Abstract:
A gear made of a resin including substantially annular toothed portion formed at a radially outer location, a shaft-supporting section formed at a radially inner location around a rotational center of the toothed portion, and a web connecting the shaft-supporting section and the toothed portion to each other. A circumferential rib is formed on the web concentrically with the toothed portion, and diametrical ribs are also formed on the web radiately to connect the circumferential rib and the shaft-supporting section to each other in a radial direction.
Abstract:
A gear made of a resin including a cylindrical toothed portion formed at a radially outer location, a shaft-supporting section formed at a radially inner location around the rotational center of the toothed portion, and a thin plate-shaped web connecting the shaft-supporting section and the toothed portion to each other, wherein the web has a circumferential rib concentric with the toothed portion inside the toothed portion, and a plurality of diametrical ribs diametrically connecting the circumferential rib and the shaft-supporting section to each other along the side of the web, each of the diametrical ribs being formed by a first diametrical rib portion extending obliquely in a direction opposite from a normal rotational direction from the outer periphery of the shaft-supporting section, and a second diametrical rib portion extending obliquely in a direction opposite from an opposite rotational direction from the outer periphery of the shaft-supporting section.
Abstract:
A gear made of a resin including a cylindrical toothed portion formed at a radially outer location, a shaft-supporting section formed at a radially inner location around the rotational center of the toothed portion, and a thin plate-shaped web connecting the shaft-supporting section and the toothed portion to each other, wherein the web has a circumferential rib concentric with the toothed portion inside the toothed portion, and a plurality of diametrical ribs diametrically connecting the circumferential rib and the shaft-supporting section to each other along the side of the web, each of the diametrical ribs being formed by a first diametrical rib portion extending obliquely in a direction opposite from a normal rotational direction from the outer periphery of the shaft-supporting section, and a second diametrical rib portion extending obliquely in a direction opposite from an opposite rotational direction from the outer periphery of the shaft-supporting section.
Abstract:
A gear made of a resin including substantially annular toothed portion formed at a radially outer location, a shaft-supporting section formed at a radially inner location around a rotational center of the toothed portion, and a web connecting the shaft-supporting section and the toothed portion to each other. A circumferential rib is formed on the web concentrically with the toothed portion, and diametrical ribs are also formed on the web radiately to connect the circumferential rib and the shaft-supporting section to each other in a radial direction.
Abstract:
A molded plastic circular gear which has removed its wall portions on the inside of a tooth root of its circumferential gear teeth portion. The gear has a circular rim formed at a distance from and on an inside of the tooth root. The gear is further formed by injection of resin through gates located in the web portion of the inside of the rim. The gear is further characterized in that the thickness in the axial direction of the web portion of the inside of the rim is made larger than that of the web portion on the outside of the rim.
Abstract:
A gear 1 made of a resin includes webs 5 (5a and 5b) formed so that the rigidity of the web is increased by a first circumferential rib 8, a second circumferential rib 10, first diametrical ribs 11 and second diametrical ribs 12, and the circumferential sectional shape of the outermost web 5c is a corrugated shape, whereby the rigidity of the outermost web 5c is increased. As a result, it is possible to increase the rigidity of the outermost web 5c without increasing of the thickness of the outermost web 5c; to form a toothed portion 6 with a high accuracy; to reduce the deformation (for example, the amount of displacement of the toothed portion 6 and a shaft-supporting portion 4 in a rotating direction) due to an external force; and to enhance the rotation-transmitting accuracy. In this gear 1, a vibration and a noise due to the vibration can be reduced by increasing the rigidity of the web.