RU2163532C1 - Apparatus for hydraulic-abrasive working of screws - Google Patents

Abstract

FIELD: different industry branches of machine engineering, possibly trimming and finishing operations for providing high-degree roughness of surface of screw parts made of materials of any hardness, for example in screw pumps. SUBSTANCE: apparatus includes working chamber with elastic walls filled with working fluid and mechanism for driving screw part. Working chamber is in the form of casing rubberized inside with gas and oil resistant elastomer. Said casing has internal double-start threaded surface whose pitch is two times more than pitch of worked screw and whose direction is the same. Chamber is mounted on base at one side by means of bushing, at other side - by means of sleeve with flange having sealing rings. Bushing and sleeve are mutually connected by means of pipeline through throttle. Rotation of part necessary for creating working fluid pressure by means of screw gage such as screw part-chamber is realized through coupling being cardan joint with use of separate electric motor. Free end of worked screw is supported by foot in the form of thrust bearing. Such structure provides rotation of worked part, forcing through abrasive mass and use of elastic working chamber with special inner cavity as lapping. EFFECT: enlarged manufacturing possibilities, enhanced efficiency and quality of working due to uniform working of recesses and protrusions of screw. 3 cl, 3 dwg

Description

 The invention relates to the machine-building industry and can be used in cleaning and finishing operations to ensure a high class of roughness on screw parts, for example, screw pumps made of materials of any hardness.

 A device for liquid honing of microholes and surfaces is known, the working chamber of which has two symmetrical halves [1]. The workpiece is installed and secured between the two halves of the working chamber with a reliable seal. The flat elastic walls of the chamber, which is filled with a waterjet, bend alternately, creating a working pressure of the waterjet. Waterjet is pumped from chamber to chamber under pressure, passes along the surface of the hole and processes it.

 The device has limited use only for machining holes and internal surfaces of workpieces and does not allow machining of parts, such as shafts, etc. In addition, the design of the device, which requires mandatory rotation of the working chamber, is complicated, which reduces the reliability of tooling and equipment and increases the cost of processing .

 A device for abrasive-liquid processing of parts containing a working chamber with elastic walls filled with a working medium, a drive of synchronous reciprocating movement of the walls, a rotary multi-seat cartridge and rings [2].

 The known device has the following disadvantages: limited use, only for processing the inner surfaces of the holes of parts such as disks and bushings, the mandatory rotation of the working chamber complicates the design of the tool, reduces the reliability of the equipment and increases the cost of the processing process.

 The closest in technical essence and the achieved result to the invention is a device for abrasive-liquid processing of screws, comprising a base, a rotational drive of a screw with an individual electric motor and a chamber filled with a working medium, fixed to the base on one side with a glass and on the other with a sleeve with a flange having o-rings [3].

 The disadvantages of the known device are the narrow technological capabilities, low productivity and processing quality obtained as a result of the fact that the pumping working medium intensively processes mainly the protrusions of the screw and lies in hollows, forming dead zones.

 The objective of the invention is to expand the technological capabilities of the device, increasing productivity and processing quality by communicating the rotational movement of the workpiece, forcing the abrasive mass and using an elastic working chamber with a special internal cavity as a lapping agent.

 The problem is solved using the proposed device for abrasive-liquid machining of screws containing a base, a rotational drive of a screw with an individual electric motor and a chamber filled with a working medium, fixed to the base on one side with a glass, and on the other - with a sleeve with a flange having sealing rings, while the working chamber is made in the form of a rubberized inside with oil and petrol resistant elastomers of the cage with an internal two-way screw surface having the same direction, h and processed on the screw and the pitch - two times greater than its pitch, the glass sleeve and communicated with each other through the throttle duct.

 In addition, the individual electric motor of the device is connected to the screw being machined by means of a universal joint type coupling, the device being provided with a fifth in the form of a thrust bearing for supporting the free end of the screw.

 The device is designed to handle the screws of screw pumps.

 The essence of the design of the proposed device is illustrated by drawings.

 In FIG. 1 shows the design of the device, a longitudinal section; in FIG. 2 - device, top view; in FIG. 3 is a section AA in FIG. 1.

 The proposed device for abrasive-liquid processing of screws 1, for example, screw pumps consists of one part 2 (for example, left, see Fig. 1) of the chamber 3 and another part 4 (for example, right, see Fig. 1). Chamber 3 and its parts 2 and 4 are filled with a waterjet, which is periodically replenished.

 The working chamber 3, in which the machined screw 1 is installed, is made in the form of a rubberized cage, consisting of two steel pipes 5 and 6 with longitudinal grooves from one end, protrusions entering into each other (Fig. 3) and having threads from the other end. Tubes 5 and 6 of the sleeve 3 are connected and rubberized with oil and petrol resistant elastomers 7 (for example, rubber 11-3V-12 2D-405 TU 38-1051082-86). The inner rubber layer is made monolithic, not allowing separation of rubber from metal with a bond strength of rubber with metal of at least 3.9 MPa.

 The internal rubber cavity of the chamber 3 is made in the form of a two-way screw surface in the same direction and with a step twice as large as the step of the screw 1 being machined.

 The left part 2 of the chamber 3, made in the form of a glass, communicates with the right part 4 of the chamber 3, made in the form of a sleeve, by a pipe 8 through a loading choke 9, which controls the pressure of the waterjet in the working chamber 3. The drive of the machined screw 1 is carried out from an individual electric motor (not shown) through an eccentric clutch 10, which is a universal joint and consists of a leash, rollers and a housing (not shown).

 When the rotated screw 1 is rotated in the ferrule chamber 3, which form a working screw pair, as in a screw pump, suction, pressure build-up, pushing of the hydraulic abrasive, its mixing and abrasive-liquid honing of the screw surface of the screw occur.

 The creation of pressure and pushing the waterjet causes a hydraulic axial force to be applied to the screw, which is perceived by the fifth 11. The latter can be traditionally made in the form of a thrust bearing or made of silicon graphite.

 The chamber 3, connected to the left 2 and right 4 parts, is screwed onto the base 12. The right part 4 of the chamber 3 has a flange 13 and is sealed with o-rings 14.

 Waterjet is pumped from one part of the chamber to another - under pressure, passes along the screw surface of the screw and processes it. The pressure of the waterjet, which affects the processing process, is regulated by the load throttle when the waterjet returns through the pipeline. In addition, abrasive grains, penetrating into the rubber inner surface of the cage chamber, made in the form of a double-helical cavity, additionally cut off the microroughness of the screw, providing a high class of surface roughness. In this case, the clip chamber acts as a lapping agent, which acts more intensively on the surface being treated, due to which time is sharply reduced and the quality of processing improves.

 The proposed device guarantees constant mixing of the abrasive mass in the chamber, which is of great importance for the process of hydroabrasive processing of precision parts, which is ensured by the continuous rotation of the part.

 The abrasive mass, passing through the channels and cavities that are available in the clip chamber and the part, removes microroughnesses, burrs, rounds sharp edges, cleans and polishes the surface of the screw. The abrasive effect of the mass flow increases in the places of greatest restriction, these are, first of all, the protrusions of the turns of the screw surface of the screw and its depression, which are in contact with the protrusions of the inner cavity of the chamber. Therefore, the proposed device performs selective removal of microroughnesses, burrs and rounding of sharp edges by controlling the flow path using special profiling of the inner cavity of the cage in the form of a double-helical surface with a step two times larger than the step of the machined screw.

 The device creates vigorous friction of the abrasives enclosed in the paste over the machined screw surface due to the rotation of the part, the special profile of the chamber’s internal cavity, and the viscosity of the mass, which provides sufficient resistance to pumping and maintaining the highest possible speed of the paste relative to the walls.

 Thus, the use of the proposed device for abrasive-liquid machining of screws allows, by communicating the rotational movement of the workpiece, forcing the abrasive mass and using an elastic working chamber with a special internal cavity as a lapping agent, to expand technological capabilities, increase productivity and the quality of processing, evenly process as protrusions and hollows of the workpiece-screw.

Sources of information taken into account
1. Nazarov Yu.F., Bulygin V.V., Maltsev G.P., Mosichev V.E. Development of technology and equipment for liquid honing of microholes and surfaces // Herald of Mechanical Engineering. - 1991. - N 11. - S. 38-41.

 2. Auth. St. USSR N 1349974, MKI V 23 B 31/116, application N 4003499 / 40-08, decl. 01/08/86, publ. 11/07/87. Bull. N 41.

 3. Auth. St. USSR N 1815180 A1, MKI B 23 V 31/10. Rybinsk Engine-Building Production Association. Claim 05/15/93 - the prototype.

Claims (3)

 1. A device for abrasive-liquid processing of screws, containing a base, a rotational drive of a screw with an individual electric motor and a chamber filled with a working medium, fixed to the base on one side with a cup, and on the other through a sleeve with a flange having o-rings, characterized in that the working chamber is made in the form of a rubberized inside with oil and petrol resistant elastomers of the cage with an internal two-way screw surface having the same direction as the screw being machined, and the step is two times more of its steps, the glass sleeve and communicated with each other through the throttle duct.  2. The device according to claim 1, characterized in that the individual electric motor is connected to the screw being machined by means of a universal joint type coupling, the device being provided with a fifth in the form of a thrust bearing for supporting the free end of the screw.  3. The device according to claim 1 or 2, characterized in that it is intended for processing screws of screw pumps.

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