RU2375180C1 - Method for fixation of frictionless bearing in body - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention is related to the field of repair technologies and, in particular to methods for fixation of frictionless bearings in body of automatic gear box. Technical result is achieved by method of frictionless bearing fixation in body during repair of automatic gear boxes. Method includes application of adhesive substance onto contacting surfaces of seat and bearing, installation of bearing in seat and its fixation in seat. At the same time prior to application of adhesive substance, plastic deformation of mount seat surface is carried out. Hardening of adhesive substance is carried out at temperature of 90-100°C for 0.5-1.0 hours with additional makeup of adhesive substance to zone of bearing installation in process of hardening. At that as heating temperature is increased, soaking time is reduced.

EFFECT: improved vibration resistance of bearings with adhesive embedding into body parts of aluminium alloys.

1 dwg, 1 tbl

Description

The invention relates to the field of repair technologies, in particular to methods for fixing rolling bearings in the housing of an automatic gearbox (automatic transmission).

There is a method of fixing the rolling bearings in the housing parts, which consists in pressing the outer race of the bearing into the hole in the housing with interference (Aleksandrov VG Handbook of aviation materials. M .: Transport, 1972. S.60). An interference fit is ensured by the fact that the diameter of the hole in the housing part is 0.03 ... 0.05 mm less than the diameter of the outer race of the bearing. When mounting a bearing, the pressing force should be applied only to the bearing ring, which is mounted with an interference fit, preventing the transmission of force through the balls.

The disadvantage of this method of fixing the rolling bearings in the housing parts is the need for accurate fit of the dimensions of the parts to prevent radial movement and increase friction in the bearing itself. In addition, ensuring the accuracy of the landing dimensions is not always possible to comply with when performing repairs, for example, automatic gearboxes (automatic transmissions).

The closest in technical essence to the claimed method of fixing the rolling bearing during the repair of automatic gearboxes is a method based on placing between the mating surfaces of the details of the layer of adhesive (Shiryalytsikova V.I., Khrychev Yu.I., Kuzovnikova V.F. Application of adhesives in some designs. Adhesives and gluing technology. Materials of the scientific and technical conference. ONTI. 1968. S.162-164). When implementing this method, the seats should have a gap of 0.006 ... 0.08 mm A VK-9 adhesive layer is applied to the mating surfaces and the assembled unit is thermostated at a temperature of 95 ... 100 ° C for 2 hours.

A significant disadvantage of the prototype is the limitation of its scope by pairs of the same materials, for example steel-steel, aluminum-aluminum. When connecting parts from various materials (bearing made of steel, housing part made of aluminum alloy), they have significant differences in linear expansion coefficients. For this reason, the gap between the aluminum housing part and the steel bearing when heated to cure the adhesive will increase, the interference will decrease and the bonding effect will be significantly reduced.

Practical experience in the repair of automatic gearboxes has shown that the aforementioned method when installing steel bearings in aluminum housing parts is not efficient enough and does not provide the required vibration resistance of bearings with adhesive seal in the cases of automatic gearboxes made of aluminum alloys.

The proposed method of fixing the rolling bearings in the housing parts is aimed at increasing the vibration resistance of bearings with adhesive seal in the housing parts from aluminum alloys.

The technical result to which this invention is directed is achieved by the fact that the curing of the adhesive is carried out at a temperature of 90 ... 100 ° C for 1.0 ... 0.5 hours, respectively, with additional feeding with adhesive substance of the area of the bearing during curing.

In more detail, the essence of the proposed method is illustrated by the drawing, which shows a diagram of the sealing of the bearing cages with glue.

The claimed method of fixing the rolling bearing race in the housing of an automatic gearbox is as follows. Preliminarily, in the housing 1 of the repaired automatic transmission, the surface is knurled (cored) by 2 landing slots in diameter LD. This operation allows, due to plastic deformation of the surface 2 of the seat socket, to reduce the gap between the cage 3 of the bearing 4 and the surface 2 of the seat socket (LD-L) formed during operation.

Then, a layer 4 of adhesive is applied to the surface 2 of the seat socket. After applying the adhesive layer 5, the bearing 4 is installed in the seat and secured with a spacer 6.

Then, the repaired automatic gearbox is placed in an oven to cure the adhesive. The heating temperature of the furnace is set within 90 ... 100 ° C. When the heating temperature of the furnace is less than 80 ° C, the curing process of the adhesive proceeds slowly, which leads to a significant increase in the duration of the operation. At a furnace heating temperature of more than 100 ° C, the curing of the adhesive occurs intensively, which on the one hand helps to reduce the duration of this operation, and, on the other hand, is accompanied by the formation of areas with no adhesion between the adhesive and the surface of the bearing cage 3.

Therefore, the optimum temperature should be recognized as the curing temperature of the adhesive in the range of 90 ... 100 ° C.

At a curing temperature in the range of 90 ... 100 ° C, the exposure time should be 1.0 ... 0.5 hours, respectively. A decrease in the exposure time of less than 1.5 hours is accompanied by a decrease in the strength of the adhesive joint during shear by 45-55%. With an increase in the exposure time of more than 1.0 hours, a decrease in the joint strength at shear by 20–25% is also noted, apparently, due to the formation of areas with a lack of adhesion during shrinkage of the adhesive.

An important feature of the proposed method of fixing the rolling bearings in the housing during the repair of automatic transmissions is the additional feeding of the zone between the cage 3 of the bearing and the surface 2 of the seat in the housing of the automatic transmission during the curing of the adhesive. This allows you to compensate for shrinkage during curing of the adhesive, to eliminate the formation of microcracks and pores in the adhesive layer 5, which arise due to the difference in the linear expansion coefficients of the bearing material (steel) and the housing (cast aluminum alloy), and thereby provide high strength characteristics connections.

The claimed method was tested in the repair of an automatic transmission with a body made of aluminum alloy brand AL9. After removing the bearing in the automatic transmission housing, the gap between the surface of the bore hole and the bearing race was 130 ... 180 microns. After the operation of rolling the surface of the landing hole, the gap decreased to 50 ... 80 microns.

Then, a VK9 adhesive layer is applied to the surface of the mounting hole in the automatic transmission housing. After applying the adhesive, the bearing is installed in the bore hole, and the assembled unit is heated to 90 ... 100 ° C with an exposure time of 0.5 ... 1.0 hours to cure the adhesive. During the exposure during heating, the adhesive was charged with the bearing installation zone (the contact zone between the surface of the bore hole and the bearing race).

The resulting adhesive joints were subjected to vibration tests at a frequency of 25 Hz. The test results of the adhesive joints of bearings with gear housing parts are presented in the table.

Table Vibration resistance of bearings with adhesive seal in the gearbox housing Heating temperature, ° C Holding time, hour Adhesive feed during curing The number of cycles, × 10 ⁶ The nature of the destruction of the samples 95 0.75 no 0,112 Glue damage, cavities 95 0.75 there is 4,993 Destruction of the bearing cage 85 0.75 there is 2,677 Glue damage, cavities 90 0.75 there is 3,964 Destruction of the bearing cage 95 0.75 there is 4,993 one hundred 0.75 there is 4,556 105 0.75 there is 3,794 Destruction by adhesive bonding, microcracks in the adhesive layer 95 0.4 there is 2,886 Glue damage, cavities 95 0.5 there is 3,554 95 0.75 there is 4,993 Destruction of the bearing cage 95 1,0 there is 4,996 95 1,1 there is 5,002

The obtained test results allow us to conclude that the technical result, to achieve which the inventive method is developed, is fully provided.

Claims (1)

A method of fixing a rolling bearing in a housing when repairing automatic gearboxes, including applying adhesive to the contacting surfaces of the seat and the bearing, installing the bearing in the seat and fixing it in the seat, characterized in that before applying the adhesive, plastic deformation of the surface of the seat is made, and the curing of the adhesive is carried out at a temperature of 90 ... 100 ° C for 0.5 ... 1.0 h with additional feeding with adhesive substance of the bearing installation zone in the process of birth, and with increasing heating temperature, the exposure time is reduced.

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