CN103375671A

CN103375671A - Oil pump

Info

Publication number: CN103375671A
Application number: CN2013101308782A
Authority: CN
Inventors: 隈本正人; 千叶智阳; 内记长彦
Original assignee: Mikuni Corp
Current assignee: Mikuni Corp
Priority date: 2012-04-19
Filing date: 2013-04-16
Publication date: 2013-10-30
Also published as: JP2013221479A; US20130280041A1; JP6129483B2

Abstract

The present invention provides an oil pump which ensures desired pumping performance even if air or the like is mixed with oil to be sucked and provides pumping characteristics having desired high discharge pressure (discharge rate). The oil pump includes an upstream pump unit; a downstream pump unit and a housing which includes an inlet port, an ejection port, a communication port for providing communication between the upstream pump unit and the downstream pump unit, and a discharge port facing the upstream pump unit and used for discharging air-mixed oil from the downstream pump unit to the outside. Thus, the oil pump can effectively discharge the air in the oil, so as to ensure desired pumping performance and desired high discharge pressure (discharge rate).

Description

Oil pump

Technical field

The present invention relates to that oil (lubricant oil) with internal-combustion engine (motor) etc. sucks and the oil pump of ejection, particularly possess the internal rotor of trochoid formula, inscribed gear (involute) formula etc. and the oil pump of external rotor.

Background technique

The known oil pump that following motor is arranged, it possesses with inferior parts: shell; Running shaft (live axle), it is by outer casing supporting; Internal rotor make the internal rotor rotation by running shaft, and this internal rotor has external tooth; And external rotor, it has the internal tooth that engages with the external tooth of internal rotor, and cooperates with internal rotor and the pump chamber of delimiting out the variation of following volume, and for shell, it is provided with inferior parts: suction port, it is used for sucking oil; Ejiction opening, it is used for ejection oil; And air is removed hole (bubble exhaust port, degassed mouth), it is used for being blended into the Bas Discharged of oil, make the internal rotor rotation via running shaft, make external rotor to rotate with the mode of the rotating gang of internal rotor, obtain thus pumping action, come from suction port suction oil and to its pressurization, the oil after will pressurizeing from ejiction opening sprays, and will be blended into the discharges (such as reference patent documentation 1, patent documentation 2, patent documentation 3 etc.) such as air (bubble) the oil from air removal hole.

But this oil pump is the structure of the first class boost formula that only possesses one group of pump unit that is made of internal rotor and external rotor, therefore might not satisfy the desired ejection pressure of motor of application.

On the other hand, known have a kind of fluid pump that can guarantee higher ejection pressure, and it possesses: shell; Running shaft (live axle), it is by outer casing supporting; And fore pump unit and rear class pump unit, they are arranged along the axial direction of running shaft, the fore pump unit is by one group or two groups of internal rotors (internal gear) and external rotor (external gear) formation, rear class pump unit is made of one group of internal rotor (internal gear) and external rotor (external gear), be set as the spray volume of fore pump unit and the spray volume of rear class pump unit identical, be provided with one or two suction port and an ejiction opening at shell, suction port sucks oil from the outside, ejiction opening is ejected into the outside with oil, make internal rotor (internal gear) rotation of prime and rear class via running shaft, and the external rotor (external gear) that makes prime and rear class is to rotate with the mode of the rotating gang of internal rotor (internal gear), thus, the pumping action of the pumping action of the first order of acquisition fore pump unit and the second level of rear class pump unit, fluid is sucked and pressurization from suction port, and will boost (pressurization) arrives the fluid of twice from ejiction opening ejection (for example, with reference to patent documentation 4).

But, in the fluid pump of this secondary boost type, only the spray volume (ejection pressure) with fore pump unit and rear class pump unit is set as identical, and do not consider the impact that in the situation such as in the fluid that sucks entrained air the ejection characteristic brought etc., therefore, in the situation that air is sneaked into, might can't guarantee the ejection characteristic (spray volume) of expecting.

Patent documentation 1: Japanese kokai publication hei 9-203308 communique

Patent documentation 2: Japanese kokai publication hei 6-167278 communique

Patent documentation 3: the real fiche of being willing to flat 2-107738 communique (Japan is real to open flat 4-65974 number) of Japan

Patent documentation 4: TOHKEMY 2007-127071 communique

Summary of the invention

The present invention In view of the foregoing finishes, its purpose is to provide a kind of oil pump, even it still can guarantee the pump performance expected when sneaking into air etc. in the oil that sucks, and this oil pump possesses the pump characteristics of the height ejection pressure (spray volume) of the expectation of obtaining.

Oil pump of the present invention constitutes, it possesses: upstream side pump unit and the pump unit, downstream side of disposed adjacent on predetermined axial direction, described upstream side pump unit is made of upstream side internal rotor and upstream side external rotor, and pump unit, described downstream side is made of downstream side internal rotor and downstream side external rotor; And shell, this shell has suction port, ejiction opening and connecting port, and this shell is used for taking in upstream side pump unit and pump unit, downstream side, described suction port forms and faces upstream side pump unit to suck oil from the outside, described ejiction opening forms and faces pump unit, downstream side so that oil is ejected into the outside, described connecting port is communicated to pump unit, downstream side from upstream side pump unit, described shell has exhaust port, and described exhaust port forms and faces upstream side pump unit and sneak into oil with the air that will sneak into air and be discharged to the outside.

According to this structure, in the situation that oil pump is applied to motor for example (thereby suck the oil in the food tray of motor the state that pressurization is supplied with), the pumping action of oil (lubricant oil) by upstream side pump unit (upstream side internal rotor and upstream side external rotor) is drawn in its pump chamber, then, be discharged to the outside and return food tray to the oil pressurization of the entrained air that sucks and from exhaust port, then, make remaining oil boost to predetermined pressure (for example 3.0MPa), and be pumped into pump unit, downstream side (downstream side internal rotor and downstream side external rotor) from upstream side pump unit by connecting port, then, pumping action by pump unit, downstream side is drawn into oil in its pump chamber, further boost to predetermined pressure (for example 6.0MPa), and be ejected into the outside from ejiction opening, thereby pumping is to various regions of lubrication.

Here, be used for the exhaust port that the oil of entrained air is discharged is formed the upstream side pump unit that faces the first order, therefore, the density (quality) that is blended into the air (bubble) in the oil is less, namely, can by centrifugation be used for easily the inboard of air trapping at pump chamber can be discharged the air of sneaking into efficiently.

In said structure, can adopt following structure: the theoretical spray volume of upstream side pump unit is set as larger than the theoretical spray volume of pump unit, downstream side.

According to this structure, because the theoretical spray volume of the upstream side pump unit that exhaust port faces is larger than the theoretical spray volume of pump unit, downstream side, even therefore the oil with entrained air is discharged to the outside from exhaust port, also can spray by pump unit, downstream side the oil of the spray volume of expectation.

In said structure, constitute when the theoretical spray volume that establish upstream side pump unit be Qu, the theoretical spray volume of pump unit, downstream side is Qd, when the discharge capacity of discharging from exhaust port is Qe, satisfies following formula:

Qu=Qd+Qe。

According to this structure, the relation of the theoretical spray volume Qu that is set as in upstream side pump unit, the theoretical spray volume Qd of pump unit, downstream side and the discharge capacity Qe that discharges from exhaust port, satisfy Qu=Qd+Qe, namely, set and doped the theoretical spray volume that returns the amount of returning (discharge capacity) of food tray from exhaust port, therefore realize the high-pressure trend that boosts based on secondary, and can supply with to the outside spray volume that (ejection) expected.

In said structure, can adopt following structure: the discharge capacity Qe that discharges from exhaust port is set as more than or equal to 20% of the theoretical spray volume Qu of upstream side pump unit.

According to this structure, the air (bubble) that is blended in the suction stroke that is undertaken by upstream side pump unit in the oil further can be discharged efficiently.

In said structure, can adopt following structure: be Wu when establishing the thickness of upstream side pump unit at axial direction, when pump unit, downstream side is Wd at the thickness of axial direction, satisfy following formula:

Wu>Wd。

According to this structure, by making the upstream side internal rotor identical with the basic specification of downstream side internal rotor and downstream side external rotor with the upstream side external rotor, and only change them at the thickness of axial direction, it is larger than the theoretical spray volume Qd of pump unit, downstream side easily to be set as the theoretical spray volume Qu that makes upstream side pump unit.

In said structure, can adopt following structure: shell comprises: housing main body, and it has be used to the recess of taking in upstream side pump unit and pump unit, downstream side; Get involved parts, it is between upstream side pump unit and pump unit, downstream side; And outer housing cover, it connects to the opening of closure main body.

According to this structure, realized the miniaturization of the outside dimension of device, and can guarantee the pump characteristics expected, and, for housing main body, only by take in upstream side pump unit, get involved parts, pump unit, downstream side, and from the top mounting casing lid of housing main body, just can carry out simply whole assembling operation.

In said structure, can adopt following structure: exhaust port is arranged at outer housing cover, and connecting port is arranged at the intervention parts, and suction port is to be arranged at the intervention parts with exhaust port in axial direction is positioned at a side opposite with exhaust port across upstream side pump unit mode.

According to this structure, can in upstream side pump unit, pressurize reliably from the oil that suction port sucks, and the air of sneaking into is discharged from exhaust port, the oil after remaining the boosting can be passed out to pump unit, downstream side by connecting port, pump performance is as a whole improved.

In said structure, can adopt following structure: upstream side pump unit and pump unit, downstream side are made of 4 leaves, the 5 joint pumps of the internal rotor that comprises the trochoid formula and external rotor respectively.

According to this structure, the air of sneaking into can be discharged efficiently, and can guarantee the high spray volume expected, pump performance and durability are improved.

The effect of invention

According to the oil pump that forms said structure, even can obtain a kind of oil pump of pump characteristics that still can guarantee the pump performance of expecting when in the oil that sucks, sneaking into air etc. and possess the height ejection pressure (spray volume) of the expectation of obtaining.

Description of drawings

Fig. 1 is the schematic representation of oil pump of the present invention.

Fig. 2 is the plan view that a mode of execution of oil pump of the present invention is shown.

Fig. 3 is the sectional view that the inside of oil pump shown in Figure 2 is shown.

Fig. 4 is the plan view that the housing main body of a part that becomes oil pump shown in Figure 2 is shown.

Fig. 5 is the figure that the outer housing cover of a part that becomes oil pump shown in Figure 2 is shown, and (a) is the plan view of observing from rear R side (inner surface side), (b) is the sectional view along the E1-E1 line in (a).

Fig. 6 is the sectional view that the rotor housing of a part that becomes oil pump shown in Figure 2 is shown.

Fig. 7 is the figure that the end view drawing of rotor housing shown in Figure 6 is shown, and (a) is the end view drawing of observing from the place ahead F side, (b) is the end view drawing of observing from rear R side.

Fig. 8 is the figure that the side plate of a part that becomes oil pump shown in Figure 2 is shown, and (a) is the plan view of observing from the place ahead F side, (b) is the sectional view along the E2-E2 line in (a).

Fig. 9 is the sectional view that the part of oil pump shown in Figure 2 is shown, (a) being the plan view of observing upstream side pump unit (the 1st internal rotor and the 1st external rotor) from rear R side, (b) is the plan view of observing pump unit, downstream side (the 2nd internal rotor and the 2nd external rotor) from the place ahead F side.

Label declaration

H: shell;

10: housing main body (shell);

11: bearing hole;

12: inner peripheral surface;

13: end face;

14: suction passage;

15: the ejection passage;

16: positioning hole;

17: the mating face;

18: tapped hole;

19: positioning hole;

20: outer housing cover (shell);

21: bearing hole;

22: recess;

23: recess;

24: exhaust port;

Qe: from the discharge capacity of exhaust port discharge;

25: circular hole;

26,27: positioning hole;

30: running shaft;

S: axis;

31: one ends;

32: the other end;

33,34,35: axial region;

40: rotor housing;

41: cylindrical part;

42: inner peripheral surface;

43: inner peripheral surface;

44: midfeather section (intervention parts);

44a: bearing hole;

44b: suction port;

44c: upstream side ejiction opening;

44d: downstream side suction port;

44e: connecting port;

45,46: end face;

45a, 46a: positioning hole;

50: side plate;

51: circular hole;

52: ejiction opening;

53: positioning hole;

54: recess;

60:O shape ring;

70: upstream side pump unit;

Qu: the theoretical spray volume of upstream side pump unit;

Wu: upstream side pump unit is at the thickness of axial direction;

P: pump chamber;

71: the 1 internal rotors;

71a: embedding hole;

72: the 1 external rotors;

L1: axis;

72a: outer circumferential face;

80: pump unit, downstream side;

Qd: the theoretical spray volume of pump unit, downstream side;

Wd: pump unit, downstream side is at the thickness of axial direction;

81: the 2 internal rotors;

81a: embedding hole;

82: the 2 external rotors;

L2: axis;

82a: outer circumferential face.

Embodiment

Below, with reference to accompanying drawing embodiments of the present invention are described.

As shown in Figure 1 to Figure 3, the oil pump of present embodiment possesses the following parts of Denging: housing main body 10 and outer housing cover 20, and they consist of shell H; Running shaft 30, it is to be supported by shell H around axis S rotation mode freely; Rotor housing 40, it is assembled in the shell H; Side plate 50, it is connected to the end face of rotor housing 40; O shape ring 60, its along the direction of axis S to side plate 50 to the rotor housing 40 side application of forces; Upstream side pump unit 70(the 1st internal rotor 71 and the 1st external rotor 72), it is accommodated in the rotor housing 40; And pump unit, downstream side 80(the 2nd internal rotor 81 and the 2nd external rotor 82), it is adjacent with upstream side pump unit 70 on the direction of axis S, and is incorporated in the rotor housing 40.

In addition, rotor housing 40 and side plate 50 form in the mode with shell H split, but they are as the structure of taking in upstream side pump unit 70 and pump unit, downstream side 80, constitute the part of shell.

Housing main body 10 uses aluminium for lightweight etc., it forms formation can be taken in upstream side pump unit 70 and pump unit 80, downstream side with rotor housing 40 recess, as shown in Figure 3 and Figure 4, this housing main body 10 possesses the parts such as following: bearing hole 11, and it supports an end 31 of running shaft 30 for rotating freely via bearing G; Inner peripheral surface 12 cylindraceous, it embeds for rotor housing 40; The end face 13 of two ring-types, they form with the mode undergauge that forms ladder in the inboard of inner peripheral surface 12, and be formed at bearing hole 11 around; Suction passage 14, it is by cutting and Drilling operation forms to radial outside the part of inner peripheral surface 12, and suction passage 14 is used for oil is sucked; Ejection passage 15, it is formed at the bottom side of housing main body 10, the oil ejection after being used for pressurizeing; Positioning hole 16, it is used for side plate 50 is positioned; Mating face 17, it is used for engaging outer housing cover 20; Tapped hole 18, it is screwed into for the bolt B that is used for fastening outer housing cover 20; And positioning hole 19, it is used for outer housing cover 20 is positioned.

Outer housing cover 20 is formed by the aluminium identical with housing main body 10 for lightweight etc., and such as Fig. 2, Fig. 3, shown in Figure 5, outer housing cover 20 possesses with inferior part: bearing hole 21, its via bearing G with the other end 32 supportings of running shaft 30 for rotating freely; Recess 22, itself and suction port 44b described later are opposed on the direction of axis S; Recess 23, itself and connecting port 44e described later are opposed on the direction of axis S; Exhaust port 24, its air (air is sneaked into oil) for the oil that will be blended into suction is discharged; Circular hole 25, it passes for bolt B; Positioning hole 26, its be used for carrying out and housing main body 10 between the location; And positioning hole 27, it is used for rotor housing 40 is positioned.

And, opening for closure main body 10, so that be embedded in mode that the locating stud of positioning hole 19 is embedded in positioning hole 26, and so that be embedded in the mode that the locating stud of the positioning hole 45a of rotor housing 40 is embedded in positioning hole 27 outer housing cover 20 engaged with mating face 17, and bolt B passed circular hole 25 from the outside and be screwed into the tapped hole 18, thus outer housing cover 20 is linked to housing main body 10.

Here, shown in Fig. 5 (a) and Fig. 9 (a), exhaust port 24 forms and faces upstream side pump unit 70, and forms with at the radial extent that passes axis S and at its radial outside end upstream side pump unit 70(the 1st internal rotor 71 and the 1st external rotor 72) the roughly L word shape opening of sense of rotation (direction of arrow) elongation.

Here, the exhaust port 24 that is used for the oil of discharge entrained air forms the upstream side pump unit 70 that faces the first order, therefore, the density (quality) that is blended into the air (bubble) in the oil is less, namely, can by centrifugation be used for easily the inboard of air trapping at pump chamber can be discharged the air of sneaking into efficiently.

In addition, be not limited to become the exhaust port 24 of above-mentioned form as exhaust port, can adopt according to the discharge capacity of sneaking into oil as the air of target the form of appropriate expectation.

Running shaft 30 uses the materials such as steel, forms as shown in Figure 3 the direction elongation along axis S, and it possesses with inferior part: an end 31, and it is supported by the bearing hole 11 of housing main body 10 via bearing G; The other end 32, it is supported by the bearing hole 21 of outer housing cover 20 via bearing G; Axial region 33, it rotates the 1st internal rotor 71 of upstream side pump unit 70 integratedly; Axial region 34, it rotates the 2nd internal rotor 81 of pump unit, downstream side 80 integratedly; And axial region 35, it is supported by bearing G.And the binding such as running shaft 30 and the rotary component that becomes a motor part is also rotated by its driving.

Rotor housing 40 uses the formation such as steel, cast iron, sintered steel, and such as Fig. 3, Fig. 6, shown in Figure 7, it possesses with inferior part: cylindrical part 41, and it is centered by axis S; Inner peripheral surface 42, its in the inboard of cylindrical part 41 to depart from from axis S centered by the axis L1 of prearranging quatity; Inner peripheral surface 43, its in the inboard of cylindrical part 41 to depart from from axis S centered by the axis L2 of prearranging quatity; Midfeather section 44, it is as the intervention parts that are formed in axis S direction between inner peripheral surface 42 and the inner peripheral surface 43; Bearing hole 44a, it is arranged at midfeather section 44; Suction port 44b, it is arranged at midfeather section 44; (upstream side pump unit 70) upstream side ejiction opening 44c, it is arranged at midfeather section 44; (pump unit, downstream side 80) downstream side suction port 44d, it is arranged at midfeather section 44; Connecting port 44e, it is interconnected upstream side ejiction opening 44c and downstream side suction port 44d; End face 45, itself and outer housing cover 20 butts; Positioning hole 45a, it is formed at end face 45; End face 46, itself and side plate 50 butts; And positioning hole 46a, it is formed at end face 46.

Cylindrical part 41 forms following outside dimension: inner peripheral surface 12 close contacts of itself and housing main body 10, and with can according to the difference of the heat distortion amount between housing main body 10 and the rotor housing 40 (expand, shrink) come along axis S direction relatively mobile mode be embedded in the inner peripheral surface 12 of housing main body 10.

Inner peripheral surface 42 forms following size: make the 1st external rotor 72 of upstream side pump unit 70 to be connected to inner peripheral surface 42 in axis L1 rotates (slip) mode freely.

Inner peripheral surface 43 forms following size: make the 2nd external rotor 82 of pump unit, downstream side 80 to be connected to inner peripheral surface 43 in axis L2 rotates (slip) mode freely.

Suction port 44b forms with suction passage 14 and is communicated with, and faces the pump chamber P of upstream side pump unit 70().

Like this, suction port 44b is to be arranged at midfeather section 44 with exhaust port 24 is positioned at a side opposite with exhaust port 24 across upstream side pump unit 70 on axis S direction mode, therefore, can make the reliably pressurization and pass out to pump unit, downstream side 80 by connecting port 44e in upstream side pump unit 70 of the oil that sucks from suction port 44b, pump performance is as a whole improved.

Connecting port 44e forms upstream side ejiction opening 44c and downstream side suction port 44d is communicated with, importing to the pump unit, downstream side 80 by 70 oil that spray from upstream side pump unit.

And, the state that rotor housing 40 is accommodated in inner peripheral surface 42 with upstream side pump unit 70 when taking in running shaft 30 and pump unit, downstream side 80 is accommodated in inner peripheral surface 43 cooperates with end face 13, with O shape ring 60 with side plate 50 is clamped and make the locating stud that is embedded in positioning hole 16 be embedded in positioning hole 46a, thereby rotor housing 40 is assembled in the inner peripheral surface 12 of (being embedded in) housing main body 10.

Side plate 50 uses steel, cast iron, sintered steel, aluminum alloy etc. and forms discoideusly, and such as Fig. 3 and shown in Figure 8, side plate 50 possesses with inferior part: circular hole 51, and it passes for running shaft 30; Ejiction opening 52, it will be by the oil ejection after 80 pressurizations of pump unit, downstream side; Positioning hole 53; And recess 54, it takes in the distolateral of bearing G.

And side plate 50 is assembled in housing main body 10 in the following manner: make the locating stud of the positioning hole 16 that is embedded in housing main body 10 pass positioning hole 53, and sandwich O shape ring 60 between side plate 50 and end face 13.

O shape ring 60 forms ring-type by rubber material that can resiliently deformable etc., it is configured between the end face 13 and side plate 50 of housing main body 10, for to end face 46 application of forces of side plate 50 to rotor housing 40, O shape ring 60 is assembled in the mode of compressing predetermined decrement in axis S direction.

Upstream side pump unit 70 uses the formation such as steel or sintered steel, and shown in Fig. 9 (a), it has consisted of trochoid pump 72 that consist of by the 1st internal rotor 71 and the 1st external rotor, 4 leaves, 5 joints.

The 1st internal rotor 71 forms external gear, and this external gear has the embedding hole 71a chimeric with the axial region 33 of running shaft 30, and has 4 peaks and paddy (depression) in the periphery of this external gear.

The 1st external rotor 72 forms internal gear, this internal gear have to slide freely mode is embedded in the outer circumferential face 72a of the inner peripheral surface 42 of rotor housing 40, and in 5 peaks (internal tooth) and the paddy (depression) that is meshed with 4 peaks (external tooth) and the paddy (depression) of the 1st internal rotor 71 that has in interior week of the 1st external rotor 72.

And, when the 1st internal rotor 71 rotates to the direction of arrow (counter clockwise direction in Fig. 9 (a)) centered by axis S with running shaft 30, the 1st external rotor 72 rotates to the direction of arrow (counter clockwise direction in Fig. 9 (a)) centered by axis L1 in the mode of interlock, thus, by the volume-variation of the pump chamber P that both delimit, oil is then pressurized after sucking from suction port 44b, in pressure process air being sneaked into oil discharges from exhaust port 24, then remaining oil is sprayed side pump unit 80 downstream from upstream side ejiction opening 44c, and repeat continuously the trip.

Pump unit, downstream side 80 uses the formation such as steel or sintered steel, and shown in Fig. 9 (b), it has consisted of trochoid pump 82 that consist of by the 2nd internal rotor 81 and the 2nd external rotor, 4 leaves, 5 joints.

The 2nd internal rotor 81 forms external gear, and this external gear has the embedding hole 81a chimeric with the axial region 34 of running shaft 30, and has 4 peaks and paddy (depression) in the periphery of this external gear.

The 2nd external rotor 82 forms internal gear, this internal gear have to slide freely mode is embedded in the outer circumferential face 82a of the inner peripheral surface 43 of rotor housing 40, and in 5 peaks (internal tooth) and the paddy (depression) that is meshed with 4 peaks (external tooth) and the paddy (depression) of the 2nd internal rotor 81 that has in interior week of this internal gear.

And, when the 2nd internal rotor 81 rotates to the direction of arrow (clockwise direction in Fig. 9 (b)) centered by axis S with running shaft 30, the 2nd external rotor 82 rotates to the direction of arrow (clockwise direction in Fig. 9 (b)) centered by axis L2 in the mode of interlock, thus, by the volume-variation of the pump chamber P that both delimit, oil is then pressurized after sucking from downstream side suction port 44d, then with the regions of lubrication ejection of oil from ejiction opening 52 to the outside, and repeats continuously the trip.

In said structure, when the theoretical spray volume (intake) of establishing upstream side pump unit 70 is Qu, the theoretical spray volume (intake) of pump unit, downstream side 80 is Qd, and (air is sneaked into oil) of discharging from exhaust port 24 when discharge capacity is Qe, then forms and satisfy following formula:

Qu=Qd+Qe。

Like this, set doping the theoretical spray volume Qu, the Qd that turn back to the amount of returning (discharge capacity Qe) of food tray OP from exhaust port 24, therefore realized the high-pressure trend that boosts by secondary, and can supply with to the outside spray volume Qd that (ejection) expected.

Here, the discharge capacity Qe that discharges from exhaust port 24 is preferably set to the scope of more than 20% of theoretical spray volume Qu of upstream side pump unit 70～below 50%.

Thus, the air (bubble) that is blended in the suction stroke that is undertaken by upstream side pump unit 70 in the oil further can be discharged efficiently.

In addition, in said structure, as shown in Figure 6, be Wu when establishing the thickness of upstream side pump unit 70 in axis S direction, when pump unit, downstream side 80 is Wd at the thickness of axis S direction, then form satisfied:

Wu>Wd。

Like this, by changing thickness Wu, the Wd of axis S direction, can easily be set as following form: make upstream side internal rotor 71 identical with the basic specification of downstream side internal rotor 81 and downstream side external rotor 82 with upstream side external rotor 72, and make the theoretical spray volume Qu of upstream side pump unit 70 larger than the theoretical spray volume Qd of pump unit, downstream side 80.

According to the oil pump that constitutes said structure, as shown in Figure 1, when this oil pump is installed on the motor that possesses food tray OP, at first the pumping action of oil (lubricant oil) by upstream side pump unit 70 is drawn among its pump chamber P, then, be discharged to the outside and return food tray OP to the oil pressurization of the entrained air that sucks and from exhaust port 24, then, make remaining oil boost to predetermined pressure (for example 3.0MPa), and be pumped into pump unit, downstream side 80 from upstream side pump unit 70 by connecting port 44e, then, pumping action by pump unit, downstream side 80 is drawn into oil among its pump chamber P, further boost to predetermined pressure (for example 6.0MPa), and be ejected into the outside from ejiction opening 52, thereby pumping is to various regions of lubrication.

When the oil pump that constitutes said structure is assembled, adopted following structure: consist of shell H by housing main body 10 and outer housing cover 20, in the mode of in advance separating be accommodated in the rotor housing 40 of delimiting out as the midfeather section 44 that get involved parts with pump unit, downstream side 80 upstream side pump unit 70, therefore, only need upstream side pump unit 70 and pump unit 80, downstream side are disposed at rotor housing 40 with running shaft 30, and with O shape ring 60, side plate 50, rotor housing 40 is accommodated in the housing main body 10 successively, thereafter, top mounting casing lid 20 from housing main body 10 just can carry out assembling operation simply.

Then, with reference to (a) of Fig. 9 with (b) action of oil pump is described.

At first, utilize 30 rotations of engine-driving running shaft, at this moment, upstream side pump unit 70(the 1st internal rotor 71 and the 1st external rotor 72) in (a) of Fig. 9, rotate to counter clockwise direction, thus, oil process suction passage 14 → suction port 44b, and be inhaled in the pump chamber P of upstream side pump unit 70.

Then, continuous rotation by upstream side pump unit 70, be drawn into the oily pressurized of pump chamber P, sneak into oil at this pressure process Air and be discharged to the outside from exhaust port 24 energetically with predetermined discharge capacity Qe, and, theoretical spray volume Qu deducts discharge capacity Qe and the remaining oil of the amount (Qu-Qe) that obtains is boosted to predetermined ejection pressure (approximately 3.0MPa), and through downstream side pump unit 80 ejections (supply) of upstream side ejiction opening 44c → connecting port 44e → downstream side suction port 44d.

Then, pump unit, downstream side 80(the 2nd internal rotor 81 and the 2nd external rotor 82) in (b) of Fig. 9, rotate to clockwise direction, thus, oil is drawn in the pump chamber P of pump unit, downstream side 80 from downstream side suction port 44d.

Then, continuous rotation by pump unit, downstream side 80, be drawn into the oily pressurized of pump chamber P, and through regions of lubrication ejection pressure (approximately 6.0MPa) and predetermined spray volume (the theoretical spray volume Qd) ejection (supply) to be scheduled to of ejiction opening 52 → ejection passage 15 to the outside.

In fact, utilize upstream side pump unit 70(the 1st internal rotor 71 and the 1st external rotor 72) and pump unit, downstream side 80(the 2nd internal rotor 81 and the 2nd external rotor 82) between synergy, carry out continuously following a series of stroke: the oil of the first order is from the ejection of the oil of the pressurization → second level of the oil of the downstream ejection of side of remaining oil (suction of the oil of the second level) of the discharge → first order of the empty G﹠O (air is sneaked into oil) of sneaking into of the pressurization → first order of the oil of suction → first order of food tray OP → second level.

Like this, the air (bubble) that is blended in the oil is discharged from the exhaust port 24 of the upstream side pump unit 70 that faces the first order with oil (sneaking into oil as air), therefore, the density (quality) that is blended into the air (bubble) in the oil is less, can air easily be collected in by the effect of centrifugation the inboard of pump chamber, the air of sneaking into can be discharged efficiently, and, owing to set and doped the theoretical spray volume Qu that returns the amount of returning (discharge capacity Qe) of food tray OP from exhaust port 24, Qd, therefore realize the high-pressure trend that boosts based on secondary, and can supply with to the outside spray volume Qd that (ejection) expected.

In the above-described embodiment, show in the inboard of shell (housing main body 10 and outer housing cover 20) possesses as the structure of the rotor housing 40 of the 2nd shell and side plate 50 etc. and adopt situation of the present invention, but be not limited thereto, also can in the structure of having abolished rotor housing 40 and side plate 50 etc., use the present invention.

In the above-described embodiment, show and possessing upstream side pump 70(the 1st internal rotor 71 and the 1st external rotor 72) and downstream side pump 80(the 2nd internal rotor 81 and the 2nd external rotor 82) secondary trochoid formula pump in adopt situation of the present invention, but be not limited thereto, also can in the structure of the internal rotor that possesses inscribed gear (involute) formula and external rotor etc., use the present invention.

In the above-described embodiment, show and in the structure that shell is separated into housing main body and outer housing cover, adopt situation of the present invention, but be not limited thereto, also can use the present invention possessing by delimiting out respectively in structure recess, that be divided into the shell that two-part the 1st shell halfbody and the 2nd shell halfbody consist of.

In the above-described embodiment, show the situation that oil pump of the present invention is applied to be installed on the motor of automobile etc., but be not limited thereto, also can be applied in for example stepless speed variator (CVT, Continuously Variable Transmission) etc. beyond the motor for example.

Utilizability on the industry

As mentioned above, according to oil pump of the present invention, even in the oil that sucks, sneaked into air etc., still can guarantee the pump performance expected, and the height that can realize obtaining expectation sprays the pump characteristics of pressure (spray volume), therefore, not only can be applied to be installed in the motor in automobile etc., can also use two-wheel vehicle, other the vehicle that motor is installed or need the stepless speed variator (CVT) of pumping lubricant oil or other mechanism etc.

Claims

1. oil pump, it possesses:

Upstream side pump unit and the pump unit, downstream side of disposed adjacent in order to be divided into that two stages boost and on predetermined axial direction, described upstream side pump unit is made of upstream side internal rotor and upstream side external rotor, and pump unit, described downstream side is made of downstream side internal rotor and downstream side external rotor; And

Shell, this shell has suction port, ejiction opening and connecting port, and this shell is used for taking in described upstream side pump unit and pump unit, downstream side, described suction port forms and faces described upstream side pump unit to suck oil from the outside, described ejiction opening forms and faces pump unit, described downstream side so that oil is ejected into the outside, described connecting port is communicated to pump unit, described downstream side from described upstream side pump unit

Described oil pump is characterised in that,

Described shell has exhaust port, and described exhaust port forms and faces described upstream side pump unit and sneak into oil with the air that will sneak into air and be discharged to the outside.

2. oil pump according to claim 1 is characterized in that,

The theoretical spray volume of described upstream side pump unit is set as larger than the theoretical spray volume of pump unit, described downstream side.

3. oil pump according to claim 1 and 2 is characterized in that,

When the theoretical spray volume of establishing described upstream side pump unit is Qu, the theoretical spray volume of pump unit, described downstream side is Qd, when the discharge capacity of discharging from described exhaust port is Qe, satisfies following formula:

Qu=Qd+Qe。

4. oil pump according to claim 3 is characterized in that,

The discharge capacity Qe that discharges from described exhaust port is set as more than or equal to 20% of the theoretical spray volume Qu of described upstream side pump unit.

5. each described oil pump in 4 according to claim 1 is characterized in that,

Be Wu when establishing described upstream side pump unit at the thickness of described axial direction, pump unit, described downstream side satisfies following formula when the thickness of described axial direction is Wd:

Wu>Wd。

6. each described oil pump in 5 according to claim 1 is characterized in that,

Described shell comprises: housing main body, and it has be used to the recess of taking in described upstream side pump unit and pump unit, downstream side; Get involved parts, it is between described upstream side pump unit and pump unit, described downstream side; And outer housing cover, it connects to the opening of the described housing main body of sealing.

7. oil pump according to claim 6 is characterized in that,

Described exhaust port is arranged at described outer housing cover,

Described connecting port is arranged at described intervention parts,

Described suction port is to be arranged at described intervention parts with described exhaust port in described axial direction is positioned at a side opposite with described exhaust port across described upstream side pump unit mode.

8. each described oil pump in 7 according to claim 1 is characterized in that,

Described upstream side pump unit and pump unit, downstream side are made of 4 leaves, the 5 joint pumps of the internal rotor that comprises the trochoid formula and external rotor respectively.