US1990456A

US1990456A - Bond or tie for built-up crank shafts

Info

Publication number: US1990456A
Application number: US647163A
Authority: US
Inventors: Kylen Karl Erik
Original assignee: SKF AB
Current assignee: SKF AB
Priority date: 1932-09-12
Filing date: 1932-12-14
Publication date: 1935-02-05
Anticipated expiration: 1952-02-05

Description

Feb. 5, 1935. K. E. KYLEN BOND ORTIE FOR BUILT-UP CRANK SHAFTS Filed Dec. 14, 1932 5 SheetsQ-Sheet 1 y a .Z a D INVENTOR I KARL ERIK KYLE/v J4. 1 AM ATTORNEY Feb." 5, 1935. K. E. KYLEN 1,990,456

BOND OR TIE FORBUILT-UP CRANK SHAFTS Filed Dec. 14. 1952 5 Sheets-Sheet 2 INVENTOR I KARL ERIK KYLE/v A; ATTORNEY Feb. 5; 1935. K. E. KYLEN 1,990,456

BOND OR TIE FOR BUILT-UP CRANK SHAFT'S Filed Dec. 14, 1952 5. SheetS-Sheej s 54 v A so 3a INVENTOR I KARL ER/K/(YL su L ATTORNEY Feb. 5, 1935. K. KYLEN 1,990,456

' BOND 0R TIE FOR BUILT-UP CRANK SHAFTS Filed Dec. '14. 1932 s Sheets-Sheet 4 INVENTOR AML ERIK KY4 E'N BY M ATTORNEY Feb. s, 1935. K. E. KYLEN 1,990,456

BOND 0R TIE FOR BUILT-UP CRANK SHAFTS Filed'Dec. 14, 1932 5 Sheets-Sheet 5 INVENTOR, KARL ERIK An EN ATTORNEY atented Feb. 5, i935 1,990,456 noun on rm gs gum-ore Karl Erik Kyln, Gottenborg, Sweden. assignor to Aktiebolaget Svenska Kullagerfabriken, Gottenborg, Sweden, a corporation of Sweden Application December 14, 1932, Serial No. 647,163

In Sweden September 12,1932

7 7 Claims. (01. 74 -598) 5 another member by means of a plug or the like inserted in the hole or cavity of the first mentioned member.

It has been previously known to make built-up crankshafts in which the crank pins are made hollow and have a conical or tapering innersurface. The crank pin is then fixed to the web by means of a tapering plug, which is driven or pressed into the conical hole with such force that the crank pin is expanded in the web and held rigidly in position by the pressure between the members. Such method of building up crankshafts has the great disadvantage that it is impossible to definitely fix the amount of grip between the members, since the grip depends upon the extent to which the tapering plug is forced into the crank pin. After having had the crankshaft apart for repairs there is always a risk that the plug willnot be pressed home sufiiciently tight, and that the joint will loosen, thereby destroying the crankshaft. This risk is, of .course, especially great when the repairs are made in a small machine shop by mechanics having insufficient experience with the type of crankshaft in question, or where proper machinery for the assembly of the crankshaft is not available.

The object of the present invention is to provide a device in which the grip can be previously fixed, and in which the grip will always be the same upon reassembling the crankshaft after repairs. For this purpose the plugs are made with a substantially cylindrical, instead of conical,

outer surface and with outer dimensions somewhat larger than the hole in the member into which they are to be inserted. The difference in dimensions will depend upon the amount of grip required. The greater the diflerence in dimensions, the greater will be the grip, but the greater will also be the force required to press home the plug. For this reason it is desirable to make the grip conform to that which will be required by the conditions at hand.

The accompanying drawings illustrate a number of forms of plugs and methods for assembling and dismantling the bond according to the invention.

In which drawings:

Figure 1 shows a method of mountin a pair of plugs, one in each end of a crank pin having a through hole.

Figs. 2 to 9 each shows an end view and an axial section of atom of plug according to the invention.

Figs. 10 to 12 show methods of assembling plugs in crankshafts .in which the crank pin is made in one piece with one of the webs.

Fig. 13 shows a method of dismantling a plug by means of a tool such as is illustrated in Fig. 15.

Figs. 14 and 15 respectively show a side elevation and end view, of two tools for assembling and dismantling a crankshaft.

Figs. 16 and 17 show two methods of removing a plug.

Fig. 18 shows a crank shaft in which one plug is used in two joints.

Fig. 19 shows plugs consisting of two concentric annular members.

Fig. 20 shows the invention applied to fixing a gudgeon pin in a connecting rod, and

Fig. 21 a device for increasing the friction in the joint.

The webs 1' in Fig. 1 are provided with through holes in which the crank pin 2 is to be fixed. The crank pin has a through hole in which the

plugs

3 and 4 are inserted. The plugs are formed as annular members and are preferably chamfered at their inner ends to facilitate their insertion in the crank pin. A threaded bolt 5 is inserted through the holes in the plugs, which are forced home by drawing the nut 6. Between the plugs and-the head of the bolt and the nut respectively are inserted washers 8 and 9 having an outer diameter larger than the outer diameters of the plugs. These washers serve to prevent either or both of the plugs from being forced too far into the crank pin. r

The plug illustrated in Fig. 2 has been given a special form calculated to facilitate its removal. The plug is removed with the aid of a tool of the kind shown in Fig. 14 and in the manner shown in Fig. 13. In the inner wall of the plug are two slots 11,- and on its inner end a cross slot'12, the width of the latter being about the same as the width of the former. threaded at one. end 14 and is provided at the other end with a head 65. The head is provided with projections 15 so that its form is nearly the same as that of the-hole in the plug. To remove the plug the head of the tool is passed'through the hole in the plug and the tool turned a quarter of a revolution so that the projections 15 engage with the slot 12 as shown'in Fig. 13. Thisprevents the tool from turning relative to the plug, thereby enabling the plugto be withdrawn by,

turning the nut. Anannular member 16 and a washer 17 are passed over the tool after which The dismantling tool 13 is.

the nut 18 is screwed on and drawn until the plug is removed.

Fig. 3 shows a plug which differs from the plug illustrated in Fig. 2 in that it has four slots 18 and two cross slots 19. The plug is removed by means of the tool 20 illustrated in Fig. 15. The head of the tool is provided with four projections 21. After the tool has been inserted in the plug, it is turned an eighth of a revolution, and the plug can then be removed in the manner described in connection with Fig. 13.

Figs. 4 and 5 show two plugs of substantially the same shape and adapted for use in the respective ends of the same crank pin. The

plugs

22 and 23 are provided with circular through

holes

24 and 25 and with cross slots 26 and 27. The plug 22 is removed in the manner shown in Fig. 13 by means of a tool of the kind shown in Fig. 14. The diameter of the shaft of the tool is such that it fits the hole 24, and the diameter of the head across the projections is greater than the diameter of the hole 24, but less than the diameter of the hole 25. The tool is passed through the hole 25 with the threaded end-first so that the projections engage with the slot 26. The plug 22 can then be removed in the manner described above. The other plug-23 can then be removed in a similar manner by means of a larger tool of the same form, which is inserted from the opposite direction.

Figs. 6 and 7 show two forms of plugs adapted for use in pairs. The plug 28, as shown in Fig. 6, is solid while the plug 29 is provided with a cylindrical hole, as shown in Fig. 7. To dismantle the shaft the plug 28 is first knocked or forced out by means of a mandrel inserted through the hole in the plug 29. The plug 29 can then be removed with the aid of a mandrel of larger diameter inserted from the opposite direction.

Fig. 8 shows a plug 30 having a threaded hole. The plug is removed in the manner shown in Figs.

' 16 and 1'7. As shown in Fig, 16, a. threaded tool 31 is screwed into the plug, which is then removed with the aid of an annular member 16, a washer 1'7, and anut 18, in the manner described in connection with Fig. 13.

According to Fig. 17 the crank pin is made in one piece with one of the webs 33 and is partly hollowed out to receive a plug such as 30 for fixing the crank pin in the other web 34. The plug is forced out in this instance by means of a threaded tool 35 pressing against the bottom 36 of the hollow in the crank pin.

The plugs illustrated in Figs. 2 to 8 are preferably hardened, but the form shown in Fig. 9 is most suitably made of unhardened material. The plug is shown provided with an axial slot or channel 64. When it is desired to remove the plug its center part is drilled, or turned out almost to the bottom of the channel. Theremaining annular part of the plug will exert so little pressure against the inner wall of the crank pin that it can be easily removed.

Several methods of assembling crankshafts in which the crank pin is made in one piece with one of the webs are shown in Figs. 10 to 12. According to Fig. 10 a threaded hole 38 is formed at the bottom of the hollow 37 of the crank pin into which a tool 39 can be screwed. The hollow plug 40 and the stop washer 41 are passed ovei the tool after which'the nut 42 is applied and drawn. When the plug has been forced in as far as the stop washer will allow the tool 39 is screwed out of the threaded hole and removed.

According to Fig. 11 both thecrank pin 48 and the web 44 are drilled through to allow a tool 46 provided with a head to be passed through the hole. The plug can then be forced home in the manner described above.

In Fig. 12 the tool 47 is threaded to enable it to be screwed into a threaded hole in the web. The head of the tool 48 is made large enough to perform the duty of a stop washer.

Fig. 18 shows a device in which a single plug 49 serves to fix the crank pin 50 to both the

webs

51 and 52. The pin should preferably not be expanded between the webs. The crank pin, or the plug, or both, are therefore formed so that there will be a clearance 53 between them along this part of the crank pin.

Fig. 19 shows a device in which each plug consists of two concentric annular members. By this means it is possible to increase the pressure against the pin 54. When assembling the crankshaft the larger member 55 is first pressed home in the pin 54 and expands the pin to fix it to the web. The smaller member 56 is then inserted in the larger one 55 which is expanded. This expansion is communicated to the pin 54,

,further increasing the friction between the pin and the web.

Fig. 20 shows the invention applied to a gudgeon pin having its bearings in the piston bosses. The gudgeon pin 5'7 is fixed to the connecting rod 58 by means of a plug 59 which is preferably made in one of the above mentioned forms to facilitate dismantling.

Fig. 21 shows an arrangement for increasing the friction and strength of a joint. The plugs 60 are provided with flanges 61, which are secured to the webs in some suitable manner, for instance by means'of rivets 62. If'desired, the flange 64 of a crank shaft plug may be secured by providing it with a hole and allowing the crank pin to pro-' ject through this hole as shown at the left hand side in Fig. 21. By these means a part of the torque can be transmitted from the web to the shaft by means of the friction between the plug and the shaft. Similar flanges as 65 also on the left hand side of Fig. 21, may be provided on the plugs 63 of the crank pin, if desired.

-By a suitable choice of the diameters of the plug and the hole in the crank pin it is possible to adapt the grip according to the requirements. In cases where one of a pair of plugs is thicker than the other, the thinner plug may be made slightly larger than the other so that the pressures exerted by both plugs will be substantially equal. In order to guard the pin from dangerous tension, and to increase the pressure between the pin and the surrounding part, the outer diameter of the pin can be made slightly greater than the diameter of the hole into which it is to be inserted. In this manner it'will be possible to obtain an initial pressure between the pin and the surrounding part which will compress the end of the pin somewhat when it is driven, forced or shrunk in. When the plug is forced into place the pin is again expanded to its original diameter, thus sparing it from being subjected to considerable tension.

The invention is not confined to the forms illustrated, but can be applied to a number of Having thus described my invention I claim and desire to secure by Letters Patent:

1. A bond for a built-up crankshaft, one member having a bond receiving cavity and another member having a bond portion seated in such cavity, there being a plug receiving cavity in such bond portion formed with an uninterrupted cylindrical wall, and a plug havinga cylindrical outer surface seated in the hollow cavity in the said bond portion expanding it into the bond receiving cavity in the first named member, the plug constituting the sole means for bonding the two members.

2. A bond for a built-up crt, one member having a bond receiving cavity and another member having a bond portion seated in such cavity, there being a plug receiving cavity in such bond portion formed with an uninterrupted cylindrical wall, and a plug having a cylindrical outer surface seated in the hollow cavity in the said bond portion expanding it into the bond receiving cavity in the first named member, the plug constituting the sole means for bonding the two members, such plug being formed with a hole extending axially through it for facilitating its insertion and removal.

3. A bond for a built-up crankshaft, one member having a bond receiving cavity and another member having a bond portion seated in such cavity, there being a plug receiving cavity in such bond portion formed with an uninterrupted cylindrical wall, and a plug having a cylindrical outer surface seated in the hollow cavity in the said bond portion expanding it into the bond receiving cavity in the first named member, the plug constituting the sole means for bonding the'two members, such plug being formed with a screw threaded hole extending axially through it for facilitating its insertion and removal.

4. A built-up crankshaft comprising a pair of members each formed with a bond receiving cavity, a hollow crank pin having its ends seated in such cavity, the internal walls of the end portions of the pin being formed with uninterrupted cylindrical surfaces, and plugs having cylindrical outer surfaces seated in the respective ends of the pin expanding them into the cavities in the first named member, the plugs constituting the sole means for bonding the members. I

5. A built-up crankshaft comprising a pair of members each formed with a bond receiving cavity, a hollow crank pin having its ends seated in such cavity, the internal walls of the end portions of the pin being formed with uninterrupted cylindrical surfaces, and plugs having cylindrical outer surfaces seated in the respective ends of the pin expanding them into the cavities in the first named member, the plugs constituting the sole means for bonding the members, at least one of such plugs being formed with a hole extending axially through it, such hole having one or more maximum dimensions and one or more minimum dimensions.

6. A built-up crankshaft comprising a pair of members each formed with a bond receiving cavity, a hollow crank pin having its ends seated in such cavity, the internal walls of the end portions of the pin being formed with uninterrupted cylindrical surfaces, and plugs having cylindrical outersurfaces seated in the respective ends of the pin expanding them into the cavities in the first named member, the plugs constituting the sole means for bonding the members, such .plugs being formed with holes extending axially through them, the maximum cross sectional dimension of the hole in one of the plugs being greater than the minimum cross sectional dimension of the hole in the other plug.

7. A built-up crankshaft comprising a pair of members each formed with a bond receiving cavity, a hollow crank pin having its ends seated in such cavity, the internal walls of the end portions of the pin being formed with uninterrupted cylindrical surfaces, and plugs having cylindrical outer surfaces seated in the respective ends of the pin expanding them into the cavities in the first named member, the plugs constituting the sole means for bonding the members, at least one of such plugs being formed with a hole extending axially through it, the axially extending hole in the plug having one or more cross sectional maximum dimensions and one or more cross sectional minimum dimensions.

KARL ERIK KYLEN.