DE102006036851A1 - Cam shaft for internal combustion engine, has base bodies separately manufactured and axially engaged on shaft through sliding, and fixation formed by using ball bearing and provided on bodies - Google Patents

Abstract

The shaft (1) has base bodies (10) separately manufactured and axially engaged on the shaft through sliding, and cams (2-9) fixed on the base bodies. A fixation (11) is formed by using a ball bearing (17) and provided on the bodies. The ball bearing comprises an exterior ring (18) and interior ring (20), which is axially fixed and integrated in rotation on the bodies for fixing an antifriction bearing (19) on the bodies of the shaft. An independent claim is also included for a method for manufacturing a base body axially engaged on a shaft.

Description

The The invention relates to shafts having at least one separately manufactured therefrom, and on this attached functional bodies, such as joined camshafts, which are storable within an internal combustion engine, and method for producing such waves and thus equipped internal combustion engines.

Compound Camshafts, and processes for their manufacture, in which produced by itself Cams are set on a shaft, are e.g. by DE-OSs 198 31 333, 199 38 791 and 101 01 539 become known.

such, Compound camshafts provide over conventional, forged camshafts a number of advantages. For example, be through the individual production the cam and fixing it on the shaft in the overall cost reductions achieved, especially the expensive and elaborate blacksmith tools and Manufacturing processes are eliminated, and it can be used for the shafts and the cams different and respectively optimal materials are used. Other advantages, namely Weight and cost reductions arise during use of hollow waves. Furthermore, the principle of compound allows Camshafts significantly wider and cheaper travels to Production of modifications, adjustments and variants. In addition, that can complex hardening the total wave is eliminated.

The Storage of camshafts, be they massive, with one-piece molded Cams, or compound, is done either via sliding bearings or by means of shared rolling bearings, because closed, ie undivided bearings for use between two adjacent cams not axially beyond the, a larger diameter as the bearings having cams can be pushed. It So it was from the o. a. establish not possible, Use camshafts as preassembled units and use them connected mounting options exploit and not the benefits of rolling bearings, such as lower power losses.

Further composite shafts within internal combustion engines, to the the invention also relates, e.g. Balance shafts and like. Also for such compound waves are the o.a. Disadvantages. The bearings for such waves in the corresponding housing sections of the internal combustion engine have also been designed as slide bearings or shared rolling bearings, in any case, as far as bearings are concerned, between two balance weights are provided.

Accordingly, the was Invention, the object, the disadvantages of the previous camshafts (Also from other waves, especially those where the diameter the functional body is larger as that of the bearings and where the shaft body through the functional body extending therethrough).

Especially should improve the assembly of engines, simplified and cheaper and reduces the power loss and thus save fuel. Furthermore should the manufacturing accuracy of separately produced from waves and then axially pressed-on functional bodies with deviating from the circular shape, in particular their functional surfaces at Cam so their acting on the valve stem surfaces improved become.

According to the invention This is at a wave or, with such a wave equipped Internal combustion engine achieved by that for the storage of the shaft, up the at least one functional body axially pressed and fixed against rotation, that of the shaft so penetrated - to Example, a so-called "joined camshaft" -, at least one of the bearings as rolling bearing is formed, wherein on the shaft at least one undivided, So is provided in self-contained element of a rolling bearing and the shaft with the at least one element of a rolling bearing thus forms a prefabricated unit.

there can be applied to the shaft a complete undivided bearings, ie such with inner and outer ring and between them provided rolling elements.

A second embodiment a rolling bearing may be formed such that the rolling bearing elements, namely rolling elements with undivided cage and undivided outer ring are mounted on the shaft and the rolling elements are directly on the shaft roll off, So a storage without inner ring is formed.

A third execution a storage can be designed such that only the over each other an undivided cage held together rolling elements, for Needles are mounted on the shaft, the rolling elements so on the one hand directly roll on the shaft and on the other hand directly on in the cylinder head mounted Abwälzbereichen.

A fourth version a rolling bearing can be formed so that on the shaft an inner bearing ring together over each other an undivided cage mounted rolling elements mounted is.

In embodiments in which directly on the shaft at least one career for the Rolling is provided, so in the above-mentioned second and third embodiments, it may be desirable if the shaft is made of a material which has the quality of bearing rings. The bearing can also be hardened and ground or finely turned.

Becomes used a bearing with inner ring, so a complete camp with inner and outer ring and Rolling elements or a bearing only with inner ring and rolling elements, so it may be advantageous be if - beside the functional bodies, like the cam - too the inner ring over axially a press fit is rotatably mounted on the shaft.

By the invention makes it possible the advantages of rolling bearing, e.g. in the storage of camshafts, exploit, in particular even in those in which the radial cam extension over the Radius of the bearing seat on the shaft goes out.

there It is particularly advantageous if the camshaft is hollow, so that then lubricating oil fed through the hollow shaft can be, for what expediently leads from the cavity a hole to the bearing point. When using a rolling bearing with Inner ring, it is useful if either in the inner region of the inner ring an annular groove is provided or such a groove in the region of the bearing seat is attached, in which the already mentioned, reaching through the shaft bore opens. Conveniently, in the inner ring of the bearing itself a hole is attached, the on the one hand into the groove and on the other hand into the orbit the rolling element opens.

at Use of a roller bearing without inner ring and with undivided outer ring and over one undivided cage held together rolling elements is expediently the mentioned radial bore mounted in the shaft, which is in the range of rolling elements in the orbit opens. In the same way, the lubricant supply during storage without inner and outer ring, So only with over an undivided cage held together rolling elements are executed.

at Use of a camshaft according to the invention e.g. in a cylinder head where the oil supply in conventional Way done by provided in the cylinder head holes, ie when using a rolling bearing with outer ring, it may be appropriate if in the outer contour of the outer ring and / or in the bearing surrounding the bearing contour of the cylinder head an annular groove is provided and the outer ring an at least approximate radially from the groove out to the orbit of the rolling body leading bore has.

Around the passing oil flow To limit, it may be advantageous, the annular groove and / or the bore at least in a partial area as a throttle train.

It but can also on at least one side of the rolling bearing a - also one-piece - sealing be provided, but advantageously on both sides of the Rolling elements, there then with a corresponding design of the seals as a gap seal These seals can produce a throttle effect.

to axial guidance the camshaft in the cylinder head or engine block may be appropriate if an axial and radial bearing is used, its outer ring set in a recess of the cylinder head or engine block can be.

The axial fixing of the shaft can also be done via a positive connection by means of an outgoing from the shaft radial contour in interaction with a counter contour on the cylinder head or engine block.

The Radial outgoing from the shaft can be formed on the shaft be, but the contour can also by the axially pressed disc or be formed or the same by at least one snap ring.

The However, the invention also extends to the fact that with a balance shaft for one Internal combustion engine, this balance shaft is manufactured as an assembled component, consisting of a wave body and manufactured separately and axially pushed or pressed and axially and rotationally fixed thereon balancing weights, which expediently according to one of the DE-OS'en 19831333, 19938791 or 10101539 described method their storage, in particular in the descriptive manner over at least a one-piece element of a rolling bearing can be done. The invention further relates to such Waves equipped Internal combustion engines.

The However, the invention is not on camshafts or balance shafts limited, but also affects other waves that have a deferred or pressed-on functional body penetrate.

Another inventive idea relates to the production of so-called joined waves with non-circular functional bodies, so for example camshafts in which cams are fixed by axial pressing on a shaft body. It has been shown that in such camshafts, where the cams ge only on their nominal contour grind and then pressed, the outer shape of the cam deviates from the nominal contour in such a way that the engine control is adversely affected. Not only is the cylindrical attachment area deformed, but also in the elevation area of the cam there are deformations. Accordingly, the present further inventive concept was based on the object to avoid such deformations and in particular to provide camshafts in which the outer contour of the functional body, so for example the cam, even in the installed state corresponds to the intended contour. This is achieved in that when grinding the outer contour of a clamping of the cam via its inner bore by means of a clamping element, for example a hydraulic or mechanical mandrel, wherein a widening of the cam is generated, which corresponds to that expansion, which after joining the cam on the Camshaft corresponds. As a result, the outer contour can be produced exactly to the target contour.

One Another inventive idea relates to the design of functional bodies, in particular of cams for a joined Camshaft. This part of the invention was based on the object Save material, reduce camshafts and unbalance to reduce at camshafts. This is inventively characterized achieved that the cam in the area of the cam lobe one in the axial direction the cam at least partially penetrating groove introduced is. This groove can be continuous in the axial direction or possibly only partially penetrate the cam. The groove - in the direction seen on the front of the cam - may be crescent-shaped and only on one side, but also introduced from both sides become. The groove can also be a continuous, and at least approximately circular recess be.

It It can be seen that a not inconsiderable part of the expensive material, which is otherwise used with full cam, can be saved.

Based on 1 - 3 let the invention be explained in more detail.

It shows the 1 a camshaft mounted in a cylinder head,

2 a view of a cam according to the line II-II and

3 a section along the line III-III.

The joined or assembled according to 1 camshaft 1 has cams 2 - 9 on the shaft body 10 are fixed by axial pressing both in the axial direction and in the forming direction. Also axially slid, provided between each two adjacent cams, formed differently in the illustrated embodiment Wälzlagerausbildungen 11 - 15 ,

To form the illustrated storage 11 is a complete ball bearing 17 with outer ring 18 and rolling bearings 19 and inner ring 20 used.

The axial fixing of the camshaft 1 is here through four circlips 21 - 24 given. For axial securing of the bearing on the shaft body and thus also the camshaft in the cylinder head but also the inner ring as well as the cams axially and rotationally fixed on the camshaft body 10 be secured by at least one of the DE-OSs 19831333, 19938791 or 10101539 - which are integral parts of the present application - described manner.

At the depository 11 The lubrication of the bearing in a particularly advantageous manner over the cavity 25 in the main body 10 be done by, as shown below the center line, in the wave body 10 a hole 26 is provided in an inner ring 10 provided annular cavity 27 flows from the turn from a radial bore 28 going out in the runway of the balls 19 ends. In the embodiment shown above the center line, the lubricant supply opening in the shaft main body 10 With 26a referred to in the annular cavity 27a in the shaft body 10 empties. In the area of this cavity 27a leads a hole 28 to the career of the balls 19 , To limit the passing through the bearing lubricant volume, the bore 28 , the annulus 27 and the hole 28 be designed as a throttle, but it can also be effective as a gap seal sealing elements 29 . 30 be provided.

In the case of training camps, as example, the depository 12 shows, the preassembled, provided with undivided elements of a roller bearing camshaft includes both rolling elements 31 passing through an equally undivided cage 37 held together, as well as the outer ring 32 , For lubrication can turn a hole 28 the wave body 10 penetrate. For throttling the lubricating oil flow can seals 34 . 35 be designed as gap seals. The securing of the outer ring 32 takes place here via an annular approach 35 in the case and a snap ring 36 in the case. The securing of the camshaft relative to the housing takes place via two annular projections mounted in the housing 38 and an approach or an annular disc 39 that too through axial pressing on the shaft body 10 is attached.

In one embodiment of a storage location 13 is in a manufactured as a preassembled unit camshaft only by the expediently by a one-piece cage 37 held together element of a rolling bearing, namely the rolling elements 40 , pre-assembled. In the same way as at the depository 11 can also at the depository 13 the lubrication through a hole 28 done and the throttling of the oil flow through appropriate gap seals 33 . 34 ,

In one embodiment of a storage location 14 includes the preassembled unit, namely camshaft and at least undivided elements of a rolling bearing, pushed onto the bearing seat or pressed undivided inner ring 41 and the rolling elements 42 that have an undivided cage 43 are held together. Laterally the rolling elements 42 can in turn seals 33 . 34 , be provided. For lubricant supply, as well as at the bearing point 11 , a hole 26 in the main body 10 be provided, furthermore, an annular cavity 27 in the inner ring and a hole 28 in the outer ring. The annular cavity can also be mounted in the shaft body and in the form of the annular space 27a from which then the bore 28a enters the raceway.

For the formation of bearings according to the 15 designated bearing point, the camshaft turn complete rolling bearings in the form of needle bearing 44 with pushed-on or pressed-on inner ring 45 , Outer ring 46 and rolling elements 47 , Cage 48 and designed as a throttle seals 49 . 50 , The outer ring 46 can here - and also at the depository 11 - Be fixed axially by a press fit and used as a bearing such with axial guidance.

The lubricant supply takes place here in the usual way via a provided in the cylinder head oil supply hole 51 to one around the outer bearing ring 45 applied annular cavity 52 , to a radial bore 53 in the outer ring. The hole 51 But it can also be an external storage 46 provided annular cavity 54 lead and from there through a hole 55 to the running surface of the rolling elements 47 ,

In an embodiment of the bearings accordingly 12 or 13 a raceway for the rolling elements is provided directly on the shaft main body. In such an embodiment, it may be advantageous if the shaft main body has the Qualitiät of bearing rings.

The bearings of the shafts according to 12 . 13 but can also be hardened, ground or finely turned.

In the embodiments according to the 12 and 13 designated bearings the bearings for the outer raceways are processed with the appropriate quality.

The Invention is, as already mentioned, not limited to camshafts, but also refers to other waves, in particular balance shafts, So those waves in which functional elements protrude beyond the shaft diameter and wherein the shaft is on both sides of the functional elements to the their bearing points extending further extends and their functional body, in particular be determined by axial pressing radially and rotationally fixed, as e.g. in already mentioned DE-OSen is described.

2 shows the cam 3 in view according to the line II-II of 1 and 3 a section along the line III-III of 2 ,

The cam 3 has a hole 60 on and a partially cylindrical area 61 who is in a sublime area 62 passes. In the raised cam area 62 is a groove 63 for saving material and weight. The groove 63 can also be formed continuously in the axial direction.

Such cams are by appropriate processing, namely forging, optionally blasting, turning the bore 60 , Hard turning of the bore to the joining dimensions, grinding of the peripheral contour and, if necessary, final vibratory finishing made to their final dimensions. When axially pressing the cam over its bore 60 However, the outer shape of the cam changes with respect to the predetermined nominal contour, not only in the cylindrical area 61 , but also in the survey area 62 , In order to ensure a shape of the neck that corresponds exactly to the desired contour, even with a pressed-on cam, the cam is 3 when grinding the outer contour 64 over its circular inner bore 60 taken on a jig, which widens the cam in a similar manner as is the case with the axial pressing. For this purpose, then the cam can be added to a mechanical or hydraulic clamping element which produces the same kind of overlap as when pressed onto the shaft cam. As a result, the outer contour can be made exactly to the target contour, after relaxing the element is an inappropriate shape, but after mounting the cam back the target shape.

Claims (37)

Wave with at least one, separately made, on these axially deferred and non-rotatable functional body, the is penetrated by the wave, such as so-called "joined camshaft", which within a Internal combustion engine is storable, wherein at least one bearing point through a rolling bearing formed, and on the shaft at least one undivided element of a roller bearing is provided. Shaft, in particular according to claim 1, characterized in that the at least one element of a roller bearing is provided between two joined functional bodies is. Shaft, in particular according to claim 1 or 2, characterized in that both the at least one element of the rolling bearing as well as the one or more functional body pushed axially on the shaft and rotationally fixed by a press fit are on the wave. Shaft, in particular according to one of claims 1 to 3, characterized in that the element is an undivided element is. Shaft, in particular according to one of claims 1 to 4, characterized in that on the same at least one rolling bearing with inner and outer ring is attached. Shaft, in particular according to one of claims 1-4, characterized characterized in that the storage such without interior and / or outer ring is. Shaft, in particular according to one of the preceding claims, characterized characterized in that provided directly on the same a raceway for rolling elements is. Wave, especially after one of the previous ones Claims, characterized in that it consists of a material which the quality possesses of bearing rings. Wave, especially after one of the previous ones Claims, characterized in that the tread is hardened. Wave, especially after one of the previous ones Claims, characterized in that the tread is ground. Wave, especially after one of the previous ones Claims, characterized in that the bearing is finely turned. Wave, especially after one of the previous ones Claims, characterized in that arranged around the raceway a ring of rolling elements is held together by an undivided cage. Shaft, in particular according to claim 12, characterized in that that the bearing is one with rolling elements and outer ring, but without inner ring. Wave, especially after one of the previous ones Claims, characterized in that the storage such without internal and outer ring is. Wave, especially after one of the previous ones Claims, characterized in that the storage such with inner ring and held together rolling elements is. Shaft, in particular according to one of claims 1-15, characterized characterized in that it is at least partially hollow. Shaft, in particular according to claim 16, characterized that a bore leads from the cavity to the bearing point. Wave, especially after at least one of the previous ones Claims, characterized in that when using a rolling bearing with inner ring this in its interior an annular groove has. Wave, in particular after at least one of the preceding Claims, characterized in that when using a rolling bearing with inner ring, the shaft in the region of the bearing seat an annular groove has. Shaft, in particular according to one of claims 16 or 17, characterized in that the inner ring an at least approximately radially has extending bore. Shaft, in particular according to claim 20, characterized that the hole ends in the raceway of the rolling elements. Wave, or internal combustion engine with a particular according to one of the preceding claims, characterized that when using a rolling bearing with outer ring and an oil supply in the outer contour the bearing point in the outer contour of the outer ring and / or in the bearing encompassing the contour of the bearing block of the motor housing an annular Groove is provided. Shaft, in particular according to claim 22, characterized in that the outer ring to one has at least approximately radially extending bore. Shaft, in particular according to claim 23, characterized that the hole ends in the raceway of the rolling elements. Shaft, in particular according to one of the preceding claims, characterized characterized in that the annular Groove and / or the bore at least in a partial area is designed as a throttle. Shaft, in particular according to one of claims 1 to 25, characterized in that on at least one side of the Storage a seal is provided. Shaft, in particular according to claim 26, characterized that the seal is a gap seal. Shaft, in particular according to one of the preceding claims, characterized characterized in that the axial securing thereof in the engine block, like the cylinder head, by axial clamping of the outer bearing ring designed as an axial and radial bearing rolling bearing takes place in a recess, the cylinder head or engine block. Shaft, in particular according to one of the preceding claims, characterized characterized in that their axial fixing via a positive connection means an outgoing from her radial contour in cooperation with a counter contour on the cylinder head or engine block takes place. Shaft, in particular according to claim 29, characterized that the positive connection formed by at least one snap ring is. Wave, namely Balance shaft for Internal combustion engine, characterized in that it is a joined Shaft acts, consisting of a wave body and manufactured separately and axially deferred and axially and rotationally fixed thereto Counterweights. Shaft, in particular according to claim 31, characterized that it is designed according to at least one of claims 1-31 or 33. Wave, namely Balancing shaft, in particular according to one of the preceding claims, characterized characterized in that the same one of the in DE OS'en 198 31 333, 199 38 791 or 101 01 539. Internal combustion engine, characterized in that at least one wave according to at least one of the preceding claims contains. Shaft, in particular camshaft, in particular after one of the preceding claims, characterized in that the cam at its elevation area has a groove extending in the axial direction. Shaft, in particular according to claim 35, characterized that the groove is axially continuous. Method for producing axially aufzupressenden on waves function fields with a shape deviating from the circular shape, such as cam for a camshaft, characterized in that the cams for grinding the final functional shape over their Inner bore spanned on a mandrel and there during the Grinding in a state applied to the camshaft corresponding state deformed.