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
  • F16H—GEARING
  • F16H3/00—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion
  • F16H3/44—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion using gears having orbital motion
  • F16H3/46—Gearings having only two central gears, connected by orbital gears
  • F16H3/48—Gearings having only two central gears, connected by orbital gears with single orbital gears or pairs of rigidly-connected orbital gears
  • F16H3/52—Gearings having only two central gears, connected by orbital gears with single orbital gears or pairs of rigidly-connected orbital gears comprising orbital spur gears
  • F16H3/54—Gearings having only two central gears, connected by orbital gears with single orbital gears or pairs of rigidly-connected orbital gears comprising orbital spur gears one of the central gears being internally toothed and the other externally toothed
• • 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
  • F16D23/00—Details of mechanically-actuated clutches not specific for one distinct type
  • F16D23/02—Arrangements for synchronisation, also for power-operated clutches
  • F16D23/04—Arrangements for synchronisation, also for power-operated clutches with an additional friction clutch
  • F16D23/06—Arrangements for synchronisation, also for power-operated clutches with an additional friction clutch and a blocking mechanism preventing the engagement of the main clutch prior to synchronisation
• • 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
  • F16H—GEARING
  • F16H3/00—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion
  • F16H3/44—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion using gears having orbital motion
  • F16H3/78—Special adaptation of synchronisation mechanisms to these gearings
• • 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
  • F16H—GEARING
  • F16H37/00—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00
  • F16H37/02—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00 comprising essentially only toothed or friction gearings
  • F16H37/04—Combinations of toothed gearings only
  • F16H37/042—Combinations of toothed gearings only change gear transmissions in group arrangement
  • F16H37/046—Combinations of toothed gearings only change gear transmissions in group arrangement with an additional planetary gear train, e.g. creep gear, overdrive

Definitions

• This invention relates to planetary gearing according to the preamble to attached claim 1.
• a planetary gear is used in particular but not exclusively for auxiliary gear boxes intended in use to be inserted between a main gear box and a transmission to the driving wheels of a motor vehicle, especially heavy duty trucks.
• Auxiliary gear boxes are typically used for doubling the number of gear change possibilities and usually comprise planetary gearing by means of which the gear change possibilities of the vehicle can be diverted into a low gear range and a high gear range.
• planetary gearing by means of which the gear change possibilities of the vehicle can be diverted into a low gear range and a high gear range.
• In the high gear range there is no gear reduction to the planetary gearing system, and in the low gear range use is made of the gear changing in the planetary gearing system.
• planetary gearing is disclosed in European Patent EP-B-239,555 which describes planetary gearing in which the input shaft is rotatably fast with the sun gear of the planetary gearing, and the output shaft is rotatably fast with a planet wheel carrier.
• the ring gear of the planetary gearing is connectable to either a fixed wall or the like of the gear box housing or directly to the input shaft for obtaining low range or high range of the gear box.
• the present invention seeks to provide planetary gearing similar to that described in SU-A- 914843 which is more axially compact.
• the second clutch ring is rotationally fast with the output shaft, preferably through intermeshing teeth at the inner radial portion of said second clutch ring.
• the sun gear on the output shaft intermeshes with a plurality of circumferential- ly spaced planet gears.
• the planetary gearing houses a pair of synchronising rings located one on each axial side of the ring gear between the ring gear and a respective clutch ring characterised in that each synchronising ring has external teeth for meshing with the internal teeth on the clutch sleeves.
• the gearing further includes a shift shaft having one end connected to a first of said clutch sleeves slidably mounted on the external teeth the first clutch ring so that the shaft is supported for axial movement on the gearbox housing via the first clutch ring.
• Fig. 1 is a longitudinal section through planetary gearing according to the invention showing only a portion above the longitudinal axis of rotation and with the gearing in a high range condition, and
• Fig. 2 is a similar drawing to that of Fig. 1 showing the gearing in a low range condition.
• the auxiliary gearbox comprises a housing 11 having an input shaft 12 passing therein from the main gearbox not shown.
• the input shaft 12 is rotatably mounted in the main gear box and housing 11 by bearings 14 mounted in an inner end wall 15 of the housing 11.
• a sun gear 16 is mounted rotatably fast with the input shaft 12 by means of splines.
• the sun gear 16 is formed with external teeth which mesh with at least one, and preferably a plurality of, for example five, circumferentially spaced planet gears 17.
• Each planet gear 17 is rotatably mounted on a tubular stub shaft 18 one end of which is secured to a planet gear carrier 19 and to the other of which is secured a planet gear keeper 21.
• the planet gear keeper 21 retains the respective planet gear on its respective stub shaft 18.
• the planet gear carrier 19 is integral with an output shaft 13 which is rotatably mounted in an outer end wall 5 not shown on the gear box housing 11 coaxially with the input shaft, as is well known in the art, typically by means of bearings as shown for the input shaft.
• a first clutch ring 22 formed with external axially extending teeth 23 is mounted coaxially of the shaft 12 rotationally fast on the gearbox housing inner end wall 15 by means of pins 24, 10 to one side of the planet gears.
• a second clutch ring 25 formed with external axially extending teeth 26 is coaxially mounted rotationally fast on the planet gear carrier 19 by means of teeth or splines 27 on its radially inner peripheral margin engaging with like teeth or splines 28 on the planet gear 15 carrier 19.
• the second clutch ring 28 is located on the other side of the planet gears 17 from the first clutch ring 22.
• a coaxial ring gear 29 is located axially between the two clutch rings 22, 25 and concentri ⁇ cally with sun gear 16 and enclosing the planet gears 17.
• the ring gear 29 has internal teeth 20 31 for meshing with the planet gears 17, and external teeth 32 which are in radial alignment with and have the same form as the external teeth 23 , 26 on the two clutch rings 22 , 25.
• the coaxial ring gear 29 is held in axial alignment with the planet gear 17 by a pair of internal circlips 33.
• the external teeth 32 are located axially centrally of the ring gear 29 which is then formed on each axial side thereof with lesser diameter frustoconical shoulders
• the two frustoconical shoulders 34, 35 form outwardly directed friction surfaces which are intended for connection with corresponding inwardly directed friction surfaces on a pair of synchronising rings 36, 37.
• the two coaxial synchronising rings 36, 37 are arranged with a first synchronising ring 36
• Each synchronising ring 36, 37 is formed with external teeth 38 with are radially aligned with the teeth 23, 26 on the two clutch rings 22, 25 and has a radially inwardly directed frustoconical surface 39, 41 for engagement with the like surfaces 34, 35 on the ring gear 29.
• the first synchronising ring 36 has axially extending bars 42, sometimes called cogs, that engage with circumferential play in apertures 43 in the first clutch ring 22.
• the synchronising ring 36 is spring biased, out of the paper, by spring means acting between the bars 42 of the synchroni ⁇ sation ring 36 and the sides of the apertures 43.
• the second synchronising ring 37 has axially extending bars 44 which engage with circumferential play in apertures 45 in the second clutch ring 25.
• the second synchronising ring 37 is spring biased oppositely to the first synchronising ring 36 also by spring means acting between the bars 44 and the sides of the apertures 45.
• Each clutch sleeve 46, 47 has internal teeth 48, 49 for meshing with the external teeth 23, 38, 32 , 26 on the clutch rings 22, 25 ring gear 29 and synchroni ⁇ sing rings 36, 37.
• the axially inner sleeve 46 has a flange 51 which is secured, preferably bolted, to a gear shift control shaft 52.
• the axially outer sleeve 47 is also axially fixed to the shaft 52 and is axially spaced from the first sleeve 46.
• the second sleeve 47 is rotatably located in a slot 53 in the shaft 52 so that the sleeve 47 can rotate around its axis relative to the shaft 52.
• the first sleeve 46 acts as a bearing support for the shaft 52 since it rests on the clutch ring 22 which is fixed to the housing 11.
• the second sleeve 47 will first engage the second synchronising ring 37 which will be pushed against the ring gear 29 so that frustoconical inner surface 41 engages the like shoulder 35 on the ring gear 29 developing a torque load on the second synchronising ring 37 causing it to move against the bias of the spring means in the opposite rotationl direction to the first synchronising ring 46 .
• This movement may block engagement of the teeth 49 on the sleeve 47 with the external teeth 32 on the ring gear 29 until such time as the torque load is reduced and the spring bias causes the teeth 38 on the second synchronising ring 37 to re ⁇ align with the teeth 49 on the sleeve 47.
• the shaft 52 then pushes the sleeve 47 over the ring gear reengaging the high gear range.
• the second clutch sleeve 47 is free to rotate relative to the shaft 52 during the above operations.
• the second clutch ring 25 could be fixed to the sun gear or input shaft.
• the above described gearbox has the advantage that it is axially short, with short overhang for the sun gear, and has small rotating and displaceable masses. Furthermore the number of teeth 23,48 on the clutch rings 22, 25 can differ from the number of teeth 31 on the ring gear 29. This gives a greater number of different combinations for connections thereby reducing problems with sun gears having facetted teeth caused by having only a few combinations.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Retarders (AREA)
• Structure Of Transmissions (AREA)
• Mechanical Operated Clutches (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

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ID=20396485

Family Applications (1)

Country Status (3)

Cited By (3)

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Citations (2)

Family Cites Families (3)

• 1994
  • 1994-12-28 SE SE9404528A patent/SE504070C2/sv not_active IP Right Cessation
• 1995
  • 1995-12-20 WO PCT/SE1995/001547 patent/WO1996020358A1/en active Application Filing
  • 1995-12-20 DE DE19581879T patent/DE19581879B4/de not_active Expired - Fee Related

Patent Citations (2)

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