Camshaft adjuster including a blocking pin for pressure relief of the hydraulic channel covered by a slotted gate

Patent metadata

Field	Value
Publication number	US-10316706-B2
Application number	US-201515312084-A
Country	US
Kind code	B2
Filing date	Jan 26, 2015
Priority date	May 21, 2014
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

A camshaft adjuster for an internal combustion engine, having a stator, a rotor mounted rotatably in the interior of the stator, and a locking cover connected to the stator. A hydraulically actuatable locking element is received in the rotor and engages into the locking cover in at least one blocking position, so as to block a rotation of the rotor relative to the stator, and is arranged in at least one unlocking position so that the rotor can be rotated relative to the stator. A blocking pin acts in at least one hydraulic channel connected hydraulically to the locking element so that the hydraulic channel is connected to a recovery tank or is disconnected from the recovery tank depending on the position of the blocking pin, wherein the hydraulic channel has a first channel section in the locking cover, and the first channel section and the blocking pin are arranged so that the blocking pin seals the hydraulic channel from the recovery tank in at least one first end position, in a first pressure range which prevails in the hydraulic channel by way of contact with the locking cover.

First claim

The invention claimed is:

1. A camshaft adjuster for an internal combustion engine, the camshaft adjuster comprising:
a stator;
a rotor rotatably supported in an interior of the stator;
a locking cover connected to the stator;
a hydraulically actuatable locking element being accommodated in the rotor, the locking element engaging with the locking cover in at least one blocking position and blocking a rotation of the rotor relative to the stator and being situated in at least one unblocking position in such a way that the rotor is rotatable relative to the stator;
a blocking pin acting in at least one hydraulic channel hydraulically connected to the locking element, in such a way that the at least one hydraulic channel is connected to a recovery tank or is disconnected from the recovery tank depending on a position of the blocking pin,
the at least one hydraulic channel including a first channel section introduced into the locking cover configured for fluid to flow through and into the recovery tank in the at least one unblocking position, the first channel section and the blocking pin being designed and situated relative to each other in such a way that a first end face of the blocking pin axially abuts the locking cover at the first channel section to seal the at least one hydraulic channel from the recovery tank in at least one first end position, within a pressure range prevailing in the at least one hydraulic channel by way of contact with the locking cover, the blocking pin being arranged with respect to the first channel section such that the first end face of the blocking pin directly axially seals at least one portion of the first channel section in the at least one first end position.

2. The camshaft adjuster as recited in claim 1 wherein to switch from the at least one blocking position into the at least one unblocking position, the blocking pin is displaceable in an axial direction within the rotor between the at least one first end position, in which the blocking pin is situated up to a predetermined first hydraulic pressure value, and a second end position, in which the blocking pin is situated upon reaching a second hydraulic pressure value.

3. The camshaft adjuster as recited in claim 1 wherein the blocking pin has a second end face facing away from the locking cover, the second end face abutting the at least one hydraulic channel in a second end position on a rotor side to seal the recovery tank.

4. The camshaft adjuster as recited in claim 1 wherein the first end face has an annular design and a hydraulic pressure set in the at least one hydraulic channel is applied to the first end face in the at least one first end position.

5. The camshaft adjuster as recited in claim 1 wherein the blocking pin is hollow and includes a continuous through-hole in an axial direction.

6. The camshaft adjuster as recited in claim 5 wherein the blocking pin includes a flow diaphragm reducing a cross section of the through-hole.

7. The camshaft adjuster as recited in claim 5 wherein the through-hole is situated in such a way that a flow of hydraulic medium is prevented in the at least one first end position of the block pin.

8. The camshaft adjuster as recited in claim 1 wherein the first channel section is hydraulically connected to a second channel section of the at least one hydraulic channel introduced into the rotor.

9. The camshaft adjuster as recited in claim 1 wherein the blocking pin is spring-pretensioned to abut the locking cover and seal the at least one hydraulic channel from the recovery tank in the at least one blocking position.

10. The camshaft adjuster as recited in claim 1 wherein the blocking pin seals the first channel section from the recovery tank in the at least one first end position by the first end face of the blocking pin axially contacting the locking cover.

11. The camshaft adjuster as recited in claim 1 wherein the first end face of the blocking pin axially contacts a projection area of the locking cover, the first channel section being recessed away from the projection area.

12. The camshaft adjuster as recited in claim 1 wherein the first channel section is configured to direct fluid into the recovery tank in the at least one unblocking position.

13. The camshaft adjuster as recited in claim 1 wherein the at least one hydraulic channel includes a second channel section formed in the rotor, the first channel section configured for providing fluid from the second channel section to the blocking pin in the at least one unblocking position.

Assignees

• Schaeffler Technologies Ag

Inventors

• Thielen Jochen
• Boese Olaf
• Zschieschang Torsten

Classifications

• F01L2001/34423

  Details relating to the hydraulic feeding circuit · CPC title

• F01L2001/34453

  Locking means between driving and driven members · CPC title

• F01L1/3442 Primary

  using hydraulic chambers with variable volume to transmit the rotating force · CPC title