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
  • F16H48/00—Differential gearings
  • F16H48/20—Arrangements for suppressing or influencing the differential action, e.g. locking devices
  • F16H48/22—Arrangements for suppressing or influencing the differential action, e.g. locking devices using friction clutches or brakes
• • 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
  • F16H48/00—Differential gearings
  • F16H48/06—Differential gearings with gears having orbital motion
  • F16H48/08—Differential gearings with gears having orbital motion comprising bevel gears
• • 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
  • F16H48/00—Differential gearings
  • F16H48/12—Differential gearings without gears having orbital motion
  • F16H48/18—Differential gearings without gears having orbital motion with fluid gearing
• • 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
  • F16H48/00—Differential gearings
  • F16H48/12—Differential gearings without gears having orbital motion
  • F16H48/19—Differential gearings without gears having orbital motion consisting of two linked clutches
• • 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
  • F16H48/00—Differential gearings
  • F16H48/20—Arrangements for suppressing or influencing the differential action, e.g. locking devices
  • F16H48/27—Arrangements for suppressing or influencing the differential action, e.g. locking devices using internally-actuatable fluid pressure, e.g. internal pump types
• • 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
  • F16H2200/00—Transmissions for multiple ratios
  • F16H2200/20—Transmissions using gears with orbital motion
  • F16H2200/203—Transmissions using gears with orbital motion characterised by the engaging friction means not of the freewheel type, e.g. friction clutches or brakes
  • F16H2200/2071—Transmissions using gears with orbital motion characterised by the engaging friction means not of the freewheel type, e.g. friction clutches or brakes using three freewheel mechanism
• • 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
  • F16H48/00—Differential gearings
  • F16H48/20—Arrangements for suppressing or influencing the differential action, e.g. locking devices
  • F16H48/30—Arrangements for suppressing or influencing the differential action, e.g. locking devices using externally-actuatable means
  • F16H48/32—Arrangements for suppressing or influencing the differential action, e.g. locking devices using externally-actuatable means using fluid pressure actuators

Definitions

• the present invention relates to a device to oppose relative rota-tional movement between two rotatable shafts, comprising at least one first braking means rotating together with one of the mentioned shafts, and at least one second braking means rotating together with, which is so adapted that the resistance of the pistons against back pressing at a least relative rotational speed between said shafts causes said axial displacement of the rotatable element and consequently a braking contact between the braking means, the other of said shafts, said two braking means being designed to be adjusted between a releasing position and a contact position so, that upon a relative rotational movement between the two shafts the braking means can be brought into a braking contact with each other in order to oppose said relative rotational movement.
• the purpose of this invention is to present a simple but at the same time effective arrangement to oppose differences in speed between two rotating shafts and offer a solution to the driving and traction problems in the modern vehicle.
• one of the shafts has an element which is rotatable together with said shaft and contains a inclined surface slightly deviating from a perpendicular position relative to the longitudinal axis of said shaft, that said element being connected with the braking means which belongs to the mentioned shaft, which braking means follows the motions of said rotating element, that said element being movable slightly axially relative to the braking means which belongs to the other shaft, that connected to and rotating with, at least one of the shafts there is a device comprising movable pistons relative to the above mentioned inclined surface and each piston placed in a chamber with pressure fluid, that the pistons are enable to cooperate with the mentioned inclined surface in such a way that upon a torsional movement of the inclined surface relative to the pistons the inclined surface is forcing at least one of the pistons into its pressure chamber against the pressurised fluid being pressurised to resist the piston movement caused by the slightest difference in relative speed variation between the two mentioned shafts, will cause
• fig 1 is showing a partly broken sectional view of a differential arrangement incorporating the invention
• fig 2 is showing a section II-II according to fig 1
• fig 3 is showing a section through the device in a second embodiment
• fig 4 is showing a section through the device in a third embodiment.
• the arrangement in fig 1 is showing a conventional differential incorporating the device of this invention, the so called limited slip differential.
• the arrangement is showing the drive shafts
• braking elements solidly fixed to one side of the differential casing 4 and for each one of the braking elements there is a matching braking element fixed to the rotatable differential crown wheel 9, which is rotating with the outgoing drive shaft 1.
• Both differential crown wheels 9, 10 are also slightly movable sideways relative to the differential casing 4.
• the drive shaft 1, 2 are floating in splines inside the differential crown wheels 9, 10.
• the differential crown wheel 10 is showing an angled surface 16 opposite its conical teeth 44. This surface 16 is slightly of 90 degree angle from the drive shaft 2. Further more there is a round even disc 17 that can move freely against the surface 16 inside the differential casing 4.
• FIG. 1 Showing inside this casing (see also fig 2) are several evenly pitched piston chambers 18, 19, 20, 21, 22, 23 containing movable pistons 24, 25.
• the inside of the piston chambers is designed to contain pressurised fluid to force the pistons 24, 25 against the disc 17.
• To each of the pressure chambers 18-23 is an inlet 26, 27, 28, 29, 30, 31. Due to fig 1 inlets are communicating through the openings 45, 46 in to a grove 32 in the tubular part of the differential crown wheel 10. This inlet leads on to the pressure chambers 26-31 showing on fig 2.
• Connected to each of the chambers is on outlet opening 34, 35 containing a valve to prevent pressurised fluid to re-enter the pressure chambers 26- 31.
• pressure valves 41 are fitted in the inlet openings, allowing fluid to enter the pressure chambers but preventing the fluid to escape.
• a circular bore 42 connecting all outlets 47.
• the adjustable valve 43 Through the adjustable valve 43, the circular bore 42, is leading to a not pressurised oil pan or sump.
• the adjustable valve is a piston 48 movable in its bore 49 by the spring 50 that is forcing the valve outwards from centre. Due to influence from pressurised fluid, the valve could be moved inwards to change its operation.
• the cylindrical part on the valve 48 has a close fit in the bore 49 but there is also a conical part 51.
• Variations in the pressure of the inlet side 18-23 does not effect the valve operation.
• the inlet openings 26-31 are connected to a pressure source through the openings 45-46 to achieve constant pressure in the chambers. Due to the fact, that the sleeve 3 is rotating together with the differential casing when in motion, the pressure fluid is transferred in a known fashion, through a circular none rotating casing that is forming a seal over the sleeve 3 and surrounding the openings 45, 46. The pressure could be rather low and still create enough force to move the pistons 24, 25 against the angled surface 16.
• both shafts 1, 2 are rotating with same revolution speed as the differential crown wheel 10, whereby no relative rotational movement is taking place between the differential crown wheel 10 and the pistons 24, 25.
• the braking elements 14, 15 are running free of each other, and are not showing any difference in relative rotational speed.
• the differential casing will rotate together with the set of pistons 24, 25 around the shaft 2 relative to the angled surface 16, and if sufficient decrease will appear in the pressure fluid, depending on the sitting of the regulating valve, the pushing in of the pistons 24, 25 in to the pressure chambers will be opposed through the volume decrease created fluid media pressure.
• the device due to the invention is applied on two relative to each other rotatable shafts 52, 53 without any differential gears.
• the device would brake the increase in rotation speed, and transfer the power to the none slipping axle.
• the device could be of the same design as in the previous example. Therefore the cut in fig 2 could represent the same cut in fig 3.
• the pistons 24, 25 and the pressure chambers 18-23 are located in a casing solidly fixed to the drive shaft 52, for instance coupled to the front axle of the vehicle.
• the other drive shaft 53 is rotatable through the tubular sleeve 55 which also can be moved sideways inside the casing 54.
• space is left 57 to allow the sleeve to move sideways, but still give enough support 56 to the drive shaft 53.
• the casing 54 is showing a set of braking elements 14, solidly fixed, to rotate with the casing 54 and the shaft 52.
• the tubular sleeve 55 is also showing a set of braking elements 15, solidly fixed, to rotate with shaft 53. The amount of braking elements could vary due to the forces being transmitted.
• the sleeve 55 contains the angled surface 16 and washer 17.
• both drive shaft 52, 53 are rotating with same revolutionary speed, whereby the sleeve 55 is in the right outside position and both seats of braking elements 14, 15 are running free of each other.
• the angled surface 16 is turned relatively to the set of pistons 24, 25 and thereby trying to push the pistons in to pressure chambers 18, 19.
• the system pressure will prevent the pistons 24, 25 to be pushed in, and the mentioned torsional movement will instead force the sleeve 55 sideways with its braking elements 15 to engage against the other braking elements 14 belonging to the casing 54, whereby the fastest rotating shaft will be slowed down and receive the same rotational speed as the other shaft.
• Fig 4 is showing the third embodiment according to the invention, applied in a gear box differential.
• the main features are similar to the first example, where a conventional differential is used in conjunction with the device due to the invention.
• Similar to the first example there is a set of movable pistons 24, 25 inside pressure chambers, running in line with the shafts 1, 2.
• the same fluid system could be used as in the first example, with its entrance 60 from the pressure source, and via the valve 61 communicating with the pressure chambers 18, 19 and additional valves only allowing inflow from the pressure source.
• each pressure chamber has got an outlet to the circular bore 42, and each of the outlets fitted with the valve only allowing outlet from the pressure chambers but preventing inflow.
• the rotatable unit 64 with the angled surface 65 is formed as a separate part, not attached to any of the differential crown wheels and separately sideways movable relative to the shaft 1 on splines and rotating together.
• the rotating unit 64 is also containing the braking elements 15, where as the other set of braking elements 14 is fixed to the differential casing 4.
• the whole device due to the invention is fitted to one side of the differential casing, which means that the unit containing the pistons and the pistons chambers and the rotating unit with its angled surface and braking elements are fitted to the same side of the differential, whereby no sideways movement of the central unit is required, and that this sideways movement is only done by the rotatable unit containing its braking elements.
• the principle function of the device due to the invention is similar in both cases, that is to say that a certain variation in rotational movement between the rotatable unit and the differential casing is allowed up to a certain speed, before the pistons are being forced back into the pressure chambers. At the time when this speed is reached, a sideways movement is taking place of the rotatable unit 64, leading to the engagement of the braking elements, which leads to a reduction of the difference in rotational speed between the two shafts 1, 2.
• the invention described and shown on the drawings, is not only limited to those applications.
• the angled surface could be part of a sleeve surrounding the differential casing and connecting one side of the braking elements and the whole assembly rotatable and movable sideways .
• the device due to the invention could also be used in other applications where variations in rotational speed is going to be opposed.
• a separate fluid could be used together with a separate pressure source, but by using the same fluid for the whole system, a good solution is presented to the transfer of fluid to the moving unit and the dumping of excess fluid.
• the braking elements could be either discs or shoes and the total amount could vary depending on the forces to be transferred.
• the regulating valve could be preset and fixed at a suitable pressure, but this would prevent regulating the resistance in the pistons and cut down on the flexibility of the device.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Braking Arrangements (AREA)
• Retarders (AREA)
• Actuator (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20368970

Family Applications (1)

Country Status (5)

Cited By (3)

Families Citing this family (14)

Citations (4)

Family Cites Families (8)

• 1987
  • 1987-06-25 SE SE8702625A patent/SE460551B/sv not_active IP Right Cessation
• 1988
  • 1988-06-27 US US07/438,431 patent/US5087228A/en not_active Expired - Lifetime
  • 1988-06-27 EP EP88906195A patent/EP0368893B1/en not_active Expired - Lifetime
  • 1988-06-27 WO PCT/SE1988/000355 patent/WO1988010378A1/en active IP Right Grant
  • 1988-06-27 JP JP63505746A patent/JP2837169B2/ja not_active Expired - Fee Related

Patent Citations (4)

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