RU2119865C1 - Mechanical stripper - Google Patents

Abstract

FIELD: equipment for dismantling connections, in particular, for pressing off shaft-sleeve type connections. SUBSTANCE: mechanical stripper has casing with threaded opening, forcing screw positioned in casing and adapted for engagement with part to be pressed off through thrust bearing, stem positioned in axial opening of forcing screw and provided with conical striker. Stem is engageable with thrust bearing. Wedged sleeve is secured on forcing screw end engageable with thrust bearing. Sleeve end faced to thrust bearing is provided with channel defining, together with its surface, annular cavity where balls are placed for contact with surfaces of sleeve, thrust bearing and conical surface of stem striker. EFFECT: increased efficiency and reduced power consumption. 1 dwg

Description

 The invention relates to tools for the development of tightened joints, in particular for extrusion of shaft-sleeve joints.

 Known mechanical puller (AS USSR N 1174247, class B 25 B 27/02, 1984) containing a housing (traverse) with grips and located in its threaded hole power screw. A drawback of this type of puller is the impossibility of increasing the initial pulling force when unpressing the joints.

 This disadvantage was eliminated in a mechanical puller (USSR AS N 1351771 class B 25 B 27/02, 1986), containing a housing with grips, an intermediate sleeve having an external and internal thread, a thrust screw interacting with the internal thread of the intermediate sleeve, on which with the possibility of axial movement is mounted a drive element that interacts with axial displacement with the intermediate sleeve.

 However, the creation of a significant initial removal effort of a static nature does not always contribute to the efficiency of the process of extruding parts. The most effective in this matter are pullers, working on the principle of creating a preliminary static force with the subsequent application of additional forces of shock nature or communication, dismantled parts of oscillatory movements (vibration). This allows you to reduce energy consumption for molding, to reduce the weight of the puller, to increase labor productivity.

 The closest in technical essence to the claimed object is a puller on.with. USSR N 1187977, class B 25 B 27/02, 1983, comprising a housing with a threaded hole, in which a power screw is installed to interact through the thrust bearing with the extruded part, a hammer rod with a hammer located in the axial hole of the power screw and interacting with the thrust bearing.

 However, this puller is effective only when pressing parts (axles, rods, etc.) from body parts or parts having a mass significantly higher than the mass of pressed parts, since its principle is based on the relatively greater inertia of the parts in contact with the gripper in relation to the inertia of the parts in contact with the thrust bearing of the power screw. That is, by striking the hammer rod, and accordingly the shaft end, we create axial micromotion of the shaft with respect to the inertial part, for example, the housing. When removing pulleys, sprockets, bearings, bushings, etc. from massive shafts, the movement of which in the axial direction is also limited, this puller loses its advantages over a conventional screw puller.

 The purpose of the invention is to increase productivity and reduce energy consumption.

 This goal is achieved by the fact that the firing pin of the rod-striker is made conical, a proppant sleeve is fixed on the end of the power screw interacting with the thrust bearing, having a groove on the end surface facing the thrust bearing, forming an annular cavity with its surface, inside of which are balls contacting the surfaces wedged bush, thrust bearing and tapered surface of the hammer striker rod.

 The drawing shows a mechanical puller, a longitudinal section.

 The mechanical puller comprises a housing 1 with grippers 2, a power screw 4 is installed in its threaded hole 3, a screw 5 is fixed at one end of it and the other through a proppant sleeve 6 and the thrust bearing 7 interacts with the shaft 8. In the annular cavity 9 formed by the sleeve 6 and a thrust bearing 7 contains balls 10 in contact with the surfaces of the base plate 11 of the thrust bearing 7, the sleeve 6 and the conical striker 12 of the rod-hammer 13, which is located in the through axial hole 14 of the power screw 4, the locking mechanism of the grips (not shown).

 Mechanical puller works as follows.

 The grippers 2 are brought into contact with the removed part 15, and the toe of the thrust bearing 7 is in contact with the shaft 8. Rotating the knob 5, the power screw 4 creates a preliminary pressing force between the part 15 and the shaft 8. Apply several blows with a hammer to the head 16 of the rod-hammer 13 Under the action of the impact, the rod-hammer 13 moves in the axial hole 14 of the power screw 4 and the conical part of the hammer 12, displaces the balls 10 in the radial direction. Balls 10 moving in a radial direction in the annular cavity 9 wedge in the axial direction of the sleeve 6 and the base plate 11 with a thrust bearing 7, thereby creating a sharp increase in the pressing force. After impact, the rod-hammer 13 under the influence of reactive forces from the sleeve 6 and the base plate 11, acting through the balls 10 of the strikers 12, returns to its original position.

 The spring 17 also contributes to the return of the hammer rod 13 from its original position. After a series of strokes, in which the part 15 is displaced relative to the shaft 8, the screw 4 is retightened. After the retraction, the strokes are repeated. Operations are repeated until the uncompression force is reduced or parts are completely unpressed.

Using a two-stage wedge in a puller
1 stage - "the conical surface of the striker rod-hammer - balls",
Stage 2 - "balls - the surface of the wedged sleeve and thrust bearing".

 With external impact, the rod-hammer allows you to create extrusion forces many times higher than the forces created by a conventional screw puller.

где
m - масса ударника (молотка), кг;
v - скорость перемещения ударника, м/с;
t - время соударения, с;
α,β - - углы клина 1 и 2 ступеней.Pressing Impulses

Where
m is the mass of the hammer (hammer), kg;
v is the velocity of the drummer, m / s;
t is the collision time, s;
α, β - - wedge angles of 1 and 2 steps.

 The proposed mechanical puller, working on the principle of creating a preliminary static pressing force, followed by the application of additional pulsed forces, will reduce the energy consumption for pressing, reduce the weight of the puller, increase labor productivity.

Claims (1)

 A mechanical puller, comprising a housing with a threaded hole, in which a power screw is installed for interaction through the thrust bearing with the extruded part, a firing pin with a striker located in the axial bore of the power screw and interacting with the thrust bearing, characterized in that the firing pin of the firing rod is made conical, at the end of the power screw interacting with the thrust bearing, a proppant sleeve is fixed, having on the end surface facing the thrust bearing a groove forming an annular cavity with its surface, which balls are placed in contact with the surfaces of the riving sleeve, the thrust bearing and the conical surface of the striker, the striker rod.