Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C14/00—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations
  • F04C14/10—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by changing the positions of the inlet or outlet openings with respect to the working chamber

Definitions

• This invention relates to pumps of the kind comprising a gerotor set of rotor with n lobes meshed internally of an annulus with n+1 lobes. This creates a set of chambers each defined between successive crests of the rotor lobes. When one rotor lobe is fully meshed with the interlobe space of the annulus, the chambers immediately next to that rotor lobe will be of minimum volume, whereas those more or less diametrically opposed will be of maximum volume. In use, both rotor and annulus turn, albeit at different speeds, and about parallel axes, and each chamber moves about the axes increasing in volume and then decreasing in volume.
• Inlet and outlet ports are located at one or both axial ends of the chambers, and as the chambers move over the inlet port they increase in volume and suck, and as they move over the outlet port they decrease in volume and expel. This is responsible for the pumping action.
• the output volume is directly related to drive speed.
• a known type of this kind of pump has the annulus duplicated so that it forms two end-to-end and relatively angularly movable portions.
• Each annulus lies in an eccentric ring, arranged to be turned to vary the eccentricity of the corresponding annulus relative to the rotor.
• the chambers formed between the rotor and annuli will not be at minimum volume when they first register with the inlet port and in one case will be reducing in volume for a first part of their orbit, and will not have reached maximum volume when they move out of register with the inlet port: in the other case the chambers will be increasing in volume when they first register with the inlet but will reach and pass maximum volume and hence either not fill completely or will expel some fluid into the inlet port before leaving the inlet port. So the total output is reduced.
• Such a pump may be used in situations where relatively large volume is needed at low speeds but relatively lower volumes at higher speeds, for example.
• EPA 0 076 033 shows a pump of the kind described in the preceding paragraph, but one which has been found difficult to operate.
• EPA 0 17.4 734 shows an improved versio -of the same pump using needle roller bearings in an attempt to overcome the difficulties and
• EPA 0 284 226 shows a more refined version of the pump in a form which has been commercially successful, but which is expensive to manufacture.
• the object of the present invention is to provide similar res.ults but to simplify design and manufacture and hence enable less expensive pumps to be made.
• a gerotor pump has a single annulus, and two axially adjacent rotors which are arranged to be relatively angularly adjusted.
• one of the rotors is angularly fixed in relation to a drive shaft, and the other is movable between two extreme positions in which it is respectively synchronised or wholly in phase with the first rotor, and 180 degree shifted to be wholly out of phase with the first.
• Figures 1-5 are diagrammatic representations showing a five lobe rotor engaged in a six lobe annulus and illustrating five different relative angular positions between the two rotor parts •
• Figure 6 is a sectional elevation of a presently preferred embodiment of the invention.
• Figure 7 is a section taken on the line 7-7 of Figure 6.
• the rotor consists of two axially arranged, i.e. end-to-end five lobed rotors 10 12. They are located within an annulus 16 having six lobes. These figures also show the inlet port 18 formed in body 20 and the outlet port 22 also formed in the body. The two ports are gene-rally symmetrical of the plane PP which contains the axis 14 of the rotor 10 and the axis 24 of the annulus.
• Figure 1 shows the zero position in which the two rotor parts are phase synchronised: both rotate about axis 14.
• the rotor lobe which is symmetrically arranged relative to the plane PP is fully engaged with an annulus interlobe space and the maximum diameter chamber is diametrically opposite, i.e. as indicated by the reference numeral 28.
• the smallest chamber 30 overlaps one end of the inlet port 16 and the next largest chamber 32 overlaps the other end of the inlet port.
• chambers 34 36 which are generally opposite to chambers 32 30 overlap the outlet port.
• FIG 2 shows the situation when the two rotor parts have been shifted so as to be 45 degrees out of phase.
• Rotor 10 is still on axis 14 but rotor 12 is on axis 40 which is now spaced from axis 14 and also from axis 24 which is that of the annulus.
• Each chamber may now be considered to be divided into two axially arranged i.e. end-to-end portions (which necessarily communicate with one another) but the portion composed of the space radially located between rotor 10 and annulus 16 is as in Figure 1, but that between rotor 12 and the annulus is phase shifted so that effectively over the area of the inlet port it is smaller, but over the area of the outlet port is larger.
• FIG. 3 shows the phase shift carried on so that the axis of the rotor part 12 is now shown by the
• SUBSTITUTE SHEET reference 40 is 90 degree removed from the plane PP about the point 24.
• the minimum volume chamber for rotor 12 has shifted to be wholly located within the inlet port whereas two equal large volume chambers are both substantially aligned with the outlet port.
• Figure 4 shows 135 degree phase shift
• Figure 5 shows 180 degree phase shift. In the latter case, the maximum volume chamber for the rotor 10 is angularly aligned with the minimum volume chambers for the rotor 12 and the total effect is a zero pumping action.
• Figure 1 shows the pump set for maximum pumping activity
• Figure 5 shows the pump set for minimum or zero pumping activity
• Figures 2-4 show intermediate stages between these two extremes.
• the pinion is meshed with a rack 66 which conveniently is mounted on piston rod 68 carried by piston 70 and slidable in a cylinder diagrammatically illustrated by the reference numeral 72.
• the cylinder may be supplied with fluid at either end via shuttle valve 74.
• the shuttle valve may be connected to pump output or for example the main lubricant gallery of an I.C. engine being supplied by the pump, so that pressure is communicated via the pipe 76 and can act upon the spool 78 resisted by the spring 80.
• fluid flows through the spool, through radial ports in the spool and via the passage 82. It can act upon the piston 70 to displace the rack and turn the pinion.
• rotor 12 is driven indirectly by rotor 10 via the annulus. That is to say the shaft 50 turns the rotor 10 which turns the annulus, and the annulus turns the rotor 12.
• rotor 12 is journalled on an eccentric bush carried on an extension of the shaft 50.
• the annulus is driven, and the two rotors are journalled on respective eccentric bushes each provided with straight tooth spur pinion gears carried on a common axis which is co-axial to the annulus.
• These pinions are located outside the rotors, i.e. at opposite axial ends of the pump, and arranged to be driven through equal and opposite amounts by a gear drive system for example operated by pump hydraulic pressure acting in a piston and cylinder to drive a rack turning the gears.
• a gear drive system for example operated by pump hydraulic pressure acting in a piston and cylinder to drive a rack turning the gears.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Rotary Pumps (AREA)
• Reciprocating Pumps (AREA)
• Details And Applications Of Rotary Liquid Pumps (AREA)
• Valve Device For Special Equipments (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)
• Vehicle Body Suspensions (AREA)
• Jet Pumps And Other Pumps (AREA)
• Lubrication Of Internal Combustion Engines (AREA)

Priority Applications (4)

Applications Claiming Priority (4)

Publications (1)

Family

ID=26300673

Family Applications (1)

Country Status (11)

Cited By (2)

Families Citing this family (7)

Citations (1)

Family Cites Families (2)

• 1993
  • 1993-04-05 GB GB9307074A patent/GB2265946B/en not_active Expired - Fee Related
  • 1993-04-06 DK DK93302689.0T patent/DK0565340T3/da active
  • 1993-04-06 WO PCT/GB1993/000720 patent/WO1993021443A1/en active IP Right Grant
  • 1993-04-06 EP EP93302689A patent/EP0565340B1/en not_active Expired - Lifetime
  • 1993-04-06 JP JP5518089A patent/JPH06508416A/ja active Pending
  • 1993-04-06 AT AT93302689T patent/ATE131579T1/de active
  • 1993-04-06 ES ES93302689T patent/ES2083824T3/es not_active Expired - Lifetime
  • 1993-04-06 DE DE69300999T patent/DE69300999T2/de not_active Expired - Fee Related
  • 1993-12-07 FI FI935470A patent/FI105283B/fi active
  • 1993-12-08 NO NO934469A patent/NO304752B1/no not_active IP Right Cessation
  • 1993-12-08 NO NO934469D patent/NO934469D0/no unknown
• 1996
  • 1996-02-07 GR GR960400317T patent/GR3018911T3/el unknown

Patent Citations (1)

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