DE102010018205A1 - Phase adjustment device, particularly for displacement of phase position of cam shaft opposite crankshaft, has drive wheel and cam shaft, where displacement member is formed by two sections in axial direction - Google Patents

Abstract

The phase adjustment device has a drive wheel (100) and a cam shaft (200), where a displacement member (300) is formed by two sections in an axial direction. The former section is engaged with a drive wheel, where the latter section is engaged with a cam shaft. The displacement member is movable in the axial direction relative to the drive wheel and the camshaft.

Description

Field of the invention

The invention relates to an adjusting drive for rotating an axle section in the circumferential direction relative to a second axle section. In particular, the invention relates to an adjusting drive for adjusting a phase angle of a camshaft relative to a crankshaft.

Background of the invention

From the DE 41 01 676 A1 an adjusting device for the relative displacement of a camshaft relative to a driving drive wheel is disclosed. The adjusting device has an electric motor, which is arranged axially displaceably with a first threaded portion on a stationary held second formed on a shaft threaded portion. In the case of a rotary movement of the rotor, a relative adjustment via an adjusting element, which engages via an inner and outer splines in the corresponding teeth of the drive wheel and the cam end piece. One of the splines is formed here as a helical toothing, so that takes place according to the principle of the inclined plane relative displacement at an axial displacement.

However, such a phaser has both a large radial and axial space. Furthermore, high moments of inertia must be overcome during the adjustment. In addition, such transmissions, due to mechanical friction, a moderate efficiency. The existing friction has a relatively strong effect on the required drive torque. However, this adjustment energy must be applied in the form of electrical energy from the electrical system of a motor vehicle.

Summary of the invention

It is an object of the invention to provide an adjustment drive which has an improved efficiency and an improved installation space. These and other objects are achieved by the adjustment drive according to claim 1. Further embodiments are described in the dependent claims. According to the invention, an adjusting drive can be used in particular for adjusting a phase position of a camshaft.

The adjusting drive according to the invention is based on the basic principle of helical gearing with rolling bodies arranged in the toothing, preferably balls. This converts a linear, translational motion into a rotational one. About the course of the helical gearing and the pitch of a thread of a spindle, the translation of the two movements can be defined.

In general, an adjusting drive according to an embodiment of the invention comprises a drive wheel, a camshaft and a displacement member having a first portion and a second portion in the axial direction. The first portion of the sliding member is engaged with the drive wheel and the second portion of the sliding member is engaged with the camshaft, wherein the sliding member is displaceable in the axial direction relative to the drive wheel and the camshaft and wherein at least one of the portions, that is, the first and the second portion is formed with a Wälzgeführten helical teeth.

The rolling guides of the helical gearing consist of oblique ball grooves in the drive wheel and in the displacement member, wherein balls should be arranged therein without play, so that no rattling noises occur. In the case of a clearance occurring between the parts, the alternating loads of the camshaft would cause these noises.

The thread groove may be formed as a ball groove. Further, the first and second portions of the sliding member may each have a ball groove.

In order to achieve the desired adjustment between the drive wheel and the camshaft, the pitch of the ball groove of one section differs from the pitch of the ball groove of the other section.

It is noted that in the extreme case, with a slope of 0 °, the ball groove of one of the sections may be formed linearly in the axial direction. It is also possible that the slope of one section is formed in opposite directions to the slope of the other section. In other words, it is also possible that the slope of one section is negative and the slope of the other section is positive.

According to a further embodiment of the invention, the adjusting drive has a spindle drive for displacing the displacement member. Here, the spindle drive can be designed as a ball screw drive. At least part of the spindle drive can be arranged within the displacement member. Furthermore, the spindle drive can be driven electrically.

In the event that the drive of the spindle drive fails or is inactive, according to a further embodiment of the invention Spindle drive and the helical gearing be designed so that the displacement member moves to a predetermined position, in other words, the adjustment drive may have the property of having an adapted to the friction of the adjustment pitch of the Schrägkugelnut and the spindle drive thread, so that in case of failure of the spindle drive, the drive shaft aligns independently relative to the camshaft and thus prevents damage to the motor.

According to a further embodiment of the invention, the spindle drive is arranged at least partially within the camshaft. The displacement member may be formed as a sleeve, wherein the spindle drive is arranged within the displacement member and wherein outside of the displacement member, the camshaft and the likewise hollow drive wheel are arranged.

By arranging the gear elements in one another, a compact design with a radial extent of less than 65 mm in diameter can be achieved. Preferably, a diameter of less than 55 mm can be realized. According to a preferred embodiment of the invention, the diameter of the adjusting drive is not more than 35 mm.

By arranging the elements of the adjusting drive within a small diameter, a reduced mass moment of inertia of less than 30 kg mm ² can be achieved.

It is noted that an adjusting drive according to the invention can be used for adjusting shafts of any type.

The above-described aspects and other aspects, features, and advantages of the invention may also be had from the examples of the embodiments, which are described below with reference to the attached drawings.

Brief description of the drawings

1 is a sectional view of an adjusting drive according to the invention.

2 is a side view of a sliding member according to a first embodiment of the invention.

3 is a schematic representation of a sliding member according to a second embodiment.

4 is a schematic representation of a sliding member according to a third embodiment.

Detailed description of the embodiments

1 shows a sectional view of the arrangement of the individual elements of an adjusting drive according to the invention. The adjustment drive has a drive wheel 100 , a camshaft 200 , a displacement member 300 and a spindle drive.

The drive wheel is constructed in two parts according to this embodiment, that is, the drive wheel 100 is with an intermediate part 110 firmly connected, which is different from the drive wheel 100 in the axial direction in the direction of the camshaft 200 extends. For storage of the drive wheel is an area 130 at the intermediate part 110 as radial and Axialgleitlager for mounting the device, or the camshaft 200 provided in a cylinder head, not shown.

The spindle drive has a spindle 400 with a ball screw drive 410 and a nut corresponding to the screw drive 310 on.

The shift member 300 is hollow and carries on the inner diameter of the recording, that is the mother 310 for the ball screw drive 410 and on the outer surface the corresponding functional ball grooves. The two sections 320 and 330 , on which the ball grooves are formed, are arranged axially one behind the other, in order to comply with the small radial space. The number of balls and the ball diameter can be chosen so that the material-specific surface pressure is not exceeded.

The balls can in the section 320 through a ball cage 120 and in the section 330 through a ball cage 220 held together. The spindle 400 with the ball screw 410 can be arranged interchangeable, so that the translation of the phaser can be easily adjusted in hindsight by using different thread pitches. Furthermore, depending on the requirements, a right-handed or left-handed spindle is selected in order to produce an independent adjustment in one direction with no current supply. (Fail-safe function)

Preferably, the mother 310 the spindle drive axially and with respect to the torque fixed to the sliding member 300 connected while the spindle 400 is operated by a preferably electric actuator of any type (not shown). Alternatively, the stage can be reversed (nut operated, Spindelverschiebeteil fixed) are constructed. The coupling of the actuator to the spindle preferably takes place via a coupling 420 of any type to compensate for misalignment errors.

By adjusting the lead screw pitch and the pitch of the helical ball guide, the adjustment accuracy or adjustment speed can be adjusted.

In 2 a first embodiment of a sliding member according to the invention is shown. The shift member 300 points in a first section 320 a helical toothing 340 on. In the second section 330 of the displacement member is formed in the axial direction of a linear ball groove.

The ball grooves in the first section 320 are formed running obliquely to the longitudinal center axis of the device to produce a certain rotation at a defined displacement relative to the Gegenkugelnut. Due to the linear ball grooves in the second section 330 There is no rotation of the displacement member relative to the Gegenkugelnut in a longitudinal movement of the displacement member.

The two sections engage with rolling elements positioned therein each in a correspondingly shaped Gegenkugelnut, which is located in a camshaft and in a fixed part to the drive wheel. The two camshaft and drive wheel-fixed parts must be axially fixed to each other.

In the case of an axial displacement of the displacement member, the rotation caused by the portion extending obliquely to the longitudinal axis is transmitted via the linear portion to the counterpart component. Thus, there is a relative movement between the drive wheel and the camshaft.

As in 3 and 4 shown, the same adjustment functionality can be achieved by means of two oppositely shaped oblique grooves.

The 3 and 4 each show further embodiments of sliding members according to the invention. In 3 are the spiral grooves 340 at the displacement member 300 with a comparable slope, but designed in opposite directions.

According to 4 is the slope of the ball groove 340 in the first part 320 steeper than the slope of the oblique groove 340 in the second section 330 , wherein also here the oblique grooves are formed in opposite directions.

While the invention has been illustrated and described in detail in the drawings and the foregoing description, it is intended that such illustrations and descriptions be merely illustrative or exemplary and not restrictive, such that the invention is not limited by the disclosed embodiments.

In the claims, the word "comprising" does not exclude other elements and the indefinite article "a" does not exclude a plurality. The mere fact that certain features are mentioned in various dependent claims does not limit the scope of the invention. Combinations of these features can be used advantageously. The reference signs in the claims are not intended to limit the scope of the claims.

LIST OF REFERENCE NUMBERS

100

drive wheel

110

intermediate part

120

ball cage

130

Radial and axial plain bearings

200

camshaft

220

ball cage

300

displacement member

310

spindle nut

320

first section

330

second part

340

ball groove

400

spindle

410

Ball Screw

420

clutch

430

spindle bearing

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 4101676 A1 [0002]

Claims (10)

Device for phase adjustment, comprising: a drive wheel ( 100 ), a camshaft ( 200 ), and a displacement member ( 300 ), which in the axial direction a first section ( 320 ) and a second section ( 330 ), the first section ( 320 ) in engagement with the drive wheel ( 100 ), the second section ( 330 ) in engagement with the camshaft ( 200 ), the displacement member ( 300 ) is displaceable in the axial direction relative to the drive wheel and the camshaft, and wherein at least one of the first and the second section with a helical toothing ( 340 ) is trained. Apparatus according to claim 1, wherein in the helical gearing ( 340 ) Rolling elements are arranged. Device according to claim 2, wherein the first section ( 320 ) of the displacement member ( 300 ) has a first groove with a first slope extending obliquely to the longitudinal central axis, wherein the second portion ( 330 ) of the displacement member has a second groove with a second slope extending obliquely to the longitudinal center axis, wherein the first slope is different from the second slope. Apparatus according to claim 3, further comprising rolling elements, for a power transmission from the drive wheel ( 100 ) on the camshaft ( 200 ). Apparatus according to claim 1, further comprising a spindle drive for displacing the displacement member. Apparatus according to claim 5, wherein the spindle drive is designed as a ball screw drive and wherein at least a part of the spindle drive within the displacement member (US Pat. 300 ) is arranged. Apparatus according to claim 5, wherein the spindle drive is electrically driven. Apparatus according to claim 1, wherein the second section ( 330 ) of the displacement member within the camshaft ( 200 ) is arranged. Apparatus according to claim 1, wherein the radial extent of the adjusting drive is less than 65 mm in diameter, preferably less than 55 mm in diameter, more preferably less than 35 mm in diameter. The apparatus of claim 7, wherein the spindle drive and the helical gear are designed so that the displacement member moves to a predetermined position when the drive of the spindle drive is inactive.

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