GB2128712A

GB2128712A - A sleeve or roller chain of a chain drive

Info

Publication number: GB2128712A
Application number: GB08327516A
Authority: GB
Inventors: Wolfram Dahm; Roland Noll
Original assignee: Daimler Benz AG
Current assignee: Daimler Benz AG
Priority date: 1982-10-16
Filing date: 1983-10-14
Publication date: 1984-05-02
Also published as: JPS5989853A; IT8349106A0; GB8327516D0; FR2534652A1; IT1171865B; DE3238368C2; DE3238368A1

Abstract

A sleeve or roller chain, particularly for use as a timing chain for an internal combustion engine, in which supply openings 5, are provided for the lubrication of the chain links in an oil bath and by subjection to oil jets, through which supply openings the lubricating oil reaches the relative sliding parts namely pins 4 and sleeves 2. <IMAGE>

Description

SPECIFICATION A sleeve or roller chain of a chain drive The invention refers to a sleeve or roller chain of a chain drive, particularly but not exclusively for use as timing chainforan internal combustion engine, in which, in operation,the chain is immersed in an oil bath or is subjected to oil jets.

In orderto improve the lubrication of a chain immersing in an oil bath, it has been disclosed in German Auslegeschrift 1,030,123, to capture the oil thrown off by the chain by means of a guide strip with a U-shaped cross-section and to supply this oil through tubes to the inner side ofthe chain. It has also been disclosed to permit play between the inner straps and outer straps of a chain in order to provide a greater possibility of access for lubricating oil. Nevertheless, only imperfect lubrication is attained by these measures, particularly in the case of high-speed chain drives, because, on immersing the chain in an oil bath or on spraying with an oil jet, the lubricating oil does not pass in sufficient quantity to the region where it should fulfil its lubricating and cooling duty, i.e. into the links ofthe chain.This is indeed achieved with a lubrication device according to U.S. Patent3,528,526, in which a capsule supplied with lubricant is located between co-axial shafts, each of which carries a chain wheel and a double chain on the two chain wheels represents a type of shaft coupling, butthistype of lubrication cannot be accommodated in the chain drive of a timing chain. This is also applies to a lubrication deviceforatransportchain known from French Patent 2,408,079, according to which the lubricating oil is sprayed, by means of a rotatable disc equipped with protrusions engaging in the chain, through the protrusions against the chain links.

The present invention seeks therefore to improve lubrication ofthe links of a chain for an internal combustion engine without special devices being necessaryforthis purpose.

According to the present invention there is provided a sleeve or roller chain of a chain drive adapted, in use, to be immersed in an oil bath or subjected to oil jets, in which supply openings for lubricating relatively sliding parts ofthe chain are provided atthe links ofthe chain consisting of pins and sleeves. Due to the arrangement of such supply openings, a certain quantityofoil istaken up byeach supply opening on immersion ofthe chain in an oil bath or on spraying with oil and this certain quantity of oil isfurther guided in the direction towards the pin, so that an oil fiim can be built up and oil scavenging attained, which also serves to facilitate cooling and removal of any foreign particles.

In an advantageous embodiment ofthe invention, each sleeve and/or each roller can be provided with a radial supply opening or each pin can be provided with a central tapping hole extending to the middle of the pin, with which tapping hole a radial hole is connected and, in the arrangement of a roller on the sleeve,the latter can be provided with a radial hole. In a rolled sleeve, the opening can preferably be made when punching outthe sleeve in elongated form by punching out semi-circular recesses. Where the chain is sprayed with a directed oil jet, the supply openings can be correspondingly oriented during the manufacture ofthe chain.

Recesses, which interruptthe annular end faces of each sleeve, can also be used as supply openings because lubricating oil is collected in these recesses and guided further between sleeve and pin.

In addition, in the case of a sleeve chain, the hole for the pin can be conically widened on both sides of each sleeve. This achieves the resultthatwhen load is applied to the chain links, the contact between the inside of the sleeves and the pins takes place continuously from insidetowardsthe outside with increasing load. In consequence ofthis, oil initially present is driven out and, when the chain is unloaded, oil is again sucked into the hollow space then formed.

Positive scavenging ofthe chain is thus achieved.

In orderto ensure a sufficient flow of oil to the chain, each outer strap can be provided with a hole.

Embodiments of the invention will now be described by way of example with reference to the drawings, in which: Figure 1 shows a part of a sleeve chain with supply openings in the sleeves, Figure 2 shows a linkofa sleeve chain with supply openings in the pin, Figure 3 shows part of a roller chain with supply openings on the endfaces ofthesleeve, Figure 4 shows a link of a sleeve chain, in which the hole inthesleeve isconicallywidened on both sides, and Figure 5 shows the link according to Figure 4when load is applied to the sleeve.

The sleeve chain according to Figure 1 consists of inner straps 1, sleeves 2, outer straps 3 and pins 4. The inner straps 1 are solidlyfixed to the sleeves 2, whereas the outer straps 3 are solidly fixed to the pins 4 located in the sleeves 2. The sleeves 2, which are formed as rolled sleeves, show supply openings 5, through which, on immersion ofthe sleeve chain in an oil bath or on subjection to oil jets, lubricating oil passes in the arrow direction 6 on the chain links to the relatively sliding parts consisting ofthe sleeve 2 and the pin 4. The supply openings 5 can be provided at any given point on the sleeves. They are advantageously provided when punching the sleeves by punching out semi-circular recesses on the rising edge of the sleeve which has notyet been rolled.In the manufacture of the chain, the supply openings 5 areso oriented that corresponding oil entersthesupply openings. Instead ofthe round supply openings, openings of any given cross-section can, of course, also be provided.

In the case of the sleeve chain according to Figure 2, a central axial hole 7 in the pin 4 is arranged as the supply opening for lubricating the chain link, with which central hole 7 a radial hole 8, which emerges on the outersurface ofthe pin 4, connects. This arrangement is particularly suitable if oil jets are directed in the arrow direction 9 onto the side of the sleeve chain in order to lubricate the chain. Lubrication is then still furtherimproved bythefactthatthe holes 10 serving as supply openings are located in the outer straps 3, through which holes 10 an oil jet can pass between the sleeve chain and from outside onto the chain links.

In the case ofthe roller chain shown in Figure 3, a roller 11 sits on the sleeve 2 connecting the inner straps 1. So that sufficient lubricating oil can be guided into the sleeve 2, the annular end faces 12 of the sleeve 2 are interrupted by recesses 13 serving as supply openings. Lubricating oil collects in the recesses 13 and passes in the arrow direction 14 into the gap between sleeve and pin (the pin is not shown). In this case, the sleeve 2 can be provided with a radial hole corresponding to the embodiment according to Figure 1 for lubricating the roller 11 seated on it.

In the sleeve chain shown in Figures 4 and 5, the sleeve2isformedon both sidewith conically widening openings 15, which serve as supply openings. This arrangement makes it possible for lubricating oil to pass in sufficient quantity in the arrow direction 16 between the sleeve 2 and the pint 4. When the sleeve chain and hence the chain iinks are subjected to load, the contact between the sleeve 2 and the pin 4 occurs continuously from the inside towards the outside as the load increases. This has the consequence that the lubricating oil is driven out in the arrow direction 17 and then, when the load is removed from the sleeve chain, when the movement occurs in the opposite direction, lubricating oil is again sucked in the arrow direction 16 into the hollow space which then appears. Positive scavenging with lubricating oil is ensured forthe sleeve chain.

The individual measures for improving the lubrication on sleeve chains or roller chains which can be taken from embodiments shown in the drawings can also be combined with one another so that, for example, the radial supply openings in a sleeve 2 shown in Figure 1 can be used together with the recesses 13 on the end faces of the sleeve 2 shown in Figure3.

Claims

1. A sleeve or roller chain or a chain drive adapted, in use, to be immersed in an oil bath orsubjectedto oil jets, in which supply openings for lubricating relative sliding parts ofthe chain are provided at the links of the chain consisting of pins and sleeves.

2. Achain according to claim 1, wherein rollers are concentrically mounted on said sleeves, supply openings being provided for supplying lubricating oil between said rollers and sleeves.

3. Achain according to claim 1 or2,whereineach sleeveand/oreach roller is provided with a radial supply opening, or each pin is supplied with a central tapping hole extending to the middle ofthe pin, with which central tapping hole a radial hole connects and, when a roller is concentrically mounted on the sleeve, the iatter is provided with a radial hole.

4. Achain according to claim 1, 2 or 3wherein the annular end face of each sleeve are interrupted by recesses.

5. Achain according to claim 1,2,3 or4, wherein in the case of a sleeve chain, the bore for the pin is conically widened towards both outer ends of each sleeve.

6. Asleeve or roller chain of a chain drive substantially as described herein with reference to and as illustrated in any one or more ofthe accom panying drawings.