A point-contact conjugate hourglass worm drive based on the meshing theory of conjugate tooth surfaces generated by two generating surfaces. (August 2022)

• Record Type: Journal Article
• Authors: Ren, Wen; Li, Haitao; Xu, Zhaokuan; Lei, Baozhen; Li, Miaomiao
• Is Part Of: Mechanism and machine theory. Volume 174(2022)
• Publication Date: 2022-08
• Subjects: Mesh theory -- Point contact -- Conjugate -- Hourglass worm -- Two generating surfaces; Machine theory -- Periodicals; Machinery -- Periodicals; Machines -- Périodiques; Génie mécanique -- Périodiques; Machine theory; Machinery; Periodicals; 621.81
• DOI: 10.1016/j.mechmachtheory.2022.104877
• Languages: English
• ISSNs: 0094-114X

Abstract

Highlights: A novel point-contact conjugate hourglass worm drive (PCHW drive) is proposed. The design method for the PCHW drive is presented. The formation mechanism of the conjugate surfaces of the PCHW drive is studied. The meshing behavior with manufacturing and assembly errors is investigated. The proposed method is verified by numerical calculation and experiment. Abstract: To solve the problems of narrow contact area and small contact ratio of the involute cylindrical worm helical gear drive, this paper proposed a point-contact conjugate hourglass worm drive (PCHW drive) based on the meshing theory of conjugate tooth surfaces generated by two generating surfaces. The hourglass worm and worm gear are generated by the helix surface of an involute helical gear and that of an involute cylindrical worm. A mathematical model of the drive is established and a method for solving contact points based on involute pitch point is given. The instantaneous transmission ratio is proved theoretically to be constant and transmission error is zero. The formation mechanism of the conjugate surfaces of the drive is revealed. The results of the tooth contact analysis for a numerical example show that he contact area of this drive is wider, the contact ratio is slightly increased compared to the involute cylindrical worm helical gear drive. Furthermore, the drive is insensitive to manufacturing and assembly errors. A prototype is manufactured and meshing test is performed to verify the theoretical correctness.