Sprocket tooth profile
AssigneesInstitute of High Performance Computing, Sunstar Logistic Singapore Pte Ltd.
InventorsYu Yong Wang, Gui Rong Liu, Chun Lu, Kwang Peng Quek, Yoshihisa Noguchi
Life of this patent
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Abstract
An improved tooth profile for a roller chain sprocket enables noise reduction from impact and polygonal action during the meshing process. The profile of the engaging flank consists of three portions which are the seating, impact and distal portions all three of which are arcs with well-defined radii and arc centers. The profile of the disengaging flank is determined in accordance to a modified form of the JIS standard in which the sprocket pitch is smaller than the roller chain pitch. The impact point is located at the tangent point, thus permitting a gradual change of the roller velocity, thereby lessening the impact level and the effects of polygonal action.
Claims25
A sprocket for use with a roller chain having a succession of serially connected rollers, said sprocket comprising:
- a plurality of teeth spaced apart around a periphery thereof for driving engagement with the rollers, at least one of said teeth having a tooth profile including an engaging flank adapted to contact a roller as that roller moves into engagement with said at least one tooth, and a disengaging flank;
- wherein said engaging flank has an impact point at initial engagement with a roller, said impact point being located on a line tangent to a circular seating portion of the tooth profile, which tangent line intersects a center or rotational axis of the sprocket.
A sprocket for use with a roller chain having a succession of serially connected rollers, said sprocket comprising:
- a plurality of teeth spaced apart around a periphery thereof for driving engagement with the rollers, at least one of said teeth having a tooth profile including an engaging flank adapted to contact a roller as that roller moves into engagement with said at least one tooth, and a disengaging flank;
- wherein said engaging flank includes an impact point at initial engagement with a roller, said impact point being located on a tangent to promote a minimum initial impact and a gradual change in the velocity of said roller such that said change of velocity in the tangential direction first, followed by a gradual change in the radial direction;
- and
- wherein said engaging flank includes a seating portion, an impact portion and a distal portion, each of said seating, impact and distal portions comprising a circular arc defined by a radius and an arc center, and wherein the impact point is located in the impact portion of the engaging flank at a tangent to the circular arc of the seating portion, which tangent intersects a center or rotational axis of the sprocket.
A method of designing a sprocket tooth profile for a sprocket in a chain drive system, the sprocket tooth profile including an engaging flank adapted to contact a chain roller as that roller moves into engagement with the tooth, and a disengaging flank, the method including the steps of:
- determining a root circle radius for the sprocket tooth to define a circular seating portion for a roller at a base of the engaging flank profile;
- and
- defining the location of an impact point at initial engagement with a roller on a line tangent to the circular seating portion, which tangent line also intersects a center or rotational axis of the sprocket.
Dependencies are inferred from the claim text.