Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
  • F01D17/00—Regulating or controlling by varying flow
  • F01D17/10—Final actuators
  • F01D17/12—Final actuators arranged in stator parts
  • F01D17/14—Final actuators arranged in stator parts varying effective cross-sectional area of nozzles or guide conduits
  • F01D17/141—Final actuators arranged in stator parts varying effective cross-sectional area of nozzles or guide conduits by means of shiftable members or valves obturating part of the flow path
  • F01D17/143—Final actuators arranged in stator parts varying effective cross-sectional area of nozzles or guide conduits by means of shiftable members or valves obturating part of the flow path the shiftable member being a wall, or part thereof of a radial diffuser
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
  • F01D17/00—Regulating or controlling by varying flow
  • F01D17/10—Final actuators
  • F01D17/12—Final actuators arranged in stator parts
  • F01D17/14—Final actuators arranged in stator parts varying effective cross-sectional area of nozzles or guide conduits
  • F01D17/16—Final actuators arranged in stator parts varying effective cross-sectional area of nozzles or guide conduits by means of nozzle vanes
  • F01D17/167—Final actuators arranged in stator parts varying effective cross-sectional area of nozzles or guide conduits by means of nozzle vanes of vanes moving in translation
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2220/00—Application
  • F05D2220/40—Application in turbochargers

Definitions

• This invention relates to turbocharger apparatus and it relates more especially to variable turbocharger apparatus.
• turbocharger apparatus Different types of turbocharger apparatus are known.
• One known type of turbocharger apparatus comprises a housing, a compressor mounted for rotation in the housing, a turbine mounted for rotation in the housing, a first inlet for enabling air to be conducted to the compressor, an outlet for air from the compressor, a second inlet for enabling exhaust gases from an engine to be conducted to the turbine, and a chamber which surrounds the turbine and which receives the exhaust gases from the second inlet before the exhaust gases are conducted to the turbine.
• This known type of turbocharger apparatus is such that there is a fixed gap through which the exhaust gases in the chamber can pass to the turbine. The size of this gap is chosen to be a compromise between the various different sizes of gap that are ideally required for different engine operating conditions.
• the gap is not exactly correct and the turbocharger apparatus thus operates at less than its optimum performance.
• the turbocharger apparatus gives a quick response but excessive pressure tends to build up in the chamber.
• the build up of excessive pressure in the chamber is avoided but then the response time of the turbine apparatus is slow.
• variable turbocharger apparatus comprising a housing, a compressor mounted for rotation in the housing, a turbine mounted for rotation in the housing, a first inlet for enabling air to be conducted to the compressor, an outlet for air from the compressor, a second inlet for enabling exhaust gases from an engine to 'be conducted to the turbine, a chamber which surrounds the turbine and which receives the exhaust gases from the second inlet before the exhaust gases are conducted to the turbine, and a piston which is positioned between the turbine and the housing and which is slidable backwards and forwards to form a movable wall separating the turbine from the chamber which surrounds the turbine, the piston having a plurality of vanes, the piston being such in its closed position it terminates short of an adjacent part of the housing so that there is always a gap between the end of a piston and the adjacent part of the housing whereby exhaust gases from the 5 chamber can always pass through the gap to act on the turbine, the
• the fork means enables the piston to be moved backwards and forwards in an axial direction without forcing the piston to one side and thus causing it to bind in the variable turbocharger apparatus.
• the piston comprises a cylindrical body portion having the groove provided at that end of the body portion remote from the gap.
• a lug for receiving a pin for preventing rotation of the piston.
• the piston will usually be arranged to slide in a cylindrical part of the housing.
• the fork means is located on a shaft that is mounted in the housing.
• the shaft may be connected to an actuator valve which enables movement to be applied to the fork means.
• the fork means is preferably a bifurcated fork but other types of fork means may be employed.
• the variable turbocharger apparatus may include an air bleed passage which leads from the outlet for air from the compressor to the actuator valve, the air bleed passage enabling air to be directed against a diaphragm in the actuator valve in order to cause movement of the actuator valve, whereby movement of the actuator valve can be transmitted to the fork means and the piston in dependence upon air bleed pressure.
• the air bleed pressure will usually be dependent upon the speed of rotation of the compressor.
• a separate air supply may be used.
• the separate air supply may be provided by a small separate electronic compressor.
• micro-processors can be used to monitor a selected parameter or parameters and to compute the position of the piston to give the required piston position.
• variable turbocharger apparatus may be one in which the piston is provided with a lug which co-operates with a pin for preventing rotation of the piston.
• variable turbocharger apparatus is one in which the vanes on the piston co-operate with vanes provided on or engaging the turbine housing.
• the vanes on or engaging the turbine housing are preferably on an insert secured to the turbine housing. If desired however the vanes may be cast as part of the turbine housing.
• the vane arrangement may allow a close down of over 50% between the vanes in the closed position, whilst maintaining the vanes in an overlapping position when in the open position, so that the vanes are able to direct all the available gases at an appropriate angle onto the turbine.
• the vanes on the piston co-operate with slots in a heat shiel
• the heat shield may have a chamber into which the vanes project, the chamber being sealed tight so as to prevent gas leakage to a low pressure side of the turbine.
• the vane arrangeme may be one in which the heat shield has through slots which accommodate inlet vanes mounted on the piston, the inlet vanes entering into the chamber which is a part of the back of the heat shield.
• the piston will be spring biased to its closed position.
• the piston is spring biased to its closed position by a single coil spring.
• the single coil spring is axially positioned inside the actuator valve.
• more than one spring may be employed.
• biasing means other than springs may be employed.
• the variable turbocharger apparatus may include sealing means for forming a sliding seal between the piston and the housing.
• the sealing means may comprise at least one sealing piston ring.
• sealing piston ring Pre erably, only one sealing piston ring is employed but more than one sealing piston ring may be employed if desired.
• the or each sealing piston ring may be located in a cylindrical body portion of the piston. Alternatively, the or each sealing piston ring may be mounted in the housing.
• the end of the piston adjacent the gap may be chamfered. This chamfered end of the piston may help to prevent the build up of products of combustion at this point with some types of engine, for example 2- and 4- stroke petrol driven engines.
• variable turbocharger apparatus may include at least one bearing against which the sealing means slides backwards and forwards.
• bearing When a bearing is employed, it is preferred that the bearing be located in the housing adjacent the cylindrical body portion of the piston.
• the variable turbocharger apparatus may include a heat shield.
• the variable turbocharger apparatus includes a heat shield which is positioned inside the piston such that the piston is slidable backwards and forwards over the heat shield.
• the heat shield may be mounted over the bearing housing so as to leave an air space between the bearing housing and the heat shield.
• the heat shield may have a flange at one end so that it can be held in position on the bearing housing by screws or by any other desired and appropriate means.
• the housing is separable into at least two parts. This may facilitate assembly of the variable turbocharger apparatus and it may also facilitate fixing of the variable turbocharger apparatus in various engine compartments of various vehicles.
• the housing may be separable into three parts comprising two end parts and a central part *
• the variable turbocharger apparatus may advantageously include a chamber in which the fork means locates , the piston being such as to cover the chamber to prevent a heat build-up on the fork means and to prevent a turbulent gas flow at an exit part of the turbine.
• variable turbocharger apparatus may be one in which the piston has an end in which is mounted a conical diffuser, the conical diff ser being for facilitating gas extraction from the turbine.
• the variable turbocharger may advantageously be one in which the piston includes at least one solid piston ring.
• the variable turbocharger apparatus may be one in which the piston is mounted inside the turbine housing such that the piston slides directly over the turbine to allow a large gas exit area. This in effect means that the turbine is so constructed that it does not have a trim part.
• the present invention also extends to an engine when provided with the variable turbocharger apparatus.
• the engine may be any general type of engine including diesel and ' petrol driven engines.
• Figure 1 is a cross section through first variable turbocharger apparatus
• Figure 2 is a side view of the piston shown in Figure 1;
• Figure 3 is an end view of the piston shown in Figure 2;
• Figure 4 is an end view of part of the first variable turbocharger apparatus;
• Figure 5 is a side view of a heat shield showing an air gap over a bearing housing;
• Figure ⁇ is a cross section through an air actuator valve;
• Figure 7 is a cross section through second variable turbocharger apparatus;
• Figure 8 is a cross section through third variable turbocharger apparatus;
• Figure 9 is a cross section through fourth variable turbocharger apparatus
• Figure 10 is an end view of the second, third and fourth variable turbocharger apparatus shown in Figures 7, 8 and 9;
• Figure 11 is an end view of a heat shield provided with vanes
• Figure 12 is a side view of the heat shield shown in Figure 11;
• Figure 13 illustrates how the vanes enter slots
• Figure 14 is a side view showing a first vane arrangement in an open position
• Figure 15 is a side view showing the first vane arrangement of Figure- 14 in a closed position
• Figure 16 is a cross sectional view showing a second vane arrangement in an open position
• Figure 17 is a cross sectional view showing the second vane arrangement in a closed position
• Figure 18 is an end view of the second vane arrangement
• Figure 19 is a side view showing the vanes of the second vane arrangement in an open position
• FIG 20 is a side view showing the vanes of the second vane arrangement in a closed position.
• first variable turbocharger apparatus 2 comprises a housing 4 and a compressor ⁇ .
• the compressor 6 has blades 8.
• the compressor 6 is mounted for rotation in the housing 4 by being mounted on a central shaft 10.
• a turbine 12 is also mounted for rotation in the housing 4 by being mounted on the shaft 10.
• the turbine 12 has blades 14.
• the housing 4 has a first inlet l ⁇ for enablin air to be conducted to the compressor 6.
• the housing 4 also has an outlet 18 for air from the compressor.
• the outlet 18 enables air from the compressor 6 to be conducted to an engine (not shown).
• the housing 4 has a second inlet 20 for enabli exhaust gases from the engine to be conducted to the turbine 12.
• a chamber 22 surrounds the turbine 12 and this chamber 22 receives the exhaust gases from the second inlet 20 before the exhaust gases are conducted to the turbine 12.
• the chamber 22 may be regarded as a volute-shaped toroidal chamber.
• a piston 24 is positioned between the turbine 12 and the housing 4.
• the piston 24 is slidable backwards and forwards to form a movable wall separating the turbine 12 from the chamber 22 which surrounds the turbine 12.
• the piston 24 is such that in its closed position it terminates short an adjacent part 2 ⁇ of the housing 4 so that there is always a gap 28 between the end 30 of the piston 24 and the adjacent part 26 of the housing 4. This means that exhaust gases from the chambe 22 can always pass through the gap 28 to act on the blades 14 of the turbine 12.
• the piston 24 is such that in its open position, the gap 28 is increased.
• the piston 24 is biased to its closed position against pressure from exhaust gases in the chamber 22 during use of the variable turbocharger apparatus 2 so that the piston 24 slides backwards and forwards to vary the gap 28 in dependence upon engine operating conditions
• the piston 24 is biased by means of an actuator valve 7.
• the piston 24 comprises a cylindrical body portion 34 having a groov 36 at that end of the body portion 34 remote from the gap 28.
• fork means in the form of a bifurcated fork 21 is located in the groove 36.
• the fork 21 is also fitted to a shaft 54 which can rotate in a bearing housing 68.
• a metal bar 91 On top of the shaft 54 is a metal bar 91 which is connected to the actuator valve 7.
• the actuator valve 7 thus acts as control means.
• the first variable turbocharger apparatus 2 includes sealing means in the form of a sealing piston ring 52.
• the sealing piston ring 52 is for forming a sliding seal between the piston 24 and the housing 4.
• the sealing piston ring 52 is located in the turbine housing 66.
• the sealing piston ring 52 can alternatively be located in the piston 24 as shown by dotted lines 58 in Figure 2.
• the end 30 of the piston 24 is chamfered as shown so that any products of combustion from the exhaust gases in the chamber 22, which may tend to build up on the part of the piston 24 forming the movable wall, may tend to break away and thus not hinder the sliding movement of the piston 24.
• the variable turbocharger apparatus 2 includes a heat shield 17.
• the heat shield 17 has a flange 19. .0 T ⁇ e heat shield 17 is mounted with screws 20 over the bearing housing 68.
• Figure 5 shows an air gap between the bearing housing 68 and the heat shield 17.
• a sealing ring may be located in the heat shield 17 as shown in Figure 5 by dotted
• sealing ring may be located inside the bore of the piston 24, as shown in Figure 1 by dotted lines 75, to operate on the outside of the heat shield 17.
• turbocharger apparatus shown in Figures 1 to 6 is that the housing 4 is separable into two end parts 64,66 and a central part 68. This may facilitate positioning of the variable turbocharger apparatus 2 in various required positions in various engine compartments in vehicles or in other apparatus.
• the end part 64 is secured to the central part 68 by means of a cir-clip 70.
• the end part 66 is secured to the central part 68 by locking washers 72 which are held in position by bolts 74.
• the end part 64 forms a compressor housing, the end part 66 forms a turbine housing, and the central part 68 forms a bearing housing.
• the variable turbocharger apparatus 2 is also provided with an oil intake pipe 76 for providing oil for bearings (not shown) on the shaft 10.
• the shaft 10 is formed with a friction welded head 78 at one end.
• the other end of the shaft 10 is screw threaded as shown to receive a nut 80, which is effective to hold the compressor 6 in position.
• An oil return pipe 82 is also provided for enabling the oil provided for the bearings via the oil intake pipe 76 to drain away.
• the second inlet 20 is provided with a flange 86.
• the flange 86 has bolt holes 88 so that the flange 86 can be bolted to an exhaust outlet (not shown) of the engine.
• the compressor 6 is surrounded by a chamber 90 which is somewhat similar to the chamber 22.
• a seal in the form of an 0-ring seal 92 is provided as shown.
• the exhaust gases from the engine are able to drive the turbine 12 at substantially always the required rate to enable the compressor 6 to provide the amount of air required by the engine from the variable turbocharger apparatus 2, via the outlet 18.
• the bleeding of air along the air bleed passage 60 is effective to act on the actuator valve 7 to cause the piston 24 to slide towards its open position in which the size of the gap 28 is increased.
• the piston 24 is provided with an annular groove, shown by the dotted lines 58, for receiving the sealing piston ring 52.
• the sealing piston ring 52 may be located in the housing 4 as shown in Figure 1.
• the groove 36 is also shown in Figure 2, for receiving the fork 21.
• Figures 2, 3 and 4 show that on the piston 24 there is a lug 146 which may have a slot 144 as shown, or a hole (not shown), for location on to a pin 142.
• the pin 142 may be mounted in the bearing housing 68 as shown, or alternatively in the turbine housing 66.
• the pin 142 and the lug 146 are provided to prevent rotation of the piston 24.
• the piston 24 is such that the face 100 of the end 30 is provided with vanes 102.
• the vanes 102 are oriented so that they direct the incoming gas flow in a tangential direction to provide the appropriate gas flow.
• the vanes 102 are cut or otherwise provided in the end 30 of the piston 24.
• Vanes 104 are also provided in the turbine housing 66,the vanes 104 being provided in the form of an insert 31 as shown in Figure 1. Alternatively, the vanes 104 may be cast into the turbine housing 66.
• the angular positions of the vanes 102,104 in the turbin housing 66 and the piston 24 are such that the- vanes 102 on the piston 24 are interposed with the vanes 104 in the turbine housing 66. Relative displacement of the piston 24 varies the extent of overlap of the vanes 102,104.
• FIG 7 there is shown second variable turbocharger apparatus in which similar parts as in Figure 1 have been given the same reference numera and will not again be described.
• Figure 7 shows how the heat shield 17 is used as an insert to hold the vanes 104.
• the insert is also shown in Figure 11 and Figure 12.
• Figures 11 and 12 show respectively an end view and a side view of the heat shield 17, provided with the ' vanes 104.
• FIG 8 there is shown third variable turbocharger apparatus in which similar parts as in Figure 7 have been given the same reference numerals and will not again be described.
• a trim 136 as shown in Figure 7 on the turbine 12 has been removed. This is to allow a larger exit area from the turbine 12.
• the piston 24 is slightly different in that the piston 24 terminates in a conical diffuser 132.
• Figure 9 shows fourth variable turbocharger apparatus 2 which is similar to the variable turbocharger apparatus 2 shown in Figure 8 but which employs a longer piston 24 to prevent gases building up in an area 134. Also, turbulent gas flow in the area 134 and turbulent gas flow leading to the outlet of the variable turbocharger apparatus 2 is avoided or reduced.
• the longer piston 24 of Figure 9 also has the conical diffuser 132.
• turbocharger apparatus 2 which may be the variable turbocharger apparatus 2 shown in either of Figures 7, 8 or 9. Again similar parts as in the previo Figures have been given the same reference numerals and their precise construction and operation will not again be given.
• a control arm 91 which terminates in a connection member 140 for connecting to the actuator valve 7.
• the actuator valve 7 takes pressure from the compressor side of the turbine 12.
• the pressure may be taken from an engine management system (not shown)
• Figure 10 also shows a pin 142 which locates in an aperture 144 in a lug 146 formed on the piston 24.
• the pin 142 acts to stop rotation of the piston 24 during the backwards and forwards sliding movement of the piston 24.
• Figure 10 further shows how the fork 21 has two arms 148, 150.
• the arm 148 has a pin 152 and the arm 150 has a pin 154.
• the pins 152, 154 locate in the groove 36 and thus enable the piston 24 to be moved backwards and orwards without putting undue sideways pressure on the piston 24 which could move it out of axial sliding alignment and could thus cause the piston 24 to bind.
• the fork 21 is attached to a rod 54 which is mounted in the turbine housing 66.
• the rod 54 connects to the control arm 91 as shown.
• the slots 10 are provided in the piston 24.
• the slots 10 receive the vanes 104 and the vanes 104 may extend from an insert.
• the reverse arrangement may be employed in which the slots are in the insert, and in which the vanes 104 for the slots then project from the piston 24.
• the slots may be cast in the turbocharger apparatus housing.
• the slots 10 may be omitted.
• the slots that may be omitted may thus be in the piston
• the above described variable turbocharger apparatus employs sealing means in the form of a sealing piston ring 52.
• the sealing means may be a sealing ring other than a split piston ring. Where a split piston ring is employed, this may be inwardly sprung to bear against the outer surface of the piston 24 in order to effect the required seal against gases. Such a split piston ring 52 will rub on the surface of the piston 24 and thus some friction will be created. Whilst this is satisfactory in many circumstances, if it is desired to reduce or obviate this friction, then a solid piston ring may be employed. Because this solid piston ring does not have a split in it, it is not inwardly sprung and thus friction is reduced.
• variable turbocharger apparatus operates, exhaust gases will be contacting the piston ring.
• these exhaust gases may cause the split piston ring to operate with a hammering effect on the surface of the piston 24, and this can be disadvantageous and can cause undesirable wear on the surface of the piston 24.
• the use of the solid piston ring may help to avoid this hammering effect and may thus again reduce undesirable wear on the surface of the piston 24. Irrespective of whether a split piston ring or a solid piston ring is employed, it may be advantageous to produce the piston ring from a material which has substantially the same, rate of expansion as the material from which the piston 24 is produced.
• the piston 24 and the piston ring can expand at substantially the same rate to avoid creating unnecessary friction as might be the case if the piston 24 expanded more than the piston ring.
• the piston 24 and the piston ring can be made of the same or different materials.
• FIG. 16 and 17 a second vane arrangement is shown in which the heat shield 17 is replaced by a heat shield 201.
• the heat shield 201 has a chamber
• the chamber 203 is preferably a sealed unit along a face 320.
• Figures 18, 19 and 20 illustrate the heat shield 201.
• Figure 18 is an end view which shows the heat shield 201 with the vanes 102 entering slots 260 in the heat shield 201.
• Figure 19 shows the vanes 102 in the open position, whilst Figure 20 shows the vanes 102 in the closed position.
• the movement of the piston 24 on this second vane arrangement is the same as described above with reference to Figures 7, 8 and 9.
• the vanes 102, 104 may take a different shape to those shown, and more or less vanes than those shown may be employed.
• the vanes 104 may be cast into the turbine housing 4 or they may be located in the turbine housing 4 as a separate part. If desired, the vanes may be reversed to allow a reverse rotation of the turbine 12.
• variable turbocharger apparatus 2 may be produced in various sizes commensurate with the size of engine to which the variable turbocharger apparatus 2 is to be fitted.
• the shape of the housing 4 can be varied as may be desired. Water cooled bearings may be incorporated.
• the housing 4 and the various components within the housing 4 can be made of any desired and suitable materials. Also, sealing ringsmay be added or dispensed with as desired.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Supercharger (AREA)
• Iron Core Of Rotating Electric Machines (AREA)

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• 1989
  • 1989-05-26 EP EP95107138A patent/EP0678657B1/de not_active Expired - Lifetime
  • 1989-05-26 EP EP89906165A patent/EP0442884B1/de not_active Expired - Lifetime
  • 1989-05-26 AU AU36930/89A patent/AU3693089A/en not_active Abandoned
  • 1989-05-26 DE DE68928865T patent/DE68928865T2/de not_active Expired - Lifetime
  • 1989-05-26 WO PCT/GB1989/000584 patent/WO1989011583A1/en active IP Right Grant
  • 1989-05-26 DE DE68925977T patent/DE68925977T2/de not_active Expired - Lifetime
  • 1989-05-26 AT AT95107138T patent/ATE173794T1/de not_active IP Right Cessation
  • 1989-05-26 AT AT89906165T patent/ATE135440T1/de not_active IP Right Cessation
• 1992
  • 1992-03-31 GB GB929206950A patent/GB9206950D0/en active Pending

Non-Patent Citations (1)

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