US20150300216A1 - Camshaft for a variable-stroke exchange valve train - Google Patents

Camshaft for a variable-stroke exchange valve train Download PDF

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Publication number
US20150300216A1
US20150300216A1 US14/440,996 US201314440996A US2015300216A1 US 20150300216 A1 US20150300216 A1 US 20150300216A1 US 201314440996 A US201314440996 A US 201314440996A US 2015300216 A1 US2015300216 A1 US 2015300216A1
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US
United States
Prior art keywords
cam
bearing
camshaft
roller bearing
cams
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US14/440,996
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English (en)
Inventor
Andreas Wedel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Schaeffler Technologies AG and Co KG
Original Assignee
Schaeffler Technologies AG and Co KG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Schaeffler Technologies AG and Co KG filed Critical Schaeffler Technologies AG and Co KG
Assigned to Schaeffler Technologies AG & Co. KG reassignment Schaeffler Technologies AG & Co. KG ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: WEDEL, ANDREAS
Publication of US20150300216A1 publication Critical patent/US20150300216A1/en
Abandoned legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L13/00—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations
    • F01L13/0015—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque
    • F01L13/0036—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque the valves being driven by two or more cams with different shape, size or timing or a single cam profiled in axial and radial direction
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/02—Valve drive
    • F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
    • F01L1/08—Shape of cams
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/02—Valve drive
    • F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
    • F01L1/047—Camshafts
    • F01L2001/0471—Assembled camshafts
    • F01L2001/0473—Composite camshafts, e.g. with cams or cam sleeve being able to move relative to the inner camshaft or a cam adjusting rod
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/02—Valve drive
    • F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
    • F01L1/047—Camshafts
    • F01L2001/0476—Camshaft bearings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L13/00—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations
    • F01L13/0015—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque
    • F01L13/0036—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque the valves being driven by two or more cams with different shape, size or timing or a single cam profiled in axial and radial direction
    • F01L2013/0052—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque the valves being driven by two or more cams with different shape, size or timing or a single cam profiled in axial and radial direction with cams provided on an axially slidable sleeve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L2303/00—Manufacturing of components used in valve arrangements

Definitions

  • the invention relates to a camshaft of a variable stroke gas exchange valve train of an internal combustion engine.
  • the camshaft comprises a carrier shaft and a cam part that is supported locked in rotation and axially displaceable on the carrier shaft and has at least one first cam group of at least two directly adjacent cams with different strokes and an axial connecting link in which an actuation element for shifting the cam part on the carrier shaft can be coupled, as well as a bearing journal that runs between the first cam group and the axial connecting link and on which a roller bearing supporting the cam part is held so that it can rotate in a camshaft bearing point of the internal combustion engine.
  • a gas exchange valve train which is also often called a sliding cam valve train with such a camshaft is known from DE 10 2009 030 373 A1.
  • the cam parts supported with a central bearing journal between two intake or exhaust valves of an engine cylinder comprise two identical cam groups each with three cams and an end-side axial connecting link in which two actuation pins for shifting the cam part into the three axial positions can be coupled selectively.
  • the publication alternatively proposes a roller bearing for the cam part in addition to the hydrodynamic sliding bearing.
  • the known valve train has a very compact axial construction. This is achieved in that the cams adjacent to the bearing journals can dip into the camshaft bearing point when they are not instantaneously active.
  • a geometric requirement here is a corresponding dimensioning of the rotational bearing, whose diameter must be greater than the surrounding circle of the cams entering within this circle. In the case of a roller bearing of the cam part, this dimensioning would, however, lead to a camshaft bearing point with an undesirably large radial construction.
  • the present invention is based on the objective of improving a camshaft of the type noted above such that, despite the roller bearing of the cam part, it allows the most compact radial construction possible.
  • the inner raceway of the roller bearing is formed by the bearing journal
  • the outer raceway of the roller bearing is formed by a one-part bearing ring
  • the cam part and the bearing ring have the following geometric properties:
  • r GK Base circle radius of the cams of the first cam group
  • r AK Circumferential radius of the axial connecting link
  • FIG. 1 a known variable stroke gas exchange valve train
  • FIG. 2 a first embodiment of a cam part according to the invention in perspective view
  • FIGS. 2 a - e the first cam part in different mounting positions of the bearing ring
  • FIG. 3 the geometry of a cam part according to the invention in schematic view A according to FIG. 2 ,
  • FIGS. 4 a - f the second cam part from FIG. 4 in different mounting positions of the bearing ring
  • FIG. 5 a third embodiment of a cam part according to the invention in longitudinal section
  • FIG. 6 a fourth embodiment of a cam part according to the invention in longitudinal section
  • the displacement of the cam part 102 required for operating point-dependent activation of each cam 103 , 104 , or 105 on the carrier shaft 1 is realized by a groove-shaped axial connecting link 108 in which, depending on the instantaneous axial position of the cam part, one of two pin-shaped actuation elements 9 , 10 of an electromagnetic actuator (not shown) is coupled, in order to displace the cam part within the common reference circle phase of the cam.
  • a locking device is used that runs (not visible here) in the interior of the carrier shaft 1 and locks in the interior of the cam part.
  • the cutaway and greatly simplified roller bearing 213 is a needle bearing with cage-supported needles 214 , whose inner raceway 215 is formed by the bearing journal 211 and whose outer raceway 216 is formed by a one-part bearing ring 217 drawn onto the cam part 202 .
  • the plastic needle cage 218 is shown as needle ring 19 below in connection with the needles held therein, i.e., as 219 in FIG. 2 .
  • the width of the bearing ring 217 is approximately twice as large as the length of the needles 214 that roll, depending on the axial position of the cam part, either in one axial raceway half or in the other axial raceway half of the bearing ring mounted in the internal combustion engine.
  • FIG. 2 a The needle ring 219 open on the periphery is expanded elastically in the radial direction and is snapped onto the bearing journal 211 from the lateral direction.
  • the width of the needle cage 218 and the width of the bearing journal are essentially the same size, so that the needle cage is supported directly in the axial direction from the facing end sides 221 and 222 of the inner cam 204 of the second cam group and cam 203 , respectively, adjacent to the bearing journal.
  • FIG. 2 b The bearing ring 217 is threaded eccentric to the camshaft axis 20 onto the outer cam 204 .
  • the smaller stroke h 1 extends with respect to its angular position completely within the larger stroke h 2
  • the drawn radius r AK designates the outer circumferential radius of the axial connecting link 208 and is also greater than the outer raceway radius r L :
  • FIG. 2 c The bearing ring 217 is pushed into the eccentric position over the outer cams 203 , 204 until the outer cam 204 is free.
  • FIG. 2 d The bearing ring 217 is centered on the camshaft axis 20 .
  • FIG. 2 e The bearing ring 217 is pushed over the needles 214 .
  • FIG. 4 shows a second embodiment of a cam part 402 according to the invention. This differs from the previously explained cam part 202 essentially by the axial support of the needle cage 418 . Pulling the bearing ring 417 onto the cam part will be explained with reference to FIGS. 4 a to 4 f.
  • FIG. 4 a The bearing ring 417 is threaded eccentric to the camshaft axis 20 onto the outer cam 404 and pushed over the outer cams 403 and 404 until the outer cam 404 is free.
  • the needle ring 419 is pushed toward the inner cam group to create an axial opening for the bearing ring 417 .
  • FIG. 4 b The needle ring 419 and the bearing ring 417 centered relative to the camshaft axis 20 are pushed one onto the other.
  • FIG. 4 c A plastic spacer ring 423 that is open on the periphery is expanded elastically in the radial direction and snapped onto the bearing journal 411 from the lateral direction.
  • FIG. 4 d The spacer ring 423 is inserted into a ring groove 424 between the inner raceway 415 and the inner cam 404 of the second cam group.
  • FIG. 4 e The bearing ring 417 is displaced toward the inner cam 404 until another ring groove 425 is freely accessible between the inner raceway 415 and the outer cam 403 .
  • FIG. 4 f As in FIG. 4 c , another spacer ring 423 is inserted into the other ring groove 425 so that the facing cam end sides 421 and 422 support the needle cage 418 in the axial direction by means of the spacer rings 423 .
  • FIG. 5 shows a third embodiment of a cam part 502 according to the invention.
  • the bearing journal 511 is formed with large steps in the radial direction with a raised inner raceway 515 , wherein both end sides 526 and 527 of the radial step support the needle cage 518 surrounding these sides in the axial direction.
  • FIG. 6 shows a fourth embodiment of a cam part 602 according to the invention.
  • the axial support of the needle cage 618 is formed from a combination of the support in the second embodiment and the third embodiment:
  • the axial support is realized on one side on the cam end side 621 by means of the spacer ring 623 and on the other side directly on the end side 626 of the radial step.
  • FIG. 7 shows a fifth embodiment of a cam part 702 according to the invention.
  • This fifth embodiment is a variant of the fourth embodiment in the way that the spacer ring 723 is formed in one piece on the needle cage 718 .

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)
  • Rolling Contact Bearings (AREA)
  • Valve Device For Special Equipments (AREA)
US14/440,996 2012-11-07 2013-10-25 Camshaft for a variable-stroke exchange valve train Abandoned US20150300216A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE102012220210.2 2012-11-07
DE201210220210 DE102012220210A1 (de) 2012-11-07 2012-11-07 Nockenwelle eines hubvariablen Gaswechselventiltriebs
PCT/DE2013/200245 WO2014071940A1 (de) 2012-11-07 2013-10-25 Nockenwelle eines hubvariablen gaswechselventiltriebs

Publications (1)

Publication Number Publication Date
US20150300216A1 true US20150300216A1 (en) 2015-10-22

Family

ID=49765242

Family Applications (1)

Application Number Title Priority Date Filing Date
US14/440,996 Abandoned US20150300216A1 (en) 2012-11-07 2013-10-25 Camshaft for a variable-stroke exchange valve train

Country Status (4)

Country Link
US (1) US20150300216A1 (de)
CN (1) CN104812998B (de)
DE (1) DE102012220210A1 (de)
WO (1) WO2014071940A1 (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20170254237A1 (en) * 2016-03-01 2017-09-07 Cummins Inc. Systems and methods for reducing the oil volume and windage in fuel pumps

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102015006375B3 (de) * 2015-05-20 2016-09-15 Audi Ag Brennkraftmaschine
DE102015217886A1 (de) * 2015-09-17 2017-03-23 Thyssenkrupp Ag Verschiebeelement zum Verschieben eines Nockensegmentes
DE102017003790A1 (de) * 2017-04-20 2018-10-25 Daimler Ag Ventiltriebvorrichtung

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100129023A1 (en) * 2007-10-03 2010-05-27 The Timken Company Positioning means for camshaft roller bearing
US20100175652A1 (en) * 2007-03-02 2010-07-15 Dirk Schoeneberg Valve Drive for Gas Exchange Valve of an Internal Combustion Engine, Comprising an Axially Movable Bearing
US20120006292A1 (en) * 2009-06-25 2012-01-12 Schaeffler Technologies Gmbh & Co. Kg Valve drive of an internal combustion engine
US8887682B2 (en) * 2012-12-11 2014-11-18 Mahle International Gmbh Low friction camshaft

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Publication number Priority date Publication date Assignee Title
DE3126280C1 (de) * 1981-07-03 1983-01-13 Ford-Werke AG, 5000 Köln Nockenwellenlagerung
DE102004032587A1 (de) * 2004-07-06 2006-02-09 Daimlerchrysler Ag Verfahren und Montagesystem zur Herstellung einer gebauten Nockenwelle
JP2006097485A (ja) * 2004-09-28 2006-04-13 Musashi Seimitsu Ind Co Ltd カムシャフト及びその組み立て方法
DE102006004726A1 (de) * 2006-02-02 2007-08-23 Bayerische Motoren Werke Ag Verfahren zur Herstellung einer gebauten Nockenwelle
FR2901571B1 (fr) * 2006-05-29 2013-07-26 Peugeot Citroen Automobiles Sa Systeme de montage d'un arbre a cames muni de roulements
DE102007024092A1 (de) * 2007-05-22 2008-11-27 Mahle International Gmbh Nockenwelle
CN101377140A (zh) * 2007-08-29 2009-03-04 徐敬东 排气量可调内燃机
DE102007051739A1 (de) * 2007-10-30 2009-05-07 Schaeffler Kg Ventiltrieb einer Brennkraftmaschine

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100175652A1 (en) * 2007-03-02 2010-07-15 Dirk Schoeneberg Valve Drive for Gas Exchange Valve of an Internal Combustion Engine, Comprising an Axially Movable Bearing
US20100129023A1 (en) * 2007-10-03 2010-05-27 The Timken Company Positioning means for camshaft roller bearing
US8568038B2 (en) * 2007-10-03 2013-10-29 Koyo Bearings Usa Llc Positioning means for camshaft roller bearing
US9062709B2 (en) * 2007-10-03 2015-06-23 Koyo Bearings North America Llc Positioning means for camshaft roller bearing
US20120006292A1 (en) * 2009-06-25 2012-01-12 Schaeffler Technologies Gmbh & Co. Kg Valve drive of an internal combustion engine
US8887682B2 (en) * 2012-12-11 2014-11-18 Mahle International Gmbh Low friction camshaft

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20170254237A1 (en) * 2016-03-01 2017-09-07 Cummins Inc. Systems and methods for reducing the oil volume and windage in fuel pumps
US10677119B2 (en) * 2016-03-01 2020-06-09 Cummins Inc. Systems and methods for reducing the oil volume and windage in fuel pumps

Also Published As

Publication number Publication date
CN104812998A (zh) 2015-07-29
CN104812998B (zh) 2017-09-12
DE102012220210A1 (de) 2014-05-08
WO2014071940A1 (de) 2014-05-15

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Legal Events

Date Code Title Description
AS Assignment

Owner name: SCHAEFFLER TECHNOLOGIES AG & CO. KG, GERMANY

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:WEDEL, ANDREAS;REEL/FRAME:035576/0541

Effective date: 20150215

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION