Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D25/00—Fluid-actuated clutches
  • F16D25/12—Details not specific to one of the before-mentioned types
  • F16D25/123—Details not specific to one of the before-mentioned types in view of cooling and lubrication
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D13/00—Friction clutches
  • F16D13/58—Details
  • F16D13/74—Features relating to lubrication
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D21/00—Systems comprising a plurality of actuated clutches
  • F16D21/02—Systems comprising a plurality of actuated clutches for interconnecting three or more shafts or other transmission members in different ways
  • F16D21/06—Systems comprising a plurality of actuated clutches for interconnecting three or more shafts or other transmission members in different ways at least two driving shafts or two driven shafts being concentric
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D2300/00—Special features for couplings or clutches
  • F16D2300/06—Lubrication details not provided for in group F16D13/74
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D2300/00—Special features for couplings or clutches
  • F16D2300/10—Surface characteristics; Details related to material surfaces
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/60—Other road transportation technologies with climate change mitigation effect

Definitions

• the present invention relates to a dual clutch transmission comprising two wet clutches.
• a dual clutch transmission is a new type of transmission with two generally coaxially arranged transmission input shafts, each of which is assigned a separate friction clutch and a group of gear stages.
• a major advantage of the dual clutch transmission compared to a conventional multi-speed transmission is the largely interruption-free gear changes, through which better acceleration capacity in traction mode and better deceleration capacity in overrun mode are achieved.
• One advantage over a manual transmission is the lower consumption. Due to the lack of traction interruption, it is superior to the automated manual transmission, but offers the user similar options to an automated transmission.
• DE 101 34 118 A1 describes a dual clutch transmission with a dry clutch. Dual clutch transmissions with wet clutches are also known which use two multi-plate clutches running in oil.
• the problem with the previously known double clutch transmissions with wet-running clutches is the fact that there are increased demands on the lubricants used, which are not met by the oils commonly used for manual transmissions.
• the lubricant requirements are also significantly higher than those for the usual multi-step automatic transmissions.
• the double clutch transmission in particular requires a very soft positive coefficient of friction at sliding speeds of between 0 and approx. 0.5 m / s, for example, which ensures adequate anti-shudder behavior.
• the positive coefficient of friction should remain over the life of the gear unit. It should be taken into account here that considerable temperature differences can occur in the transmission, which in the area of the clutch can be, for example, between approximately -40 ° C. and up to 180 ° C. In so-called hot spots in the plate packs, temperatures of, for example, over 200 ° C. can also occur.
• the previous double clutch transmissions were used, for example Paper lamellae, however, with which one can only achieve a comparatively low load capacity with a Hertzian pressure in the range of, for example, approximately 1 to 1.5 N / mm 2.
• a double clutch gearbox due to the increased demands on the lubricant
• the use of special gear oils is required Due to the combination of a manual transmission with an automatic transmission, the seizure resistance, pitting behavior and synchronous behavior of the manual transmission are required on the one hand and on the other hand there are special requirements for the multi-plate clutch, i he must also be regulated in the micro slip area.
• the object of the present invention is to provide a double clutch transmission of the type mentioned at the outset, in which the couplings and, if appropriate, further transmission components meet the aforementioned complex requirements.
• At least one of the clutches and / or the transmission comprises at least one component which is subject to wear and which at least partially consists of a carbon-containing material at least in the surface area.
• a preferred development of the invention provides that at least the surface of the clutch plates consists at least partially of a material which comprises carbon fibers.
• the carbon fiber-containing materials mentioned have the advantage of high thermal stability.
• the specific resilience of carbon fiber-containing materials in the area of clutch plates is higher than with previous paper coverings. This opens up the possibility of reducing the number of friction linings used in a clutch, if necessary. This in turn makes it possible to reduce the size of the double clutch transmission.
• the carbon fiber-containing linings mentioned a soft, positive coefficient of friction profile can be achieved, in particular at low sliding speeds, which ensures adequate anti-shudder behavior.
• not only the surface of the clutch plates, but also, for example, synchronizer rings and / or shift plates of the shift forks can be made at least partially from a carbon fiber-containing material.
• a carbon fiber-containing material In the area of the clutch linings, such materials can allow a load with a Hertzian pressure of more than 2 N / mm 2, preferably more than 5 N / mm 2 , more preferably at least about 10 N / mm 2 up to about 15 N / mm 2 .
• the number of disks used per clutch can be reduced, for example to less than ten disks per clutch.
• the carbon-containing material used according to the invention preferably comprises at least partially a material woven from fibers.
• carbon fiber-containing materials can be considered which comprise at least one granulate which can be bound with a binder.
• a dual clutch transmission (direct shift transmission) according to the invention preferably requires lubricants which are similar in their characteristics to ATF oils.
• the ATF oils (automatic transmission fluid) used according to the invention are preferably fully synthetic oils which are used to design the coefficient of friction of the clutch, in particular for In order to achieve a positive course of the coefficient of friction, corresponding additives, in particular “friction modifiers”, are included.
• the conventional manual transmission oils were generally not suitable for the double clutch transmissions known to date.
• hypoid gearboxes i.e. bevel gearboxes with offset axles, which are used, for example, in the rear axle clutch of vehicles.
• hypoid gearboxes i.e. bevel gearboxes with offset axles
• These are particularly high-alloyed hypoid oils, which are required because stronger rolling movements occur between the contacting tooth flanks during rolling.
• it is difficult to achieve a positive coefficient of friction curve with such hypoid oils, as is required in a double clutch transmission of the type according to the invention. Therefore, the known hypoid oils are also out of the question as lubricants for a double clutch transmission.
• manual transmission oils with improved friction coefficient behavior can be considered, particularly in the area of the clutch plates, due to the carbon-containing materials used.
• a manual transmission oil or a similar lubricant should be used, the properties of which correspond at least to performance class GL4 of the API (American Petroleum Institute).
• the gear oil should preferably correspond at least to performance class GL5 of the API.
• the gear oil also preferably contains additives which improve the seizure resistance and / or the pitting behavior, which has the advantage that one can do without specific surface coatings or special materials in the components used in the gear or in the clutch.
• the gear oil should furthermore preferably have an appropriate thermal stability and can in particular be provided with appropriate additives for this purpose.
• the gear oil further contains at least one additive for improving the viscosity behavior and / or temperature behavior and / or wear protection behavior and / or oxidation protection behavior and / or foam behavior and / or corrosion protection behavior and / or friction coefficient behavior.
• the present invention furthermore relates to a wet-running clutch or a transmission component for a dual clutch transmission with the features of one of claims 17 or 18.
• the invention further relates to a motor vehicle which, according to claim 19, comprises a double clutch transmission of the aforementioned type.
• FIG. 1 The illustration shows an example of a diagram of a coefficient of friction curve as is aimed at in a dual clutch transmission according to the invention.
• the coefficient of friction ⁇ is plotted against the sliding speed [mm / s].
• the diagram shows exemplary sliding speeds in the range up to 100 mm / s, that is to say approximately 0.1 m / s.
• the coefficient of friction increases gradually and only slightly in the speed range shown.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Mechanical Operated Clutches (AREA)
• Lubricants (AREA)
• Braking Arrangements (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Related Child Applications (1)

Publications (1)

Family

ID=33441473

Family Applications (2)

Family Applications Before (1)

Country Status (7)

Cited By (1)

Families Citing this family (4)

Family Cites Families (21)

• 2004
  • 2004-05-05 CN CNA2004800070831A patent/CN1761821A/zh active Pending
  • 2004-05-05 DE DE502004011621T patent/DE502004011621D1/de not_active Expired - Lifetime
  • 2004-05-05 JP JP2006529738A patent/JP2007500326A/ja active Pending
  • 2004-05-05 AT AT08018355T patent/ATE479849T1/de active
  • 2004-05-05 EP EP08018355A patent/EP2019225B1/fr not_active Expired - Lifetime
  • 2004-05-05 EP EP04731159A patent/EP1633990A2/fr not_active Withdrawn
  • 2004-05-05 WO PCT/EP2004/004747 patent/WO2004106763A2/fr active Application Filing
  • 2004-05-07 DE DE102004022652A patent/DE102004022652A1/de not_active Withdrawn
• 2005
  • 2005-11-30 US US11/290,260 patent/US20060169571A1/en not_active Abandoned

Non-Patent Citations (1)

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