Course Design for Machine Parts "General Purpose Drive Design"

3. technical project

3.1. Drive Design Layout

The purpose of the structural layout is the structural design of the parts and assemblies of the gearbox of the open transmission and frame.

The design of the gearbox is made on millimeter A1 paper with a pencil in contour lines, preferably at a scale of 1:1. The gear is most often made integral with the shaft (gear shaft). The design dimensions of the wheel are given below. Wheels of small dimensions are usually made of stamped blanks without recesses and holes.

The structural dimensions of the housing are given below. When designing the gearbox housing, they adhere to installed casting slopes, dimensions of mating elements, flanges. For oil filling and inspection, a window is made in the cover of the housing, which is closed by the cover.

Holes are made in base of housing for selected oil indicator and drain plug.

Bearings are closed by cast-iron blind and through screwed covers. Holes for cuff seals and for passage of output end of shaft are made in through covers. To adjust clearances in bearings, a set of steel gaskets (~ 1 mm thick) is installed under the flange of the covers.

Retaining rings are installed between end faces of bearings and thrust shoulders of shafts (spacer bushing). Clearance between ring and reducer housing; exit to the end of the housing 1... 2 mm.

The length of the output ends of the shafts is determined by the length of the half-coupling (the length of the hub of the open gear). Shafts are structurally made in places of bearing hubs, spacer rings installation - chamfers, radii of rounding (fillets), grooves for grinding wheel outlet and threaded equipment are selected. Sprocket on slow-moving shaft is fixed by endplate.

To ensure accurate relative position, the electric motor and the reduction gear are located on the frame, which we make from steel rolled stock - channels, angles, sheets. To determine the configuration and dimensions of the frame, draw the contours of the coupling on a sheet of paper on a scale. One half-coupling is connected with electric motor shaft and the other with reduction gear shaft. Draw the contours of reduction gear box and electric motor. After that draw contours of frame and determine its length L and width B and difference of heights h of supporting surfaces of electric motor and reduction gear box. Dimensions L and B are rounded to standard values. We determine the height of the main channel, along which we select the nearest larger size of the channel. The width of the channel shelf is checked for the possibility of placement and installation of fasteners.

With a small size h, sheets of the required thickness or support plates are welded onto the frame (plate height 5... 6 mm). At high value h frame is increased by channels. To attach the frame, we use foundation bolts (with a frame length of up to 700 mm, 4 foundation bolts with a diameter of more than 700... 1000 mm are installed - 6 bolts with a diameter of L more than 1000 to 1500 mm - 8 bolts with a diameter) On the inner surface of the channel flanges at the place of installation of bolts, we weld oblique washers to provide the ends of the bolt heads and nuts relative to the bolt axes.

In a belt drive for adjusting belt tension, the electric motor is mounted on slides which are bolted to the frame.

Specifications

The gearbox assembly drawing and the general drive view drawing are listed in standard form. The BOM sections are arranged in the following order:

Documentation;

Assembly units;

Parts;