RU2190045C2 - Apparatus for microarc applying of oxide coating on pressure race and bearing race of gear pump - Google Patents

Abstract

FIELD: applying oxide coating onto aluminum alloys at restoration of pressure and bearing races of gear pumps. SUBSTANCE: apparatus for microarc applying of oxide coating includes electrodes, bath-electrolyzer, tank for storing electrolyte, system for supplying electrolyte, power source. Bath-electrolyzer includes housing of dielectric material inside which electrodes in the form of solid cylinders with inserts of dielectric material are mounted. Pressure and bearing races are arranged onto said electrodes and they are connected with first terminal of power source; electrodes are connected with second terminal of power source. Gap between outer surfaces of electrodes and oxidized surfaces of races is in range 12-15 mm. EFFECT: enhanced quality of applied oxide coating due to optimization of structural members of apparatus, improved efficiency due to simultaneous restoration of both pressure and bearing races. 2 dwg

Description

 The invention relates to a device for producing oxide coatings on aluminum alloys in the repair of pinch and bearing cages of gear pumps.

 In repair production, local deposition of alloys with a stationary electrolyte is known. The hole in the body part is sealed from below, the electrolyte is poured into it, the anode is installed and connected to a current source. The hole itself serves as a bath. This method is often used to restore bearings under bearings in housing parts [1].

 This device does not provide intensive mixing of the electrolyte and replenishment with new enriched portions of the desired concentration, which affects the quality of the resulting coatings.

 A device is known for the restoration of wells of pump housings by electroplating with zinc-iron or zinc-nickel alloys. The device has two electrodes of a special design. Each electrode consists of a cylinder with a spiral sector. In the spiral sector there are grooves used to supply fresh electrolyte to the tampon [2].

 However, the resulting coatings do not provide high wear resistance of the restored surface.

 The closest to the proposed device in technical essence and the achieved result is a device for microarc oxidation (MAO) of the wells of the gear pump housing, containing an electrode, a bath-electrolyzer, a power source, a tank for collecting electrolyte, an electrolyte pumping system, while the bath-electrolyzer body is connected with the first terminal of the power source, and the electrode is connected to the second terminal. The electrode is made in the form of two hollow cylinders connected by a jumper and installed in the wells of the gear pump housing, which at the same time are a bath-electrolyzer [3].

 However, this device does not allow to restore the pinch and bearing clips of gear pumps.

 The objective of the invention is to improve the quality of the resulting coating by optimizing the structural elements of the device and increasing productivity due to the simultaneous restoration of the clamping and bearing cages of gear pumps.

 This object is achieved in that in a device for microarc oxidation containing electrodes, an electrolytic cell bath, an electrolyte collecting tank, an electrolyte supply system and a power source, according to the invention, the electrolytic cell is made in the form of a housing made of a dielectric material inside which electrodes are placed in the form of continuous cylinders with liners of dielectric material, with clamping and bearing cages mounted on them, connected to the first terminal of the power source, and ode connected with its second terminal, moreover, the clearance between the outer surfaces of the electrodes, and oxidizable surfaces of yokes is in the range 12 ... 15 mm.

 The proposed device provides high quality coatings and the simultaneous restoration of two clips.

 With a gap between the outer surfaces of the electrodes and the oxidized surfaces of the cages in the range of 12 ... 15 mm, a more uniform coating with optimal porosity and physico-mechanical properties is formed. In addition, the quality of the coatings is improved by intensively mixing the electrolyte and replenishing it with new enriched portions of the required concentration.

 The invention is illustrated by drawings, where figure 1 shows the proposed device, General view; figure 2 is a section aa in figure 1.

 A device for microarc oxidation of the clamping and bearing cages of a gear pump contains two stainless steel electrodes 1 in the form of solid cylinders with inserts 2 of dielectric material. The liners 2 are connected to the electrodes 1 with an epoxy resin. On the liners 2 are mounted bearing 3 and clamping 4 cages of the gear pump. The liners 2 provide a distance between the outer surfaces of the electrodes and the oxidized surfaces of the 5 and 6 rings for the pivots and the ring gears, respectively, in the range of 12 ... 15 mm, and also insulate the inner surfaces of the rings that are not subjected to MAO. The electrodes 1 with clips 3 and 4 are installed in the housing 7 of a dielectric material. The housing 7 through the ring 8 with holes 9 is attached to the plate 10, which is mounted and mounted on the bath 11. The bath 11 serves to collect and cool the electrolyte, and the holes 9 of the ring 8 - to drain the electrolyte. Ring 8 and plate 10 are made of dielectric material. The electrodes 1, bearing 3 and pinch 4 of the gear pump cage are connected to an AC source.

 A device for microarc oxidation of clamping and bearing cages of a gear pump operates as follows.

 An alkali-resistant pump with an electric motor is turned on, after which an electrolyte is fed through the system of caprolon pipelines into the cavity of the housing 7. When the electrolyte begins to overflow through the holes 9 of the ring 8, the power source is turned on. Between the electrodes 1 and the surfaces 5 and 6 of the cages 3, 4, microarc discharges occur. The duration of the process is 90 minutes, after which a durable wear-resistant coating with a thickness of 90 ... 100 microns is formed on the oxidized surfaces of the cages.

 The use of the proposed device for microarc oxidation can improve the quality of the resulting coating by optimizing the structural elements of the device and increase productivity due to the simultaneous restoration of the clamping and bearing cages of gear pumps. The proposed device is advisable to apply not only when restoring worn out clamping and bearing cages of gear pumps, but also when hardening new ones.

Sources of information
1. Prince "Machine Repair", ed. Telnova N.F. - M.: Agropromizdat, 1992 .-- 560 p., P. 183 ... 185, fig. 2.35.

 2. Prince Novikov A.N. Repair of parts from aluminum and its alloys. Tutorial. - Orel: Oryol State Agricultural Academy, 1997. - 57 p., P.25.

 3. RF patent 2147324, C 25 D 17/02, publ. in B.I. 10, 2000 - a prototype.

Claims (1)

 A device for microarc oxidation of the clamping and bearing cages of a gear pump, comprising electrodes, an electrolysis bath, an electrolyte collection tank, an electrolyte supply system and a power source, characterized in that the electrolysis bath is made in the form of a housing made of dielectric material, inside of which electrodes in the form of continuous cylinders with inserts of dielectric material, with clamping and bearing cages mounted on them, connected to the first terminal of the power supply I, and the electrodes are connected to its second terminal, moreover, the clearance between the outer surfaces of the electrodes, and oxidizable surfaces of yokes is in the range of 12-15 mm.

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