CN106460836B

CN106460836B - Petrolift

Info

Publication number: CN106460836B
Application number: CN201580024262.4A
Authority: CN
Inventors: 林宣博
Original assignee: Denso Corp
Current assignee: Aisan Industry Co Ltd
Priority date: 2014-11-11
Filing date: 2015-11-04
Publication date: 2018-10-19
Anticipated expiration: 2035-11-04
Also published as: KR101851537B1; WO2016075898A1; CN106460836A; KR20160122821A; DE112015005116T5; JP6319056B2; JP2016089809A

Abstract

Pump chamber (40) be defined in the internal tooth (300) of external gear (30) and the external tooth (200) of internal gear (20) closest between position, be connected to multiple.Reference axis (Ae) is defined on eccentric direction (De), definition is from the drift angle (θ) of reference axis (Ae) on the direction of rotation (Rig) of internal gear (20), and defines the quadrature axis (Ao) for having rectangular drift angle (θ) relative to reference axis (Ae).In this case, the drift angle (θ) of middle position (P) on the direction of rotation (Rig) of suction inlet (120) is set at than quadrature axis (Ao) closer to low-angle side, and about drift angle (θ), suction inlet (120) from the volume enlargement amount of each pump chamber (40) of per unit angle become the maximum amount of peak angle to low-angle lateral deviation from, and configure on quadrature axis (Ao).

Description

Petrolift

The application is with the Japanese patent application submitted on November 11st, 2014 the 2014-229156th, disclosure of which It quotes in this manual.

Technical field

The present invention relates to the petrolifts that fuel is drawn into pump chamber from suction inlet and is sprayed from the pump chamber.

Background technology

In the past, the known external gear with multiple internal tooths and the positive displacement with formation pump chamber between the internal gear of external tooth Petrolift.

Such as in the petrolift disclosed in patent document 1,2, internal gear is eccentric to eccentric direction and is engaged with external gear And it rotates, the volume enlargement of the pump chamber between two gears or diminution as a result,.At this moment, fuel is inhaled into the side of volume enlargement Pump chamber, side of the pump chamber along with the rotation of two gears and as volume reducing, to spraying fuel with pressurized state. Here, the external tooth being arranged in the internal tooth and internal gear of external gear is connected closest to the pump chamber between position is multiple, so can lead to It crosses each pump chamber while realizing the sucking and ejection of fuel.

In petrolift disclosed in patent document 1,2, in the pump case for rotatably accommodating two gears, formed useful In the suction inlet that fuel is drawn into pump chamber.Here, define reference axis in eccentric direction, in the direction of rotation of internal gear definition from The drift angle of reference axis, and the quadrature axis for having rectangular drift angle relative to reference axis is defined, in the combustion disclosed in patent document 1,2 In material pump, relative to reference axis and quadrature axis, the range for the drift angle that suction inlet is configured is different.

Specifically, in petrolift disclosed in patent document 1, about drift angle, than quadrature axis more to low-angle side The whole region of suction inlet is configured in the range of deviation.In the case of configuring like this, it is located at the small of the low-angle side of drift angle The pump chamber of volume is opposed with suction inlet, so the practical fuel quantity sucked to the opposed pump chamber of the suction inlet tails off.As a result, with Suction inlet compared to drift angle closer in the pump chamber of large angle side, across pump case and two gears and from the opposed pump of suction inlet The fuel quantity of room supply is reduced, so the efficiency of pump declines.

On the other hand, in petrolift disclosed Patent Document 2, on the direction of rotation of internal gear, in suction inlet The drift angle of centre position is set to right angle, to configure suction inlet on quadrature axis.In the case of this configuration, it is located at orthogonal The pump chamber of big volume on axis is opposed with suction inlet, to increase the fuel quantity that can be sucked to pump chamber.But if it is just Suction inlet in quadrature axis ensures to inhibit the big opening area of the pressure loss, then in the pump chamber opposed with suction inlet, with drift angle The volume enlargement amount of relevant per unit angle excessively increases, so the fuel quantity correspondingly actually sucked with the volume enlargement amount It is insufficient.As a result, in pump chamber of the drift angle closer to large angle side compared with suction inlet, across pump case and two gears and from The fuel quantity of the opposed pump chamber supply of suction inlet is reduced, so the efficiency of pump declines.

In such a case, the present inventor be conceived to the volume enlargement amount about each pump chamber of drift angle per unit angle at For the maximum amount of peak angle, it was found that suitably set the drift angle that suction inlet is configured relative to the peak angle and quadrature axis Range, to improve the efficiency of pump.

Existing technical literature

Patent document

Patent document 1：Japanese Unexamined Patent Publication 2012-197709 bulletins

Patent document 2：Japanese Unexamined Patent Publication 2011-132894 bulletins

Invention content

Present invention has been made in view of the above circumstances, it is intended that providing a kind of petrolift that the efficiency of pump is high.

In the present invention, a kind of petrolift is provided, is had：External gear has multiple internal tooths；Internal gear has multiple outer Tooth is prejudicially engaged with external gear to eccentric direction；And pump case, be formed with the suction inlet of sucking fuel, by external gear and Internal gear rotatably accommodates.External gear and internal gear make volume enlargement or the diminution one for the pump chamber being formed between two gears on one side Side rotates, to which fuel is drawn into pump chamber from suction inlet and is sprayed from the pump chamber.Pump chamber is defined in internal tooth and external tooth most It is thus multiple to be connected close between position.Reference axis is defined on eccentric direction, is defined from base on the direction of rotation of internal gear The drift angle of fiducial axis, and the quadrature axis for having rectangular drift angle is defined relative to reference axis.In this case, suction inlet is above-mentioned The drift angle of middle position on direction of rotation be set at than quadrature axis more lean on low-angle side, and suction inlet relative to drift angle from The volume enlargement amount of each pump chamber of per unit angle becomes the maximum amount of peak angle and is deviated to low-angle side, and configures just In quadrature axis

According to the construction of the petrolift, on the direction of rotation of internal gear, although the drift angle of middle position is more than quadrature axis Suction inlet by low-angle side configures on quadrature axis, but from the volume enlargement of each pump chamber relative to drift angle per unit angle Amount become the maximum amount of peak angle to low-angle lateral deviation from.It is located at the pump chamber and suction inlet of the big volume on quadrature axis as a result, It is opposed, to increase the fuel quantity that can be sucked to pump chamber.Moreover, in the pump chamber opposed with suction inlet, per unit angle Volume enlargement amount is suppressed than maximum smaller, so as to prevent the fuel correspondingly actually sucked with the volume enlargement amount Amount is insufficient.As a result, in pump chamber of the drift angle closer to large angle side compared with suction inlet, it can be ensured that pass through pump case and two teeth The fuel quantity fed from the opposed pump chamber of suction inlet between wheel, so the efficiency of pump can be improved.

Description of the drawings

Fig. 1 is the partial cross section front elevation for the petrolift for indicating an embodiment of the invention.

Fig. 2 is the figure for the petrolift for indicating an embodiment, is the II-II line sectional views of Fig. 3.

Fig. 3 is the III-III line direction views of Fig. 2.

The IV-IV line sectional views of Fig. 4 Fig. 2.

Fig. 5 is the V-V line sectional views of Fig. 2.

Fig. 6 is the line VI -- VI sectional view of Fig. 2.

Fig. 7 is the schematic diagram of the detailed configuration of the petrolift for illustrating an embodiment.

Fig. 8 is the chart of the characteristic of the petrolift for illustrating an embodiment.

Fig. 9 is the chart of the efficiency of pump of the petrolift for illustrating an embodiment.

Specific implementation mode

Hereinafter, based on description of the drawings an embodiment of the invention.

As shown in Figure 1, the petrolift 1 of an embodiment of the invention is the trochoid pump (trochoid of positive displacement pump).Petrolift 1 has the pump main body 3 being contained in inside the cylindric pump housing 2 and electro-motor 4.Also, petrolift 1 has Side cover 5, the electro-motor 4 in the pump housing 2 stretches out the side cover 5 from the outside portion in opposite side of pump main body 3 in axial direction. This, side cover 5 is provided integrally with the electric connector 5a for being powered to the electro-motor 4 and ejection port 5b for spraying fuel. In such petrolift 1, by being powered from external circuit via electric connector 5a, electro-motor 4 is driven in rotation.As a result, Using the rotary force of electro-motor 4, the fuel by pumping the sucking of main body 3 and pressurization is sprayed from port 5b is sprayed.In addition, about combustion Material pump 1, can spray gasoline as fuel, can also spray light oil.

Following detailed description pump main body 3.As shown in Figure 1, 2, pump main body 3 has pump case 10, internal gear 20 and external gear 30.Here, pump case 10 is made of being overlapped pump cover 12 and pump case 14.

Pump cover 12 is formed as discoid by metal.Pump cover 12 in axial direction the electro-motor 4 in the pump housing 2 and from side The outside portion in opposite side of cover 5 is stretched out.

As shown in Fig. 1,3,4, pump cover 12 is formed with the poroid suction inlet 120 of cylinder and circle to suck fuel from outside The suction passage 122 of arc channel-shaped.Suction inlet 120 is along the axis direction of pump cover 12 by the interior center of the slave internal gear 20 in pump cover 12 The privileged site Ss perforations of line Cig bias.Pump case 14 side opening of the suction passage 122 in pump cover 12.As shown in figure 4, sucking The inner peripheral portion 122a of access 122 extends to the length of discontented half cycle along the direction of rotation Rig of internal gear 20 (with reference to Fig. 6).It inhales The peripheral part 122b for entering access 122 extends to the length of discontented half cycle along the direction of rotation Rog of external gear 30 (with reference to Fig. 6).

Here, suction passage 122, from the 122c of front end, the terminal part 122d more towards direction of rotation Rig, Rog is wide Degree is bigger.In addition, by making suction inlet 120 be open in the privileged site Ss of trench bottom 122e, suction passage 122 and the suction inlet 120 connections.In turn, as shown in Figure 3,4, the sucking in the whole region of the privileged site Ss of the opening of suction inlet 120, diameter direction The width Wip of access 122 is smaller than the diameter phi of suction inlet 120.

As shown in Fig. 2, pump case 14 is formed as bottomed cylindrical by metal.It is covered by pump cover 12 opening portion 140 in pump case 14 Lid, to closed throughout complete cycle.As shown in Fig. 2,5,6, the inner peripheral portion 147 of pump case 14 is formed as from the interior center of internal gear 20 The cylinder of line Cig bias is poroid.

As shown in Figure 1,5, pump case 14 is formed with the poroid ejection access 142 of circular arc, to pass the fuel through the pump housing 2 and electronic Fuel passage 6 between motor 4 and sprayed from port 5b is sprayed.Spray the concave bottom portion that access 142 penetrates through pump case 14 along axis direction 141.As shown in figure 5, the inner peripheral portion 142a for spraying access 142 extends to discontented half cycle along the direction of rotation Rig of internal gear 20 Length.The peripheral part 142b for spraying access 142 extends to the length of discontented half cycle along the direction of rotation Rog of external gear 30.

Here, spraying access 142 from the 142c of front end, the terminal part 142d more towards direction of rotation Rig, Rog is wide It spends smaller.In addition, spraying access 142 by being preceding for being broken by inhibiting ribs 143 of the diameter Direction distortion of pump case 14 The end sides 142c and the sides terminal part 142d.In turn, spray access 142 the both sides of the front end sides 142c and the sides terminal part 142d with Fuel passage 6 shown in FIG. 1 is connected to.

As shown in Figure 1,5, in the concave bottom portion 141 of pump case 14, (detailed feelings of pump chamber 40 between two gears 20,30 Condition remains aftermentioned) position opposed with suction passage 122, it is accordingly formed with the shape for axially projecting access 122 The suction tank 144 of circular arc channel-shaped.As a result, in pump case 14, sprays access 142 and be symmetrically arranged with 144 line of suction tank.Another party Face, as shown in Fig. 1,4, in pump cover 12 across pump chamber 40 with spray the opposed position of access 142, with by access 142 along axis The shape of direction projection is accordingly formed with the spray tank 124 of circular arc channel-shaped.As a result, in pump cover 12, suction passage 122 and spray Go out 124 line of slot to be symmetrically arranged.

As shown in Figure 1, 2, on the interior center line Cig in the concave bottom portion 141 of pump case 14, in order to accept electricity on diameter direction It moves the rotary shaft 4a of motor 4 and is fixed with journal bearing 146.On the other hand, on the interior center line Cig in pump cover 12, It is fixed with thrust bearing 126 in order to accept rotary shaft 4a in axial direction.

As shown in Figure 2,6, the concave bottom portion 141 of pump case 14 and inner peripheral portion 147 mark off receiving internal gear together with pump cover 12 20 and external gear 30 accommodation space 148.Internal gear 20 and external gear 30 are to form the tooth curve of respective tooth 200,300 For the so-called trochoid gear of secondary pendulum curve.

In internal gear 20, by keeping interior center line Cig consistent with rotary shaft 4a, prejudicially configured in accommodation space 148. The inner peripheral portion 202 of internal gear 20 is accepted by journal bearing 146 on diameter direction, and the concave bottom portion 141 for passing through pump case 14 It is accepted in axial direction with pump cover 12.By these bearings, internal gear 20 can be around interior center line Cig to certain rotation Direction Rig rotates.

Internal gear 20 has the multiple external tooths equally spaced arranged on such direction of rotation Rig in peripheral part 204 200.As a shown in Figure 6, each external tooth 200 can with the rotation of internal gear 20 accordingly in axial direction with access 122,142 and Slot 124,144 is opposed, to inhibit the stretching to concave bottom portion 141 and pump cover 12.

As shown in Figure 2,6, external gear 30 is eccentric relative to the interior center line Cig of internal gear 20, in accommodation space 148 Interior configuration is on the same axis.As a result, relative to external gear 30, internal gear 20 is inclined on the eccentric direction De as a diameter direction The heart.The peripheral part 302 of external gear 30 is accepted by the inner peripheral portion 147 of pump case 14 on diameter direction, and passes through pump case 14 Concave bottom portion 141 and pump cover 12 are accepted in axial direction.By these bearings, external gear 30 can be around from interior center line Cig Eccentric outer center line Cog is rotated to certain direction of rotation Rog.

External gear 30 has the multiple internal tooths equally spaced arranged on such direction of rotation Rog in inner peripheral portion 304 300.Here, the quantity of the internal tooth 300 on external gear 30 than the external tooth 200 on internal gear 20 quantity more than one.Such as Fig. 1,6 institutes Show, each internal tooth 300 can with the rotation of external gear 30 correspondingly in axial direction with 124,144 pairs of access 122,142 and slot It sets, to inhibit the stretching to concave bottom portion 141 and pump cover 12.

Internal gear 20 engages by the relative eccentric of eccentric direction De with external gear 30.As a result, in accommodation space 148 In two gears 20,30 between, as shown in fig. 6, pump chamber 40 have it is multiple be connected and formed.

Here, as shown in fig. 7, define reference axis Ae on eccentric direction De of the internal gear 20 relative to external gear 30, Bias angle theta of the definition from reference axis Ae on the direction of rotation Rig of internal gear 20.In addition, relative to reference axis Ae at a right angle (90 Degree) bias angle theta orthogonal direction Do on define quadrature axis Ao.In turn, the region that bias angle theta is 0 degree~180 degree is defined as sucking Region Ti.In addition, in inhalation area Ti, the external tooth 200 of internal gear 20 and the internal tooth 300 of external gear 30 are closest, so will rule The position for determining the both ends of pump chamber 40 is defined as using positive integer n closest to position Sa [n].

Under these definitions, each pump chamber 40 of inhalation area Ti is across bias angle theta closest to position Sa [n] and bias angle theta Smaller angle side is prescribed respectively closest between position Sa [n-1].Here, in inhalation area Ti, will determine each The both ends of pump chamber 40 closest to the large angle side in position Sa [n], Sa [n-1] closest to the bias angle theta at position Sa [n] It is particularly defined as drift angle (hereinafter referred to as " pump chamber angle ") θ r of each pump chamber 40.In addition, in the figure 7, it is schematic using double dot dash line Ground is shown closest to position Sa [n].

Under above definition, in the bias angle theta from reference axis Ae across the inhalation area Ti of the range of quadrature axis Ao, close In being opposed to the pump chamber being connected to 40 with suction passage 122 and suction tank 144, the pump chamber angle θ r as bias angle theta are bigger, then volume is got over Expand.As a result, in inhalation area Ti, fuel is inhaled into pump chamber 40 from suction inlet 120 by suction passage 122.At this moment, from Front end 122c is more more widened towards terminal part 122d (with reference to Fig. 4), the i.e. bigger position of bias angle theta, suction passage 122, so Correspond to the volume enlargement amount Δ V of pump chamber 40 shown in Fig. 8 by the fuel quantity that the suction passage 122 is inhaled into.In turn, it is inhaling Enter region Ti, using unit angle Δ θ related with pump chamber angle θ r, the volume of the pump chamber 40 from the θ r of pump chamber angle is subtracted into pump chamber Difference obtained from the volume of pump chamber 40 at the θ r- Δs θ of angle is defined as the volume enlargement amount Δ V of per unit angle delta θ.In addition, Unit angle Δ θ is set as 5 degree in fig. 8, but unit angle Δ θ can also can be set as such as 1 degree.

In volume enlargement amount the Δ V, inhalation area Ti shown in Fig. 8 of each pump chamber 40 of such per unit angle delta θ, Become maximum in the peak angle θ rp as pump chamber angle θ r.Here, in the present embodiment, suction inlet 120 is made to be configured The whole region Ta of bias angle theta is from peak angle θ rp to small angle lateral deviation from and being set on quadrature axis Ao.Meanwhile at this In embodiment, the bias angle theta at the middle position P on the direction of rotation Rig of suction inlet 120 is set to smaller than quadrature axis Ao Angle side.

On the other hand, relative to the inhalation area Ti illustrated so far, the region that bias angle theta is 180 degree~360 degree is determined Justice is ejection region To.In the To of the ejection region, the pump chamber being connected to is opposed to about with ejection access 142 and spray tank 124 40, the pump chamber angle θ r as the bias angle theta defined according to inhalation area Ti are bigger, then volume more reduces.As a result, spraying area Simultaneously, fuel is ejected into combustion to above-mentioned intake function in domain To, with inhalation area Ti from pump chamber 40 by spraying access 142 Expect access 6.At this moment, it sprays access 142 more towards the bigger position of terminal part 142d, i.e. bias angle theta from front end 142c and more contracts It is narrow, so corresponding to the smaller volume amount of pump chamber 40 by the fuel quantity that the ejection access 142 sprays.In addition, at this moment fuel is logical Road 6 is connected to port 5b is sprayed, so coming the ejection fuel of fuel passage 6 further from the spray by spraying access 142 Exit port 5b is ejected into outside.

Here, to passed through the fuel spray volume substantially proportional efficiency of pump η for spraying access 142 as shown in figure 9, with It the bias angle theta of the middle position P on the direction of rotation Rig of suction inlet 120 and changes.From the Fig. 9 it is found that even if internal gear 20 Rotating speed Nr is transformed to 4000rpm, 6000rpm and 8000rpm, and efficiency of pump η also shows similar alteration trend.Here, at this In embodiment, the bias angle theta of middle position P shown in Fig. 3,4,6,7 is set in extra high 70 degree~85 degree of efficiency of pump η's Range Tp.In addition, showing that it is 843.6kg/m to contemplate density as fuel in Fig. 9³And viscosity is 2.53 × 10^- ³The light oil of Pas and the example the case where depth of the suction passage 122 in the axis direction of pump case 10 is set as 1.5mm Son.

(function and effect)

Illustrate the function and effect of petrolift 1 described above below.

According to petrolift 1, the bias angle theta of middle position P is than quadrature axis Ao smallers on the direction of rotation Rig of internal gear 20 The suction inlet 120 of angle side configures on quadrature axis Ao, but about the pump chamber angle θ r as bias angle theta, per unit angle delta θ's The volume enlargement amount Δ V of each pump chamber 40 from as the maximum amount of peak angle θ rp to low-angle lateral deviation from.It is located at as a result, orthogonal The pump chamber 40 of big volume on axis Ao is opposed with suction inlet 120, and the fuel quantity so as to be sucked to pump chamber 40 increases.Moreover, In the pump chamber 40 opposed with suction inlet 120, the volume enlargement amount Δ V of per unit angle delta θ is suppressed smaller than maximum, institute The fuel quantity correspondingly actually sucked with volume enlargement amount Δ V can be prevented insufficient.As a result, compared with suction inlet 120 Pump chamber angle θ r are in the pump chamber 40 of large angle side, it can be ensured that pass through pump case 10 and two from the opposed pump chamber 40 of suction inlet 120 The fuel quantity fed between gear 20,30, so efficiency of pump η can be improved.

In addition, according to petrolift 1, the bias angle theta for configuring the middle position P of the suction inlet 120 on quadrature axis Ao is set For 70 degree~85 degree of range Tp, so can ensure the volume of the pump chamber 40 opposed with the suction inlet 120 as wide as possible.And And the bias angle theta of middle position P is the suction inlet 120 of 70 degree~85 degree of range Tp, even if increasing to inhibit the pressure loss Opening area can also be reliably achieved arrangement and whole region that middle position P more leans on low-angle side than quadrature axis Ao The arrangement that Ta deviates from peak angle θ rp.Thereby it is ensured that improving the reliability of the effect of efficiency of pump η.

In turn, according to petrolift 1, in the inhalation area Ti for sucking fuel from suction inlet 120, the sucking opposed with pump chamber 40 Access 122 is then more to be widened in the bigger position of bias angle theta.It is bigger as the pump chamber angle θ r of bias angle theta as a result, in volume enlargement In the pump chamber 40 of the sides inhalation area Ti, for the fuel quantity actually sucked from suction inlet 120, it can be ensured that with suction passage 122 Size accordingly amount and avoid deficiency.Therefore, in addition to it is such to suction passage 122 be open suction inlet 120 it is special Above-mentioned effect caused by arrangement, additionally it is possible to realize high efficiency of pump η.

In addition, according to petrolift 1, in inhalation area Ti, across pump chamber 40 and with the opposed position of suction passage 122, Suction tank 144 is formed as the shape for projecting the access 122.As a result, large angle side is more leaned on than suction inlet 120 in pump chamber angle θ r In pump chamber 40, it can reliably ensure by suction tank 144 between pump case 10 and two gears 20,30 from suction inlet 120 Opposed pump chamber 40 feed fuel quantity.Therefore, efficiency of pump η, and the suction tank opposed with suction passage 122 can not only be improved 144 especially effectively.

In addition, according to petrolift 1, be formed as the poroid suction inlet 120 of cylinder, even identical opening area, itself The whole region Ta of the privileged site Ss configured can also narrow as much as possible on the direction of rotation Rig of internal gear 20.Cause This, the suction inlet 120, even if whole region Ta easy to implement is from peak value if increasing opening area to inhibit the pressure loss The arrangement that angle, θ rp deviates.Therefore, efficiency of pump η can not only be improved, and the poroid suction inlet 120 of cylinder is especially effectively.

(other embodiment)

An embodiment of the invention is explained above, but the present invention is not limited to the embodiments, are not departing from this In the range of the purport of invention, various embodiments can be suitable for.

It, can will be in suction inlet 120 as long as more lean on low-angle side than quadrature axis Ao specifically, in variation 1 The bias angle theta of centre position P is set as the angle outside 70 degree~85 degree of range Tp.But in the case of variation 1, certainly Need to make the whole region Ta of suction inlet 120 from peak angle θ rp to low-angle lateral deviation from and be set on quadrature axis Ao.

In variation 2, the width of suction passage 122 can be set as to real from front end 122c towards terminal part 122d It is constant width in matter.In addition, in variation 3, the width for spraying access 142 can be set as from front end 142c directions Terminal part 142d is essentially constant width.

In variation 4, ribs 143 can also be not provided in pump case 14 and used between both ends 142c, 142d The ejection access 142 of not disjunction.In addition, in variation 5, can not also be arranged suction tank 144 and spray tank 124 at least certain One side.

In variation 6, suction inlet 120 can also be formed as cylinder it is poroid other than shape, it is for example oval poroid or Rectangle is poroid etc..In addition, in variation 7, suction inlet 120 can also be made obliquely to be passed through relative to axis direction in pump cover 12 It is logical.

Claims

1. a kind of petrolift, has：

External gear (30) has multiple internal tooths (300)；

Internal gear (20) has multiple external tooths (200), is prejudicially engaged to eccentric direction (De) with the external gear (30)；With And

Pump case (10) is formed with the suction inlet (120) of sucking fuel, can by the external gear (30) and the internal gear (20) Rotatably accommodate,

The pump chamber (40) that the external gear (30) and the internal gear (20) make to be formed between the two gears by one side Volume enlargement or diminution rotate on one side, fuel from the suction inlet (120) are drawn into the pump chamber (40) and from the pump chamber (40) it sprays,

The pump chamber (40) be defined in the internal tooth (300) and the external tooth (200) closest between position, to multiple It is connected,

Reference axis (Ae) is defined on the eccentric direction (De), is defined on the direction of rotation (Rig) of the internal gear (20) From the drift angle (θ, θ r) of the reference axis (Ae), and defines and having the rectangular drift angle just relative to the reference axis (Ae) Quadrature axis (Ao),

The drift angle of middle position (P) on the direction of rotation (Rig) of the suction inlet (120) is set at than described Quadrature axis (Ao) closer to low-angle side,

The suction inlet (120) is, each pump chamber of the drift angle of the suction inlet (120) from per unit angle (Δ θ) (40) volume enlargement amount (Δ V) become the maximum amount of peak angle (θ rp) to low-angle lateral deviation from, and configure it is described just In quadrature axis (Ao).

2. petrolift as described in claim 1,

The drift angle of the middle position (P) of the suction inlet (120) is set in 70 degree~85 degree of range (Tp).

3. petrolift as claimed in claim 1 or 2,

The pump case (10) is right with the pump chamber (40) from the inhalation area (Ti) that the suction inlet (120) sucks fuel The position set forms suction passage (122), which is formed as, and in the bigger position in the drift angle, width is got over Greatly,

The suction inlet (120) is open towards the suction passage (122).

4. petrolift as claimed in claim 3,

The pump case (10) is opposed with the suction passage (122) across the pump chamber (40) in the inhalation area (Ti) Position formed suction tank (144), which is the shape for projecting the suction passage (122).

5. petrolift as claimed in claim 1 or 2,

It is poroid that the suction inlet (120) is formed as cylinder.