Systematic Method for the Synthesis of South Pointing Chariot With Planetary Gear Trains

Abstract

South pointing chariots have been the fascinating mechanical devices for designers for a long time. Up to date, the gear trains used in the south pointing chariots are the planetary gear trains with two degrees of freedom and with train value -1. The purpose of this work is to present a systematic approach for the kinematic design of south pointing chariots with planetary gear trains. According to train circuit equation, we propose equation of motion of PGTs. Then, based on the equation of motion of PGTs, we derive two constrained equations for the kinematic design of south pointing chariots. Finally, based on these two equations, we synthesize the corresponding south point chariots for arbitrary planetary gear trains with two degrees of freedom. Some design examples are illustrated to demonstrate the design process.

Structural Synthesis of South Pointing Chariots With a Fixed Axis Wheel System

“…All existing designs of South Pointing Chariots can be decomposed into four sub-systems: two inputs, one transmission SUb-system, one passive feedback mechanism, and one output [22]. And, the mechanical components include linkages [5][6][7][11][12][13][14][15][16][17][18][19], gears [5-7, 11-19,23], ropes and pulleys [5,6,19], and frictional wheels [19].…”

“…According to another hypothetical structure, in 1947, Lanchester [7] proposed a South Pointing Chariot with a differential mechanism. Thereafter, Needham [8], Lee [9] and Lu [10] sununarized the studies of South Pointing Chariots and some scholars focused on designing different interior mechanisms [11][12][13][14][15][16][17][18][19].…”

A Systematic Approach for the Structural Synthesis of Differential-Type South Pointing Chariots

“…The mechanical components include linkages (5) - (7), (11) - (19) , gears (5) - (7), (11) - (19) , ropes and pulleys (5), (6), (19) , and frictional wheels (19) . Many different designs have the same topological structures after the process of generalization (24) - (29) , e.g., Lanchester's (7) design and Hsieh's (18) design as shown in Fig. 1.…”

“…For non-revolute pairs, there are three connecting types: perpendicular, in-(a) Lanchester's design (7) (b) Hsieh's design (18) J characteristic of joint type of joint in which the subscript denotes the type of joint and the superscript denotes the characteristic of the joint. For revolute pairs, there are two characteristics: vertical (V) or horizontal (H) to the ground.…”

On the design and prototype manufacturing of multi-speed transmission device of bicycle

“…However, train value method [3][4] is the simplest one that is used for the kinematic analysis of planetary gear trains. According to the kinematic analysis, many studies focused on the kinematic design [5][6][7][8] of planetary gear trains for specified engineering purpose. The meshing efficiency of planetary gear train is an important factor of planetary gear train.…”