Case 4: Pull-up robot

Case Introduction

Design a pull-up robot that simulates the pull-up action.

Teaching Preparation

Name	Graphic
Nezha Pro Sports Package

Teaching Objectives

Understand the characteristics and construction methods of worm gears Inspire interest in engineering and robotics.

Course Introduction

Welcome children to join our wonderful STEAM journey! Today, we will explore how to make a pull-up robot without programming. In this project, we will learn how to control the movement of the robot through simple mechanical transmission. You don't need complex programming knowledge, just assemble and adjust it by hand, and you can create a pull-up robot. Let's start this exciting STEAM learning journey together and stimulate your creativity and problem-solving skills!

Learning Exploration

What are the characteristics of a worm gear?

Build steps

Case Demonstration

Press the button on the Nezha Pro to start the pull-up robot.

Summary and sharing

Extended knowledge

Basic characteristics of worm gear structure Unidirectional transmission (self-locking)

Core features: The worm can drive the worm wheel, but the worm wheel cannot reversely drive the worm (self-locking), which is suitable for scenarios that need to prevent reversal (such as cranes and elevators).

Principle: When the helical lead angle of the worm is less than the friction angle, the reverse transmission is locked by friction.

Exception: Multi-start worms or worms with larger lead angles may lose self-locking.

High reduction ratio and low efficiency

Transmission ratio formula: If the worm is single-start (1 helical tooth), the transmission ratio = the number of worm wheel teeth: 1. For example, the transmission ratio of the Lego worm wheel (24 teeth) is 24:1.

Low efficiency: Due to the sliding friction between the worm and the worm wheel, the energy loss is large (the efficiency is usually less than 50%).

Space staggered axis transmission

The axes of the worm and worm wheel are staggered at 90°, with a compact structure, suitable for vertical power transmission (such as fans and rotating tower models).

Transmission stability

The meshing between the worm and worm wheel is line contact, with less vibration and noise。