Modernization of excavator hydraulic drive

Introduction

Course design for engineering specialties, universities is an important stage in the process of creating the knowledge of a mechanical engineer. The course project, in addition, is a preparatory work for a diploma project.

Course design consolidates, deepens and summarizes knowledge obtained during lecture or practical classes, teaches to use reference literature , state standards, tables, nomograms, norms, skillfully combining reference data with theoretical knowledge obtained during the course study.

Currently, there are many problems associated with improving the hydraulic drive of earth-moving machines. One of them is removal of air dissolved in working fluid. The working fluid can contain from 10 to 20% of air. This leads to the fact that in the first, covitational wear increases, and in the second, productivity decreases, due to an increase in the response time of the hydraulic cylinders. The purpose of this course project is to develop the design of a hydraulic tank with a mechanism for removing air from the liquid.

Analysis of found patent solutions 

As a result of the patent search, several copyright certificates were found related to the solution of this problem. Consider the disadvantages of these inventions (the copyright evidence found is presented in the appendix).

The main disadvantage of all the most found solutions is that the designs of the presented inventions are complex and time consuming to manufacture. In addition, there are other drawbacks that we will consider separately for each copyright certificate.  

1. A.S. No. 1435266 and No. 1780803. These two constructs are similar in design. In addition to the above, they have large dimensions associated with the installation of the liquid degassing device;

2. AMPERE-SECOND. NO. 1692944. The device has a simple design, but it does not provide a system for regulating the discharge in the upper cavity of the tank.

3. AMPERE-SECOND. NO. 1719015. In addition to the fact that the device is quite complex in design, this idea cannot be applied to a standard tank, that is, it is necessary to design a completely new tank structure, and establish the production of this product.

The technical proposal is presented in Figure 1.1. This construction has a number of advantages over those inventions as discussed above. This is a simple design, the possibility of application in a standard tank. The closest in design is the scheme presented in copyright certificate No. 1692944. The difference is that in the technical proposal there is a device for regulating the discharge in the upper part of the tank.