to rotate about an axis. The drive sprocket assembly includes a circular hub disposed concentrically about an axis. The circular hub has an outer peripheral edge. The drive sprocket assembly includes a plurality of arcuate segments disposed about an outer peripheral edge of the hub. Each of the arcuate segments has a first end, a second end, and an intermediate portion. The first and second ends have a tip relief. The arch segment is
It has a plurality of cantilever teeth formed thereon and a reduced transverse web extending outwardly.

The present invention provides a sprocket assembly having tooth segments, the tooth segments flexing to absorb impact energy between the track chain and the cantilever teeth to reduce noise during use. Has cantilever teeth. Further, the tooth segment has an end portion having a tip relief portion for preventing wear between the segment and the hub portion due to an impact when the end portion is bent.

[0007]

DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1, a machine 10, such as a tracked tractor, includes a power drive system 12, an elastic drive sprocket assembly 14 embodying the present invention, and first and second idler wheels 16,18. And an endless crawler chain assembly 20 surrounding the sprocket assembly and idler wheels 16, 18
including. The endless track chain includes a plurality of bushes 21 adapted to interact with sprockets to advance the machine. Sprocket assembly 14 is adapted to transmit power from machine 10 to track assembly 20. It should be understood that many mechanical components, including the sprocket assembly 14, idler wheels 16, 18, and track chain assembly 20, are the same on non-illustrated sides of the machine 10. Since these similar components operate similarly to the components shown, the description and operation of the components shown apply to both sides of the machine.

The elastic drive sprocket assembly 14 is shown in FIG.
3 around the central axis 22 as shown in FIG. The resilient drive sprocket assembly 14 includes a housing 24 concentrically disposed about an axis 22 and a housing 2.
4 includes a plurality of arcuate drive tooth segments 26 disposed about the four central axes. The housing 24 includes the mounting portion 2
8, a circular hub portion 30 having a radially outer surface 32, and a circular flange 34 extending radially outward from the hub portion 30
And all are concentrically arranged around the axis of rotation 22. The circular flange 34 has a plurality of holes 36 arranged at regular intervals around the central axis of the circular flange 34. Each drive tooth segment of the plurality of arcuate segments 26 includes an inner or mounting base 38, an outer portion 4 having a plurality of cantilevered teeth 42 with a track assembly mating surface 43.
0, and an intermediate portion 44. The mounting base 38 has a curved surface 46 adapted to mate with the radially outer surface 32 of the circular hub portion 30. The mounting base 38 has a plurality of axially extending holes 48 aligned with respective holes in the flange 34 of the hub portion 30. Bolt 4
9 are inserted into holes 36 and 48 to attach the segment to the hub. Each tooth of the plurality of teeth 42 can have limited deflection due to the reduced transverse web 50 at the intermediate portion 44. The web 50 is disposed between the radially outer crawler belt assembly mating surface 43 and the base 38. Each of the adjacent webs 50 has a structure including a window 52 for limiting the bending of the cantilever teeth 42. Slot 53
Extends radially from the track engagement surface 43 to the window 52,
Slots 53 have an arched width ranging from 1 mm to 5 mm.

As shown in FIGS. 3 and 4, each drive tooth segment has a first end 54, a second end 56, and an intermediate portion 58. Each of the first and second ends 54, 56 has a tip relief 60 to form a gap “G” between the ends 54, 56 of the drive tooth segments and the outer surface 32 of the hub 30. I do. Voids are provided to reduce wear between components when the tip teeth flex in contact with the track chain assembly. The tip relief portion 60 has a curved surface 6.
2 is larger than the curved surface 28 at the intermediate portion 44 of the mounting portion 28,
6 to an end 66. The tip relief portion 60 has an end 6
With an angle 67 extending from 7.2 degrees to 21 degrees extending from 6 to the contact 64, the gap "G" at the tip relief is:
It is in the range of 0.1 mm to 0.5 mm. The outer surface 32 of the hub portion 30 also includes a relief portion 68 that cooperates with the tip relief portion of the segment to further reduce wear between the tip teeth when they flex. Contact 7 on outer surface 32
0 is spaced from flange 34 by a distance 72, with distance 72 ranging from 29.5 mm to 60.5 mm. A radius 74 ranging from 1820 mm to 4050 mm extends generally axially from the contact 70 toward the flange 34. With a radius of 3 mm, the radius 74 is
Connect to 4. Distance 7 between connection point and outer surface of hub part
6 ranges from 0.1 mm to 0.5 mm. To have the proper amount of cantilever deflection, window 52 must be flat 78
Must not intersect with The flat surface 78 extends from the center of the tip tooth head to the corner between the tip relief portion 60 and the end portion 66.

Referring to FIG. 5, there is shown a predetermined size and shape of a window 52 between adjacent teeth that ensures proper deflection of the cantilever teeth. A horizontal plane 80 having a predetermined length ranging from 34 mm to 51 mm is provided to determine the width of the window 52. A radius 82 ranging from 6 mm to 11.5 mm is given from the endpoint of the horizontal plane 80 and defines the width of the window 52. The vertical plane 84 intersects the midpoint of the horizontal plane 80 and extends downward by a predetermined length in the range of 14-17.6 mm. The radius 86 is given from the extension end point of the vertical plane 84 and defines the lower limit of the window 52. The ratio of the length of the horizontal plane 80 divided by the length of the vertical plane 84 is 1.5
Must be in the range of -3.5. Radius 90 is equal to radius 8
2 and the radius 86. Radius 92 bounds radius 82 and defines the upper limit of window 52. Instead of radii 90, 92, other radii, such as straight lines, may be used to connect the radii without departing from the invention.

Referring to FIG. 6, the segments 26 and window 52 are similar to those described above, but if additional damping is required, an elastomeric material such as rubber 94 may be placed within the window 52 to provide a sprocket. The noise from the track chain assembly 20 in contact with 14 is further attenuated.

A cantilevered drive sprocket assembly 14 embodying the present invention is particularly useful for earthmoving machines, and more particularly for self-propelled crawler machines such as machine 10. Power from the engine of machine 10 is transmitted to drive system 12 to rotate sprocket assembly 14. As the sprocket assembly 14 rotates, the cantilevered teeth 42 contact portions of the endless track chain assembly 20, such as the bushing, to advance the machine 10. Accordingly, the track bush of the endless track chain assembly 20 meshes with the resilient cantilever teeth 42.
Because the cantilevered teeth 42 have reduced transverse webs 50 and windows 52, the teeth will flex and absorb at least a portion of the kinetic energy of the impact to reduce noise.

In view of the foregoing, the structure of the present invention flexes to absorb the impact of track components and reduce noise.
A reduced noise level sprocket assembly for driving the endless crawler chain assembly 20 utilizing a plurality of segments 26 having a plurality of cantilevered teeth is provided.

[0014] Other aspects, objects, and advantages of the invention can be understood from a review of the drawings, the disclosure, and the appended claims.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a machine incorporating the sprocket of the present invention.

FIG. 2 is a schematic side view of a sprocket assembly embodying the present invention.

FIG. 3 is an enlarged side view of a sprocket segment embodying the present invention.

FIG. 4 is a schematic sectional view taken along line 4-4 in FIG. 2;

FIG. 5 is an enlarged view of FIG. 3 generally taken along line 5-5.

FIG. 6 is a side view of a sprocket segment showing another embodiment.

[Explanation of symbols]

 Reference Signs List 12 drive system 14 sprocket assembly 20 endless crawler chain assembly 42 cantilever 50 reduced transverse web 52 window

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Maurice e Taft United States of America Illinois 61614 Pioria North Briarwood Lane 5913 (72) Inventor Stephen Sea Todd Illinois of the United States 61550 Morton Westshore Drive 213 F-term (reference) 3J030 AA01 AA02 AA11 BA07 BB08 BB17

Claims (20)

[Claims] 1. A drive sprocket assembly adapted to rotate about an axis, comprising: a circular hub portion concentrically disposed about the axis and having an outer peripheral edge; and the outer peripheral edge of the hub portion. A plurality of arcuate segments disposed around each of said arcuate segments, each of said arcuate segments having a first end, a second end, and an intermediate portion;
A drive sprocket, wherein the first and second ends have a tip relief, and wherein the arcuate segment is formed with a plurality of cantilevered portions having outwardly extending reduced transverse webs. Assembly. 2. The segment wherein the segment has an arcuate inner mounting portion having a curved surface with the tip relief, the arcuate outer portion with the plurality of tooth portions, and allows the tooth portions to flex. And an intermediate portion having the reduced transverse web. 3. The drive sprocket assembly of claim 2, wherein each tooth portion of the plurality of tooth portions is formed on the outer portion and extends outwardly and includes a track assembly engaging surface. . 4. The drive of claim 3 wherein said intermediate portion includes a reduced transverse web portion defining a window disposed between said track assembly mating surface and said inner mounting portion. Sprocket assembly. 5. The slot of claim 4, wherein a slot extends between the track assembly mating surface and the window.
A drive sprocket assembly according to claim 1. 6. The segment having a tip portion, the tip portion defining a structure adapted to interact with a tip portion of an adjacent segment to form the window. The drive sprocket assembly according to claim 5, wherein 7. The drive sprocket assembly according to claim 1, wherein the tip relief portion contacts the arcuate inner portion and extends from the contact point toward the end. 8. The drive sprocket assembly according to claim 7, wherein said end and said contact point are in a range of 7.2 degrees to 21 degrees. 9. The drive sprocket assembly according to claim 8, wherein said tip relief is in a range of 0.1 mm to 0.5 mm. 10. The drive sprocket assembly according to claim 4, wherein said window is U-shaped and has an arched upper surface. 11. The drive sprocket assembly according to claim 5, wherein said slot has an arcuate width ranging from 1 mm to 5 mm. 12. A drive sprocket assembly adapted to rotate about an axis, comprising: a circular hub portion concentrically disposed about the axis and having an outer peripheral edge; and the outer peripheral edge of the hub portion. A plurality of cantilevered teeth formed in the arcuate segment, each tooth of the plurality of teeth having a reduced transverse web; The assembly of any preceding claim, wherein the assembly extends radially outward from the arcuate segment. 13. The reduced transverse web wherein the arcuate segment has an arcuate inner mounting having a curved surface, an outer portion comprising the tooth portion, and a predetermined window for limiting deflection of the tooth portion. 13. A drive sprocket assembly according to claim 12, including an arched intermediate portion comprising: 14. The arcuate segment includes a first end and a second end, each of the ends between the hub and the arcuate segment as the tooth portion flexes. 14. The drive sprocket assembly according to claim 13, further comprising a tip relief on the curved surface of the attachment to reduce wear. 15. The method according to claim 14, wherein the predetermined window is U-shaped and has an arched upper surface.
A drive sprocket assembly according to claim 1. 16. The width of the window is 1 mm, intersecting a horizontal plane having a length in the range of 34 to 51 mm and a midpoint of the horizontal plane.
A vertical plane extending in a range of 4 mm to 17.6 mm, wherein a ratio of the length of the horizontal plane divided by the length of the vertical plane is in a range of 1.5 to 3.5. The drive sprocket assembly according to claim 15, wherein: 17. An arcuate drive sprocket segment having first and second portions having end surfaces and an intermediate portion having a curved surface, wherein the first and second ends have a tip relief formed thereon. An arcuate drive sprocket segment formed with a plurality of cantilevered teeth portions and having a reduced transverse web. 18. The arched drive segment of claim 17, wherein the tip relief contacts the curved surface and extends from a contact to the end surface of the end. 19. The arcuate drive segment of claim 18, wherein said end face and said contact have an angle in the range of 7.2 degrees to 21 degrees. 20. The apparatus according to claim 19, wherein the tip relief portion is in a range of 0.1 mm to 0.5 mm.
An arch-shaped drive segment according to claim 1.