FI105283B - Improvements in pumps - Google Patents

Abstract

A variable output pump is of the gerotor type with a multi-lobed rotor meshed internally of an annulus with one extra lobe, the rotor comprising two parts axially arranged end-to-end and one of which is arranged to be phase shifted by relative rotation. After a 180 degree shift (Figure 5) the chambers formed between the rotors and annulus will comprise one axial part between rotor 10 and annulus 16 which is at maximum volume whilst the adjacent and communicating part between rotor 12 and the annulus will be at minimum volume and hence the pump will be in zero output condition. When both rotor parts are phase synchronised the pump is in maximum output condition; it can be turned to any intermediate position. <IMAGE>

Description

105283

IMPROVEMENTS RELATED TO PUMPS The present invention relates to pumps comprising a rotor gerotor group having n blades internally in contact with a ring having n + 1 blades. This provides a group of chambers, each defined between successive ridges of the rotor blades. When one of the rotor blades is in full contact with the space between the blades of the ring, the chambers immediately adjacent to that rotor blade are of minimal volume, while the more or less diametrically opposed ones are at maximum volume. In use, both the rotor and the ring rotate, albeit at different speeds and around the parallel axes, and each chamber moves about the axes to increase volume and then decrease volume. The inlet and outlet openings are located at one or both axial ends of the chambers, and as the chambers move over the inlet, their volume increases and sucks, and when they move over the outlet, they decrease in volume and expel. This is responsible for the pumping effect.

With the simple form of the pump described herein, the outlet volume is directly proportional to the operating speed.

The known type of such a pump has a ring which is shaped to form two end-to-end and relatively angular sections. Each ring is on an eccentric rim arranged to rotate to vary the eccentricity of the respective tire relative to the rotor. When both are synchronized in the normal position, where the plane containing the rotary axes of both the ring and rotor is generally between the inlet 25 and the outlet, maximum power is obtained, but twisting the two * · ·: i rings in opposite directions reduces power. This is thought to be due to: 1 · 1: that the chambers formed between the rotor and the rings are minimized in volume when first aligned with the inlet, and in one case their volume decreases in the first part of their orbit and, 1 ··. 30 they have not reached their maximum volume when they move out of focus • · - .1 ··. inlet: in the second case, the volume of the chambers increases when they first contact the inlet, but reach and • bypass the maximum volume, and therefore do not fill completely or drive some liquid out of the inlet before leaving the inlet. : ·] 35 Total power is thus reduced. Such a pump can be used, for example, in situations where relatively large volumes are required at low speeds but relatively smaller volumes at higher speeds.

EP-A 0 076 033 discloses a pump of the kind described in the preceding paragraph but it has been found difficult to operate. EP-A-0 174 734 5 discloses an improved version of the same pump which uses a needle bearing in an attempt to overcome these difficulties and EP-A-0 284 226 discloses a refined version of the pump in a form which has been commercially successful but is expensive to manufacture.

It is an object of the present invention to provide similar results, but to simplify construction and manufacture and therefore to make cheaper pumps.

A gero-rotor pump according to the invention having a single ring and adjustable power is known according to the invention from two axially adjacent rotors between which the angle can be adjusted.

Preferably, one of the rotors is mounted at an angle to the drive shaft and the other can move between end positions where it is respectively synchronized or fully in phase with the first rotor and 180 ° offset to be completely different from the first. This would provide power across the pump that ranges from zero to maximum, but in alternative designs they would be between minimum and maximum, that is, not up to zero.

The invention will now be described in more detail with reference to the accompanying drawings, in which Figs. 1-5 are schematic representations of a type 1, ·· 'rotor engaging a six-bladed ring and illustrating two

• I

Fig. 6 is a vertical sectional view of the presently preferred embodiment of the invention, and Fig. 7 is a sectional view taken along line 7-7 of Fig. 6.

Referring first to Figures 1-5, the rotor consists of two axially arranged, i.e. end to end, end-to-end rotors 10,. ···. 30 12. They are inside a ring 16 with six blades. These patterns represent: ···. also an inlet 18 formed in the body 20 and an outlet V 22 also formed in the body. These two openings are generally symmetric with respect to the plane PP, which includes the shaft 14 of the rotor 10 and the axis 24 of the ring.

Fig. 1 shows a zero position with two rotor parts in phase;

f «I

') Ti! synchronized: both rotate about axis 14. The rotor blade, which is arranged symmetrically with respect to the plane PP, is fully engaged in the space between the blades of the ring and the maximum diameter chamber is diametrically opposite, i.e. as indicated by reference numeral 28. When rotation occurs in the direction of arrow A in Figure 1, the smallest chamber 30 overlaps the inlet opening 16 brought to 5 with the head and the next largest chamber 32 overlaps the other end of the inlet opening. Similarly, the chambers 34, 36, which are generally opposed to the chambers 32, 30, pass over the outlet.

Figure 2 illustrates a situation in which two rotor parts are rotated so that they are at 45 ° in different phases. The rotor 10 is still on the shaft 14 but the rotor 10 12 is on the shaft 40, which is now separated from the shaft 14 and also from the shaft 24 which is the ring axis. Each chamber can now be thought of as being divided into two axially arranged, i.e. end to end (which are necessarily interconnected) but part consisting of a space radially between rotor 10 and ring 16 is as in Figure 1 but part of rotor 12 15 and the ring, is phase shifted so that it is effectively smaller than the inlet area but larger than the outlet area.

Fig. 3 shows a phase shift executed such that the axis of the rotor part 12 is now represented by reference numeral 40 and has moved 90 ° from the plane PP around point 24. In this position, the minimum volume chamber 20 of the rotor 12 is rotated to be completely within the inlet, while the two equal volume chambers are each aligned with the outlet. Figure ... 4 shows a phase shift of 135 ° and Figure 5 shows a phase shift of 180 °. In the latter case, the maximum volume chamber of the rotor 10 is aligned with the angle of the earth with the minimum volume chambers of the rotor 12 and the total effect is a zero pumping job.

Briefly, Fig. 1 shows a pump set for maximum pumping activity, Fig. 5 shows a pump set for minimal or zero pumping activity, and Figs. 2-4 show the steps between the two extremes.

. Turning now to Fig. 6, which illustrates phase-aligned rotors, "the same reference numerals as those used in Figs. 1-5. Rotor 10 is mounted on a *! * Shaft 50 also mounted on a drive gear 52, and the shaft is held at 54. the rotor 12 is bushed from position 56 to the non-Kesko 58 supported by shaft 60. In either case, bushings 35 are only recommended. The shaft 60 is on the shaft 62 which is concentric with the ring. The shaft 60 is also secured gear wheel 64.

• · 105283 4

The gear wheel is in contact with a rack 66 which is suitably mounted on a piston rod 68 supported by a piston 70 and can slide in a cylinder schematically represented by reference numeral 72. Fluid can be supplied to both cylinders via a bypass valve 74.

The changeover valve may be connected to a pump outlet or, for example, to an I.C. motor lubricant main channel fed by a pump so that the pressure is transmitted through a tube 76 and can act on a spindle 78 which is resisted by a spring 80. In the position illustrated, fluid flows through the mandrel, through radial openings in the mandrel, and through conduit 82. It can act on the piston 70 to move the ham-10 mast and to rotate the tooth bar.

When the pressure is sufficient to move the spindle against the spring, line 82 communicates with web 84 on spindle and what was return line 86 is contacted with line 76 so that the direction of movement of piston 70 is reversed. By selecting the spring according to that oil pressure, the 15 pumps can be automatically rotated between minimum and maximum positions and adjusted between them.

It will be understood that rotor 12 is indirectly driven by rotor 10 through a ring. This means that the shaft 50 rotates the rotor 10 which rotates the ring and the ring rotates the rotor 12.

In another embodiment, not illustrated, the rotor 12 is disposed in an eccentric sleeve supported by an extension of shaft 50.

... In yet another embodiment, not described, the ring is used and two rotors are mounted on respective eccentric sleeves, each of which are provided with straight-toothed pinions which are supported by a common shaft, • ·: · I wheels are located outside the rotors, i.e. at the opposite axial ends of the pump, and are arranged to be operated in the same and opposite manner by a gear drive system, for example by the hydraulic pressure of the pump acting on the piston and cylinder Therefore, the rotor shaft can be displaced, for example, by 90 ° and • · up to opposite directions, which rises to 180 ° gear shift capability, with the same consequences as in the first embodiment. This gives extra clever and simple construction.

Those skilled in the art will fully appreciate the simplicity of the present invention, particularly in the version illustrated in Figures 6 and 7, particularly by comparing the &quot; 1 &quot;

Claims (7)

1. Single-ring gerotor pump (16) whose effect is adjustable, characterized by two axially adjacent rotors (10, 12), the intermediate relative angle of which is adjustable. Pump according to claim 1, characterized in that one rotor (10) is angularly fixed in relation to a drive shaft (50), and the second rotor (12) is movable between extreme positions in relation to the first rotor (10). Pump according to claims 1 and 2, characterized in that the second rotor (12) is stored on an extension of the shaft (50) which supports the first rotor (10). Pump according to any of the preceding claims, characterized in that the second rotor (12) is mounted on an eccentric (58) supported by a shaft (50) stored on the shaft (24) and arranged to rotate for displacement - the phase of the other rotors (12) in relation to one rotor (10). Pump according to claim 4, characterized in that the drive shaft (50) and the coaxial shaft (60) with the ring are positioned end to end. Pump according to claims 4 and 5, characterized in that the second shaft (60) carries a gear (64) in engagement with a rack (66). 7. Pump according to any of the preceding claims, characterized in that the pump body (20) is provided with inlet openings (18) at opposite axial ends as well as outlet openings (22) at opposite axial ends. f «f I * III I {« I (I «« <«c • · · · · · · · · # · * ·« · * ·· ♦ «· · · · ♦ · • · · · · ·» ♦ · ··· • «• · ·« «Ml • I • · ···« CI <«« ·! (· I »• · f 1« t • · «l · i«