Tesis profesional presentada por Roberto Sanz Camacho [roberto.sanzco@udlap.mx]

Miembro del Programa de Honores. Licenciatura en Ingeniería Mecánica. Departamento de Ingeniería Industrial y Mecánica. Escuela de Ingeniería, Universidad de las Américas Puebla.

Jurado Calificador

Presidente: Dr. René Ledesma Alonso
Vocal y Director: Dr. Tadeusz Majewski Szymiec
Secretario: Dr. Jorge Arturo Yescas Hernández

Cholula, Puebla, México a 7 de diciembre de 2018.

Resumen

The mathematical modelling of a Dynamic Eliminator of Vibrations is presented. This model is based on two drums that rotate in opposite directions with a speed equal to the excitation frequency of the system. These drums contain the same amount of free elements such as rollers or spheres that translate in a viscous environment and compensate the excitation forces with the action of their centrifugal force. Also, a rotary hammer working principle is modelled with a novel method for the mathematical implementation of the DEV to this system, to determine the possibility of vibrations damping. Several systems of equations are developed and solved numerically using different input parameters. Results of these simulations where vibrations reduction (of 99%) is illustrated, are presented throughout this work, starting from simpler models up to systems with several degrees of freedom.

Palabras clave: Vibrations, dynamic eliminator, rotary hammer, damping.

Table of content

Portada

Agradecimientos

Índices

Capítulo 1. Introduction

  • 1.1 Context of the Research
  • 1.2 Research Questions
  • 1.3 Outline of the Document

Capítulo 2. Power Tools

  • 2.1 Introduction
  • 2.2 Power tools and their vibrations production
  • 2.3 Impact tools and their working principles
  • 2.4 Vibrations effects on health
  • 2.5 Damping systems for impact tools

Capítulo 3. Dynamic Eliminator of Vibrations

  • 3.1 Introduction
  • 3.2 Frahm´s undamped dynamic vibration absorber
  • 3.3 Proposed Dynamic Eliminator of Vibrations

Capítulo 4. Rotary Hammer experiments and modelling

  • 4.1 Introduction
  • 4.2 Experimental Set-up
  • 4.3 Modelling of rotary hammer - Kinetic model with algebraic equations
  • 4.4 Modelling of rotary hammer - Dynamic model with differential equations

Capítulo 5. Implementation of the Dynamic Eliminator of Vibrations to the Rotary Hammer

  • 5.1 Introduction
  • 5.2 Mathematical modelling of rotary hammer with DEV analyzed in one direction (model with 2 drums and 4 spheres)
  • 5.3 Mathematical modelling of rotary hammer with DEV analyzed in two directions (model with 2 drums and 4 spheres)

Capítulo 6. Implementation of the DEV to the rotary hammer with the addition of the chisel chuck spring

  • 6.1 Introduction
  • 6.2 Modelling of rotary hammer - Dynamic model with chisel chuck spring
  • 6.3 Mathematical modelling of rotary hammer with chisel spring connection and DEV implementation (2 directions, 2 drums, 4 spheres)

Capítulo 7. Conclusions

  • 7.1 Conclusions
  • 7.2 Future work

Referencias

Anexo 1. Appendices

Sanz Camacho, R. 2018. Modelling of a Rotary Hammer with the implementation of a Dynamic Eliminator of Vibrations. Tesis Licenciatura. Ingeniería Mecánica. Departamento de Ingeniería Industrial y Mecánica, Escuela de Ingeniería, Universidad de las Américas Puebla. Diciembre. Derechos Reservados © 2018.