Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
  • F04B1/12—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis
  • F04B1/26—Control
  • F04B1/30—Control of machines or pumps with rotary cylinder blocks
  • F04B1/303—Control of machines or pumps with rotary cylinder blocks by turning the valve plate
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
  • F04B1/04—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement
  • F04B1/06—Control
  • F04B1/07—Control by varying the relative eccentricity between two members, e.g. a cam and a drive shaft
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
  • F04B49/12—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00 by varying the length of stroke of the working members
  • F04B49/123—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00 by varying the length of stroke of the working members by changing the eccentricity of one element relative to another element
  • F04B49/125—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00 by varying the length of stroke of the working members by changing the eccentricity of one element relative to another element by changing the eccentricity of the actuation means, e.g. cams or cranks, relative to the driving means, e.g. driving shafts
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B7/00—Piston machines or pumps characterised by having positively-driven valving
  • F04B7/04—Piston machines or pumps characterised by having positively-driven valving in which the valving is performed by pistons and cylinders coacting to open and close intake or outlet ports
  • F04B7/06—Piston machines or pumps characterised by having positively-driven valving in which the valving is performed by pistons and cylinders coacting to open and close intake or outlet ports the pistons and cylinders being relatively reciprocated and rotated

Definitions

• the invention relates to a hydraulic piston pump having a drive shaft and having cylindrical pistons arranged axially or radially in a star shape thereon, which are arranged in a cylinder so as to be axially movable in a spring-loaded manner with respect to their longitudinal axis and which include a pump chamber between their end face and the cylinder, controlled, connectable by a control edge of the piston, and which is connected to an outlet valve, with a swash plate connected to the drive shaft and driving the pistons in the case of axially arranged pistons or eccentric shaft in the case of pistons arranged radially in a star shape and with a flow rate control.
• the hydraulic pump mentioned at the outset is provided for common rail injection systems.
• the object of the invention is to avoid these disadvantages mentioned.
• the aim is to achieve real delivery control while maintaining a simple and space-saving design, that is to say that only the desired amount of fuel is put under high pressure.
• the piston has on its end face a flattening or depression which forms the control edge together with the outer surface of the piston, such that the control edge of each piston is essentially oblique to the direction of the longitudinal axis of the piston, and that all pistons are provided rotating means in the same way.
• Embodiments of the invention are specified in subclaims 2 to 9.
• FIG. 1 shows a longitudinal section through a 5-cylinder pump with an axial piston arrangement (axial pump),
• FIG. 3 shows the same section as FIG. 2 with an electromagnetic rotary interlocking as a control unit
• FIG. 6 shows a longitudinal section through a 5-cylinder pump with a radial piston arrangement (radial pump),
• Fig. 7 is a supplementary representation of the piston rotation system (radial pump) and
• this conventional design of an axial piston pump with a non-adjustable delivery rate is designed in a simple manner as an adjustable pump as follows:
• the pistons 4 have, on their end facing the outlet valve 8, an oblique control edge 9 which - in the manner known from in-line injection pumps - corresponds to the inlet bore 10.
• the relevant inlet bore 10 is not closed by the oblique control edge 9 during the piston stroke (the fuel flows back - zero delivery) or, when the control edge 9 is turned away from the inlet bore 10, it is already on the front side of the piston 4 closed and all the fuel through the outlet valve 8 into the Sanxmelanschluß 11 (full delivery).
• each partial delivery can be adjusted according to the rotational position of the piston 4.
• the outlet valves 8 are arranged at the smallest distance from the pistons 4. In order to keep the pistons 4 free from lateral pressure forces at the high hydraulic pressures, two oblique control edges 9 arranged opposite to the piston 4.
• each piston head 6 has an external toothing 12 which engages in the corresponding internal toothing 13 of an adjustable ring gear 14.
• the outer toothings 12 also execute this stroke movement in the inner toothings 13. Because the adjustment forces are low, this is possible with a suitable choice of materials by the gear partners.
• prefabricated toothed segments 15 can also be placed on the piston heads 6. The fuel enters the housing 1 at the inlet opening 16 and flows from here via the cylinder space 17 to the inlet bores 10. Furthermore, fuel flows into the engine housing via the housing channel 18, cools the engine and leaves the pump at the outlet opening 19.
• Fig. 2 shows the adjustment of the ring gear 14, which in a conventional manner via a tangential
• Adjustment or restoring forces can be applied by electromagnets or by springs or the fuel pressure in the pump interior.
• an electromagnetic rotary actuator 21, z. B. a stepper motor engage directly via a partial toothing 22 in the ring gear 14 and adjust this. This results in an adjustment system integrated in the pump, which does not require any external seals.
• Fig. 5 shows the principle of a piston rotation system, in which a gear-like transmission is dispensed with.
• collars 23 are axially displaceable in the housing 1, but are held in a rotatable manner.
• These adjusting rings 23 have splines 24 in which the pistons 4 can slide with their external toothings 12 (now also splines).
• the adjusting rings 23 have machined bolts 25 which engage with their outer end via transversely drilled pivot pins 26 in the part 14. Instead of an internal toothing, this now has the corresponding number of bores for receiving the pivot pins 26.
• FIG. 6 shows the engine of a radial piston pump, which is located in a housing 1 (here in a star shape) and consists of a drive shaft 3 (here an eccentric shaft), intermediate elements such as sliding shoes, etc., shown here in simplified form by the race 27 and five pistons 4. These successively perform stroke movements out.
• a housing 1 here in a star shape
• drive shaft 3 here an eccentric shaft
• intermediate elements such as sliding shoes, etc.
• FIG. 6 shows the engine of a radial piston pump, which is located in a housing 1 (here in a star shape) and consists of a drive shaft 3 (here an eccentric shaft), intermediate elements such as sliding shoes, etc., shown here in simplified form by the race 27 and five pistons 4. These successively perform stroke movements out.
• fuel flows in via the inlet bore 10, which is located behind the piston 4.
• the bevel edge control works in the manner already described. If the oblique control edge 9 faces the inlet bore 10 such that it is not covered up to the end of the stroke
• the individual outlet valves 8 are connected to one another and to the collective outlet 11 via intermediate channels (not shown here).
• the fuel enters the pump via the inlet opening 16, flows on the one hand to the inlet bores 10, and on the other hand via the housing channel 18 through the engine to the outlet opening 19.
• the piston rotation system is designed according to the invention in such a way that each piston 4 has two machined, opposite sliding surfaces 28 has, on which the toothed segments 15 engage fork-shaped. These are held axially in housing slots and are in engagement with their external teeth 12 with counter teeth 29 of the ring gear 14.
• the gearing is designed as a bevel gear. With rotation of the ring gear 14, all the pistons 4 are adjusted in the desired sense and the delivery rate is regulated in this way.
• the control unit e.g. B. also here as an electromagnetic rotary interlocking 21, is completely integrated into the pump. It is directly connected to the ring gear 14 on the one hand and is supported in the housing 1 on the other hand.
• FIG. 7 shows a supplementary illustration of the piston rotation system in the radial pump.
• the pistons 4 with their oblique control edges 9 are supported by the race 27 on the eccentric of the drive shaft 3.
• the toothed segments 15 engage in a fork-like manner on the sliding surfaces 28 and, on the other hand, with their oblique external toothings 12 are in engagement with the counter toothing 29 of the ring gear 14.
• a hydraulic variable displacement pump can thus be manufactured in a simple manner without additional, precisely fitted elements or stroke-adjusting intermediate elements.
• FIG. 8 shows, in addition to FIG. 1 characterizing the invention, a further particularly advantageous embodiment of the invention.
• Each piston 4 moves with a fine fit in a separate cylinder liner 30.
• These cylinder liners 30 are inserted in the housing 1 and are countered by a closed pressure ring 31 by means of screws 32 the seal 33 pressed and thus sealed on the high pressure side.
• the housing 1 can be kept closed on the end face.
• the large screw connections, as shown in Fig. 1 on the front side and each of which must be sealed against high pressure, can be omitted.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Reciprocating Pumps (AREA)
• Details Of Reciprocating Pumps (AREA)
• Valve Device For Special Equipments (AREA)
• Lubrication Of Internal Combustion Engines (AREA)
• Rotary Pumps (AREA)
• Fuel-Injection Apparatus (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=7928918

Family Applications (1)

Country Status (7)

Families Citing this family (5)

Family Cites Families (8)

• 1999
  • 1999-11-13 DE DE19954639A patent/DE19954639C2/de not_active Expired - Fee Related
• 2000
  • 2000-11-13 CN CN00815556A patent/CN1390281A/zh active Pending
  • 2000-11-13 DE DE50003582T patent/DE50003582D1/de not_active Expired - Fee Related
  • 2000-11-13 AT AT00993113T patent/ATE248991T1/de not_active IP Right Cessation
  • 2000-11-13 WO PCT/DE2000/003952 patent/WO2001036820A1/fr not_active Application Discontinuation
  • 2000-11-13 AU AU28260/01A patent/AU2826001A/en not_active Abandoned
  • 2000-11-13 EP EP00993113A patent/EP1228313B1/fr not_active Expired - Lifetime
  • 2000-11-13 CZ CZ20022062A patent/CZ20022062A3/cs unknown

Non-Patent Citations (1)

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