Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B39/00—Component parts, details, or accessories relating to, driven charging or scavenging pumps, not provided for in groups F02B33/00 - F02B37/00
  • F02B39/02—Drives of pumps; Varying pump drive gear ratio
  • F02B39/04—Mechanical drives; Variable-gear-ratio drives
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B33/00—Engines characterised by provision of pumps for charging or scavenging
  • F02B33/44—Passages conducting the charge from the pump to the engine inlet, e.g. reservoirs

Definitions

• the invention relates to a drive system for systems operated with an internal combustion engine, for example motor vehicles, with control and regulating elements for setting and maintaining predeterminable operating states, with a mechanical compressor of the displacer type, with a transmission with which the driving force of the engine in two components is distributable, one of the components being transferable to the output shaft of the system and being drivable with the other component of the compressor and the compressor sucking in and compressing air for charging the engine on the one hand and transferring power back to the transmission on the other hand and the output speed steplessly by means of throttle valves is adjustable.
• Continuously variable transmissions face the fundamental problem that a change in the speed ratio of two shafts is principally only possible with a temporary or permanent partial cancellation of the Power transmission between them is possible.
• the form and time course of the system-related slip in the case of translation changes ultimately also result in the specific disadvantages of the mechanical and hydraulic types and designs of continuously variable transmissions according to the prior art, be they defined or undefined slip intervals of a mechanical or hydraulic type. Also pneumatic transmissions were easy to insert into this outline.
• Turbo-chargers which are operated with the energy of the exhaust gas, work under considerable thermal stress and achieve their effect in a manner that is strongly dependent on the engine speed. All known charger systems have in common that they consume energy and are operated independently of the power transmission. The problem of drive systems with internal combustion engines of converting the limited range of the cheapest engine speed to a larger speed range of the drive shaft is not addressed.
• the invention has for its object to integrate gearboxes and loaders so that they complement each other in their effect, the disadvantages of the known continuously variable transmission types to be avoided and the designed drive system compared to the known systems with comparable efficiency easier to set up and adjust should be.
• This object is achieved in that the compressor has an overpressure chamber on the engine side and a vacuum chamber on the intake side and the vacuum chamber has a throttle valve, that the overpressure chamber and the vacuum chamber are connected to one another in parallel with their conveying path via at least one return flow channel with a throttle valve With the help of another throttle valve, part of the compressor drive torque is used to generate negative pressure in the negative pressure chamber and a pneumatic device transmits a retroactive torque to the output shaft, this retroactive torque being proportional to the pressure difference between the pressure in the pressure chamber and in the vacuum chamber.
• Figure 1 shows the structure of the action of the drive system.
• 2 shows a preferred embodiment of the system-specific transfer case as a system component in the simplest form;
• FIG. 3 shows the structure of the pneumatic device and its interaction with the system component shown in FIG. 2, the mechanical force flow being represented by double lines, the air flow by single lines and the fuel and exhaust gas flow by dash-dot lines;
• Fig. 4 is a schematic representation of a three-stage embodiment for a switchable torque amplification with superposition of the stages and automatic phase change, as an extension of the system component shown in Fig. 2, in interaction with the system component shown in Fig. 3, with drive on one Sun gear and output to the reverse gear, not shown, from the associated planetary web.
• the system component shown in FIG. 1 is a conventional internal combustion engine as a drive source, with fuel and air supply.
• the required air can be conveyed into the combustion chambers in various ways, depending on the structural design and use of the vehicle, namely via the system-specific compressor of the pneumatic device 3 and only above or in addition, in bypass operation, via a suction valve 5 from the outside or additionally or exclusively via a further charger 4, which is advantageously driven by the system component 2.
• the rotational energy of the crankshaft is first transferred to the system component 2 in a form-fitting manner.
• the system component 2 consisting of at least one transfer case, can also be used in various designs.
• Fig. 2 a simple epicyclic gear transmission with spur gears and an internally toothed wheel is shown schematically.
• the drive takes place via the planet web 21.
• the planet gears thus distribute the driving force into a component that is available via the internally toothed wheel 23, for example for the output, and into a component that via the sun gear 22 onto the Device 3 acts.
• this ratio q can be changed continuously during operation and set to the optimum value.
• a clutch as starting or shifting aid is therefore not required.
• the system component 3 shown in FIG. 3 consists of at least one mechanical compressor 32 with a displacement effect, preferably a Roots loader or a half-roller compressor, with a special seal against penetrating oil, and an upstream vacuum chamber 31 on the intake side , a downstream pressure chamber 33 on the engine side as well as return flow channels 34 and the associated throttle valves D1, D2, D3.
• a mechanical compressor 32 with a displacement effect preferably a Roots loader or a half-roller compressor, with a special seal against penetrating oil
• an upstream vacuum chamber 31 on the intake side preferably a Roots loader or a half-roller compressor, with a special seal against penetrating oil
• an upstream vacuum chamber 31 on the intake side preferably a Roots loader or a half-roller compressor, with a special seal against penetrating oil
• an upstream vacuum chamber 31 on the intake side preferably a Roots loader or a half-roller compressor, with a special seal against penetrating
• components 2 and 3 act as pneumatically controllable superposition gears with particularly low friction losses and with partial recovery of the energy used to change the speed.
• the combination can also be viewed as a device for mechanically charging the engine with the side effect of a stepless change in the speed ratio during power transmission.
• the backflow valves D3 are mainly needed for idling and part-load operation; they are closed during the acceleration process.
• the air mass that can flow in per unit time for example through valve D1, there is a maximum value according to the flow theory (with a monotonously tapering nozzle) with the relationship in which the outlet cross section of the nozzle at D1 and p the maximum possible value of current density is with the air density and the
• Flow velocity u. is to be regarded as a constant specific for air for the current flow process; because Y applies
• the thermals of the system always remain adjustable; because the vacuum chamber 31 serves, among other things. as a cooling device against the temperature increase in the pressure chamber 33 when the engine is charging. This autonomous cooling is also advantageous when there is little external cooling, e.g. at low vehicle speed. In addition, both this negative pressure and the excess pressure of the air chamber 33 can be used for servo units outside the drive system.
• the boost pressure p 3 ⁇ P 2 arises depending on the speed of the compressor 32 and the valve setting D1, D2, D3. Determining and controlling the optimal opening of the individual valves depending on the driving situation is technically easy, in particular with the help of a microprocessor and by expanding an already existing motor electronics
• the efficiency of the drive system is only determined by affects the heat flow between the air chambers 33 and 31 negatively - more precisely: by the part of the heat released in 33 that cannot be dissipated to the chamber 31.
• this part can be additionally restricted by constructional means.
• Mechanical reduction stages in particular planetary gear sets, which are known in this function, for example with brakes and clutches, can be activated to amplify the drive torque.
• an arrangement of planetary gear sets can also be used for the drive system according to the invention, which - as an extension of the system component 2 - can advantageously be combined with the pneumatic device 3 and which does not have any for changing the individual torque phases Switching elements such as brakes, clutches and the like, and no separate switching control is required.
• Such an arrangement is essentially realized with one or more coaxially engaged group gears, the ring gear of which is supported on the housing via a freewheel, preferably according to the diagram shown in FIG. 4.
• the individual planetary gear sets are connected to the pneumatic device 3 via the sun gear 442 of the system-specific transfer case 44 and via a hollow shaft.
• the drive through the crankshaft of the engine is guided via the sun gear 421 into the collective gear 42, which is coupled to the preceding collective gear 41.
• the ring gear 413 is blocked by the freewheel 461 against reverse running, so that the drive is initially passed on only via the planetary web 422, and is reduced.
• the type of coupling and the constructively selectable design of the planetary gear sets 41 and 42 influence the degree of reduction and the adjustment range of the individual reduction phases.
• the wheel 422 conducts the correspondingly increased force via the sun gear 431 into a further collective gear 43, the ring gear 433 of which likewise cannot avoid the drive torque, due to the freewheel 463
• the resulting, in turn, increased force is thus transmitted to the planetary web 441 of the transfer case 44 and to the sun gear 451 of the inner gear set 45.
• the power transmission takes place at idle as long as the hollow 453 and the ring gear 443 firmly connected to it can move backwards.
• a 2-stage embodiment results e.g. 4 without the planetary gear sets 41 and 42. More planetary gear sets are required in each case than when using brakes and clutches, i.e. with alternative switching of individual stages, but for this - with the exception of the sun gear 442, which drives the compressor 32 - the speed of all central gears, especially the outer, most massive central gears, and the planet carrier up to the ratio 1: 1 is always lower than that Engine speed; the relative speed of the individual wheels disappears in the course of vehicle acceleration, and the activation or deactivation of the individual reduction stages takes place autonomously, i.e. without external aids, solely depending on the speed ratio between the crankshaft and compressor, depending on the position of the throttle valves D1, D2, D3.
• phase-wise superimposition of the individual reduction stages also has the advantage over the switching of alternative stages that a phase change additionally activates or deactivates a stage with a constant, in particular with a constant course of the engine speed is possible.
• this freewheel is equipped with a locking element that can be released from the outside, e.g. 48, provided.
• a separate parking lock is therefore not necessary.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Supercharger (AREA)
• Structure Of Transmissions (AREA)

Applications Claiming Priority (4)

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• 1986
  • 1986-04-01 DE DE19863611171 patent/DE3611171A1/de active Granted
• 1987
  • 1987-01-15 EP EP87900796A patent/EP0253856A1/de not_active Withdrawn
  • 1987-01-15 WO PCT/DE1987/000021 patent/WO1987004490A1/de not_active Application Discontinuation
  • 1987-11-20 US US07/117,204 patent/US4825839A/en not_active Expired - Fee Related

Non-Patent Citations (1)

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