DE102010005603B4 - Camshaft adjustment arrangement with a camshaft bearing designed as a roller bearing - Google Patents

Abstract

Camshaft adjusting arrangement (1) for changing the relative angular position of a camshaft (2) with respect to a crankshaft of an internal combustion engine, the camshaft adjusting arrangement (1) comprising a drive element (3) driven by the crankshaft, which is rotatably mounted with respect to the camshaft (2), with between the drive element (3) and the camshaft (2) at least two hydraulic chambers (4) are formed, which can be hit with a pressure fluid in order to set a defined relative rotational position between the drive element (3) and the camshaft (2), whereby to control the A control valve (5) is provided for the flow of the pressure fluid into the hydraulic chambers (4) and the control valve (5) is supplied with pressure fluid from the area of a camshaft bearing (6) via a fluid channel (7, 8, 9), characterized in that that the camshaft bearing (6) is designed as a roller bearing with an inner ring (10) and an outer ring (11), the cams shaft (2) is tubular at least in one of its axial end regions (12), the inner ring (10) being arranged in the tubular axial end region (12) of the camshaft (2) and axially contacting or with one of its end faces (13) and wherein the inner ring (10) sits together with the axial end region (12) of the camshaft (2) on a seat section (14, 14 ') of a housing element (15) connected in a rotationally fixed manner to the camshaft (2), into which the control valve ( 5) is built in.

Description

Field of the invention

The invention relates to a camshaft adjusting arrangement for changing the relative angular position of a camshaft with respect to a crankshaft of an internal combustion engine, the camshaft adjusting arrangement comprising a drive element driven by the crankshaft which is rotatably mounted with respect to the camshaft, at least two hydraulic chambers being formed between the drive element and the camshaft, which can be acted upon with a pressure fluid in order to set a defined relative rotational position between the drive element and the camshaft, a control valve being provided to control the flow of the pressure fluid into the hydraulic chambers and the control valve supplying pressure fluid from the area of a camshaft bearing via a fluid channel becomes.

Background of the invention

Camshaft adjusting devices of this type are well known in the prior art. The DE 10 2005 052 481 A1 discloses a generic adjusting device. In the camshaft adjuster there is an impeller in which vanes are molded or arranged. The blades are located in hydraulic chambers that are incorporated in an outer rotor. By appropriately applying hydraulic fluid to the respective side of the hydraulic chambers, the inner rotor can be adjusted relative to the outer rotor between an “early stop” and a “late stop”. The flow of hydraulic oil is controlled by an electrically controlled directional valve. The valve has a housing into which a valve bore is made. A control piston can move in a direction of displacement relative to the housing, for which purpose an electromagnetically actuated linear displacement element is used. During operation of the internal combustion engine, the linear displacement element of the valve is acted upon by the vehicle electrics or electronics with such a control current that - depending on the engine parameters - a desired camshaft adjustment or adjustment of the gas exchange valves is achieved.

To control the movement, hydraulic fluid is therefore fed into the hydraulic chambers by means of the control valve as required. The pressurized hydraulic oil is fed by a hydraulic pump via the cylinder head and via the area of the camshaft bearing via the aforementioned fluid channel into the hydraulic chambers.

JP 2000 - 314 304 A shows a roller bearing for a camshaft.

Object of the invention

The present invention is based on the object of developing a camshaft adjustment arrangement of the type mentioned at the beginning so that it is possible to design the fluid channel in the area of the camshaft bearing and its connection to the further fluid path in such a way that the production of the arrangement becomes simpler and therefore more cost-effective. Furthermore, it should be avoided to have to machine the camshaft in the area of its connection to the camshaft adjuster, so that its mechanical strength is weakened. Furthermore, it should also be possible to use a hollow shaft as a camshaft. Finally, the aim is to allow more energy-efficient operation of the internal combustion engine.

Summary of the invention

The solution to this problem by the invention is characterized in that the camshaft bearing is designed as a roller bearing with an inner ring and an outer ring, the camshaft being tubular in at least one of its axial end areas, the inner ring being arranged in the tubular axial end area of the camshaft and one of its end faces makes axial contact with or supports it, and the inner ring, together with the axial end region of the camshaft, is seated on a seat section of a housing element connected in a rotationally fixed manner to the camshaft, in which the control valve is installed.

The housing element preferably has a flange-like, radially enlarged section, a part of the fluid channel being formed between this and an end face of the camshaft bearing. In this case it can further be provided that the part of the fluid channel is formed by a number of radially extending recesses in the flange-like, radially enlarged section of the housing element.

According to a further development, a spacer and / or sealing ring is arranged between the flange-like, radially enlarged section of the housing element and the camshaft bearing, which provides a seal radially outward for the pressure fluid.

The control valve can comprise a central screw with which it is fixed in the housing element coaxially to the camshaft.

The camshaft is preferably attached to the housing element. For this purpose it can be provided that the attachment of the camshaft to the housing element by a press fit between an inner cylindrical section of the Camshaft and the seat portion of the housing member is formed; alternatively or additionally, it can also be provided that the camshaft is fastened to the housing element by a material connection, in particular as a soldering, preferably as a hard soldering, or as a welding, preferably as a laser beam or electron beam welding.

The housing element can furthermore have an axial contact surface for the axial end of the camshaft.

With the proposed design of the camshaft adjuster, when a central valve is used to control the pressure fluid, a tube can be used at least in sections as the base body for the camshaft, which offers corresponding weight advantages.

Furthermore, mechanical machining in the end area of the camshaft in the area of the camshaft bearing can be dispensed with, so that not only do not incur related machining costs, but also the mechanical strength of the camshaft is retained.

The use of a roller bearing allows the friction in the camshaft adjustment arrangement to be reduced. Ball bearings are preferably used as roller bearings, deep groove ball bearings having proven particularly useful.

According to the invention, the transmission of the pressure oil to the control valve is also very favorable, so that favorable flow conditions can be achieved, with no complex processing measures having to be taken.

Figure list

• 1 den Radialschnitt durch eine Nockenwellenverstellanordnung eines Verbrennungsmotors mit einer ansatzweise dargestellten Nockenwelle gemäß einer ersten Ausführungsform der Erfindung,
• 2 in der Darstellung gemäß 1 die Nockenwellenverstellanordnung gemäß 1, wobei eine Stelleinheit zur Betätigung des Steuerventils nicht dargestellt ist,
• 3 den Bereich des Steuerventils samt Nockenwellenansatz und Nockenwellenlager gemäß der Lösung nach 1 und 2 in vergrößerter Darstellung,
• 4 den Radialschnitt durch die Nockenwellenverstellanordnung nach 1 bis 3 ohne eingebautes Steuerventil,
• 5 den Radialschnitt durch eine Nockenwellenverstellanordnung in einer zu 4 geringfügig modifizierten Ausführungsform und
• 6 in perspektivischer Darstellung ein Gehäuseelement der Nockenwellenverstellanordnung samt Nockenwellenlager als isolierte Bauteile.

Exemplary embodiments of the invention are shown in the drawings. Show it:

• 1 the radial section through a camshaft adjusting arrangement of an internal combustion engine with a camshaft shown in part according to a first embodiment of the invention,
• 2 in the representation according to 1 the camshaft adjustment arrangement according to 1 , whereby an actuating unit for actuating the control valve is not shown,
• 3 the area of the control valve including the camshaft attachment and camshaft bearing according to the solution 1 and 2 in an enlarged view,
• 4th the radial section through the camshaft adjustment arrangement 1 to 3 without built-in control valve,
• 5 the radial section through a camshaft adjusting arrangement in one to 4th slightly modified embodiment and
• 6th a perspective view of a housing element of the camshaft adjusting arrangement including camshaft bearings as isolated components.

Detailed description of the figures

In the 1 to 4th is an embodiment of the camshaft adjusting arrangement according to the invention 1 an internal combustion engine shown. For the basic structure of such an arrangement 1 is referred to at the beginning DE 10 2005 052 481 A1 referenced in full by the applicant.

The phasing assembly 1 has a drive element (not shown) - mostly a chain or a toothed belt - driven drive element 3 on, which is designed, a targeted rotation by a defined relative angle of rotation between the crankshaft of the internal combustion engine and a camshaft 2 execute in order to influence the operating behavior of the internal combustion engine in a known manner. The flow of pressurized hydraulic fluid in hydraulic chambers 4th (only one of which is indicated) is controlled by a control valve 5 accomplished that by an actuator 26th (see 1 ) is actuated by moving it in the axial direction (corresponding to the axial direction of the camshaft 2 ) is moved against the action of a spring.

The control valve 5 includes a pressure medium guide insert 27 (see 3 ), which can be moved axially in the control valve 5 sits. The control valve 5 in turn is fixed in a housing element 15th arranged, which acts as an adapter. The control valve is used as a central screw for this purpose 23 formed into a thread in the housing element 15th is screwed in.

How the camshaft adjustment arrangement works 1 will turn to the DE 10 2005 052 481 A1 Referenced.

The pressurized fluid for actuating the camshaft adjustment assembly 1 must be from a - not shown - pump over the area of the camshaft bearing 6th for pressure medium control insert 27 be directed. For the line of the pressure fluid, a fluid channel is provided, which the sections 7th , 8th and 9 having. The section 7th consists of several recesses in a flange-like, radially enlarged section 16 of the housing element 15th are incorporated, the recesses extending radially. From the fluid channel 7th the pressure fluid reaches the fluid channel 8th , which as an annular space between the housing element 15th and control valve 5 is trained. From there the fluid reaches the fluid channel 9 , which is the number of radial bores in the control valve 5 is trained. The pressure fluid therefore comes from an area to the right of the camshaft bearing 6th through this through the fluid channels 7th , 8th and 9 to the control valve 5 and the pressure medium control insert 27 .

The design of the camshaft bearing is essential 6th and its installation. According to this, it is provided that the camshaft bearing designed as a roller bearing 6th an inner ring 10 and an outer ring 11 includes, between which rolling elements are arranged. The camshaft 2 is at least in one of its axial end regions 12th tubular. The inner ring 10 is in the tubular axial end region 12th the camshaft 2 arranged, he this with one of its end faces 13th axially contacted or supported.

The inner ring 10 sits together with the axial end region 12th the camshaft 2 on a seat section 14th and 14 ' the one with the camshaft 2 non-rotatably connected housing elements 15th . The camshaft 2 sits with its axial end on an axial contact surface 25th on the housing element 15th .

The housing element 15th and the camshaft 2 are permanently connected, for example by welding or soldering. Furthermore, it can alternatively or additionally be provided that between a cylindrical end section (see right axial end area of the housing element 15th in 3 ) and an inner cylindrical section 24 the camshaft 2 There is a press fit, so that the solid connection between the camshaft 2 and housing element 15th will be produced. A positive connection (e.g. by means of a thread) between the housing element would also be possible 15th and camshaft 2 .

As it is best in 3 can be seen is the outer ring 11 of the camshaft bearing 6th axially to one side by a section extending radially inward 21 and to the other side by a snap ring 22nd set, with the snap ring 22nd at the front 17th of the camshaft bearing 6th is applied.

The flange-like, radially enlarged section 16 of the housing element 15th has a sealing element in its radially outer area 19th on that on a bore surface 20th rubbing against it, the outer ring 11 also in this hole area 20th sits. Axially between the sealing element 19th and the snap ring 22nd is a spacer or sealing ring 18th arranged that a seal of the pressure oil in the fluid channel 7th done radially outward.

The advantage of this configuration is, on the one hand, that a tube can be used as a camshaft without any problems 2 can be used as the connection to the housing element 15th as explained, it can be done in a space-saving and advantageous manner. Furthermore, the camshaft must 2 themselves are not mechanically processed to the fluid channel 7th to accomplish. In the prior art, it has hitherto been necessary for recesses to be worked into the camshaft for this purpose, which not only requires a corresponding manufacturing effort, but also a mechanical weakening of the camshaft 2 entails. Through the use of the roller bearing 6th As a camshaft bearing, a low-friction bearing is also guaranteed, which increases the overall efficiency of the internal combustion engine.

In 5 is a slightly opposite 4th varied configuration of the arrangement outlined, the modification essentially the area between the flange-like, radially enlarged section 21 of the housing element 15th and the camshaft bearing 6th concerns.

In 6th is finally the housing element in perspective 15th including camshaft bearings 6th shown.

List of reference symbols

1

Camshaft timing arrangement

2

camshaft

3

Drive element

4th

Hydraulic chamber

5

Control valve

6th

Camshaft bearings

7th

Fluid channel

8th

Fluid channel

9

Fluid channel

10

Inner ring

11

Outer ring

12th

axial end of the camshaft

13th

Front side

14th

Seat section

14 '

Seat section

15th

Housing element

16

flange-like, radially enlarged section

17th

Front side

18th

Spacer and / or sealing ring

19th

Sealing element

20th

Bore area

21

radially extending portion

22nd

Snap ring

23

Central screw

24

inner cylindrical section

25th

axial contact surface

26th

Control unit

27

Pressure medium guide insert

Claims (8)

Camshaft adjusting arrangement (1) for changing the relative angular position of a camshaft (2) with respect to a crankshaft of an internal combustion engine, the camshaft adjusting arrangement (1) comprising a drive element (3) driven by the crankshaft which is rotatably mounted with respect to the camshaft (2), with between the drive element (3) and the camshaft (2) at least two hydraulic chambers (4) are formed, which can be hit with a pressure fluid in order to set a defined relative rotational position between the drive element (3) and the camshaft (2), whereby to control the A control valve (5) is provided for the flow of the pressure fluid into the hydraulic chambers (4) and the control valve (5) is supplied with pressure fluid from the area of a camshaft bearing (6) via a fluid channel (7, 8, 9), characterized in that that the camshaft bearing (6) is designed as a roller bearing with an inner ring (10) and an outer ring (11), the cam nshaft (2) is tubular in at least one of its axial end regions (12), the inner ring (10) being arranged in the tubular axial end region (12) of the camshaft (2) and axially contacting or contacting it with one of its end faces (13) and wherein the inner ring (10) sits together with the axial end region (12) of the camshaft (2) on a seat section (14, 14 ') of a housing element (15) connected non-rotatably to the camshaft (2), into which the control valve ( 5) is built in. Camshaft adjustment arrangement (1) according to Claim 1 , characterized in that the housing element (15) has a flange-like, radially enlarged section (16), a part (7) of the fluid channel (7, 8, 9) being formed between this and an end face (17) of the camshaft bearing (6) . Camshaft adjustment arrangement (1) according to Claim 2 , characterized in that the part (7) of the fluid channel (7, 8, 9) is formed by a number of radially extending recesses in the flange-like, radially enlarged section (16) of the housing element (15). Camshaft adjustment arrangement (1) according to Claim 2 , characterized in that a spacer and / or sealing ring (18) is arranged between the flange-like, radially enlarged section (16) of the housing element (15) and the camshaft bearing (6). Camshaft adjustment arrangement (1) according to Claim 1 , characterized in that the control valve (5) comprises a central screw (23) with which it is fixed in the housing element (15) coaxially to the camshaft (2). Camshaft adjustment arrangement (1) according to Claim 1 , characterized in that the camshaft (2) is attached to the housing element (15). Camshaft adjustment arrangement (1) according to Claim 6 , characterized in that the attachment of the camshaft (2) to the housing element (15) is formed by a press fit between an inner cylindrical section (24) of the camshaft (2) and the seat section (14 ') of the housing element (15) and / or that the attachment of the camshaft (2) to the housing element (15) is formed by an integral connection. Camshaft adjustment arrangement (1) according to Claim 1 , characterized in that the housing element (15) has an axial contact surface (25) for the axial end of the camshaft (2).

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