US20170082190A1 - Transfer Case Lubrication System with Disengagable Pump - Google Patents
Transfer Case Lubrication System with Disengagable Pump Download PDFInfo
- Publication number
- US20170082190A1 US20170082190A1 US15/263,746 US201615263746A US2017082190A1 US 20170082190 A1 US20170082190 A1 US 20170082190A1 US 201615263746 A US201615263746 A US 201615263746A US 2017082190 A1 US2017082190 A1 US 2017082190A1
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- United States
- Prior art keywords
- shaft
- clutch
- clutch rotor
- lubrication system
- pump
- 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
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Classifications
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- 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
- F16H57/00—General details of gearing
- F16H57/04—Features relating to lubrication or cooling or heating
- F16H57/0434—Features relating to lubrication or cooling or heating relating to lubrication supply, e.g. pumps ; Pressure control
- F16H57/0436—Pumps
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
- B60K17/00—Arrangement or mounting of transmissions in vehicles
- B60K17/34—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles
- B60K17/342—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles having a longitudinal, endless element, e.g. belt or chain, for transmitting drive to wheels
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
- B60K17/00—Arrangement or mounting of transmissions in vehicles
- B60K17/34—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles
- B60K17/344—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles having a transfer gear
- B60K17/346—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles having a transfer gear the transfer gear being a differential gear
- B60K17/3467—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles having a transfer gear the transfer gear being a differential gear combined with a change speed gearing, e.g. range gear
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- 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
- F16D27/00—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor
- F16D27/02—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor with electromagnets incorporated in the clutch, i.e. with collecting rings
- F16D27/04—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor with electromagnets incorporated in the clutch, i.e. with collecting rings with axially-movable friction surfaces
-
- 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
- F16D27/00—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor
- F16D27/02—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor with electromagnets incorporated in the clutch, i.e. with collecting rings
- F16D27/04—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor with electromagnets incorporated in the clutch, i.e. with collecting rings with axially-movable friction surfaces
- F16D27/06—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor with electromagnets incorporated in the clutch, i.e. with collecting rings with axially-movable friction surfaces with friction surfaces arranged within the flux
-
- 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
- F16H57/00—General details of gearing
- F16H57/04—Features relating to lubrication or cooling or heating
- F16H57/042—Guidance of lubricant
- F16H57/043—Guidance of lubricant within rotary parts, e.g. axial channels or radial openings in shafts
-
- 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
- F16H57/00—General details of gearing
- F16H57/04—Features relating to lubrication or cooling or heating
- F16H57/0434—Features relating to lubrication or cooling or heating relating to lubrication supply, e.g. pumps ; Pressure control
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
- B60K17/00—Arrangement or mounting of transmissions in vehicles
- B60K17/34—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles
- B60K17/344—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles having a transfer gear
-
- 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
- F16D11/00—Clutches in which the members have interengaging parts
- F16D11/08—Clutches in which the members have interengaging parts actuated by moving a non-rotating part axially
- F16D11/10—Clutches in which the members have interengaging parts actuated by moving a non-rotating part axially with clutching members movable only axially
-
- 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
- F16D27/00—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor
- F16D27/10—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor with an electromagnet not rotating with a clutching member, i.e. without collecting rings
- F16D27/108—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor with an electromagnet not rotating with a clutching member, i.e. without collecting rings with axially movable clutching members
- F16D27/112—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor with an electromagnet not rotating with a clutching member, i.e. without collecting rings with axially movable clutching members with flat friction surfaces, e.g. discs
- F16D27/115—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor with an electromagnet not rotating with a clutching member, i.e. without collecting rings with axially movable clutching members with flat friction surfaces, e.g. discs with more than two discs, e.g. multiple lamellae
-
- 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
- F16D28/00—Electrically-actuated clutches
Definitions
- a transfer case In the field of vehicle drivetrain components, a transfer case is an apparatus that distributes driving power to more than one driven axle of the vehicle.
- a typical transfer case receives driving power from the transmission of the vehicle and transfers that power to a primary output shaft and a secondary output shaft, with the secondary output shaft being driven selectively using a clutch.
- two speed transfer cases provide gear reduction to allow operation in a high range, which is typically a 1:1 drive ratio, or a low range, such as a 2:1 drive ratio.
- One transfer case design includes a pump that is mounted on one of the input shaft or the primary output shaft.
- the pump delivers lubricant to the various components of the transfer case through an axial bore that is formed through the input shaft and/or the output shaft.
- Supply ports are formed through the input shaft and/or the output shaft at locations where lubrication is needed, such that the lubricant flows from the pump, through the axial bore, and out of the supply ports. This arrangement is effective but offers little control over the rate of lubricant flow to specific components.
- the lubrication system includes a shaft having a lubricant inlet port and a hollow bore for transporting lubricant within the shaft.
- a pump has a pump housing and one or more pumping elements that are disposed in the pump housing.
- a clutch assembly has an engaged position, in which rotational force from the shaft is transferred to the one or more pumping elements to cause operation of the pump, and a disengaged position, in which rotational force from the shaft is not transferred to the one or more pumping elements.
- An actuator is operable to cause the clutch assembly to move between the engaged position and the disengaged position in response to signals received from a controller.
- a lubrication system for a transfer case includes a shaft having a lubricant inlet port and a hollow bore for transporting lubricant within the shaft.
- a pump has a pump housing and one or more pumping elements that are disposed in the pump housing.
- a first clutch rotor that is disposed on the shaft and is connected to the one or more pumping elements such that rotation of the first clutch rotor causes operation of the one or more pumping elements of the pump.
- a second clutch rotor that rotates in response to rotation of the shaft and has an engaged position, in which rotational force from the shaft is transferred to the first clutch rotor to cause operation of the pump, and a disengaged position, in which rotational force from the shaft is not transferred to the first clutch rotor.
- An actuator is connected to the second clutch rotor that is operable to cause the second clutch rotor to move between the engaged position and the disengaged position.
- a lubrication system for a transfer case includes a shaft having a lubricant inlet port and a hollow bore for transporting lubricant within the shaft.
- a pump has a pump housing and one or more pumping elements that are disposed in the pump housing.
- a first clutch rotor that is disposed on the shaft and is connected to the one or more pumping elements such that rotation of the first clutch rotor causes operation of the one or more pumping elements of the pump.
- a second clutch rotor that rotates in response to rotation of the shaft and has an engaged position, in which rotational force from the shaft is transferred to the first clutch rotor to cause operation of the pump, and a disengaged position, in which rotational force from the shaft is not transferred to the first clutch rotor.
- An electromagnetic coil that is operable to produce a magnetic field when energized and disposed on either an axial face of the first clutch rotor or an axial face of the second clutch rotor, wherein energization of the electromagnetic coil causes the second clutch rotor to move between the engaged position and the disengaged position.
- FIG. 1 is a plan view illustration showing a drivetrain that includes a transfer case
- FIG. 2 is a cross-section illustration showing a transfer case
- FIG. 3 is an illustration of a lubrication system for a transfer case according to a first example.
- FIG. 4 is an illustration of a lubrication system for a transfer case according to a second example.
- the disclosure herein is directed to a lubrication system for a transfer case in which one or more pumping elements are configured to be connected to and disconnected from a rotating shaft. This allows the pump to be disengaged such that it stops pumping a lubricant under certain conditions, which reduces the parasitic loss associated with driving the pumping elements using the rotating shaft.
- FIG. 1 shows a drivetrain 100 for a four-wheel drive vehicle.
- the drivetrain 100 includes an engine 110 that is coupled to a transmission 112 .
- the engine 110 is the prime mover of the drivetrain 100 and can be, as examples, an internal combustion engine, an electric motor/generator, or a combination of the two. Other types of prime movers can be utilized as the engine 110 to provide driving power (e.g. via a rotating output shaft) to the transmission 112 .
- the transmission 112 includes components operable to convert the speed and torque of the driving power provided by the engine 110 , such as by a gear train that provides multiple gear ratios.
- the transmission 112 can be a manual transmission, an automatic transmission, a semi-automatic transmission, a continuously variable transmission, or a dual clutch transmission.
- the transmission 112 provides driving power to a transfer case 120 .
- the transfer case 120 is operable to distribute driving power to a rear driveshaft 130 and a front driveshaft 140 .
- the transfer case 120 can, in some implementations, include components that allow the transfer case 120 to perform a mode shift between two or more different modes.
- the transfer case 120 can allow operation in a rear-wheel drive mode, in which the rear driveshaft 130 receives driving power and the front driveshaft 140 does not, and a four-wheel drive mode, in which the rear driveshaft 130 and the front driveshaft 140 both receive driving power.
- the rear driveshaft 130 is the primary driveshaft and the front driveshaft 140 is the secondary driveshaft.
- the front driveshaft 140 is the primary driveshaft and the rear driveshaft 130 is the secondary driveshaft, and the transfer case 120 performs a mode shift between a front-wheel drive mode and a four-wheel drive mode.
- the transfer case 120 does not include components that allow a mode shift, and the transfer case 120 constantly provides driving power to both of the rear driveshaft 130 and the front driveshaft 140 .
- the transfer case 120 can allow a range shift that selectively provides gear reduction to the rotational output of the transfer case 120 .
- the transfer case 120 can include components for operating in a high range, such as a 1:1 drive ratio, or a low range, such as a 2:1 drive ratio.
- the range shift changes the transfer case 120 between operation in the low range and the high range by selectively coupling and uncoupling a gear reduction mechanism of the transfer case 120 .
- Operation of the transfer case 120 can be regulated by a controller such as an ECU 122 that provides signals to components of the transfer case 120 to cause the mode shift and/or the range shift.
- the mode shift and/or the range shift can be actuated mechanically such as by a driver-operated lever that is mechanically connected to a component of the transfer case 120 .
- the rear driveshaft 130 provides driving power to a rear axle 150 via a rear differential 152 .
- the rear axle 150 can be, as examples, a solid axle or a pair of independent half axles.
- the rear axle 150 provides driving power to a pair of rear wheels 154 that are fitted with tires.
- the front driveshaft 140 provides driving power to a front axle 160 via a front differential 162 .
- the front axle 160 can be, as examples, a solid axle or a pair of independent half axles.
- the front axle 160 provides driving power to a pair of front wheels 164 that are fitted with tires.
- FIG. 2 shows the transfer case 200 , which is conventional.
- the transfer case 200 includes a housing 202 , an input shaft 204 that extends out of the housing 202 , a primary output shaft 206 that extends out of the housing 202 , and a secondary output shaft 208 that extends out of the housing 202 .
- the input shaft 204 and the primary output shaft 206 extend along a first axis 207 .
- the secondary output shaft 208 extends along a second axis 209 which is, in this example, parallel to the first axis 207 .
- the input shaft 204 is at least partially hollow, and the primary output shaft 206 extends into the hollow interior of the input shaft 204 .
- the input shaft 204 can be connected to the primary output shaft either directly, or via a gear reduction mechanism 210 .
- the gear reduction mechanism 210 can be a Ravigneaux planetary gearset that includes a sun gear 212 formed on the input shaft 204 , a plurality of planet gears 214 , and a ring gear 216 that is fixed to the housing 202 .
- a planet carrier 218 is arranged on the input shaft 204 and can rotate about the input shaft 204 .
- the planet gears 214 are arranged on stub shafts 220 that are connected to the planet carrier 218 .
- the planet gears 214 mesh with the sun gear 212 and the ring gear 216 .
- a dog clutch 222 is utilized to engage and disengage the gear reduction mechanism 210 .
- the dog clutch 222 engages the input shaft 204 and the primary output shaft 206 directly, which establishes a 1:1 drive ratio and does not utilize the gear reduction mechanism 210 .
- the dog clutch 222 is shifted axially away from the input shaft 204 , and instead engages the planet carrier 218 and the primary output shaft 206 .
- Driving power is thus routed through the gear reduction mechanism 210 , with the planet carrier rotating slower to than the input shaft 204 to establish a drive ratio such as 2:1.
- the dog clutch 222 is moved between its first and second positions by a first selector fork 224 , which moves axially along a selector shaft 226 .
- a first cam follower 228 is formed on the first selector fork 224 .
- the first cam follower 228 is disposed in a first groove 230 formed on an exterior surface of a barrel cam 232 .
- the barrel cam 232 is disposed on a rotatable shaft 234 that is rotated be an electric motor 236 in response to control signals from a controller, such as the ECU 122 of FIG. 1 .
- the transfer case 200 includes a pump 240 for pumping a lubricant (not shown) to components of the transfer case 200 that require lubrication.
- the pump 240 is arranged on the primary output shaft 206 and a pump mechanism of the pump 240 is driven by the primary output shaft 206 .
- the pump 240 can be, for example, a gerotor pump. Other types of pumping mechanisms can be utilized.
- At least a portion of the housing 202 can serve as a sump, and the pump 240 can include a conduit 242 that extends into the sump area of the housing 202 .
- the primary output shaft includes an axially extending hollow bore 244 and a plurality of lubricant ports, each of which extends radially through the primary output shaft 206 .
- the plurality of lubricant ports can include an inlet port 246 and one or more outlet ports 248 .
- the inlet port 246 is aligned with an outlet of the pump 240 and receives the lubricant under pressure from the pump 240 .
- the outlet ports 248 are positioned along the primary output shaft 206 near components that require lubrication.
- the lubricant is pressurized by the pump 240 , travels through the inlet port 246 , along the hollow bore 244 , and out of one of the outlet ports 248 to lubricate portions of the transfer case 200 . Excess lubricant then drains to the sump area inside the housing 202 .
- a first sprocket 250 is arranged on the primary output shaft 206 and is connected to the primary output shaft by a clutch 252 .
- a second sprocket 254 is arranged on the secondary output shaft 208 and connected for rotation in unison, such as by splines.
- the first sprocket 250 and the second sprocket 254 are connected by a chain 256 , such that the second output shaft is driven by the primary output shaft 206 via the first sprocket 250 , the chain 256 and the second sprocket 254 when the clutch 252 is engaged.
- the clutch 252 includes, for example, a clutch pack 253 of interleaved plates, with the clutch being engaged when pressure is applied to the clutch pack 253 by an electromagnetic actuator 258 .
- the clutch 252 can allow active control of distribution of power between the primary output shaft 206 and the secondary output shaft 208 .
- different types of clutches and other mechanisms can be utilized to control transfer of power to the secondary output shaft 208 .
- the transfer case 200 could be configured to simply couple or decouple the first sprocket 250 with respect to the primary output shaft 206 , as in well-known part-time/manual transfer cases.
- FIG. 3 shows a lubrication system 300 that includes a pump 310 that is located on and driven by a shaft 302 .
- the lubrication system 300 can be implemented in a transfer case of any suitable configuration.
- the lubrication system 300 can be implemented in the transfer case 200 in place of the pump 240 .
- the lubrication system 300 could be disposed on one of the input shaft 204 or the primary output shaft 206 of the transfer case 200 .
- the shaft 302 is a rotating member that has a hollow bore 304 for transporting lubricant within the shaft 302 from one or more fluid inlets 306 to one or more fluid outlets (not shown).
- the one or more fluid inlets 306 and the one or more fluid outlets extend radially through the shaft 302 .
- the pump 310 includes a pump housing 312 .
- the shaft 302 passes through the pump housing through an aperture 314 that extends through the pump housing 312 .
- the pump housing 312 is mounted in a manner that restrains the pump housing 312 from rotating in response to rotation of the shaft 302 .
- the pump housing 312 can be connected to a fixed structure 316 such that the pump housing 312 does not rotate in response to rotation of the shaft 302 .
- the pump housing 312 can be fixed to the housing 202 .
- the pump 310 includes one or more pumping elements that are disposed in the pump housing 312 and are operated by rotational force provided by rotation of the shaft 302 .
- the pump 310 is a gerotor pump
- the one or more pumping elements include an inner pump rotor 318 that is located on the shaft 302 , and an outer pump rotor 320 , which is an annular member that extends around the inner pump rotor 318 .
- the inner pump rotor 318 includes a first plurality of teeth and the outer pump rotor 320 includes a second plurality of teeth in greater number than the first plurality of teeth.
- the outer pump rotor 320 will include teeth in a number that is one greater than the number of teeth on the inner pump rotor 318 .
- Rotation of the inner pump rotor 318 causes rotation of the outer pump rotor 320 through meshing of their respective teeth, which creates a low pressure inlet region where the teeth diverge and a high pressure outlet region where the teeth converge.
- the inlet region can be in communication with a source of fluid (e.g. lubricant such as transmission fluid or oil) and the outlet region can be in communication with at least one of the fluid inlets 306 of the shaft 302 to pump pressurized fluid into the hollow bore 304 of the shaft via the fluid inlets 306 .
- a source of fluid e.g. lubricant such as transmission fluid or oil
- the pumping elements of the pump 310 are not driven directly by the shaft 302 .
- the inner pump rotor 318 is disposed on the shaft 302 such that the shaft 302 may rotate independent of rotation of the inner pump rotor 318 .
- the lubrication system 300 includes a clutch assembly 330 .
- the clutch assembly 330 has an engaged position in which rotational force is transferred from the shaft 302 to the inner pump rotor 318 , and a disengaged position in which rotational force is not transferred from the shaft 302 to the inner pump rotor 318 .
- the clutch assembly 330 has a first clutch rotor 340 and a second clutch rotor 350 .
- the first clutch rotor 340 rotates in unison with the inner pump rotor 318
- the second clutch rotor 350 rotates in unison with the shaft 302 .
- the second clutch rotor 350 causes rotation of the first clutch rotor 340 in the engaged position but does not cause rotation of the first clutch rotor 340 in the disengaged position by virtue of a small air gap by which the first clutch rotor 340 is spaced from the second clutch rotor 350 .
- the clutch assembly 330 may further define a fully engaged position in which the first clutch rotor 340 and the second clutch rotor 350 rotate in unison, and a partially engaged position in which the second clutch rotor 350 contacts the first clutch rotor 340 but slips with respect to it such that the first clutch rotor 340 rotates slower than the second clutch rotor 350 .
- the first clutch rotor 340 is disposed on the shaft 302 such that the shaft 302 may rotate independent of the first clutch rotor 340 .
- the first clutch rotor 340 is supported with respect to the shaft 302 by one or more bearings 332 .
- the second clutch rotor 350 can include a cylindrical portion 342 in the form of a tube with the shaft 302 passing through it.
- the cylindrical portion 342 is connected to the inner pump rotor 318 of the pump 310 , and extends out of the pump housing 312 axially along the shaft 302 .
- the first clutch rotor 340 can include a disk portion 344 that extends radially outward from the cylindrical portion 342 .
- the disk portion 344 is planar, lies in a plane that is perpendicular to the longitudinal axis of the shaft 302 , and has an axial face 348 that is oriented toward the second clutch rotor 350 .
- the first clutch rotor 340 also includes an annular rim 346 that extends from the outer end of the disk portion 344 and is concentric to the cylindrical portion 342 .
- the second clutch rotor 350 is positioned along the shaft 302 such that the first clutch rotor 340 is located between the pump 310 and the second clutch rotor 350 .
- the second clutch rotor 350 is mounted to the shaft 302 such that it rotates substantially in unison with the shaft 302 , but is able to slide axially along the shaft 302 at least over a limited distance.
- the distance by which the second clutch rotor 350 is able to slide axially along the shaft 302 is at least sufficient to allow the second clutch rotor 350 to move into and out of engagement with the first clutch rotor 340 .
- the second clutch rotor 350 includes a cylindrical portion 352 that is seated on the shaft 302 such that the shaft 302 passes through it.
- the cylindrical portion 352 can be connected to the shaft 302 by splines (not shown) to enforce uniform rotation with the shaft 302 while permitting axial sliding, or by any other suitable structure.
- a disk portion 354 is connected to and supported by the cylindrical portion 352 .
- the disk portion defines a maximum diameter for the second clutch rotor 350 that is similar to a maximum diameter for the first clutch rotor 340 , as defined by the disk portion 344 and/or the annular rim 346 of the second rotor.
- An axial face 356 of the second clutch rotor 350 faces the first clutch rotor 340 .
- the axial face 356 of the second clutch rotor 350 can be defined by a high friction material.
- the lubrication system 300 includes a biasing element that is operable to apply a spring force to the second clutch rotor 350 .
- the biasing element is an annular member that is seated on the shaft 302 , such as a wave spring 360 that exerts a spring force on the second clutch rotor 350 when compressed by engagement of cylindrical portion 352 of the second clutch rotor 350 with the wave spring 360 .
- the wave spring 360 can be a compression spring.
- the wave spring 360 is located on the shaft 302 between the second clutch rotor 350 and a stop member 362 , such as a surface defined on the shaft 302 or a stop ring that is seated on the shaft 302 such that it cannot move axially with respect to the shaft 302 .
- the stop member 362 is located on the shaft 302 between the first clutch rotor 340 and the second clutch rotor 350 .
- the wave spring 360 urges the second clutch rotor 350 axially away from the first clutch rotor 340 toward the disengaged position of the clutch assembly 330 , such that the small air gap is defined between the axial face 348 of the first clutch rotor 340 and the axial face 356 of the second clutch rotor 350 .
- the clutch assembly 330 includes an actuator in the form of an electromagnetic coil 370 .
- the electromagnetic coil 370 receives electricity from an external power source (not shown) that can be energized and de-energized.
- the electromagnetic coil 370 is disposed on the first clutch rotor 340 on the disk portion 344 opposite the axial face 348 , such that the electromagnetic coil 370 is directly behind the axial face 348 of the first clutch rotor 340 .
- the electromagnetic coil 370 can be energized to create a magnetic field that attracts ferromagnetic objects.
- all or part of the second clutch rotor 350 is formed from a ferromagnetic material.
- the electromagnetic coil 370 is energized, the second clutch rotor 350 is moved axially toward the first clutch rotor 340 as a result of the magnetic field, while compressing the wave spring 360 .
- the electromagnetic coil 370 is de-energized, magnetic attraction ceases, and the biasing force applied to the second clutch rotor 350 by the wave spring 360 moves the second clutch rotor 350 axially along the shaft 302 to place the clutch assembly 330 in the disengaged position.
- the clutch assembly 330 is in the disengaged position when the electromagnetic coil 370 is de-energized, and the clutch assembly 330 is in the engaged position when the electromagnetic coil 370 is energized.
- the operating relationship between energization of the electromagnetic coil 370 and engagement of the clutch assembly 330 can be reversed.
- the first clutch rotor 340 is formed from a ferromagnetic material and magnets (not shown) are disposed on the second clutch rotor 350 .
- the electromagnetic coil 370 is not energized, the magnets on the second clutch rotor 350 are attracted to the first clutch rotor 340 to move the second clutch rotor 350 into engagement with the first clutch rotor 340 to place the clutch assembly 330 in the engaged position.
- the electromagnetic coil 370 is configured such that the polarity of the magnetic field it produces cancels the magnetic attractive force exerted on the first clutch rotor 340 by the magnets on the second clutch rotor 350 .
- the magnetic attraction is diminished sufficiently such that the biasing force of the wave spring 360 is no longer overcome.
- the second clutch rotor 350 is moved away from the first clutch rotor 340 by the wave spring 360 to place the clutch assembly 330 in the disengaged position.
- the clutch assembly 330 is in the engaged position when the electromagnetic coil 370 is de-energized, and the clutch assembly 330 is in the disengaged position when the electromagnetic coil 370 is energized.
- the determination can be made by a controller, such as the ECU 122 of the drivetrain 100 , based on, for example, operating conditions of the drivetrain 100 .
- the clutch assembly 330 is moved to the engaged position by, for example, energizing the electromagnetic coil 370 . This moves the second clutch rotor 350 axially into engagement with the first clutch rotor 340 . As a result of this engagement, the first clutch rotor 340 and the pumping elements of the pump 310 begin to rotate.
- full engagement results, and the rotational speed of the first clutch rotor 340 matches the rotational speed of the second clutch rotor 350 .
- Rotation of the first clutch rotor 340 causes rotation of the pumping elements of the pump 310 , which results in fluid being pumped by the pump 310 .
- the electromagnetic coil 370 is de-energized and the second clutch rotor 350 is moved out of engagement with the first clutch rotor 340 by the wave spring 360 .
- FIG. 4 shows a lubrication system 400 according to an alternative implementation.
- the lubrication system 400 is similar to the lubrication system 300 and includes all elements of the lubrication system 300 except as noted herein.
- the lubrication system 400 omits the electromagnetic coil 370 that was described in connection with the lubrication system 300 .
- the lubrication system 400 includes an actuator 410 that has a moving member 412 .
- the moving member 412 is engaged with the second clutch rotor 350 to move the second clutch rotor 350 .
- the moving member 412 is seated in an annular groove 420 formed on an outer periphery of the second clutch rotor 350 .
- the actuator 410 can be operable to move the second clutch rotor 350 in a single axial direction only, in which case the wave spring 360 acts opposite the actuator 410 , or in both axial directions, in which case the wave spring 360 and the stop member 362 can be omitted.
- the actuator 410 can be any suitable type of actuator, such as an electrical actuator, a hydraulic actuator, or a pneumatic actuator.
- the moving member 412 is a shift fork that is moved in the axial direction of the shaft 302 by a barrel cam that is rotated by an electrical motor, such as the barrel cam 232 of the transfer case 200 and the electric motor 236 of the transfer case 200 .
- Operation of the lubrication system 400 is similar to operation of the lubrication system 300 , as previously described.
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Abstract
A lubrication system (300) for a transfer case (200) includes a shaft (302) having a lubricant inlet port (306) and a hollow bore (304) for transporting lubricant within the shaft (302), a pump (310) having a pump housing (312) and one or more pumping elements (318) that are disposed in the pump housing (312), and a clutch assembly (330). The clutch assembly 330 has an engaged position, in which rotational force from the shaft (302) is transferred to the one or more pumping elements (318) to cause operation of the pump (310), and a disengaged position, in which rotational force from the shaft (302) is not transferred to the one or more pumping elements (318). An actuator (370, 410) is operable to cause the clutch assembly (330) to move between the engaged position and the disengaged position in response to signals received from a controller (233).
Description
- This application is a continuation of U.S. patent application Ser. No. 14/857,296, filed on Sep. 17, 2015.
- In the field of vehicle drivetrain components, a transfer case is an apparatus that distributes driving power to more than one driven axle of the vehicle. A typical transfer case receives driving power from the transmission of the vehicle and transfers that power to a primary output shaft and a secondary output shaft, with the secondary output shaft being driven selectively using a clutch. In addition, two speed transfer cases provide gear reduction to allow operation in a high range, which is typically a 1:1 drive ratio, or a low range, such as a 2:1 drive ratio.
- Many of the components in a transfer case require lubrication. One transfer case design includes a pump that is mounted on one of the input shaft or the primary output shaft. The pump delivers lubricant to the various components of the transfer case through an axial bore that is formed through the input shaft and/or the output shaft. Supply ports are formed through the input shaft and/or the output shaft at locations where lubrication is needed, such that the lubricant flows from the pump, through the axial bore, and out of the supply ports. This arrangement is effective but offers little control over the rate of lubricant flow to specific components.
- One aspect of the disclosed embodiments is a lubrication system for a transfer case. The lubrication system includes a shaft having a lubricant inlet port and a hollow bore for transporting lubricant within the shaft. A pump has a pump housing and one or more pumping elements that are disposed in the pump housing. A clutch assembly has an engaged position, in which rotational force from the shaft is transferred to the one or more pumping elements to cause operation of the pump, and a disengaged position, in which rotational force from the shaft is not transferred to the one or more pumping elements. An actuator is operable to cause the clutch assembly to move between the engaged position and the disengaged position in response to signals received from a controller.
- In another disclosed embodiment, a lubrication system for a transfer case includes a shaft having a lubricant inlet port and a hollow bore for transporting lubricant within the shaft. A pump has a pump housing and one or more pumping elements that are disposed in the pump housing. A first clutch rotor that is disposed on the shaft and is connected to the one or more pumping elements such that rotation of the first clutch rotor causes operation of the one or more pumping elements of the pump. A second clutch rotor that rotates in response to rotation of the shaft and has an engaged position, in which rotational force from the shaft is transferred to the first clutch rotor to cause operation of the pump, and a disengaged position, in which rotational force from the shaft is not transferred to the first clutch rotor. An actuator is connected to the second clutch rotor that is operable to cause the second clutch rotor to move between the engaged position and the disengaged position.
- In yet another disclosed embodiment, a lubrication system for a transfer case includes a shaft having a lubricant inlet port and a hollow bore for transporting lubricant within the shaft. A pump has a pump housing and one or more pumping elements that are disposed in the pump housing. A first clutch rotor that is disposed on the shaft and is connected to the one or more pumping elements such that rotation of the first clutch rotor causes operation of the one or more pumping elements of the pump. A second clutch rotor that rotates in response to rotation of the shaft and has an engaged position, in which rotational force from the shaft is transferred to the first clutch rotor to cause operation of the pump, and a disengaged position, in which rotational force from the shaft is not transferred to the first clutch rotor. An electromagnetic coil that is operable to produce a magnetic field when energized and disposed on either an axial face of the first clutch rotor or an axial face of the second clutch rotor, wherein energization of the electromagnetic coil causes the second clutch rotor to move between the engaged position and the disengaged position.
- The description herein makes reference to the accompanying drawings, wherein like referenced numerals refer to like parts throughout several views, and wherein:
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FIG. 1 is a plan view illustration showing a drivetrain that includes a transfer case; -
FIG. 2 is a cross-section illustration showing a transfer case; -
FIG. 3 is an illustration of a lubrication system for a transfer case according to a first example; and -
FIG. 4 is an illustration of a lubrication system for a transfer case according to a second example. - The disclosure herein is directed to a lubrication system for a transfer case in which one or more pumping elements are configured to be connected to and disconnected from a rotating shaft. This allows the pump to be disengaged such that it stops pumping a lubricant under certain conditions, which reduces the parasitic loss associated with driving the pumping elements using the rotating shaft.
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FIG. 1 shows adrivetrain 100 for a four-wheel drive vehicle. Thedrivetrain 100 includes anengine 110 that is coupled to atransmission 112. Theengine 110 is the prime mover of thedrivetrain 100 and can be, as examples, an internal combustion engine, an electric motor/generator, or a combination of the two. Other types of prime movers can be utilized as theengine 110 to provide driving power (e.g. via a rotating output shaft) to thetransmission 112. Thetransmission 112 includes components operable to convert the speed and torque of the driving power provided by theengine 110, such as by a gear train that provides multiple gear ratios. As examples, thetransmission 112 can be a manual transmission, an automatic transmission, a semi-automatic transmission, a continuously variable transmission, or a dual clutch transmission. - The
transmission 112 provides driving power to atransfer case 120. Thetransfer case 120 is operable to distribute driving power to arear driveshaft 130 and afront driveshaft 140. - The
transfer case 120 can, in some implementations, include components that allow thetransfer case 120 to perform a mode shift between two or more different modes. For example, thetransfer case 120 can allow operation in a rear-wheel drive mode, in which therear driveshaft 130 receives driving power and thefront driveshaft 140 does not, and a four-wheel drive mode, in which therear driveshaft 130 and thefront driveshaft 140 both receive driving power. In this example, therear driveshaft 130 is the primary driveshaft and thefront driveshaft 140 is the secondary driveshaft. In other implementations, thefront driveshaft 140 is the primary driveshaft and therear driveshaft 130 is the secondary driveshaft, and thetransfer case 120 performs a mode shift between a front-wheel drive mode and a four-wheel drive mode. In other implementations thetransfer case 120 does not include components that allow a mode shift, and thetransfer case 120 constantly provides driving power to both of therear driveshaft 130 and thefront driveshaft 140. - The
transfer case 120 can allow a range shift that selectively provides gear reduction to the rotational output of thetransfer case 120. For example, thetransfer case 120 can include components for operating in a high range, such as a 1:1 drive ratio, or a low range, such as a 2:1 drive ratio. The range shift changes thetransfer case 120 between operation in the low range and the high range by selectively coupling and uncoupling a gear reduction mechanism of thetransfer case 120. - Operation of the
transfer case 120 can be regulated by a controller such as anECU 122 that provides signals to components of thetransfer case 120 to cause the mode shift and/or the range shift. In other implementations, the mode shift and/or the range shift can be actuated mechanically such as by a driver-operated lever that is mechanically connected to a component of thetransfer case 120. - The
rear driveshaft 130 provides driving power to arear axle 150 via arear differential 152. Therear axle 150 can be, as examples, a solid axle or a pair of independent half axles. Therear axle 150 provides driving power to a pair ofrear wheels 154 that are fitted with tires. - The
front driveshaft 140 provides driving power to afront axle 160 via afront differential 162. Thefront axle 160 can be, as examples, a solid axle or a pair of independent half axles. Thefront axle 160 provides driving power to a pair offront wheels 164 that are fitted with tires. -
FIG. 2 shows thetransfer case 200, which is conventional. Thetransfer case 200 includes ahousing 202, aninput shaft 204 that extends out of thehousing 202, aprimary output shaft 206 that extends out of thehousing 202, and asecondary output shaft 208 that extends out of thehousing 202. Theinput shaft 204 and theprimary output shaft 206 extend along afirst axis 207. Thesecondary output shaft 208 extends along asecond axis 209 which is, in this example, parallel to thefirst axis 207. - The
input shaft 204 is at least partially hollow, and theprimary output shaft 206 extends into the hollow interior of theinput shaft 204. Theinput shaft 204 can be connected to the primary output shaft either directly, or via agear reduction mechanism 210. Thegear reduction mechanism 210 can be a Ravigneaux planetary gearset that includes asun gear 212 formed on theinput shaft 204, a plurality of planet gears 214, and aring gear 216 that is fixed to thehousing 202. Aplanet carrier 218 is arranged on theinput shaft 204 and can rotate about theinput shaft 204. The planet gears 214 are arranged onstub shafts 220 that are connected to theplanet carrier 218. The planet gears 214 mesh with thesun gear 212 and thering gear 216. - A
dog clutch 222 is utilized to engage and disengage thegear reduction mechanism 210. In a first position of thedog clutch 222, thedog clutch 222 engages theinput shaft 204 and theprimary output shaft 206 directly, which establishes a 1:1 drive ratio and does not utilize thegear reduction mechanism 210. In a second position of the dog clutch 222 (not shown), thedog clutch 222 is shifted axially away from theinput shaft 204, and instead engages theplanet carrier 218 and theprimary output shaft 206. Driving power is thus routed through thegear reduction mechanism 210, with the planet carrier rotating slower to than theinput shaft 204 to establish a drive ratio such as 2:1. - The
dog clutch 222 is moved between its first and second positions by afirst selector fork 224, which moves axially along aselector shaft 226. Afirst cam follower 228 is formed on thefirst selector fork 224. Thefirst cam follower 228 is disposed in afirst groove 230 formed on an exterior surface of abarrel cam 232. Thebarrel cam 232 is disposed on arotatable shaft 234 that is rotated be anelectric motor 236 in response to control signals from a controller, such as theECU 122 ofFIG. 1 . - The
transfer case 200 includes apump 240 for pumping a lubricant (not shown) to components of thetransfer case 200 that require lubrication. Thepump 240 is arranged on theprimary output shaft 206 and a pump mechanism of thepump 240 is driven by theprimary output shaft 206. Thepump 240 can be, for example, a gerotor pump. Other types of pumping mechanisms can be utilized. At least a portion of thehousing 202 can serve as a sump, and thepump 240 can include aconduit 242 that extends into the sump area of thehousing 202. - To route lubrication to various components of the
transfer case 200, the primary output shaft includes an axially extendinghollow bore 244 and a plurality of lubricant ports, each of which extends radially through theprimary output shaft 206. The plurality of lubricant ports can include aninlet port 246 and one ormore outlet ports 248. Theinlet port 246 is aligned with an outlet of thepump 240 and receives the lubricant under pressure from thepump 240. Theoutlet ports 248 are positioned along theprimary output shaft 206 near components that require lubrication. The lubricant is pressurized by thepump 240, travels through theinlet port 246, along thehollow bore 244, and out of one of theoutlet ports 248 to lubricate portions of thetransfer case 200. Excess lubricant then drains to the sump area inside thehousing 202. - A
first sprocket 250 is arranged on theprimary output shaft 206 and is connected to the primary output shaft by a clutch 252. Asecond sprocket 254 is arranged on thesecondary output shaft 208 and connected for rotation in unison, such as by splines. Thefirst sprocket 250 and thesecond sprocket 254 are connected by achain 256, such that the second output shaft is driven by theprimary output shaft 206 via thefirst sprocket 250, thechain 256 and thesecond sprocket 254 when the clutch 252 is engaged. The clutch 252 includes, for example, aclutch pack 253 of interleaved plates, with the clutch being engaged when pressure is applied to theclutch pack 253 by anelectromagnetic actuator 258. In the illustrated example, the clutch 252 can allow active control of distribution of power between theprimary output shaft 206 and thesecondary output shaft 208. In alternative implementations, different types of clutches and other mechanisms can be utilized to control transfer of power to thesecondary output shaft 208. Thus, for example, thetransfer case 200 could be configured to simply couple or decouple thefirst sprocket 250 with respect to theprimary output shaft 206, as in well-known part-time/manual transfer cases. -
FIG. 3 shows alubrication system 300 that includes apump 310 that is located on and driven by ashaft 302. Thelubrication system 300 can be implemented in a transfer case of any suitable configuration. For example, thelubrication system 300 can be implemented in thetransfer case 200 in place of thepump 240. Thus, thelubrication system 300 could be disposed on one of theinput shaft 204 or theprimary output shaft 206 of thetransfer case 200. - The
shaft 302 is a rotating member that has ahollow bore 304 for transporting lubricant within theshaft 302 from one or morefluid inlets 306 to one or more fluid outlets (not shown). The one or morefluid inlets 306 and the one or more fluid outlets extend radially through theshaft 302. - The
pump 310 includes apump housing 312. Theshaft 302 passes through the pump housing through anaperture 314 that extends through thepump housing 312. Thepump housing 312 is mounted in a manner that restrains thepump housing 312 from rotating in response to rotation of theshaft 302. For instance, thepump housing 312 can be connected to a fixedstructure 316 such that thepump housing 312 does not rotate in response to rotation of theshaft 302. In implementations where thelubrication system 300 is implemented in a transfer case such as thetransfer case 200, thepump housing 312 can be fixed to thehousing 202. - The
pump 310 includes one or more pumping elements that are disposed in thepump housing 312 and are operated by rotational force provided by rotation of theshaft 302. In the illustrated example, thepump 310 is a gerotor pump, and the one or more pumping elements include aninner pump rotor 318 that is located on theshaft 302, and anouter pump rotor 320, which is an annular member that extends around theinner pump rotor 318. As in conventional gerotor pumps, theinner pump rotor 318 includes a first plurality of teeth and theouter pump rotor 320 includes a second plurality of teeth in greater number than the first plurality of teeth. Typically, theouter pump rotor 320 will include teeth in a number that is one greater than the number of teeth on theinner pump rotor 318. Rotation of theinner pump rotor 318 causes rotation of theouter pump rotor 320 through meshing of their respective teeth, which creates a low pressure inlet region where the teeth diverge and a high pressure outlet region where the teeth converge. The inlet region can be in communication with a source of fluid (e.g. lubricant such as transmission fluid or oil) and the outlet region can be in communication with at least one of thefluid inlets 306 of theshaft 302 to pump pressurized fluid into thehollow bore 304 of the shaft via thefluid inlets 306. As will be explained further herein the pumping elements of thepump 310 are not driven directly by theshaft 302. Instead, theinner pump rotor 318 is disposed on theshaft 302 such that theshaft 302 may rotate independent of rotation of theinner pump rotor 318. - In order to provide a rotational input force to the
pump 310, thelubrication system 300 includes aclutch assembly 330. Theclutch assembly 330 has an engaged position in which rotational force is transferred from theshaft 302 to theinner pump rotor 318, and a disengaged position in which rotational force is not transferred from theshaft 302 to theinner pump rotor 318. - The
clutch assembly 330 has a firstclutch rotor 340 and a secondclutch rotor 350. The firstclutch rotor 340 rotates in unison with theinner pump rotor 318, while the secondclutch rotor 350 rotates in unison with theshaft 302. The secondclutch rotor 350 causes rotation of the firstclutch rotor 340 in the engaged position but does not cause rotation of the firstclutch rotor 340 in the disengaged position by virtue of a small air gap by which the firstclutch rotor 340 is spaced from the secondclutch rotor 350. Theclutch assembly 330 may further define a fully engaged position in which the firstclutch rotor 340 and the secondclutch rotor 350 rotate in unison, and a partially engaged position in which the secondclutch rotor 350 contacts the firstclutch rotor 340 but slips with respect to it such that the firstclutch rotor 340 rotates slower than the secondclutch rotor 350. - The first
clutch rotor 340 is disposed on theshaft 302 such that theshaft 302 may rotate independent of the firstclutch rotor 340. In the illustrated example, the firstclutch rotor 340 is supported with respect to theshaft 302 by one ormore bearings 332. The secondclutch rotor 350 can include acylindrical portion 342 in the form of a tube with theshaft 302 passing through it. Thecylindrical portion 342 is connected to theinner pump rotor 318 of thepump 310, and extends out of thepump housing 312 axially along theshaft 302. Opposite theinner pump rotor 318, the firstclutch rotor 340 can include adisk portion 344 that extends radially outward from thecylindrical portion 342. In the illustrated example, thedisk portion 344 is planar, lies in a plane that is perpendicular to the longitudinal axis of theshaft 302, and has anaxial face 348 that is oriented toward the secondclutch rotor 350. In the illustrated example, the firstclutch rotor 340 also includes anannular rim 346 that extends from the outer end of thedisk portion 344 and is concentric to thecylindrical portion 342. - The second
clutch rotor 350 is positioned along theshaft 302 such that the firstclutch rotor 340 is located between thepump 310 and the secondclutch rotor 350. The secondclutch rotor 350 is mounted to theshaft 302 such that it rotates substantially in unison with theshaft 302, but is able to slide axially along theshaft 302 at least over a limited distance. The distance by which the secondclutch rotor 350 is able to slide axially along theshaft 302 is at least sufficient to allow the secondclutch rotor 350 to move into and out of engagement with the firstclutch rotor 340. - The second
clutch rotor 350 includes acylindrical portion 352 that is seated on theshaft 302 such that theshaft 302 passes through it. Thecylindrical portion 352 can be connected to theshaft 302 by splines (not shown) to enforce uniform rotation with theshaft 302 while permitting axial sliding, or by any other suitable structure. Adisk portion 354 is connected to and supported by thecylindrical portion 352. In the illustrated example, the disk portion defines a maximum diameter for the secondclutch rotor 350 that is similar to a maximum diameter for the firstclutch rotor 340, as defined by thedisk portion 344 and/or theannular rim 346 of the second rotor. - An
axial face 356 of the secondclutch rotor 350 faces the firstclutch rotor 340. Optionally, theaxial face 356 of the secondclutch rotor 350 can be defined by a high friction material. - The
lubrication system 300 includes a biasing element that is operable to apply a spring force to the secondclutch rotor 350. In the illustrated example, the biasing element is an annular member that is seated on theshaft 302, such as awave spring 360 that exerts a spring force on the secondclutch rotor 350 when compressed by engagement ofcylindrical portion 352 of the secondclutch rotor 350 with thewave spring 360. Thus, thewave spring 360 can be a compression spring. Thewave spring 360 is located on theshaft 302 between the secondclutch rotor 350 and astop member 362, such as a surface defined on theshaft 302 or a stop ring that is seated on theshaft 302 such that it cannot move axially with respect to theshaft 302. In the illustrated example, thestop member 362 is located on theshaft 302 between the firstclutch rotor 340 and the secondclutch rotor 350. Thus, thewave spring 360 urges the secondclutch rotor 350 axially away from the firstclutch rotor 340 toward the disengaged position of theclutch assembly 330, such that the small air gap is defined between theaxial face 348 of the firstclutch rotor 340 and theaxial face 356 of the secondclutch rotor 350. - To move the
clutch assembly 330 between the disengaged position and the engaged position, theclutch assembly 330 includes an actuator in the form of anelectromagnetic coil 370. Theelectromagnetic coil 370 receives electricity from an external power source (not shown) that can be energized and de-energized. In the illustrated example, theelectromagnetic coil 370 is disposed on the firstclutch rotor 340 on thedisk portion 344 opposite theaxial face 348, such that theelectromagnetic coil 370 is directly behind theaxial face 348 of the firstclutch rotor 340. - In one implementation, the
electromagnetic coil 370 can be energized to create a magnetic field that attracts ferromagnetic objects. In this implementation, all or part of the secondclutch rotor 350 is formed from a ferromagnetic material. Thus, when theelectromagnetic coil 370 is energized, the secondclutch rotor 350 is moved axially toward the firstclutch rotor 340 as a result of the magnetic field, while compressing thewave spring 360. When theelectromagnetic coil 370 is de-energized, magnetic attraction ceases, and the biasing force applied to the secondclutch rotor 350 by thewave spring 360 moves the secondclutch rotor 350 axially along theshaft 302 to place theclutch assembly 330 in the disengaged position. Thus, in this implementation, theclutch assembly 330 is in the disengaged position when theelectromagnetic coil 370 is de-energized, and theclutch assembly 330 is in the engaged position when theelectromagnetic coil 370 is energized. - In an alternative implementation, the operating relationship between energization of the
electromagnetic coil 370 and engagement of theclutch assembly 330 can be reversed. In this implementation, the firstclutch rotor 340 is formed from a ferromagnetic material and magnets (not shown) are disposed on the secondclutch rotor 350. When theelectromagnetic coil 370 is not energized, the magnets on the secondclutch rotor 350 are attracted to the firstclutch rotor 340 to move the secondclutch rotor 350 into engagement with the firstclutch rotor 340 to place theclutch assembly 330 in the engaged position. Theelectromagnetic coil 370 is configured such that the polarity of the magnetic field it produces cancels the magnetic attractive force exerted on the firstclutch rotor 340 by the magnets on the secondclutch rotor 350. The magnetic attraction is diminished sufficiently such that the biasing force of thewave spring 360 is no longer overcome. As a result, the secondclutch rotor 350 is moved away from the firstclutch rotor 340 by thewave spring 360 to place theclutch assembly 330 in the disengaged position. Thus, in this implementation, theclutch assembly 330 is in the engaged position when theelectromagnetic coil 370 is de-energized, and theclutch assembly 330 is in the disengaged position when theelectromagnetic coil 370 is energized. - In operation, a determination is made as to whether or not to operate the
pump 310 of thelubrication system 300. The determination can be made by a controller, such as theECU 122 of thedrivetrain 100, based on, for example, operating conditions of thedrivetrain 100. If the pump is to be operated, theclutch assembly 330 is moved to the engaged position by, for example, energizing theelectromagnetic coil 370. This moves the secondclutch rotor 350 axially into engagement with the firstclutch rotor 340. As a result of this engagement, the firstclutch rotor 340 and the pumping elements of thepump 310 begin to rotate. In some implementations, full engagement results, and the rotational speed of the firstclutch rotor 340 matches the rotational speed of the secondclutch rotor 350. Rotation of the firstclutch rotor 340 causes rotation of the pumping elements of thepump 310, which results in fluid being pumped by thepump 310. When operation is no longer needed, theelectromagnetic coil 370 is de-energized and the secondclutch rotor 350 is moved out of engagement with the firstclutch rotor 340 by thewave spring 360. -
FIG. 4 shows alubrication system 400 according to an alternative implementation. Thelubrication system 400 is similar to thelubrication system 300 and includes all elements of thelubrication system 300 except as noted herein. - The
lubrication system 400 omits theelectromagnetic coil 370 that was described in connection with thelubrication system 300. To move theclutch assembly 330 between the engaged position and the disengaged position, thelubrication system 400 includes anactuator 410 that has a movingmember 412. The movingmember 412 is engaged with the secondclutch rotor 350 to move the secondclutch rotor 350. In the illustrated example, the movingmember 412 is seated in anannular groove 420 formed on an outer periphery of the secondclutch rotor 350. - The
actuator 410 can be operable to move the secondclutch rotor 350 in a single axial direction only, in which case thewave spring 360 acts opposite theactuator 410, or in both axial directions, in which case thewave spring 360 and thestop member 362 can be omitted. - The
actuator 410 can be any suitable type of actuator, such as an electrical actuator, a hydraulic actuator, or a pneumatic actuator. In one implementation, the movingmember 412 is a shift fork that is moved in the axial direction of theshaft 302 by a barrel cam that is rotated by an electrical motor, such as thebarrel cam 232 of thetransfer case 200 and theelectric motor 236 of thetransfer case 200. - Operation of the
lubrication system 400 is similar to operation of thelubrication system 300, as previously described. - While the disclosure has been made in connection with what is presently considered to be the most practical and preferred embodiment, it should be understood that the disclosure is intended to cover various modifications and equivalent arrangements.
Claims (20)
1. A lubrication system (300) for a transfer case (120, 200), comprising:
a shaft (302) having a lubricant inlet port (306) and a hollow bore (304) for transporting lubricant within the shaft (302);
a pump (310) having a pump housing (312) and one or more pumping elements (318) that are disposed in the pump housing (312);
a clutch assembly (330) having an engaged position, in which rotational force from the shaft (302) is transferred to the one or more pumping elements (318) to cause operation of the pump (310), and a disengaged position, in which rotational force from the shaft (302) is not transferred to the one or more pumping elements (318); and
an actuator (370, 410) that is operable to cause the clutch assembly (330) to move between the engaged position and the disengaged position in response to signals received from a controller (233).
2. The lubrication system (300) of claim 1 , wherein the actuator (410) is one of an electrical actuator, a hydraulic actuator, or a pneumatic actuator.
3. The lubrication system (300) of claim 1 , wherein the clutch assembly (330) includes a first clutch rotor (340) that rotates independent of the shaft (302) when the clutch assembly (330) is in the disengaged position and a second clutch rotor (350) that rotates in response to rotation of the shaft (302).
4. The lubrication system (300) of claim 3 , wherein the actuator (410) has a moveable member (412) that engages the second clutch rotor (350) of the clutch assembly (330).
5. The lubrication system (300) of claim 4 , wherein the moveable member (412) of the actuator (410) is seated in an annular groove (42) formed on an outer periphery of the second clutch rotor (350) of the clutch assembly (330).
6. The lubrication system (300) of claim 4 , wherein the moveable member (412) of the actuator (410) is a shift fork.
7. The lubrication system (300) of claim 1 , wherein the actuator (370, 410) is operable to move the clutch assembly (330) in a first direction.
8. The lubrication system (300) of claim 7 , further comprising:
a biasing element (360) that is operable to move the clutch assembly (330) in a second direction, wherein the second direction is opposite the first direction.
9. The lubrication system (300) of claim 1 , wherein the actuator (370, 410) is operable to move the clutch assembly (330) in a first direction and a second direction.
10. The lubrication system (300) of claim 1 , wherein the actuator is an electromagnetic coil (370) that is operable to produce a magnetic field when energized, and energization of the electromagnetic coil (370) causes the clutch assembly (330) to move from the engaged position toward the disengaged position.
11. The lubrication system (300) of claim 1 , wherein the actuator is an electromagnetic coil (370) that is operable to produce a magnetic field when energized, and energization of the electromagnetic coil (370) causes the clutch assembly (330) to move from the disengaged position toward the engaged position.
12. A lubrication system (300) for a transfer case (120, 200), comprising:
a shaft (302) having a lubricant inlet port (306) and a hollow bore (304) for transporting lubricant within the shaft (302);
a pump (310) having a pump housing (312) and one or more pumping elements (318) that are disposed in the pump housing (312);
a first clutch rotor (340) that is disposed on the shaft (302) and is connected to the one or more pumping elements (318) such that rotation of the first clutch rotor (340) causes operation of the one or more pumping elements (318) of the pump (310);
a second clutch rotor (350) that rotates in response to rotation of the shaft (302) and has an engaged position, in which rotational force from the shaft (302) is transferred to the first clutch rotor (340) to cause operation of the pump (310), and a disengaged position, in which rotational force from the shaft (302) is not transferred to the first clutch rotor (340); and
an actuator (370, 410) connected to the second clutch rotor (350) that is operable to cause the second clutch rotor (350) to move between the engaged position and the disengaged position.
13. The lubrication system (300) of claim 12 , wherein the first clutch rotor (340) rotates independent of the shaft (302) when the second clutch rotor (350) is in the disengaged position.
14. The lubrication system (300) of claim 12 , wherein the actuator (410) is one of an electrical actuator, a hydraulic actuator, or a pneumatic actuator.
15. The lubrication system (300) of claim 12 , wherein the actuator is an electromagnetic coil (370) that is operable to produce a magnetic field when energized, and energization of the electromagnetic coil (370) causes the second clutch rotor (350) to move from the engaged position toward the disengaged position.
16. The lubrication system (300) of claim 12 , wherein the actuator is an electromagnetic coil (370) that is operable to produce a magnetic field when energized, and energization of the electromagnetic coil (370) causes the second clutch rotor (350) to move from the disengaged position toward the engaged position.
17. A lubrication system (300) for a transfer case (120, 200), comprising:
a shaft (302) having a lubricant inlet port (306) and a hollow bore (304) for transporting lubricant within the shaft (302);
a pump (310) having a pump housing (312) and one or more pumping elements (318) that are disposed in the pump housing (312);
a first clutch rotor (340) that is disposed on the shaft (302) and is connected to the one or more pumping elements (318) such that rotation of the first clutch rotor (340) causes operation of the one or more pumping elements (318) of the pump (310);
a second clutch rotor (350) that rotates in response to rotation of the shaft (302) and has an engaged position, in which rotational force from the shaft (302) is transferred to the first clutch rotor (340) to cause operation of the pump (310), and a disengaged position, in which rotational force from the shaft (302) is not transferred to the first clutch rotor (340); and
an electromagnetic coil (370) that is operable to produce a magnetic field when energized and disposed on either an axial face (348) of the first clutch rotor (340) or an axial face (356) of the second clutch rotor (350), wherein energization of the electromagnetic coil (370) causes the second clutch rotor (350) to move between the engaged position and the disengaged position.
18. The lubrication system (300) of claim 17 , energization of the electromagnetic coil (370) causes the second clutch rotor (350) to move from the engaged position toward the disengaged position.
19. The lubrication system (300) of claim 17 , energization of the electromagnetic coil (370) causes the second clutch rotor (350) to move from the disengaged position toward the engaged position.
20. The lubrication system (300) of claim 17 , wherein the electromagnetic coil (370) causes the second clutch rotor (350) to move in a first direction between the engaged position and the disengaged position, and a biasing element (360) causes the second clutch rotor (350) to move in a second direction between the engaged position and the disengaged position.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US15/263,746 US20170082190A1 (en) | 2015-09-17 | 2016-09-13 | Transfer Case Lubrication System with Disengagable Pump |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US14/857,296 US9440532B1 (en) | 2015-09-17 | 2015-09-17 | Transfer case lubrication system with disengagable pump |
US15/263,746 US20170082190A1 (en) | 2015-09-17 | 2016-09-13 | Transfer Case Lubrication System with Disengagable Pump |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US14/857,296 Continuation US9440532B1 (en) | 2015-09-17 | 2015-09-17 | Transfer case lubrication system with disengagable pump |
Publications (1)
Publication Number | Publication Date |
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US20170082190A1 true US20170082190A1 (en) | 2017-03-23 |
Family
ID=56881228
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
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US14/857,296 Active US9440532B1 (en) | 2015-09-17 | 2015-09-17 | Transfer case lubrication system with disengagable pump |
US15/263,746 Abandoned US20170082190A1 (en) | 2015-09-17 | 2016-09-13 | Transfer Case Lubrication System with Disengagable Pump |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
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US14/857,296 Active US9440532B1 (en) | 2015-09-17 | 2015-09-17 | Transfer case lubrication system with disengagable pump |
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US (2) | US9440532B1 (en) |
DE (1) | DE102016117433B4 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
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US20180319276A1 (en) * | 2017-05-04 | 2018-11-08 | Borgwarner Inc. | Tubeless lubrication delivery system for a compact transfer case |
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JP6177270B2 (en) * | 2015-03-25 | 2017-08-09 | 株式会社豊田中央研究所 | Engaging device and automatic transmission |
US9440532B1 (en) * | 2015-09-17 | 2016-09-13 | Borgwarner Inc. | Transfer case lubrication system with disengagable pump |
DE102017127522A1 (en) | 2016-12-09 | 2018-06-14 | Borgwarner Inc. | Transfer case lubrication system with damper |
US10309522B2 (en) * | 2017-01-23 | 2019-06-04 | Borgwarner Inc. | Transfer case pump with multiple flow paths to internal components |
US11146157B2 (en) * | 2018-05-03 | 2021-10-12 | Schaeffler Technologies AG & Co. KG | Dual rotor electric machine in an automotive application |
DE102019217821B3 (en) * | 2019-11-19 | 2020-10-08 | Magna Pt B.V. & Co. Kg | Actuator arrangement for a motor vehicle drive train |
CN113803379B (en) * | 2021-09-24 | 2022-08-05 | 滨海县恒丰粮食机械有限公司 | Clutch device and method of pneumatic grain elevator |
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JP4203527B1 (en) * | 2007-07-18 | 2009-01-07 | アイシン・エィ・ダブリュ株式会社 | Hybrid vehicle drive device |
WO2009035678A1 (en) * | 2007-09-12 | 2009-03-19 | Borgwarner Inc. | Transfer case employing an itm coupling at the output shaft of the transfer case |
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2015
- 2015-09-17 US US14/857,296 patent/US9440532B1/en active Active
-
2016
- 2016-09-13 US US15/263,746 patent/US20170082190A1/en not_active Abandoned
- 2016-09-15 DE DE102016117433.5A patent/DE102016117433B4/en active Active
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US3180469A (en) * | 1960-12-14 | 1965-04-27 | Zahnradfabrik Friedrichshafen | Spring-pressed clutch with electromagnetic release |
US7624853B2 (en) * | 2005-09-12 | 2009-12-01 | Magna Powertrain Usa, Inc. | Torque coupling with disconnectable lubrication pump |
US9440532B1 (en) * | 2015-09-17 | 2016-09-13 | Borgwarner Inc. | Transfer case lubrication system with disengagable pump |
Cited By (2)
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US20180319276A1 (en) * | 2017-05-04 | 2018-11-08 | Borgwarner Inc. | Tubeless lubrication delivery system for a compact transfer case |
US10583734B2 (en) * | 2017-05-04 | 2020-03-10 | Borgwarner Inc. | Tubeless lubrication delivery system for a compact transfer case |
Also Published As
Publication number | Publication date |
---|---|
US9440532B1 (en) | 2016-09-13 |
DE102016117433A1 (en) | 2017-03-23 |
DE102016117433B4 (en) | 2017-09-28 |
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