GB2092499A - A tool for use in exchanging bearing bushes in mountings - Google Patents

Abstract

A tool for use in exchanging bearing bushes in mountings comprises a device for peening bearing bushes (130) in the form of a portable hand tool having a casing block (110) with exchangeable inserts (120) carrying press dies (117) and counter elements (118) of the same size and a hydraulic actuating cylinder (111) acting on the press die (117) through a two armed lever (116). <IMAGE>

Description

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GB 2 092 499 A 1

SPECIFICATION

A tool for use in exchanging bearing bushes in mountings

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The invention relates to a tool for use in exchanging bearing bushes in mountings, such as in mounting members of aircraft and in particular comprises a device for peening on new bearing bushes. 10 The peening device is provided with a press die which may be operated by an hydraulic acutating element which presses annular lips provided on the bearing bushes against the annular bevels provided at the ends of the receiving bores in the mountings. 15 Bearings of ball-and-socket joints are frequently locked in bores by having peened over annular lips provided on their end faces. The annular lips are thus pressed on peened against annular bevels provided at the ends of the receiving bores by 20 appropriate tools, e.g. presses. Therefore it is necessary to cut away the peened over annular lips of these bearing bushes whenever they have to be exchanged. However this is not always easy, particularly not if bearing bushes on aircraft mountings 25 have to be exchanged.

In the past is has always been conventional to dismantle the mountings too and to cut out the peened over annular lips of the bearing bushes with the aid of a special cutting in a workshop. Forcing or 30 pulling the relevant bearing bush out was then possible with the aid of a known pulling device.

Recently, however, there has been an increasing demend for bearing bushes which can be exchanged in aircraft mountings insitu. However, this requires a 35 special tool for peening overthe annular lips, which can be used even in inaccessible places. A known tool which is provided for the purpose of cutting off rivet like annular extensions of bearing bushes comprises a guide spindle which may be inserted 40 through a bearing bush and a support sleeve resting against the mounting, in which a stop sleeve having a cutter may be screwed on to the guide spindle inserted through the bore. As already mentioned,

this tool which has been provided for cutting off rivet 45 like annular extensions, has the disadvantage that the force transmission for the rotary movement produced by manual displacement and necessary for cutting is effected via prestressed threaded nuts which ensure that the cutter is entrained. However if 50 this measure is implemented there is relatively high wear on the threaded elements and thus these elements have to be replaced quite frequently.

In order to peen overthe annular lips of new bearing bushes in mounting members, these lips are 55 usually pressed against the annular bevels provided at the ends of the receiving bores with the aid of stamps of large presses. Peening bearing bushes in receiving bores is therefore always possible when the respective receiving members permit manipula-60 tion by means of a press. While this is of course quite easy in newly manufactured items it is difficultto exchange defective bearing bushes because the receiving members also have to be dismantled in order to do this.

65 In aircraft it is frequently necessry for safety reasons to exchange bearing bushes and thus also to dismantle the respective mountings. This dismantling is caused not by the need to remove the defective bearing bush and to put in a new bearing 70 bush but rather by the peening operation. As mentioned previously, bearing bushes are peened over with the air of presses because the force required for this is of the order of magnitude of some thousands of daN (decaNewtons). Although it is 75 basically possible to dismantle defective bearing bushes and install new bearing bushes on installed mountings, the previously known techniques require dismantling of the mountings which is both expensive and time-consuming in order to peen overthe 80 newly inserted bearing bush.

The invention seeks to provide a peening device, for use in exchanging bearings in the receiving bores of mounting members such as those of the type stated at the outset, which device enables the 85 exchange of bearing bushes and, peening of them insitu on installed mountings.

According to the invention, there is provided a tool for use in exhanging bearing bushes in mountings comprising a device for peening the bearing bushes 90 having a press die which is hydrauIically operated for pressing annular lips on the bearing bush against annular bevels at bores for receiving the bearings wherein the device is constructed as a portable hand tool and comprising a casing block with exchangable 95 inserts for press dies and counter elements of the same size, the casing block having an actuating cylinder whose piston acts on the press die via a two armed lever.

The peening device provided in accordance with 100 the invention may be capable of producing a force of up to 20,000 daN, and this is sufficient to peen over bearing bushes up to certain sizes. Thus the exchangeable inserts may comprise a U-shaped profiled block, the crosspiece of which has a projection 105 on both sides, in each case, which engages into corresponding recesses of the casing block, the limb of the profiled block being provided with bores designed to receive the press die and the mating counter element. This measure provides the oppor-110 tunity of matching the device to a bearing which is to be exchanged according to the requirement present in each case. The cross-pieces of the U-shaped profiled blocks thus contain a threaded borehole into which a fixing screw may be scrwewed, this fixing 115 screw projecting from the casing block.

Furthermore, it is advantageous if the piston of the actuating cylinder arranged in the casing block acts on the two-armed lever via an adjustable screw provided in the power arm for the purpose of 120 adjusting the stroke and if the load arm of the two-armed lever mounted on the casing block is half the length of the power arm in order to achieve the desired operating force. As a result, on the one hand it is possible to achieve positive connection between 125 the pressure stamp and the piston of the actuating cylinderthrough thetwo armed lever and the other hand to create the required free space for exchanging the inserts and/or pressure stamp and counter elements by screwing the adjustable screw into the 130 two-armed lever.

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GB 2 092 499 A

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The invention will now be described in greater detail, by way of example, with reference to the drawings, in which:-Figure 1 shows a front view of a peening over 5 device in accordance with the invention;

Figure 2 shows a side view of the device according to Figure 1, and

Figure 3 shows a portion of the peening over device according to Figure 1 for a second operation. 10 A peening over device comprises a casing block 110 to which a hydraulic adjusting cylinder 111 is fixed by means of a fixing clip 112 and corresponding screws 113. The piston 114 of the hydraulic adjusting cylinder 111 abuts an adjustable screw 115 15 on the power arm of a two-armed lever 116, the load arm of which lever, which is half as long as the power arm, pressing against a press die 117. The two-armed lever 116 is mounted in known manner in the casing block 110. By use of the two-armed lever, 20 the device may be kept small since the lever,

because of its ratio, results in doubling of the force produced by the hydraulic adjusting element. Press die 117 is inserted into a corresponding bore of a U-shaped profile block 120 i.e. in one limb of this 25 profiled A counter element is inserted into a corresponding bore in the second limb of the U-shaped profiled block, which counter element is in alignment with the press die. The profiled block 120 has a projecting projection 121 on both sides of its cross-30 piece, these projections 121 enggaging in corresponding bores 119 in the casing block. As a result, an appropriate support for peening over is provided. Moreover, a threaded bore is provided in the crosspiece of the U-shaped profiled block 120 into 35 which a fixing screw 122, provided on the casing block 110, may be screwed for fixing purposes.

The U-shaped profiled blocks 120, which may be exchanged for the purpose of matching them to different bearings, contain a centering pin 125. This 40 centering pin 125 is inserted into a corresponding bore in the counter element 118 through a bore 126 of the profiled block 120 and engages into the bore of the bearing 130 which is to be peened over. As may be seen from Figure 1,the bearing bush 130 is 45 peened over in an aperture 131 of mounting 132 which is installed in an aircraft. The bearing bush 130 is therefore provided with annular lips 133 at both end faces while, in each case, one annular lip is peened over in one operation.

50 Figure 1 shows the first operation in which the lefthand annular lip is peened over by the press die 117. The press die 117 is selected in accordance with the size of the bearing 130 and is provided with a conical end face. The counter element 118 has a set 55 back flat end face which thus can abut both the bearing 130 and the aperture 131 of the mounting 132. Hydraulic fluid is supplied to the hydraulic actuating cylinder 11 for peening overthe annular lips and is in fact supplied via a pressure line 140 60 having a quick-acting coupling 141. The hydraulic fluid may be taken from a supply system; however it is also possible to produce the system pressure for the hydraulic actuating element using a hand pump. In the latter case it is possible to calibrate the 65 pressure-indicating device of the hydraulic hand pump not in pressure but rather in power and in fact in the power of the force arising during peening. It is advisable to allow the hydraulic pressure and thus the force produced on the respective annular lip to 70 act for a certain, period of time, preferably 15 to 20 sec, in order to achieve a reliable peening action.

After carrying out peening overthe one annular lip in a first operation it is necessary to exchange the counter element 118 in order to peen overthe 75 annular lip at the other side of the bearing. Figure 3 shows a portion of the device in which the counter element 118 is replaced by a counter element 134. This counter element 134 has a construction similar to the press die 117 whereby safe abutment of this 80 counter element for peening the second annular lip is possible. The press die 117 remains the same as in the first operation. The process of peening is carried out in the same way as in the first operation.

As already mentioned, it is possible to exchange 85 the U-shaped porfiled blocks 120, in the form of inserts, for peening over bearings of different size. The fixing screw 122 is released for this purpose and the insert may be removed. In the case of this type of exchange, it is necessary to release the adjusting 90 screw 115 on the two-armed lever in order to achieve the required free space for the operation. However it is necessary to screw the adjusting screw in completely in order to exchange the press die and the counter element for carrying out different operations 95 in order to be able to remove these components from the fitted bore of the U-shaped profiled blocks. The adjusting screw 115 also makes it possible to achieve positive connection between the piston of the Actuating cylinder and the press die through the 100 two-armed lever without any play between. The quick-acting coupling 141 on the pressure line 140 makes it possible to separate or connect the pressure line easily and in this way facilitates sensible operation. In the actuating cylinder, a resetting 105 spring (not shown) is provided which ensures return of the piston in each case after an operation has taken place.

Both the resetting spring and the quick-acting coupling which are provided with sealing elements 110 prevent airfrom penetrating into the adjusting cylinder and therefore ensure a perfect mode of operation. The above described device is distinguished by the fact that it facilitates peening of bearing bushes in inaccessible mountings.

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Claims (9)

1. A tool for use in exchange bearing bushes in mountings comprising a device for peening the

120 bearing bushes having a press die which is hyd-raulically operated for pressing annular lips on the bearing bush against annular bevels at bores for receiving the bearings wherein the device is constructed as a portable hand tool and comprises a 125 casing block with exchangeable inserts for press dies and counter elements of the same size, the casing block having an actuating cylinder whose piston acts on the press die via a two armed lever.

2. Atool according to claim 1, wherein the 130 exchangeable inserts comprise a U-shaped profile

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GB 2 092 499 A 3

block, the crosspiece of which has a projection on both sides which engages into corresponding recesses of the casing block and the limbs of which are provided with corresponding bores for receiving the 5 press die and the counter element.

3. A tool according to claim 2 wherein the crosspiece of the U-shaped profiled block has a theaded borehole into which a fixing screw may be screwed, the fixing screw projecting out of the

10 casing block.

4. A tool according to claim 2 or 3 wherein the piston of the actuating cylinder arranged in the casing block acts on the two-armed lever via an adjustable screw provided for the purpose of adjust-

15 ing the stroke of the power arm of the lever, and the load arm of the two-armed lever is half the length of the power arm so as to achieve the desired operating force for the press die.

5. Atool according to anyone of claims 2 to 4

20 wherein the counter element inserted into the bofre of the U-shaped profiled block has a bore with a longitudinally displaceable centring pin which may be used forthe purpose of aligning the peening device.

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6. Atool according to any one of claims 2 to 5, wherein two counter elements are provided ex-changeably for first and second operations are differently constructed at their end faces, the end face of the counter element for the first operation

30 having a setback shape abutting the end face of ther bearing bush and the mounting and the end face of the counter element for the second operation has a conical shape abutting the peened over annular lip.

7. Atool according to any one of claims 2 to 6

35 wherein the actuating cylinder in the casing block contains a resetting spring forthe piston.

8. A tool according to any one of claims 2 to 7 wherein the actuating cylinder is supplied with hydraulic fluid via a pressure line which contains a

40 quick-acting coupling arranged directly at the casing block having sealing elements for carrying out rapid separation and/or connection.

9. Atool for use in exchanging bearing bushes in mountings substantially as described herein with

45 reference to the drawings.

Printed for Her Majesty's Stationery Office, by Croydon Printing Company Limited, Croydon, Surrey, 1982.

Published by The Patent Office, 25 Southampton Buildings, London, WC2A1 AY, from which copies may be obtained.