WO2022176544A1

WO2022176544A1 - Tandem-type oil pump

Info

Publication number: WO2022176544A1
Application number: PCT/JP2022/002863
Authority: WO
Inventors: 亮松村; 英俊楊
Original assignee: 日立Astemo株式会社
Priority date: 2021-02-16
Filing date: 2022-01-26
Publication date: 2022-08-25
Also published as: JP2022124698A; JP7408589B2; CN116867969A

Abstract

According to the present invention, a pump-rotor bearing part (42) that is provided between a pump-rotor housing part (22) and a drive-shaft bearing part (24), that is larger in diameter than the drive-shaft bearing part (24), that is smaller in diameter than the pump-rotor housing part (22), and that is continuous with the pump-rotor housing part (22) is formed in a pump body (11). Furthermore, a pump-rotor small-diameter shaft part (41) is formed in a pump rotor (38), the pump-rotor small-diameter shaft part (41) is borne by the pump-rotor bearing part (42), and a lubrication passage (46) for supplying oil from a high-pressure oil pump to the pump-rotor bearing part (42) is formed in the pump body (11). Accordingly, high-pressure oil can be supplied from the high-pressure oil pump to the pump-rotor bearing part (42) via the lubrication passage (46), thus making it possible to suppress the occurrence of a burn-in phenomenon and an abrasion phenomenon between the pump-rotor small-diameter shaft part (41) and the pump-rotor bearing part (42).

Description

tandem oil pump

The present invention relates to an oil pump, and more particularly to a tandem oil pump having two oil pumps.

A tandem-type oil pump applied to an internal combustion engine mounted on an automobile has a well-known configuration, for example, as disclosed in Japanese Patent Application Laid-Open No. 2008-163925 (Patent Document 1).

A tandem-type oil pump disclosed in Patent Document 1 includes a first pump having the same shape and a second pump arranged with a rotation phase shifted with respect to the first pump, in a pump body formed in a cylindrical shape with a bottom. An annular partition member for partitioning between the pumps, and a pump body slidably supported in the pump body penetrates both pumps and the partition member to transmit driving force to the inner rotors of both pumps. Each pump performs a pumping action when the drive shaft is rotationally driven by the driving force transmitted from the internal combustion engine. The first pump and the second pump are pumps having substantially the same discharge pressure.

Apart from this, a tandem oil pump that combines a high-pressure oil pump and a low-pressure oil pump has also been proposed. For example, a scavenging oil pump (low-pressure oil pump) that collects engine oil (hereinafter simply referred to as oil) from the oil pan, and supplies pressurized oil to the variable valve mechanism and the main oil gallery of the internal combustion engine. BACKGROUND ART A tandem oil pump combined with a variable capacity oil feed pump (high pressure oil pump) is known. A gear-type oil pump is used as the scavenging oil pump, and a vane-type oil pump is used as the variable displacement oil feed pump.

By the way, in a tandem-type oil pump that combines a high-pressure oil pump and a low-pressure oil pump, one end of the drive shaft that drives the pump rotor is not supported. Therefore, when the drive shaft rotates, a phenomenon occurs in which the end portion of the drive shaft vibrates. When the end of the drive shaft vibrates, the pump rotor fixed to the end of the drive shaft also vibrates and changes its position in the radial direction, which may cause abnormal noise and oil leakage from the hydraulic oil chamber.

In order to suppress the vibration of the pump rotor, it is effective to adopt the following configuration. For example, a pump rotor bearing in which a pump rotor attached to the end of a drive shaft is integrally formed with a pump rotor diameter small shaft portion extending in the axial direction of the drive shaft, and the pump rotor diameter small shaft portion is formed in the pump body. If the bearing is provided at the end of the drive shaft, vibration of the pump rotor at the end of the drive shaft can be suppressed. Note that this configuration will be described in detail in the description of the embodiment.

Here, the present invention is directed to a tandem-type oil pump in which a high-pressure oil pump and a low-pressure oil pump are combined. It is not limited.

JP 2008-163925 A

However, when the pump rotor of the low-pressure oil pump is attached to the end of the drive shaft, oil for lubrication is lost at the contact portion between the small diameter shaft portion of the pump rotor and the pump rotor bearing portion that bears it. Insufficient, there is a risk of seizure phenomenon or rapid wear phenomenon at this contact portion.

These phenomena are caused by the fact that the gap between the pump rotor bearing part that suppresses the vibration of the pump rotor of the low-pressure oil pump and the small diameter shaft part of the pump rotor narrows due to the vibration of the drive shaft, resulting in a thin oil film. The main reason is that it is difficult to supply a sufficient amount of oil to the contact portion between the pump rotor diameter small shaft portion and the pump rotor bearing portion because the oil film runs out due to the low pressure oil pump and the low discharge pressure of the low pressure oil pump. is a factor.

An object of the present invention is to prevent seizure at the contact portion between the pump rotor diameter small shaft portion formed in the pump rotor of the low pressure oil pump and the pump rotor bearing portion formed in the pump body when a high pressure oil pump and a low pressure oil pump are combined. Alternatively, another object of the present invention is to provide a novel tandem-type oil pump capable of suppressing the occurrence of a wear phenomenon.

The present invention
a first pump rotor accommodating portion and a second pump rotor accommodating portion; a partition wall that partitions the first pump rotor accommodating portion and the second pump rotor accommodating portion; and a first pump rotor accommodating portion formed in the partition wall. a pump body having a drive shaft bearing portion connected to the second pump rotor accommodating portion;
a drive shaft rotatably supported by the drive shaft bearing and driven to rotate by an external power source;
It has a first pump rotor that is arranged in the first pump rotor accommodating portion and is rotationally driven by the drive shaft, and the first pump rotor is rotationally driven by the drive shaft to absorb oil introduced from the first suction portion. a first oil pump that pressurizes and discharges from the first discharge part;
It has a second pump rotor that is arranged in the second pump rotor accommodating portion and is rotationally driven by the drive shaft, and the second pump rotor is rotationally driven by the drive shaft to absorb oil introduced from the second suction portion. , a second oil pump that discharges from the second discharge part at a pressure lower than the pressure discharged from the first discharge part of the first oil pump,
Further, in the pump body, a second rotor housing portion is provided between the second pump rotor housing portion and the drive shaft bearing portion and has a larger diameter than the drive shaft bearing portion and a smaller diameter than the second pump rotor housing portion. A second pump rotor bearing portion is formed continuously with the pump rotor accommodating portion, and the second pump rotor is formed with a second pump rotor diameter small shaft portion integral with the second pump rotor. The pump rotor diameter small shaft portion is accommodated and supported by the second pump rotor bearing portion, and
An oil supply passage for supplying oil from the first oil pump to the second pump rotor bearing is formed in the pump body.

In addition, the present invention
a high-pressure pump rotor housing portion and a low-pressure pump rotor housing portion; a partition wall that separates the high-pressure pump rotor housing portion and the low-pressure pump rotor housing portion; a pump body having a drive shaft bearing connecting between
a drive shaft positioned in the high-pressure pump rotor accommodating portion and the low-pressure pump rotor accommodating portion and rotatably driven by an external power source rotatably supported by the drive shaft bearing;
a high-pressure oil pump having a high-pressure pump rotor disposed in the high-pressure pump rotor accommodating portion and rotationally driven by the drive shaft, and performing a pumping action at a first discharge pressure by rotation of the high-pressure pump rotor;
a low-pressure oil pump having a low-pressure pump rotor disposed in the low-pressure pump rotor accommodating portion and rotationally driven by the drive shaft, and performing a pumping action at a second discharge pressure lower than the first discharge pressure by rotation of the low-pressure pump rotor; , and
Further, in the pump body, a low-pressure pump rotor accommodating portion is provided between the low-pressure pump rotor accommodating portion and the drive shaft bearing portion, and has a diameter larger than the drive shaft bearing portion and smaller than the diameter of the low-pressure pump rotor accommodating portion. The low-pressure pump rotor is formed with a low-pressure pump rotor diameter small shaft portion integrated with the low-pressure pump rotor, and the low-pressure pump rotor diameter small shaft portion is formed continuously with the low-pressure pump rotor. Housed in and supported by the pump rotor bearing,
The pump body is characterized in that an oil supply passage for supplying oil from the high-pressure oil pump to the low-pressure pump rotor bearing is formed in the pump body.

According to the present invention, in a tandem-type oil pump that combines a high-pressure oil pump and a low-pressure oil pump, high-pressure oil is supplied from the first oil pump (high-pressure oil pump) to the second pump rotor bearing through the oil supply passage. It is possible to suppress the occurrence of a seizure phenomenon or an abrasion phenomenon between the second pump rotor diameter small shaft portion formed in the second pump rotor and the second pump rotor bearing portion. .

1 is an external perspective view of a tandem-type oil pump according to the present invention, viewed obliquely from above; FIG. FIG. 2 is a front view of the tandem oil pump shown in FIG. 1 viewed from the side of a variable displacement oil feed pump; FIG. 2 is a rear view of the tandem oil pump shown in FIG. 1 as seen from the scavenging oil pump side; FIG. 2 is an exploded perspective view of a variable displacement oil feed pump, viewed obliquely from above; FIG. 3 is a cross-sectional view for explaining the internal structure of a pump portion of a variable displacement oil feed pump; FIG. 4 is an exploded perspective view of the scavenging oil pump when viewed obliquely from above; FIG. 4 is a cross-sectional view for explaining the internal structure of the pump portion of the scavenging oil pump; FIG. 3 is an exploded perspective view for explaining the shapes of the inner rotor and drive shaft of the scavenging oil pump; FIG. 2 is a sectional view showing the AA section of the tandem oil pump according to the first embodiment of the present invention shown in FIG. 1; FIG. 10 is an enlarged cross-sectional view showing a portion (near an oil supply passage) of the tandem-type oil pump shown in FIG. 9; FIG. 10 is a sectional view showing the BB section of the tandem oil pump shown in FIG. 9; FIG. 10 is an external perspective view of the pump body of the tandem-type oil pump shown in FIG. 9 as viewed from the high-pressure oil pump side; FIG. 10 is an enlarged sectional view enlarging a part (near the oil supply passage) of the first modification of the tandem oil pump shown in FIG. 9; FIG. 10 is an enlarged cross-sectional view enlarging a part (near the oil supply passage) of the second modification of the tandem-type oil pump shown in FIG. 9; FIG. 10 is a cross-sectional view showing a cross section corresponding to FIG. 9 of the tandem oil pump according to the second embodiment of the present invention; FIG. 16 is a sectional view showing a CC section of the tandem oil pump shown in FIG. 15; FIG. 16 is an enlarged cross-sectional view enlarging a part (near the oil supply passage) of the modification of the tandem-type oil pump shown in FIG. 15;

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments, and various modifications and applications can be made within the technical concept of the present invention. is also included in the scope.

FIG. 1 shows a tandem-type oil pump according to an embodiment of the present invention as seen obliquely from above. A high-pressure pump cover 13 (corresponding to the first pump cover in the claims) attached at 12, and a low-pressure pump cover 15 (see FIG. 3) attached to the rear portion 11B of the pump body 11 with bolts 14 (see FIG. 3). (corresponding to the second pump cover).

Although the details will be described later, the pump body 11 on the side of the high-pressure pump cover 13 houses a variable displacement oil feed pump, which is a high-pressure oil pump (corresponding to the first pump in the claims). A scavenging oil pump, which is a low-pressure oil pump (corresponding to a second pump in the claims), is accommodated in the pump body 11 on the low-pressure pump cover 15 side. Here, the pump body 11 is formed in a substantially rectangular parallelepiped box shape, but in reality, the shape is changed according to the external shape and size of the internal combustion engine. However, even if the external shape changes, the basic idea of the present invention does not change.

The tandem-type oil pump 10 includes a drive shaft 16 extending through a high-pressure pump cover 13 and a pump body 11 to a low-pressure pump cover 15. The drive shaft 16 is rotationally driven by a crankshaft of an internal combustion engine or an electric motor. be. The drive shaft 16 is shared by the high-pressure oil pump and the low-pressure oil pump, and the drive shaft 16 rotates the pump rotors of the high-pressure oil pump and the low-pressure oil pump, respectively.

In addition, on the upper surface portion 11U of the pump body 11 located between the high-pressure pump cover 13 and the low-pressure pump cover 15, a low-pressure side connected to the suction portion (corresponding to the second suction portion in the claims) of the low-pressure oil pump is provided. A suction hole 17 (corresponding to a second suction hole in the claims) is formed.

A pair of attachment portions 11A to be attached to the oil pan of the internal combustion engine are provided on the upper surface portion 11U of the pump body 11. Fixing bolts are inserted through the attachment portions 11A to be fixed to the internal combustion engine. A low-pressure side suction hole 17 is formed in the mounting portion 11A. The pair of attachment portions 11A are provided so as to sandwich the pump body 11 from both sides at radial positions with respect to the drive shaft 16 provided in the pump body 11, and are attached to the internal combustion engine. Therefore, when the tandem-type oil pump 10 is attached to the internal combustion engine, the oil in the oil pan can be easily guided to the low-pressure side suction hole 17 .

FIG. 2 shows the front of the tandem-type oil pump 10 on the side on which the high-pressure pump cover 13 is provided. (pump chamber). The high-pressure pump cover 13 is attached to the pump body 11 along a plane perpendicular to the axis of the drive shaft 16 .

A high-pressure oil pump connected to a discharge portion (corresponding to a first discharge portion in the claims) of the high-pressure oil pump is provided on the high-pressure pump cover 13 located radially outside the drive shaft center of the drive shaft 16 . A side discharge hole 18 (corresponding to a first discharge hole in the claims) is formed. The high-pressure side discharge hole 18 supplies pressurized oil to at least the main oil gallery of the internal combustion engine in this embodiment, but it may also supply the variable valve mechanism.

FIG. 3 shows the rear surface of the tandem-type oil pump 10 on the side where the low-pressure pump cover 15 is provided. forms part of The low-pressure pump cover 15 is attached to the pump body 11 along a plane perpendicular to the axis of the drive shaft 16 . A suction portion (corresponding to a first suction portion in the claims) of a high-pressure oil pump is connected to the rear surface portion 11B of the pump body 11 located radially outside the drive shaft center of the drive shaft 16. A high-pressure side suction hole 19 (corresponding to a first suction hole in the claims) is formed.

The low-pressure pump cover 15 has a low-pressure side discharge hole 20 (corresponding to the second discharge hole in the claims) connected to the discharge part (corresponding to the second discharge part in the claims) of the low-pressure oil pump. is formed.

Next, the configurations of the high-pressure oil pump and the low-pressure oil pump will be described with reference to FIGS. 4 to 7. FIG. FIG. 4 shows the disassembled state of the high-pressure oil pump after the low-pressure oil pump is assembled, and FIG. 6 shows the disassembled state of the low-pressure oil pump after the high-pressure oil pump is assembled. Here, as described above, the high-pressure oil pump is a vane-type oil pump (variable displacement type) using vanes, and the low-pressure pump is a gear-type oil pump using a trochoid gear.

As shown in FIG. 4, one side of the pump body 11 is formed with a vane pump rotor accommodating portion 21 (corresponding to the first pump rotor accommodating portion/high pressure pump rotor accommodating portion in the claims) of the vane type oil pump. Further, as shown in FIG. 6, on the other side of the pump body 11, a gear pump rotor accommodating portion 22 (corresponding to the second pump rotor accommodating portion/low-pressure pump rotor accommodating portion in the claims) of the gear type oil pump is provided. do) is formed. A partition wall 23 that partitions the vane pump rotor accommodating portion 21 and the gear pump rotor accommodating portion 22 is formed between the vane pump rotor accommodating portion 21 and the gear pump rotor accommodating portion 22 .

Since the partition wall 23 is integrally formed with the pump body 11, the vane-type oil pump can be assembled from one side of the pump body 11, and the gear-type oil pump can be assembled from the other side of the pump body 11. can. A bearing through hole 24 (corresponding to a drive shaft bearing portion in the claims) through which the drive shaft 16 passes is formed in the partition wall 23 (see FIG. 8).

　The configuration of the vane-type oil pump will be described using FIGS. 4 and 5, but since this vane-type oil pump has a well-known configuration, the description will be brief. Here, FIG. 5 shows a pump portion of a well-known vane-type oil pump taken in a cross section perpendicular to the axis.

4 and 5, a pump body 25 is housed in a recessed vane pump rotor housing portion 21 formed in the pump body 11. As shown in FIG. A vane pump rotor 26 (corresponding to a first pump rotor/high-pressure pump rotor in the claims) press-fitted with the drive shaft 16 is arranged substantially in the center of the vane pump rotor accommodating portion 21, and a swinging rotor 26 is arranged on the outer side thereof. An adjustment ring 27 is arranged with its dynamic center eccentric to the drive shaft 16 . Since the vane pump rotor 26 is press-fitted onto the drive shaft 16 in this way, it is firmly fixed so as to restrict relative movement in the drive axis direction and the rotational direction.

The adjustment ring 27 is pivotable about the pivot 28, and in the initial state, the adjustment ring 27 is pushed rightward in FIG. and the eccentricity is at its maximum setting.

The vanes 31 are arranged in a plurality of slits provided in the vane pump rotor 26, and when the vane pump rotor 26 rotates, the tips of the vanes slide on the inner peripheral surface of the adjustment ring 27 while appearing and disappearing from the outer peripheral surface of the vane pump rotor 26. All of the vanes 31 are supported by vane rings 32 so as not to retreat inward even when stopped.

A space formed by the outer peripheral surface of the vane pump rotor 26, the inner peripheral surface of the adjustment ring 27, and the two vanes 31 (hereinafter referred to as the hydraulic oil chamber) rotates counterclockwise as shown in FIG. The volume increases and decreases as the vane pump rotor 26 rotates. A suction portion 33 is provided on the side surface of the pump body 11 within a range where the volume of the hydraulic oil chamber increases. The suction portion 33 is connected to the high-pressure side suction hole 19 provided in the rear portion 11B of the pump body 11 on the low-pressure oil pump side.

On the other hand, a discharge part 34 is provided on the side surface of the pump body 11 within the range where the volume decreases. This discharge portion 34 is connected to a high pressure side discharge hole 18 provided in the front portion 11F of the pump body 11 on the side of the high pressure oil pump.

The vane type oil pump sucks up oil through the suction hole 19 and discharges the oil through the discharge hole 18 to the variable valve mechanism or the main oil gallery of the internal combustion engine to perform a pumping action. The compression spring 35 biases the ball valve 36, and when the discharge pressure rises above a predetermined value, the ball valve 36 is opened to reduce the discharge pressure. Since the configuration and operation of this vane type oil pump are well known, further explanation will be omitted.

Thus, the vane-type oil pump is arranged swingably in the vane pump rotor accommodating portion 21 and accommodated in the adjustment ring 27 having the vane accommodating portion therein, and the drive shaft and a plurality of vanes 31 accommodated on the outer peripheral surface of the vane pump rotor 26 and forming a plurality of hydraulic oil chambers through which oil is directed between the adjustment ring 27 and the vane pump rotor 26. Then, the oil is sucked from the suction hole 19 (see FIG. 3) whose volume increases among the plurality of hydraulic oil chambers as the drive shaft 16 rotates, and It is an oil pump that discharges oil from a discharge hole 18 (see FIG. 2) whose volume decreases.

Next, the configuration of the gear-type oil pump will be described with reference to FIGS. 6 and 7. Since this gear-type oil pump is also well-known, the description will be brief. Here, FIG. 7 shows a pump portion of a known gear-type oil pump taken in a cross section perpendicular to the axis.

In FIG. 6, a gear pump rotor accommodating portion 22 is formed on the side of the rear portion 11B of the pump body 11, and an outer rotor 37 (corresponding to a part of the second pump rotor/low-pressure pump rotor in the claims) is formed therein. ) are slidably and rotatably arranged.

Further, inside the outer rotor 37, an inner rotor 38 (corresponding to a part of the second pump rotor/low-pressure pump rotor in the claims) is arranged. As shown in FIG. 7, five internal teeth 40, one more than the external teeth 39 of the inner rotor 38, are formed on the inner peripheral side of the outer rotor 37. It meshes with the external teeth 39 of the rotor 38 .

A plurality of working oil chambers are formed between the outer teeth 39 of the inner rotor 38 and the inner teeth 40 of the outer rotor 37. When the inner rotor 38 rotates, the outer rotor 37 rotates eccentrically, thereby The volume of the oil chamber increases and decreases, thereby continuously sucking and discharging oil to perform a pump action.

Here, the inner rotor 38 is rotationally driven by the drive shaft 16. In the present embodiment, the inner rotor 38 can move relative to the drive shaft 16 in the direction of the drive axis, and the drive shaft 16 can rotate. Relative movement in the rotational direction is restricted with respect to Specifically, the drive shaft 16 to which the inner rotor 38 is fitted is formed in a shape having a width across flats, and the inner rotor 38 can move in the drive shaft direction at this portion.

Here, the width across flats means a shape formed along the axial direction of the drive shaft 16 and having planes facing each other parallel to each other. Therefore, the inner rotor 38 can move along the axial direction of the drive shaft 16 and rotate together with the drive shaft 16 in the rotational direction.

In this way, the gear-type oil pump is housed inside the gear pump rotor housing portion 22 and also housed inside the outer rotor 37 including the plurality of internal teeth 40 on the inner peripheral side and the outer rotor 37. , and an inner rotor provided on a drive shaft 16 so as to be movable in the direction of the drive axis of the drive shaft 16 and having a plurality of external teeth 39 meshing with a plurality of internal teeth 40 on the outer peripheral side. .

The inner rotor 38 is configured to be movable in the axial direction of the drive shaft 16, as shown in FIG. That is, relative movement in the direction of the drive axis of the drive shaft 16 is possible, and relative movement in the rotational direction with respect to the drive shaft 16 is restricted. Specifically, the drive shaft 16 to which the inner rotor 38 is fitted is formed in a shape having a flat surface 43 with a width across flats 43, and the inner rotor 38 can move in the drive shaft direction at this portion.

In FIG. 8, the drive shaft 16 is composed of a cylindrical portion 16C and a width across flat portion 16P. It is configured to be inserted. The fitting hole 44 has a similar shape to the width across flat portion 16P and is designed to be slightly larger than the width across flat portion 16P. The width across flat portion 16</b>P is formed longer than the axial length of the inner rotor 38 to increase the drive area and sufficiently transmit the torque of the drive shaft 16 .

A vane pump rotor 26 is press-fitted to the columnar portion 16C, and the vane pump rotor 26 is configured so as not to move in the axial direction and the rotational direction with respect to the columnar portion 16C. Furthermore, when the vane pump rotor 26 and the columnar portion 16C are serration-coupled, they can be in a more rigid fixed state.

On the other hand, the width across flat portion 16P of the drive shaft 16 is fitted with a fitting hole 44 formed in the inner rotor 38 so as to be axially movable. Therefore, as shown in FIG. 8 , even if the drive shaft 16 moves in the axial direction (leftward or rightward), the inner rotor 38 is not forced to move by the drive shaft 16 . Since the vane pump rotor 26 is press-fitted onto the drive shaft 16 , it is moved together with the drive shaft 16 .

Next, the internal configuration of the tandem oil pump 10 shown in FIG. 1 will be explained using FIGS. 9 to 12. FIG.

9, a high-pressure pump cover 13 is attached to the pump body 11 with bolts 12 on the front portion 11F of the pump body 11, and a low-pressure pump cover 15 is attached to the pump body 11 with bolts 14 on the rear portion 11B of the pump body 11. installed. A vane-type oil pump, which is a high-pressure oil pump, is accommodated in the pump body 11 on the high-pressure pump cover 13 side, and a gear-type oil pump, which is a low-pressure oil pump, is accommodated in the pump body 11 on the low-pressure pump cover 15 side. Contains the oil pump.

It also has a drive shaft 16 extending through the high-pressure pump cover 13 and the partition wall 23 formed in the pump body 11 and extending to the low-pressure pump cover 15 . The drive shaft 16 is shared by the high-pressure oil pump and the low-pressure oil pump, and rotates the vane pump rotor 26 of the high-pressure oil pump and the inner rotor 38 of the low-pressure oil pump, respectively.

A large diameter portion 16L having a circular cross section is formed on the drive shaft 16, and the large diameter portion 16L is supported by a hole formed in the high pressure pump cover 13. Further, the drive shaft 16 is supported by a bearing through hole 24 provided in the partition wall 23 . Therefore, the drive shaft 16 has a circular cross section at least up to the point where it contacts the partition wall 23 .

The drive shaft 16 abuts on the low-pressure pump cover 15 or extends until just before it abuts, and this portion is not supported by a bearing. Therefore, in the vicinity of the low-pressure pump cover 15, a phenomenon occurs in which the drive shaft 16 vibrates. If the drive shaft 16 touches, the positional relationship between the inner rotor 38 and the outer rotor 37 changes, which may cause abnormal noise and oil leakage from the working oil chamber.

For this reason, in the present embodiment, a pump rotor diameter small shaft portion 41 (second pump (corresponding to the rotor diameter small shaft portion/low pressure pump rotor diameter small shaft portion) are integrally formed.

The pump rotor diameter small shaft portion 41 has a circular cross section perpendicular to the axis of the drive shaft 16 . Further, on the side of the low-pressure pump cover 15 of the bearing through-hole 24, an inner rotor-side bearing through-hole 42 (second pump rotor bearing portion/low-pressure pump rotor ) are formed. The inner rotor side bearing through hole 42 is designed to have a larger diameter than the bearing through hole 24 .

In this way, the pump body is provided between the gear pump rotor accommodating portion 22 (corresponding to the second pump rotor accommodating portion/low-pressure pump rotor accommodating portion referred to in the claims) and the bearing through hole 24. An inner-rotor-side bearing through-hole 42 that is larger than the diameter of the hole 24 and smaller than the diameter of the gear-pump rotor-accommodating portion 22 is formed continuously with the gear-pump-rotor-accommodating portion 22 . A small diameter pump rotor shaft portion 41 is rotatably supported in the inner rotor side bearing through hole 42 with a minute gap therebetween.

Therefore, the inner rotor side bearing through-hole 42 and the pump rotor diameter small shaft portion 41 of the inner rotor 38 are in "pipe engagement". "Spigot engagement" means "a nested structure in which two parts fit together, one of which has a concave shape and the other has a convex shape". In this manner, the vicinity of the end portion of the drive shaft 16 on the low-pressure pump cover 15 side is supported by the inner rotor side bearing through hole 42 by the pump rotor diameter small shaft portion 41 of the inner rotor 38 . It is possible to suppress the vibration that occurs in the

An annular shape through which the drive shaft 16 is inserted is formed between an end face of the inner rotor side bearing through hole 42 on the vane pump rotor 26 side and an end face of the pump rotor small diameter shaft portion 41 on the vane pump rotor 26 side. An oil reservoir 45 is formed. The oil reservoir 45 is formed in the direction in which the bearing through-hole 24 formed in the partition wall 23 extends (in the direction of the drive shaft 16) and is formed so as to open along the bearing through-hole 24. is fluidly connected with The bearing through hole 24 and the oil supply passage 46 are also fluidly connected.

That is, when viewed in a cross section orthogonal to the drive shaft 16, the bearing through-hole 24 has an oil supply passage 46 formed in the shape of a rectangular "recess" or "groove". High-pressure oil is supplied to the oil supply passage 46 from the discharge portion 34 of the vane-type oil pump provided on the side surface of the pump body 11 .

A further explanation will be added based on FIGS. 10 to 12. Here, FIG. 10 is an enlarged view of the vicinity of the oil supply passage 46, FIG. 11 is a cross section taken along line BB of FIG. 9, and FIG. 12 is a view of the pump body 11 from the side of the high-pressure oil pump. be.

In FIG. 10, the axial length of the pump rotor small diameter shaft portion 41 is set to the axial length (L1), and the seizure phenomenon or wear phenomenon of the pump rotor small diameter shaft portion 41 occurs at this portion. . Therefore, it is necessary to supply oil to the minute gap formed between the inner rotor side bearing through-hole 42 and the pump rotor diameter small shaft portion 41 .

Therefore, in this embodiment, an annular oil reservoir 45 is formed. The axial length of the oil storage portion 45 is set to the axial length (L2), which is shorter than the axial length (L1) of the pump rotor diameter small shaft portion 41 of the pump. Note that the axial length (L2) is arbitrary, and may be determined to be an appropriate length in terms of design.

High-pressure oil is sent from the vane-type oil pump through the oil supply passage 46 and stored in the oil reservoir 45 . The stored oil fills the minute gap formed between the inner rotor side bearing through-hole 42 and the pump rotor small diameter shaft portion 41 by its own pressure. As shown in FIGS. 11 and 12, the oil supply passage 46 is connected to the discharge portion 34 of the vane-type oil pump via an introduction passage 47 extending in the radial direction.

The radial length of the oil supply passage 46 around the axis of the drive shaft 16 is shorter than the radial length of the inner rotor side bearing through-hole 42 around the axis of the drive shaft 16 . set and shortened by the differential length (ΔD). He is trying to supply the required amount of oil to the oil storage part 45 by this. Here, since the oil supply passage 46 is formed along the drive shaft 16 , the oil is supplied to even the minute gap formed between the drive shaft 16 and the bearing through hole 24 . Thus, the oil supply passage 46 can forcibly supply lubricating oil to both the bearing through-hole 24 and the inner rotor side bearing through-hole 42 .

Now, when the drive shaft 16 is rotated by an internal combustion engine or an electric motor, the vane pump rotor 26 press-fitted into the cylindrical portion 16C of the drive shaft 16 and the width across flat portion 16P of the drive shaft 16 can move in the axial direction. The inner rotor 38 fitted to is rotated in synchronization with the rotation of the drive shaft 16 . A pump action is thereby performed.

The rotation of the vane pump rotor 26 causes the oil to be sucked from the high-pressure side suction hole 19, and the rotation of the vane pump rotor 26 further pressurizes the oil to a high pressure (corresponding to the first discharge pressure in the claims). It is discharged from the side discharge hole 18 (see FIG. 1). Similarly, the rotation of the inner rotor 38 causes the oil to be sucked from the low-pressure side suction hole 17, and the rotation of the inner rotor 38 further pressurizes the oil to a low pressure (corresponding to the second discharge pressure in the claims). Air pressure or negative pressure may be applied) and discharged from the low-pressure side discharge hole 20 .

In this way, when the drive shaft 16 moves in the axial direction (moves in the thrust direction) while the tandem oil pump is operating, the drive shaft 16 is firmly press-fitted into the vane pump rotor 26. Therefore, the side surface perpendicular to the axial direction of the vane pump rotor 26 comes into contact with the inner end surface of the high-pressure pump cover 13 or the end surface of the partition wall 23 on the vane pump rotor 26 side.

The side surface of the vane pump rotor 26 perpendicular to the axial direction slides while rotating on the inner end surface of the high-pressure pump cover 13 or the end surface of the partition wall 23 on the vane pump rotor 26 side. For this reason, there is a possibility that a seizing phenomenon or an abrasion phenomenon may occur at this sliding portion. However, since the oil discharge pressure of the vane pump rotor 26 is high, the side surface of the vane pump rotor 26 is in contact with the inner end surface of the high-pressure pump cover 13 or the end surface of the partition wall 23 on the vane pump rotor 26 side with a large surface pressure. Also, a sufficient amount of oil can be supplied to the side surface of the vane pump rotor 26, and the side surface of the vane pump rotor 26 can be prevented from being seized or worn.

On the other hand, when the drive shaft 16 is moved in the axial direction (moved in the thrust direction) while the tandem oil pump is operating, the inner rotor 38 is fitted on the drive shaft 16 so as to be movable in the axial direction. Therefore, the inner rotor 38 is free in the axial direction of the drive shaft 16 even if the drive shaft 16 moves. Therefore, the side surface of the inner rotor 38 perpendicular to the axial direction does not contact the inner end surface of the low-pressure pump cover 15 or the inner rotor 38 side end surface of the partition wall 23 with a large surface pressure.

The side surface of the inner rotor 38 orthogonal to the axial direction slides while rotating on the inner end surface of the low-pressure pump cover 15 or the end surface of the partition wall 23 on the inner rotor 38 side. However, the side surface perpendicular to the axial direction of the inner rotor 38 does not contact the inner end surface of the low-pressure pump cover 15 or the inner rotor 38 side end surface of the partition wall 23 with a large surface pressure. The reason is that the inner rotor 38 is free in the axial direction of the drive shaft 16 .

Therefore, even if the oil discharge pressure of the inner rotor 38 is low, the side surface of the inner rotor 38 contacts the inner end surface of the low-pressure pump cover 15 or the inner rotor 38 side end surface of the partition wall 23 with a large surface pressure. Therefore, a sufficient amount of oil can be supplied to the side surface of the inner rotor 38, and the side surface of the inner rotor 38 can be prevented from being seized or worn.

As described above, in this embodiment, since the inner rotor 38 constituting the low-pressure oil pump can move in the axial direction of the drive shaft 16, it is possible to sufficiently supply oil to the side surfaces of the inner rotor 38 even when the discharge pressure is low. Therefore, it is possible to suppress the occurrence of seizure phenomenon or wear phenomenon on the side surface of the inner rotor 38 .

Further, since the vane pump rotor 26 constituting the high-pressure oil pump has a high discharge pressure, even if the side surface of the vane pump rotor 26 comes into contact with the sliding surface with a large surface pressure, the oil is sufficiently supplied to the side surface of the vane pump rotor. It is possible to suppress the occurrence of seizure phenomenon or wear phenomenon on the side surface of the vane pump rotor 26 .

Also, as shown in FIG. 11, part of the high-pressure oil pressurized by the rotation of the vane oil pump flows out from the discharge part 34 into the introduction passage 47 and reaches the oil supply passage 46. Since the oil supply passage 46 is formed along the axial direction of the bearing through hole 24 , a sufficient oil film can be formed between the drive shafts 16 .

Furthermore, the high-pressure oil flowing through the oil supply passage 46 is stored in the oil reservoir 45, as indicated by the arrow OA shown in FIG. Since the pressure of the oil in the oil storage portion 45 is higher than the discharge pressure of the gear type oil pump, the oil in the oil storage portion 45 is pushed through the inner rotor side bearing through hole 42 and the pump rotor diameter small shaft portion 41 by its own pressure. It fills the minute gaps formed in the

Therefore, even if the gap between the inner rotor side bearing through-hole 42 and the pump rotor small diameter shaft portion 41 becomes narrower due to vibration of the inner rotor 38 and the oil film becomes thinner, the oil is retained in the oil reservoir 45 . The high-pressure oil that has been pumped is forcibly delivered to the minute gap formed between the inner rotor side bearing through-hole 42 and the pump rotor diameter small shaft portion 41, so oil film breakage can be suppressed. As a result, it is possible to suppress the occurrence of a seizure phenomenon or a wear phenomenon between the inner rotor side bearing through-hole 42 and the pump rotor small diameter shaft portion 41 .

Furthermore, in addition to the action and effect of suppressing the occurrence of the seizure phenomenon or the wear phenomenon, the following action and effect can be obtained. For example, (1) oil flows out from the oil storage portion 45 to the inner rotor 38 side through a minute gap formed between the inner rotor side bearing through-hole 42 and the pump rotor diameter small shaft portion 41 . (2) The cooling action can be improved by the flowing oil. Since the oil is a solid oil, it is possible to obtain the action and effect that the cleaning effect of the sliding portion can be improved by the flowing oil.

Here, the oil supply passage 46 is configured to supply oil axially to the oil reservoir 45, but it is also possible to supply oil axially and radially to the inner rotor side bearing through hole 42. It is possible.

For example, in FIG. 13, the inner rotor side bearing through hole 42 is provided with a groove-shaped small diameter shaft portion side oil supply passage 48 formed along the small diameter shaft portion 41 of the pump rotor. The small diameter shaft portion side oil supply passage 48 is connected to the oil reservoir portion 45 , and the oil from the oil supply passage 46 is supplied to the oil reservoir portion 45 . supplied. As a result, the oil can be more efficiently supplied to the minute gap formed between the inner rotor side bearing through-hole 42 and the small diameter shaft portion 41 of the pump rotor.

The small diameter shaft portion side oil supply passage 48 is formed in the pump body 11 so as to extend from the oil reservoir 45 to the middle of the small diameter shaft portion 41 of the pump rotor. It extends to about half the length of L1). As a result, a sufficient amount of oil can be supplied to the pump rotor diameter small shaft portion 41 and the inner rotor side bearing through hole 42 .

Here, the reason why the small-diameter shaft portion side oil supply passage 48 is formed only halfway through the pump rotor small-diameter shaft portion 41 is that a large amount of high-pressure oil flows to the low-pressure gear-type oil pump side. This is for suppressing deterioration of the specified performance of the pump. By forming the small diameter shaft portion side oil supply passage 48 to the middle of the small diameter shaft portion 41 of the pump rotor, it is possible to supply a sufficient amount of oil to the small diameter shaft portion 41 of the pump rotor. can be made to leak as little oil as possible.

Here, in the embodiment described above, an example in which the oil supply passage 46 and the small diameter shaft portion side oil supply passage 48 are formed in the form of grooves on the pump body 11 side has been described. Similarly, grooves such as the oil supply passage 46 and the small diameter shaft portion side oil supply passage 48 can be formed on the outer circumference of the drive shaft 16 and the outer circumference of the pump rotor small diameter shaft portion 41 . A brief description is given below.

In FIG. 14, a groove-shaped drive shaft oil supply passage 49 is formed in the outer periphery of the drive shaft 16 in the range where the bearing through hole 24 exists. is connected to the oil reservoir 45 at its end. On the other hand, the end of the drive shaft oil supply passage 49 opposite to the inner rotor 38 is connected to the discharge portion 34 of the vane type oil pump. Therefore, high-pressure oil can be supplied to the oil reservoir 45 also with this configuration.

Furthermore, a groove-shaped pump rotor diameter small shaft oil supply passage 50 can be formed on the outer periphery of the pump rotor diameter small shaft portion 41 of the inner rotor 38 . The pump rotor diameter small shaft oil supply passage 50 is connected to the oil reservoir 45, and the oil from the drive shaft oil supply passage 49 is supplied to the oil reservoir 45. 50. As a result, the oil can be more efficiently supplied to the minute gap formed between the inner rotor side bearing through-hole 42 and the small diameter shaft portion 41 of the pump rotor.

In this example, too, the reason why the pump rotor diameter small shaft oil supply passage 50 is formed only halfway through the pump rotor diameter small shaft portion 41 is that a large amount of high pressure oil flows to the low pressure gear type oil pump side, This is for suppressing deterioration of the specification performance of the type oil pump. By forming the pump rotor small diameter shaft oil supply passage 50 to the middle of the pump rotor small diameter shaft portion 41, a sufficient amount of oil can be supplied to the pump rotor small diameter shaft portion 41, and moreover, it is possible to supply a sufficient amount of oil to the gear type oil pump side. can be made to leak as little oil as possible.

In the first embodiment, the oil supply passage 46 is formed along the drive shaft 16 and is open to the drive shaft. It is formed as a closed passageway without opening at all. 15 and 16, the same reference numerals as those in the first embodiment represent the same parts, so description thereof will be omitted.

15 and 16, the oil storage portion 45 and the discharge portion 34 of the vane type oil pump are directly connected by an internal oil supply passage 51 formed inside the pump body 11 . The internal oil supply passage 51 does not open to the drive shaft 16 side as in the first embodiment, and has a closed passage structure except for opening to the oil reservoir 45 and the discharge portion 34 . , a hole is drilled so as to connect the oil storage portion 45 and the discharge portion 34 .

As shown in FIGS. 15 and 16, part of the high-pressure oil pressurized by the rotation of the vane oil pump flows from the discharge part 34 through the internal oil supply passage 51 to the oil reservoir 45. stored. As in the first embodiment, the pressure in the oil reservoir 45 is higher than the discharge pressure of the gear-type oil pump. and fills a minute gap formed in the pump rotor diameter small shaft portion 41 . Therefore, also in this embodiment, it is possible to obtain the same functions and effects as in the first embodiment.

Here, the internal oil supply passage 51 is configured to directly supply oil from the discharge portion 34 of the vane type oil pump to the oil storage portion 45 , but the oil is supplied radially to the inner rotor side bearing through hole 42 . It is also possible to supply

For example, in FIG. 17, a small diameter shaft portion side oil supply passage 52 is formed along the small diameter shaft portion 41 of the pump rotor. The small diameter shaft portion side oil supply passage 52 is connected to the internal oil supply passage 51 , and the oil from the internal oil supply passage 51 is supplied to the oil reservoir 45 and the small diameter shaft portion side oil supply passage 52 . As a result, the oil can be more efficiently supplied to the minute gap formed between the inner rotor side bearing through-hole 42 and the small diameter shaft portion 41 of the pump rotor.

In this example as well, the small diameter shaft portion side oil supply passage 52 is formed in the pump body 11 so as to extend from the oil storage portion 45 to the middle of the small diameter shaft portion 41 of the pump rotor. It extends up to about half the axial length (L1) of . As a result, a sufficient amount of oil can be supplied to the pump rotor diameter small shaft portion 41 and the inner rotor side bearing through hole 42 .

In this example as well, the reason why the small diameter shaft portion side oil supply passage 52 is formed only halfway through the pump rotor small diameter shaft portion 41 is that a large amount of high pressure oil flows to the low pressure gear type oil pump side, This is for suppressing deterioration of the specification performance of the type oil pump. By forming the small diameter shaft portion side oil supply passage 52 to the middle of the small diameter pump rotor shaft portion 41, a sufficient amount of oil can be supplied to the small diameter pump rotor shaft portion 41, and moreover, the oil supply passage 52 can be supplied to the gear type oil pump side. can be made to leak as little oil as possible.

As described above, in the present invention, the diameter of the pump body is located between the pump rotor accommodating portion and the drive shaft bearing portion, and is larger than the diameter of the drive shaft bearing portion and more than the diameter of the pump rotor accommodating portion. The pump rotor housing portion is formed with a pump rotor bearing portion that is continuous with the small pump rotor housing portion. The pump rotor is formed with a pump rotor diameter small shaft portion, and the pump rotor diameter small shaft portion is supported by the pump rotor bearing portion. In addition, an oil supply passage for supplying oil from the high-pressure oil pump to the pump rotor bearing is formed in the pump body.

According to this, in a tandem-type oil pump that combines a high-pressure oil pump and a low-pressure oil pump, high-pressure oil can be supplied from the high-pressure oil pump to the pump rotor bearing portion through the oil supply passage. It is possible to suppress the occurrence of a seizure phenomenon or an abrasion phenomenon in the formed small diameter shaft portion of the pump rotor.

It should be noted that the present invention is not limited to the several embodiments described above, and includes various modifications. The above embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the described configurations. Moreover, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Other configurations can be added, deleted, or replaced with respect to the configuration of each embodiment.

Claims

a first pump rotor accommodating portion and a second pump rotor accommodating portion; a partition wall partitioning the first pump rotor accommodating portion and the second pump rotor accommodating portion; and the first pump formed in the partition wall. a pump body having a drive shaft bearing portion connecting between the rotor housing portion and the second pump rotor housing portion;
a drive shaft rotatably supported by the drive shaft bearing and driven to rotate by an external power source;
It has a first pump rotor that is arranged in the first pump rotor accommodating portion and is rotationally driven by the drive shaft. a first oil pump that pressurizes the spilled oil and discharges it from the first discharge part;
It has a second pump rotor that is arranged in the second pump rotor accommodating portion and is rotationally driven by the drive shaft. a second oil pump that discharges the discharged oil from a second discharge part at a pressure lower than the pressure discharged from the first discharge part of the first oil pump;
Further, the pump body is provided between the second pump rotor accommodating portion and the drive shaft bearing portion, and has a diameter larger than that of the drive shaft bearing portion and a diameter of the second pump rotor accommodating portion. a second pump rotor bearing portion formed continuously with the second pump rotor housing portion smaller than the
The second pump rotor is formed with a second pump rotor diameter small shaft portion integrated with the second pump rotor, and the second pump rotor diameter small shaft portion is housed in the second pump rotor bearing portion. Along with being bearing
A tandem type oil pump, wherein an oil supply passage for supplying oil from the first oil pump to the second pump rotor bearing is formed in the pump body.
In the tandem type oil pump according to claim 1,
Between the end of the second pump rotor diameter small shaft portion on the first oil pump side and the end of the second pump rotor bearing portion on the first oil pump side, the first oil A tandem type oil pump, wherein an oil reservoir is provided to store oil from a discharge part of the pump, and the oil supply passage is connected to the oil reservoir to supply oil from the first oil pump.
In the tandem oil pump according to claim 2,
The oil supply passage is formed along the drive shaft bearing portion, and an end portion of the oil supply passage on the side of the second pump rotor bearing portion extends in the axial direction of the drive shaft toward the oil reservoir. A tandem type oil pump characterized by being connected.
In the tandem type oil pump according to claim 3,
A small diameter shaft portion side oil supply passage is formed in the second pump rotor bearing portion along the small diameter shaft portion of the second pump rotor, and the small diameter shaft portion side oil supply passage extends into the oil reservoir. A tandem oil pump characterized by being fluidly connected.
In the tandem type oil pump according to claim 4,
The tandem type oil pump, wherein the small diameter shaft portion side oil supply passage is formed halfway through the second small diameter shaft portion of the second pump rotor in the axial direction of the small diameter shaft portion of the second pump rotor.
In the tandem oil pump according to claim 2,
The tandem oil pump, wherein the oil supply passage is an internal oil supply passage formed in the pump body and directly connecting the discharge portion of the first oil pump and the oil reservoir.
In the tandem type oil pump according to claim 6,
A small diameter shaft portion side oil supply passage is formed in the second pump rotor bearing portion along the small diameter shaft portion of the second pump rotor, and the small diameter shaft portion side oil supply passage extends into the oil reservoir. A tandem oil pump characterized by being fluidly connected.
In the tandem type oil pump according to claim 1,
Attached to the pump body are a first pump cover that closes the first pump rotor accommodating portion, and a second pump cover that is provided on the opposite side of the first pump cover and closes the second pump rotor accommodating portion. be
The first pump rotor is arranged between the first pump cover and the partition wall and fixed to the drive shaft,
The second pump rotor is arranged between the second pump cover and the partition wall, and fitted to the drive shaft so as to be axially movable relative to the drive shaft. A tandem oil pump characterized by
In the tandem oil pump according to claim 8,
The first pump cover and the second pump cover are attached to the pump body along a plane perpendicular to the axis of the drive shaft,
The first pump cover is provided with a first discharge hole that opens at a radial position with respect to the drive shaft and is connected to the first discharge portion,
A first suction hole, which opens at a radial position with respect to the drive shaft and communicates with the first suction portion, is provided on the side of the pump body on which the second pump cover is provided. Tandem type oil pump.
In the tandem type oil pump according to claim 9,
a pair of mounting portions which are provided on the pump body so as to sandwich the pump body at positions in a radial direction with respect to the drive shaft and which are mounted on an internal combustion engine;
A tandem-type oil pump, wherein at least one of the mounting portions is provided with a second suction hole communicating with the second suction portion of the second oil pump.
In the tandem type oil pump according to claim 1,
The first oil pump is
an adjustment ring arranged swingably in the first pump rotor accommodation portion and having a rotor accommodation portion provided therein; a pump rotor accommodated inside the adjustment ring; an outer peripheral surface of the pump rotor; a plurality of vanes forming a plurality of hydraulic fluid chambers through which oil is guided between the adjustment ring and the pump rotor, wherein the volumes of the plurality of hydraulic fluid chambers increase as the drive shaft rotates. Oil is sucked from the first suction portion that opens to the hydraulic oil chamber that is open to the hydraulic oil chamber, and the first discharge opens to the hydraulic oil chamber that decreases in volume among the plurality of hydraulic oil chambers as the drive shaft rotates. A tandem-type oil pump characterized by being a vane-type oil pump that discharges oil from a part.
In the tandem oil pump according to claim 10,
The second oil pump is
As the second pump rotor accommodated in the second pump rotor accommodation portion, an outer rotor including a plurality of internal teeth on the inner peripheral side, and an outer rotor accommodated inside the outer rotor and along the drive axis of the drive shaft A tandem-type oil pump characterized by being a gear-type oil pump provided movably in the direction of and having a plurality of external teeth meshing with the plurality of internal teeth on an outer peripheral side.
In the tandem type oil pump according to claim 1,
The first oil pump is a variable capacity oil feed pump that supplies pressurized oil to at least a main oil gallery of the internal combustion engine,
A tandem oil pump, wherein the second oil pump is a scavenging oil pump that collects oil from an oil pan of an internal combustion engine.
a first pump rotor accommodating portion and a second pump rotor accommodating portion; a partition wall partitioning the first pump rotor accommodating portion and the second pump rotor accommodating portion; and the first pump formed in the partition wall. a pump body having a drive shaft bearing portion connecting between the rotor housing portion and the second pump rotor housing portion;
a drive shaft arranged in the first pump rotor housing portion and the second pump rotor housing portion and rotatably driven by an external power source and rotatably supported by the drive shaft bearing portion;
a first oil pump arranged in the first pump rotor accommodating portion and a second oil pump arranged in the second pump rotor accommodating portion, which are driven by the drive shaft;
The first oil pump is
an adjusting ring arranged swingably in the first pump rotor accommodating portion and provided with a rotor accommodating portion therein; a pump rotor accommodated inside the adjusting ring and fixed to the drive shaft; and the pump rotor. and a plurality of vanes that are accommodated on the outer peripheral surface of the pump rotor and form a plurality of hydraulic oil chambers through which oil is guided between the adjustment ring and the pump rotor. Oil is sucked from a first suction portion that opens to the hydraulic oil chamber whose volume increases among the oil chambers, and is drawn into the hydraulic oil chamber whose volume decreases with the rotation of the drive shaft. A vane-type oil pump that discharges oil from an open first discharge part,
The second oil pump is
As the second pump rotor accommodated in the second pump rotor accommodating portion, an outer rotor including a plurality of internal teeth on the inner peripheral side, and an outer rotor accommodated inside the outer rotor along the drive axis of the drive shaft. A gear-type oil pump provided movably in a direction and having a plurality of external teeth that mesh with the plurality of internal teeth on the outer peripheral side,
Further, the pump body is provided between the second pump rotor accommodating portion and the drive shaft bearing portion, and has a diameter larger than that of the drive shaft bearing portion and a diameter of the second pump rotor accommodating portion. a second pump rotor bearing portion formed continuously with the second pump rotor housing portion smaller than the
The second pump rotor is formed with a second pump rotor diameter small shaft portion integrated with the second pump rotor, and the second pump rotor diameter small shaft portion is housed in the second pump rotor bearing portion. Along with being bearing
A tandem type oil pump, wherein an oil supply passage for supplying oil from the first oil pump to the second pump rotor bearing is formed in the pump body.
a high-pressure pump rotor housing portion and a low-pressure pump rotor housing portion; a partition wall that separates the high-pressure pump rotor housing portion and the low-pressure pump rotor housing portion; a pump body having a drive shaft bearing portion connected to the low-pressure pump rotor accommodating portion;
a drive shaft disposed in the high-pressure pump rotor housing portion and the low-pressure pump rotor housing portion and rotatably driven by an external power source rotatably supported by the drive shaft bearing portion;
a high-pressure oil pump having a high-pressure pump rotor disposed in the high-pressure pump rotor accommodating portion and rotationally driven by the drive shaft, and performing a pumping action at a first discharge pressure by rotation of the high-pressure pump rotor;
It has a low-pressure pump rotor disposed in the low-pressure pump rotor accommodating portion and rotationally driven by the drive shaft, and the rotation of the low-pressure pump rotor performs a pumping action at a second discharge pressure lower than the first discharge pressure. a low pressure oil pump;
Further, the pump body is provided between the low-pressure pump rotor accommodating portion and the drive shaft bearing portion, and has a diameter larger than that of the drive shaft bearing portion and larger than the diameter of the low-pressure pump rotor accommodating portion. a low-pressure pump rotor bearing portion formed continuously with the small low-pressure pump rotor accommodating portion;
The low-pressure pump rotor is formed with a low-pressure pump rotor diameter small shaft portion integrated with the low-pressure pump rotor, and the low-pressure pump rotor diameter small shaft portion is housed and supported in the low-pressure pump rotor bearing portion. 1. A tandem type oil pump, wherein an oil supply passage for supplying oil from said high pressure oil pump to said low pressure pump rotor bearing is formed in said pump body.
In the tandem oil pump according to claim 15,
The high-pressure pump rotor is press-fitted and fixed to the drive shaft and rotationally driven by the drive shaft,
A tandem-type oil pump, wherein the low-pressure pump rotor is movably attached to the drive shaft in the drive axis direction and is rotationally driven by the drive shaft.
A tandem oil pump according to claim 16,
The high-pressure oil pump is a variable displacement oil feed pump that supplies pressurized oil to a variable valve mechanism of an internal combustion engine and a main oil gallery of the internal combustion engine,
A tandem-type oil pump, wherein the low-pressure oil pump is a scavenging oil pump that collects oil from an oil pan of the internal combustion engine.
A tandem oil pump according to claim 17,
the variable displacement oil feed pump is a vane oil pump,
A tandem-type oil pump, wherein the scavenging oil pump is a gear-type oil pump.
A tandem oil pump according to claim 16,
The drive shaft has a cylindrical portion and a width across flats portion,
The high-pressure pump rotor is press-fitted and fixed to the cylindrical portion,
The low-pressure pump rotor having a fitting hole having a shape similar to that of the width across flat portion is fitted in the width across flat portion so as to be axially movable with respect to the drive shaft. Characteristic tandem type oil pump.
A tandem oil pump according to claim 19,
A tandem-type oil pump, wherein the length of the width across flats in the axial direction is longer than the length of the low-pressure pump rotor in the axial direction.