RU2265502C1 - Elastic tool for gear honing - Google Patents

Abstract

FIELD: machine engineering, possibly manufacture of tools for finishing gear wheels.

SUBSTANCE: tool is in the form of disc with working toothed rim having thinned teeth. Diamond-abrasive layer on flexible binder is applied on thinned teeth. Tool is mounted by acute angle α relative to plane normal to rotation axis of spindle with use of sleeve having axis of opening and axis of outer surface mutually inclined by acute angle α. Disc is made of elastic porous material and it is coaxially mounted with use of nut on cylindrical bushing. The last is mounted by means of bearing assemblies in said sleeve having mutually crossing axes. It provides possibility for autonomous rotation of tool.

EFFECT: enlarged manufacturing possibilities due to axial shifting of toothed hone, intensified working process without using high-cost devices, simplified process for making tool.

3 cl, 10 dwg

Description

The invention relates to mechanical engineering technology, in particular to tools for finishing gears.

Known gear hon (type 3) of a steel gear wheel with thinned teeth and an abrasive layer applied to them with a thickness of 1.5 ... 2 mm [1].

The disadvantages of hone are the need for longitudinal movement of the workpiece, as well as oscillating motion along the axis of the hone, with high precision and manufacturing complexity and a short tool life makes the process more expensive.

As a prototype, the design of the gear hone has been selected, having a working gear ring with thinned teeth with an abrasive layer applied to them, in which the working gear ring is located with axial displacement relative to the axis of rotation of the hone, while the thickness of the mentioned abrasive layer is selected in the range of 1.5 .. .2 mm [2].

The disadvantages of the known gear hone are low productivity due to the small axial dimensions and the need for longitudinal movement of the workpiece to obtain a surface identical to gear shaving, i.e. with a longitudinal direction of risks of microroughnesses, and this, in turn, requires special equipment, while high precision and manufacturing complexity and a short tool life makes the process more expensive.

The claimed invention solves the problem of expanding the technological capabilities of gear honing due to the axial displacement of the gear hone, due to which the longitudinal reciprocating movement of the diamond-abrasive working surface along the tooth is carried out, the treatment is intensified, as well as the refusal to use special expensive equipment, while the simplicity of manufacture and long term tool service will reduce the cost of the process.

This is achieved by the fact that the proposed elastic tool for gear honing is made in the form of a disk with a working gear ring with thinned teeth, on which a diamond-abrasive layer is applied, and mounted on the spindle with the possibility of independent rotation on bearings at an acute angle α to a plane perpendicular to the axis of rotation spindle, using an oblique sleeve, in which the axis of the hole and the outer surface are at an acute angle α, and the disk is made of elastic porous material and fixed with a nut on a cylindrical coaxially a sleeve which is mounted on said bearing sleeve and braid, wherein the diamond abrasive layer is deposited on the surface of teeth in a flexible bundle.

In addition, the height of the disk is taken not less than twice the width of the gear rim of the machined wheel, and the angle α is determined by the formula:

α≥arc tg (in _W / D _L)

where In _Z - the width of the workpiece;

D _D - dividing the diameter of the gear hone.

In this case, the gear honing speed is set by the rotation frequency of the workpiece, the oscillation frequency is set by the rotation speed of the tool spindle, and the oscillation amplitude A _о depends on the angle of the tool and is determined by the formula:

And _o = D _D tg α.

The design features of the proposed elastic tool for gear honing are illustrated by drawings.

Figure 1 shows an elastic tool for gear honing, a partial longitudinal section; figure 2 is a view of the end face of a in figure 1; figure 3 is a General side view; figure 4 is a General side view, the tool is rotated relative to the longitudinal axis 180 ° relative to the position shown in figure 3; Figures 5 and 6 show the influence of the angle of inclination of the hone on the captured honing width B _k and the intensive honing zone B _x , respectively, at α = 10 ° and α = 5 °; Fig.7 is a diagram of gear honing with the proposed elastic tool, general view; on Fig - 9 - gear grinding schemes with the position of the gear of the tool in the extreme, respectively, right and left positions relative to the workpiece, a longitudinal section in the contact zone; figure 10 is a section bB in figure 9, the position of the ring gear in the middle position relative to the workpiece.

The proposed elastic tool is used for gear honing and is made in the form of a disk 1 with a working gear ring with thinned teeth 2. On the lateral working surfaces of the teeth 2 a diamond-abrasive layer 3 is applied on a flexible bond. Disk 1 is mounted on the spindle 4 with the possibility of independent rotation on bearings 5 , which, in turn, are mounted on the oblique sleeve 6 at an acute angle α to a plane perpendicular to the axis of rotation of the spindle 4.

The angle α is set using an oblique sleeve 6, in which the axis of the hole and the outer surface are at an acute angle α.

The disk 1 is made of elastic porous material (for example, foam rubber, rubber sponge, felt, etc.) and is mounted on a cylindrical coaxial sleeve 7, which is installed on the mentioned bearings 5 and the oblique sleeve 6, nut 8. Since the oblique sleeve 6 the ends are made at an angle α to the axis of the hole, then for its fastening on the spindle 4 are used oblique washers 9 with ends made at the same angle, and a nut 10.

The diamond-abrasive layer 3 with a thickness of 1.5 ... 2 mm is applied to the surface of the teeth 2 on a flexible bond. Alternatively, in order to reduce the cost of manufacturing tools, apply one-sided diamond-abrasive skin. A diamond skin is distinguished by great durability, one serrated hone with teeth with a glued diamond skin (total dimensions 120 × 30 mm), one set can process 15 ... 20 thousand wheels [3].

Due to the fixing of the gear hone at an angle α, the contact zone B _{to the} tool with the workpiece oscillates in the longitudinal direction, while the width of the contact zone increases with an increase in the angle of inclination. So (see FIGS. 5-6), at a hone angle of 10 °, the contact zone B _{k10 is} larger than B _k5 at a _hone angle of 5 °. In addition, with this treatment, it is possible to isolate the intensive honing zone B _x , which decreases with increasing angle of inclination. So (see FIGS. 5-6), at an hon angle of 10 °, the intensive honing zone is B _x10 less than B _x5 at a hon angle of 5 °.

Therefore, the height B _{and the} disk 1 take at least twice the width B _{W of the} gear rim of the machined wheel 11, and the angle α is determined by the formula:

α≥arc tg (in _W / D _L)

where In _Z - the width of the workpiece;

D _D - dividing the diameter of the gear hone.

During processing, the gear honing speed is set by the rotational speed V _{s of} the workpiece 11, the oscillation frequency is set by the rotational speed V _{and the} tool spindle 4, and the oscillation amplitude A _о depends on the tilt angle and dividing diameter D _{D of the} tool and is determined by the formula:

And _o = D _D tg α.

Honing the teeth of the proposed tool is carried out on conventional machines, allowing forcibly rotate the workpiece 11 and the spindle 4 of the tool 1. Processing can be carried out on a lathe with a special head with a forcibly rotating tool spindle 4.

The hardened machined wheel 11 is forcibly rotated at a speed V ₃ in tight engagement with an abrasive gear hon 1, which is movably mounted on bearings 5 on an oblique bushing 6 with an angular displacement α, a forcibly rotating spindle 4 with a speed of V _and .

Due to this, the gear hon 1 rotates with the speed of the machined wheel Vz and is subject to longitudinal reciprocating vibrations with a frequency equal to the speed of the spindle 4, determined by the speed V _and .

Thus, tooth honing occurs and the risks from the processing grains of the diamond-abrasive layer are directed along the tooth of the wheel.

The clamping of the workpiece 11 to the gear hon 1 is carried out by feeding plunging S _in . Due to this clamping, the lateral diamond-abrasive cutting surfaces of the tooth 2 of the hon tooth gear in contact with the workpiece 11 are set parallel to the side surfaces of the tooth of the workpiece. This self-alignment of the hone tooth 1 along the tooth of the part 11 occurs due to the elastic properties of the material of which the tool is made.

In addition, at large angles of inclination α hone 1, the teeth of the ring gear exert a greater force P _t on the tooth being machined near the ends, making it barrel-shaped (see figure 10). Gears with barrel-shaped teeth, as you know, are widely used in industry.

Changing the direction of rotation of the tool (as is done with traditional gear honing) positively affects the quality of processing, therefore, when gearing with the proposed hon, we use the reverse tool 4 ... 6 times for the entire processing time of the workpiece.

The proposed elastic tool for gear honing allows to reduce the surface roughness parameter by 2 ... 2.5 times (to Ra = 0.32 ... 0.16 μm), remove nicks and burrs up to 0.25 mm in size, and reduce the sound pressure level 2 ... 4 dB and increase the durability of the gear transmission.

In the process of gear honing, errors in the engagement elements are eliminated slightly when removing metal of the order of 0.01 ... 0.03 mm on the tooth side. The rotation frequency of the gear wheel, and hence the hone, is 180 ... 200 min ^-1 , the frequency of rotation of the tool spindle, and therefore the oscillation frequency, is 180 ... 210 min ^-1 .

The time of honing the gear wheel of a car gearbox 60 ... 90 s.

The proposed elastic tool can be attributed to grinding honing [4].

A feature of grinding is a discontinuous contour of the path due to the alternation of grains in contact with the workpiece. Due to the longitudinal oscillation and the local contact zone, as well as the change of the cutting grains of the circle, the thermal balance of the tool improves, its resistance increases, and salinity decreases. The free supply of cutting fluid to the treatment area also increases gear honing performance.

It is recommended to process gears with the number of teeth that is not a multiple of the number of teeth of the gear hone.

The claimed technical solution allows:

- to intensify the processing due to the imposition of oscillating longitudinal vibrations;

- reduce the heat stress of the process of gear honing due to the variable cutting zone and the offset of the temperature field;

- to simplify the design of gear-honing equipment through the use of a new tool that allows exciting longitudinal vibrations.

Sources of information taken into account:

1. The production of gears. / Ed. B.A. Taitsa. - M.: Mechanical Engineering, 1975, p. 223-226.

2. RF patent 2118238, MKI B 23 F 21/03, 21/28. Gear Hon. / Stepanov Yu.S., Afanasyev B.I. and others. Application 96116380/02, head. 08/07/96, publ. 08/27/98. Bull. No. 24 is a prototype.

3. Reference technologist-machine builder. In 2 vols. T. 1 / Ed. A.G. Kosilova and R.K. Meshcheryakova. - 4th ed., Revised. and add. - M.: Mechanical Engineering, 1986. P.443.

4. Ermakov Yu.M., Stepanov Yu.S. Modern trends in the development of abrasive processing (Mashinstru. Pr-in. Ser. Technology and equipment. Metal processing by cutting: Review. Inform. / VNIITEMR. Issue 3) - M., 1991. With 24-26.

Claims (3)

1. An elastic tool for gear honing, made in the form of a disk with a working gear ring with thinned teeth, on which a diamond-abrasive layer is applied, and mounted on the spindle with the possibility of independent rotation on bearings at an acute angle α to a plane perpendicular to the axis of rotation of the spindle, s using an oblique sleeve, in which the axis of the hole and the outer surface are at an acute angle α, characterized in that the disk is made of elastic porous material and is fixed with a nut on a cylindrical coaxial sleeve, which I mounted on said bearing sleeve and braid, wherein on the surface of teeth coated diamond abrasive layer on a flexible bundle. 2. The elastic tool according to claim 1, characterized in that the disk is made not less than twice the width of the gear ring of the workpiece, and the angle α is determined by the formula α≥arc tg (B _Z / D _D ), where In _Z - the width of the workpiece; D _D - dividing diameter of the tool for honing. 3. An elastic tool according to claims 1 or 2, characterized in that the gear honing speed is set by the rotation speed of the workpiece, the oscillation frequency by the spindle speed, and the oscillation amplitude A _о depends on the angle of the tool and is determined by the formula A _o = D _D tgα,

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