Kinematic diagram 16K20FZ

Contents

Introduction

1 Description of lathe

2 Calculation of cutting modes

3 Kinematic calculation of the main motion drive

4 Calculation of number of gears

5 Power calculation on speed box shafts

6 Determination of gear modules of the gearbox

7 Determination of geometrical parameters of gears

8 Determination of shaft diameters

9 Calculation of belt transmission

10 Calculation of spindle assembly

Conclusion

List of sources used

Application

Introduction

This work involves the design of a lathe-analogue on the basis of the 16K20FZ machine. The designed machine must meet all the requirements of modern machine tools, the main of which are:

increase of machine efficiency by intensification of processing modes and reduction of auxiliary time;

high accuracy of processing and shaping

rigidity

durability

vibrostability

heat resistance

high efficiency of main and auxiliary mechanisms (drives).

High performance of the machining process provides due to speed, power and automation. The numerical software control device allows increasing the mobility of production and accuracy, as well as automatically setting the necessary processing modes taking into account changing conditions.

General description of lathe

The turning and screw-cutting machine 16K20F3 with the NC202 CNC device is equipped with the main Hyundai N300 drive and two HA075 feed drives along the Z and X axes. An additional feature of this machine is to equip it with a Delta VFD007 drive that performs the function of pinholes, chuck and head control. It is intended for turning in automatic mode of external and internal surfaces of parts such as bodies of revolution with stepped and curvilinear profile of various complexity according to a pre-made control program. Field of application of the machine: small-scale and mass production.

Design features:

- the high-strength bed made by casting of SCh20 brand cast iron with the thermoprocessed polished guides provide long service life and the increased processing accuracy. Machine bed has box-like shape with transverse ribs of U-shaped profile, hardened polished guides. Spindle head, carriage, longitudinal feed drive and rear head are installed on the bed. To base the carriage on the bed, the front guide has the shape of an unequal prism, the rear guide is flat. The hind head is based on the bed along a small rear prismatic guide and on the plane - on the front guide.

- main motion drive including main engine 11 kW and spindle head provides maximum torque up to 800 Nm

-The drive of longitudinal movement. Drive of longitudinal displacement includes ball transmission of screw - rolling nut, screw supports, drive DC electric motor with reduction gear or asynchronous motor with frequency adjustment and reduction gear, as well as feedback sensor, which is connected to screw through clutch. Selection of clearance in gear engagement of reduction gear is performed by displacement of transition plate with electric motor by means of eccentric rotation.

- Drive of transverse movement includes ball transmission screw - rolling nut, screw support, drive DC motor or asynchronous one with frequency control, feedback sensor connected to type through coupling .

-high-flow spindle with 55 mm hole (64 mm by order), which allows to process parts made of rod material, the processing area can be equipped with both linear adjustment and a turret, depending on the requirements

- Machine 16K20FZ uses automatic universal 6 - position head. The heads are equipped with a tool disk for six radial or three axial tools (6 - position head).

Rear panel-type fixed guard with detachable boards on the rear side of the machine and front guard - movable with transparent screen for observation, closes the cutting area

- reliable protection of ball-screw pairs ensures the durability of the mechanisms of movement along the X and Z coordinates, the machine is equipped with CNC systems and electric drives, both domestic and foreign companies

-The machine base. The base of the machine is a rigid casting on which the frame and the main movement electric motor are installed.

Kinematics of the machine. The main movement is the rotation of the spindle. Rotation of the spindle is communicated from a frequency-controlled asynchronous motor with a constant power of 202500 rpm.

Rotation of the spindle is transmitted through a wedge belt 2240L20 with a gear ratio of 1: 2.5, i.e. ∅200/∅280. Further, an option is possible: through a gearing 40/54 from I to III shaft and a transmission 65/43 to spindle IV.

Spindle Assembly Calculation

Concept of "spindle assembly"

The spindle assembly is one of the most important components of the machine, which determines the possibility of achieving high quality processing of the surfaces of parts. The assembly consists of the spindle itself and its supports. At the design stage, it is necessary to correctly select the dimensions of the spindle, select supports that provide high rigidity, vibration resistance, and reliability of the unit.

Spindle assemblies must meet a number of requirements.

1) The accuracy of spindle rotation, characterized by radial and axial run-out of the front end, has a strong effect on the accuracy of the workpieces. Permissible run-out of the spindle of universal machines must comply with state standards. The run-out of the special machine spindle shall not exceed 1/3 of the limit size tolerance of the machined part.

2) Spindle speed is estimated by d * n (mm/min), where d is the diameter of the spindle neck for the front bearing (mm), n is the rotation speed.

3) Static stiffness is determined by elastic deformations of the front end of the spindle under the influence of external forces. Elastic deformations are distinguished in balance of front end displacement:

- cantilever part of spindle;

- span (inter-support) part;

- bearings of front and rear supports.

4) Dynamic characteristics of spindle unit include natural oscillation frequency, amplitude-phase frequency characteristics, form of oscillations at natural frequency. The natural spindle speed shall be at least 30% higher than the maximum speed.

5) Energy losses are characterized by friction moment and idling power and are taken into account when selecting supports. High speed spindles have very large friction power losses at high speed.

6) Heating of supports results in change of tension in bearings and thermal displacement of the front end of the spindle. The heating of the supports is highly dependent on the lubricating device.

The service life of the spindle assembly is not regulated, but is limited by the wear of the rolling supports .

Conclusion

In this course work, the components of the machine 16K20F30 were studied and analyzed, the main NC lathe drive was modernized. The base part is a gear wheel machining. Cutting and auxiliary tools are selected. The calculation of cutting modes, gearbox, belt gears and spindle assembly was made.

The graphical part of the course work on the first sheet shows the general view of the machine with the specification of the main units and mechanisms, the technical characteristics of the base machine. The second sheet shows a kinematic diagram of the basic and projected versions of the machine, speed graphs of the basic and projected versions of the machine, a graph of powers and torques of the designed version of the machine. The third sheet includes scanning of the speed box of the designed version. The fourth sheet includes a flat pattern of the spindle assembly of the design version.

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