DE10254692A1 - Assembling, adjusting parts clamped relative to each other, e.g. in gearboxes, involves fixing parts point between new gradient increase, plastic deformation of plastically deformable clamping element - Google Patents

Abstract

The method involves inserting a plastically deformable clamping element between the parts, reducing the length of the clamping element and fixing in the clamped position. It involves measuring the length change and/or applied force, continuing the length reduction until a significant increase occurs in the force-displacement diagram and fixing the parts at the bend point between the new gradient increase and plastic deformation. The method involves inserting a plastically deformable clamping element (1) between the parts, moving the parts relative to each other by reducing the length of the clamping part and fixing the parts in the clamped position. It involves measuring the length change and/or applied force, continuing the length reduction until a significant increase occurs in the force-displacement diagram and fixing the parts at the bend point between the new gradient increase and plastic deformation.

Description

A method of assembling parts under bias to each other, in which the parts along a spatial direction moved towards each other, braced against each other and tense Be fixed to each other, as it is, for example, in the employment of Taper roller bearings of a pinion shaft of a drive axle gear takes place.

So it is, for example, when hiring tapered roller bearings of a pinion shaft of a drive axle necessary this with a defined bearing preload each other to be braced, as optimal by this defined bearing preload Operating conditions and one possible long life is ensured. So far, this setting is done indirectly by determining the coefficient of friction of the bearing or over a Force-displacement measurement. The results of these indirect measurement methods subject to a broad statistical distribution (dispersion), which is why they are quite inaccurate. This allows the real bias only be adjusted within a high fluctuation. Furthermore This method is complicated and expensive.

From the DE 44 20240 A1 is known a clamping disc with compression sleeves, which has a visual indication of the screw tightening force. In this clamping disc two pot-shaped washers are arranged around the screw shaft, the openings facing each other. Between the base surfaces of the lower washers concentric with the screw axis compression sleeves are arranged, which are compressed in a movement of the washers towards each other in the direction of movement. The compression takes place until the two open edges of the two washers lie on top of each other. The preload force thus corresponds to the force that had to be applied for the compression of the compression sleeves at adjacent edges.

Such a procedure has however, a low flexibility because the adjustable clamping force is limited to the value, the by the plant of the two edges of the washer together is fixed. For mutual tightening of two bearings, as above described, this device is unsuitable, since here first a Slump offset must be before the actual bias is applied.

The object of the invention is develop a process that has a high degree of flexibility, so that it is especially in mutually strained bearings is usable and with its help the reproducibility of the bias the parts is improved against each other.

The object is achieved with a Method solved by the method steps of claim 1. By the use of a compression sleeve between the two parts as well as their claimed deformation, Can the bias within narrow tolerances with good reproducibility be made. The plastically deformable intermediate element is usefully designed so that the parts are mounted in the but not yet pretensioned state a game, preferably one Have axial play. The determination and adjustment of the preload over the course of the elastic-plastic deformation of the intermediate element in eliminating the game by applying a force in Direction of movement, preferably in the axial direction, of the two parts towards each other.

Advantageous embodiments of Invention are the further claims removed. Otherwise, will the invention with reference to one shown in the following figures Embodiment explained in more detail. there shows

1 a detail of a Antriebsachsgetriebes a motor vehicle with a preloaded tapered roller bearings mounted pinion shaft and

2 a path-force characteristic of an assembly process of the pinion shaft bearing after 1 ,

In 1 is a section of a drive axle 7 a motor vehicle, the one on a shaft 8th mounted pinion 9 having. On the wave 8th are hissing the pinion 9 and a gear 10 of the differential gear 11 two tapered roller bearings 12 . 13 arranged. At the exposed base side of the pinion 9 is the pinion 9 with the wave 8th screwed. Between the two tapered roller bearings 12 . 13 is a compression sleeve 1 introduced, which is compressed in the assembled state, whereby the two tapered roller bearings 12 . 13 are biased against each other.

For the production of this composite, first the first tapered roller bearing 12 , then the compression sleeve 1 , then the second tapered roller bearing 13 and finally the pinion 9 on the wave 8th applied. Now the pinion 9 in the direction of the axis of rotation of the shaft 8th on the gear 10 too moved. To compensate for inequalities and subsidence, this is the axis 7 and / or the pinion 9 usefully around the axis of rotation of the shaft 8th turned. In this relative movement, the compression sleeve 1 crushed. The change in length and the applied force is measured. The reduction in length is due to the plastic deformation of the compression sleeve used as a prestressing part 1 up to another significant increase 3 made in force-displacement diagram. This is the break point 2 between renewed increase 3 and plastic deformation 4 determined.

After reaching the break point 2 the force is still applied to the system and / or moved by a certain distance, the / for the tapered roller bearings 12 . 13 is prescribed. After that, the pinion 9 with the wave 8th screwed screw 14 ), whereby the system is fixed in a strained position.

Upon reaching the break point 2 its position is checked within a break point force path window. Subsequently, the additional force-displacement diagram is extrapolated to a virtual endpoint. As a result, a virtual end point can be determined, which can also be checked for its position within a predefinable endpoint force-displacement window.

The real endpoint 5 is conveniently checked for its location within the end-force-path window. If it is outside this window, it is a reject part.

For protection, it is also useful to reduce the length when reaching a safety point 6 , which is after a maximum allowable endpoint 5 is arranged to turn off.

The determination of the break point 2 can, for example, be determined from the force-displacement diagram. At the break point 9 takes place in the present diagram (see 2 ) a renewed increase 3 the force to be expended. Another, possibly complementary method is to consider the slope of the curve and to apply the mathematical methods known from the curve discussion.

The procedure can be used for both manual and also be used for automated assembly.

In manual assembly, a hand tool is used which hydraulically generates the preload force purely axially and without friction. The pressure is controlled automatically by means of a control unit, which can be activated by the worker. For safety, this tool has an emergency stop button. For mounting the pinion 9 according to 1 The piston surface of the tickle 9 in the direction of the gear 10 moving piston designed so that a maximum of 1600 bar is generated.

To facilitate manual assembly is, is The weight of the tool usefully not more than 5 kg. So that Tool is usable with different threads, it expediently a replaceable tension element that is interchangeable and thereby can be adapted to the respective thread.

The introduction of the pressure medium via a Rotation angle connection, the favorably too rotatable under pressure by 360 ° is. The connection between the pressure generator and the tool over Quick couplings. This allows flexible handling of the tool and a quick interchangeability of the individual Tool components.

The fixation of the nut / screw 14 is done with a miniature drive and is also done automatically. Conveniently, this miniature drive and the associated gear is integrated in the tool.

At the introduction of the biasing force already setting the tapered roller bearings 12 . 13 To ensure the bearing components are rotated at preferably continuous speed. As a result, any punctual deformations of the respective contact partners are avoided at the same time.

Furthermore, it makes sense to drive of the tool so that the pressure, the torque, the Speed and also the direction of rotation can be changed.

To rotate the components, the tool has a geared motor which is fixed to the device for screwing the nut / screw 14 connected is. This device can be provided with corresponding detectors and an associated evaluation and output device for documentation of the pressure, the rotational speed and the torque.

For mounting the pinion 9 Now the tool described is screwed on the flanged geared motor. In this case, the worker only has to oppose the moment that arises when screwing in. If the tool is on, the pressurization is started.

All components (pinion 9 , Tapered roller bearing 12 . 13 etc.) are rotated during tensioning by the geared motor. In this case, the turning can be stopped only when the required bearing force (preload 15 ) is introduced.

Due to the already mentioned pressurization, the preassembled bearing package is axially, ie in the direction of the axis of rotation of the shaft 8th pressed. The compression sleeve located between the bearings 1 attached to the inner face of tapered roller bearings 12 . 13 and rests on the drive shaft directly arranged ring, is usefully designed so that prior to exhaustion of the axial play plastic deformation occurs. The compression sleeve 1 is initially in the elastic range 16 deformed, wherein the pressure up to a maximum value corresponding to the sum of required displacement force and deformation force of the compression sleeve 1 initially continuously increasing (see diagram 2 ). Is the plastic area 4 reached, the pressure falls according to the characteristic of the compression sleeve 1 Slightly until no axial play is present. In the plastic area 4 In this case, it is advantageous to stop pressing, that is to say a piston advance, until no further pressure drop occurs. This can easily especially the break point 2 be recognized, since here the plastic area 3 and so that the axial play is over.

After the axial play in the storage full is constantly used up, finds for the first time a power flow through the tapered roller bearings 12 . 13 in the situation package instead. After this break 2 is now pushed further until the predetermined preload force 15 for the tapered roller bearings 12 . 13 is reached. This force is preset and added to the deformation pressure required to eliminate axial play. The thus introduced bearing force, so the bias 15 is independent of friction and can be achieved very precisely with any selected components without pre-selection.

After reaching the desired bias, the rotation of the components is stopped. At the same time the nut / screw 14 screwed in until the system. After that, the pressure is turned off, causing now on the screw 14 the previously held pressure is applied. Finally, the tool is unscrewed by means of the flanged geared motor.

The described manual assembly is particularly in both a tape-based assembly and in Servicing to adjust the bearing voltage used

In the automated initial assembly, the pre-assembled and not yet braced workpiece is placed in a machine. Here are two cases to distinguish. For one thing, the arrangement already with the differential 11 the axis 7 connected to the other can be the wave 8th still from both ends (gear 10 or pinion 9 ) be freely accessible.

In the following description will be discussed only on the first case, since the prevailing conditions in a simple manner to the second case (including assembly of the gear side 10 ) can be transmitted.

On the workpiece is inserted into the machine pinion side a carriage assembly with a hydraulic slide unit moving in rapid traverse. The carriage unit is connected via a proportional valve, the an analog electrical voltage supplies, controlled. After one predetermined path, which can be monitored by means of a cam switch is, the carriage unit is switched to creep speed. To subsidence phenomena to compensate, the workpiece becomes put into rotation. The further force increase is over a conventional Force-measuring electronics recorded and monitored. The force-displacement measuring electronics provides an electrical boost proportional to the force Voltage to the hydraulic control. Achieve this power another Force mark, which is located in front of the break point, becomes the creep speed slows down even further.

In the further course, the measuring electronics detects a kink in a programmed force-displacement window, which is the break point 2 equivalent. At this point is the compression of the compression sleeve 1 completed. From now on, a further increase in force will affect the camp network 12 . 13 , Therefore, a force offset value permanently stored in the electronics is added to the force determined up to the break point and the final cut-off point is calculated. This offset value, ie the corresponding force, corresponds to the optimum bearing preload force specified by the bearing manufacturer 15 ,

In the course of the force increase ramp of the carriage unit is kept flatter. The determined switch-off point is detected via an endpoint force-path window. Is the endpoint 5 reached, the applied here force of the carriage unit is maintained, and the nut / screw 14 bolted to their attachment. After screwing the carriage unit is moved back.

For the subsequent quality control the coefficient of friction of the bearing is determined. Is the inside the prescribed tolerance range, the finished workpiece from the Machine removed. Rejects are rejected.

Although the invention in particular only by means of a wave 8th an axle with differential 11 is described, it can be easily transferred to other bearings or parts that must be connected to each other under a defined bias. Therefore, such assemblies are also encompassed by the inventive method claim. This applies in particular to gear parts and in this case preferably of shift or automatic transmissions.

Claims (11)

A method for assembling parts under bias to each other, wherein between the parts of a plastically deformable biasing member is introduced, the parts are moved relative to each other while reducing the length of the biasing member, the parts are braced against each other and the parts are fixed in a strained position to each other, characterized in that during the relative movement the change in length and / or the applied force is measured such that the reduction in length is due to the plastic deformation of the prestressing part, in particular a compression sleeve ( 1 ), until a further significant increase in the force-displacement diagram is made, that the break point ( 2 ) between renewed increase ( 3 ) and plastic deformation ( 4 ) is determined and that when at least the inflection point ( 2 ) the parts are fixed relative to each other. Method according to claim 1, characterized in that the break point ( 2 ) is checked for a position of a break-point force-path window and A method according to claim 1, characterized in that when the point of inflection ( 2 ) Within the break point force path window, the length reduction still by one. predeterminable force and / or a predefinable path to the end point ( 5 ) is continued A method according to claim 1, characterized in that when the point of inflection ( 2 ) is extrapolated within the kink point force path window the further force-displacement diagram up to a virtual end point and that the virtual end point is checked for its position within a predefinable end force path window. Method according to claim 1, characterized in that the real endpoint ( 5 ) is checked for a location within the endpoint force-path window. A method according to claim 1, characterized in that the length reduction on reaching a safety point ( 6 ), which is arranged after a maximum permissible end point, is switched off. Method according to claim 1, characterized in that that the length reduction hydraulically. Method according to claim 1, characterized in that that the fluid control for length reduction is made by means of a propertional valve. A method according to claim 1, characterized in that with the increase of the force, a proportional electrical voltage is generated, that by means of the voltage, the speed of the length reduction is controlled, that upon reaching the end point ( 5 ) Maintaining the force of the length reduction and a relative fixation of the parts is activated to each other, and that after fixing the force is preferably reduced to zero. Method according to claim 1, characterized in that that during during and / or before the length reduction the parts preferably about the axis of the direction of length reduction be rotated relative to each other. Use of a method according to claim 1, to Assembly of gear parts, in particular shift, automatic or differential gears.