JP2017040253A - Oil pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil pump capable of inhibiting oil pulsation occurring when an operation chamber communicates with a discharge chamber.SOLUTION: An oil pump 1 includes: an inner rotor 2; an outer rotor 3 which engages with the inner rotor 2 in an eccentric state; and a housing rotatably housing the outer rotor 3. An operation chamber 5 is formed between teeth of the inner rotor 2 and teeth of the outer rotor 3 which engage with each other, and pump operation is conducted by changing volumetric capacity of the operation chamber 5. In the housing, a suction chamber 41 is formed in an expansion area of the volumetric capacity of the operation chamber 5, and a discharge chamber 42 is formed in a reduction area of the volumetric capacity of the operation chamber 5. A oil storage space 6 which communicates with the operation chamber 5 is formed in an area between the suction chamber 41 and the discharge chamber 42 in a body 4 forming the housing.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an oil pump.

  As an oil pump, an inscribed gear pump including an inner rotor and an outer rotor that meshes the inner rotor in an eccentric state is known (for example, see Patent Document 1). In such an oil pump, working chambers are formed between the teeth of the inner rotor and outer rotor that mesh with each other, and the pump operation is performed by changing the volume of each working chamber while moving in the rotor rotation direction. Done.

  By the way, the working chamber at the boundary between the enlarged region and the reduced region of the working chamber volume becomes a cut-off space (sealed space) that does not communicate with either the suction chamber or the discharge chamber when the volume becomes maximum. The working chamber that has become the cut-off space communicates with the discharge chamber by the rotation of the rotor. At this time, the oil in the discharge chamber in a higher pressure state than the working chamber temporarily flows back into the working chamber. For this reason, there is a concern that the pressure in the working chamber suddenly increases and oil pulsation occurs.

JP 2010-242675 A

  The present invention has been made in consideration of the above-described circumstances, and an object thereof is to provide an oil pump capable of suppressing oil pulsation when an operation chamber communicates with a discharge chamber.

  In the present invention, means for solving the above-described problems are configured as follows. That is, the present invention provides an inner rotor having a plurality of external teeth, an outer rotor having a larger number of internal teeth than the external teeth and meshing the inner rotor in an eccentric state, and the outer rotor being rotatable. An oil pump, wherein a working chamber is formed between teeth engaged with each other of the inner rotor and the outer rotor, and a pumping operation is performed by a change in volume of the working chamber. The suction chamber is formed in the enlarged region of the volume of the working chamber, the discharge chamber is formed in the reduced region of the volume of the working chamber, and in the region between the suction chamber and the discharge chamber An oil storage space communicating with the working chamber is formed.

  According to the above configuration, before the working chamber communicates with the discharge chamber, the working chamber communicates with the oil storage space, and the oil in the oil storage space that is in a higher pressure state than the working chamber flows into the working chamber and operates. The pressure in the room rises. For this reason, compared with the case where oil storage space is not provided, the pressure difference in the working chamber before and after the working chamber communicates with the discharge chamber is reduced. Therefore, when the working chamber communicates with the discharge chamber, it is possible to suppress oil pulsation due to a sudden rise in pressure in the working chamber.

  In addition, when the working chamber communicates with the discharge chamber, oil in the discharge chamber flows into the working chamber and the oil storage space. That is, as compared with the case where no oil storage space is provided, the volume of the space into which the oil in the discharge chamber can flow increases by the volume of the oil storage space. Thereby, when the working chamber communicates with the discharge chamber, an increase in pressure in the working chamber is suppressed, and oil pulsation caused by a sudden increase in pressure in the working chamber can be suppressed.

  According to the oil pump of the present invention, the pressure difference in the working chamber before and after the working chamber communicates with the discharge chamber is reduced as compared with the case where no oil storage space is provided. In addition, oil pulsation caused by a sudden rise in pressure in the working chamber can be suppressed.

It is a top view which shows schematic structure of the oil pump which concerns on embodiment of this invention. It is a top view which shows the body of the oil pump of FIG. FIG. 3 is a cross-sectional view taken along line X1-X1 of FIG. It is operation | movement explanatory drawing of the oil pump of FIG. It is sectional drawing which shows the modification 1 of an oil pump. It is sectional drawing which shows the modification 2 of an oil pump. It is a top view of the oil pump of FIG. 10 is a plan view showing a body of an oil pump according to Modification 3. FIG. 10 is a plan view showing a cover of an oil pump according to Modification 3. FIG. It is a figure which expands and shows a part of FIG. It is a figure which expands and shows a part of FIG. FIG. 10 is a plan view showing a body of an oil pump according to Modification 4. 10 is a plan view showing a cover of an oil pump according to Modification 4. FIG.

  Embodiments of the present invention will be described below with reference to the drawings. Hereinafter, an oil pump used for lubricating an engine of an automobile or the like will be described as an example.

  As shown in FIG. 1, the oil pump 1 includes an inner rotor 2, an outer rotor 3, a body 4, a cover (not shown), and the like. In FIG. 1, the cover of the oil pump 1 is omitted.

  The inner rotor 2 has a plurality of (for example, ten) external teeth 21, and a rotating shaft (not shown) is fitted to the inner diameter portion 22 so as to rotate together, and is rotated in the direction of the arrow P <b> 1 around the point C <b> 2. The rotating shaft is, for example, an engine crankshaft or the like. Both side portions 23 of the inner rotor 2 are flat surfaces orthogonal to the rotation axis.

  The outer rotor 3 has a larger number (for example, 11) of inner teeth 31 than the outer teeth 21 of the inner rotor 2, and the inner rotor 2 is meshed with the inner rotor 2 in an eccentric state. The outer rotor 3 has an annular surface 32 on the outer diameter side, and is rotatably accommodated in an internal space in the body 4 corresponding to the annular surface 32. When the inner rotor 2 is rotated by the driving force of the rotating shaft, the outer rotor 3 also rotates in the same direction around the point C1 in the body 4 as the inner rotor 2 rotates. The both side portions 33 of the outer rotor 3 are flat surfaces that are orthogonal to the rotational axis and are formed on the same plane as the both side portions 23 of the inner rotor 2.

  The body 4 rotatably accommodates the outer rotor 3 meshing with the inner rotor 2. A cover (not shown) is attached to the body 4 with a fastener such as a bolt. In this embodiment, the housing of the oil pump 1 is constituted by the body 4 and the cover. That is, the housing of the oil pump 1 has a two-part structure of the body 4 and the cover.

  Inside the body 4 and the cover, as shown in FIG. 2, a suction chamber 41 communicating with the suction port, a discharge chamber 42 communicating with the discharge port, and a side wall 44 where the side portions 23 and 33 of the rotors 2 and 3 are in surface contact. Is formed. In FIG. 2, the suction chamber 41 and the discharge chamber 42 on the body 4 side are shown, but the suction chamber and the discharge chamber having the same shape are also formed on the cover side.

  As shown in FIG. 1, a working chamber 5 is formed between teeth of the inner rotor 2 and the outer rotor 3 that mesh with each other. Specifically, each working chamber 5 is surrounded by the two outer teeth 21 and 21 of the inner rotor 2, the two inner teeth 31 and 31 of the outer rotor 3, and the side walls of the body 4 and the cover. It is a space. The volume of each working chamber 5, in other words, the interdental volume of the inner rotor 2 and the outer rotor 3 increases and decreases as the rotor rotates. In FIG. 1, the region on the substantially right half of the oil pump 1 is an enlarged region in which the volume of the working chamber 5 gradually increases as the rotor rotates. In this enlarged region, the working chamber 5 communicates with the suction chamber 41. On the other hand, the region on the substantially left half of the oil pump 1 is a reduced region in which the volume of the working chamber 5 gradually decreases as the rotor rotates. In this reduced region, the working chamber 5 communicates with the discharge chamber 42. In addition, the working chamber 5 in a position where the enlarged region and the reduced region overlap (boundary region) has a cutoff space (sealed space) that does not communicate with either the suction chamber 41 or the discharge chamber 42 when the volume is maximum. Become.

  In the oil pump 1 having the above configuration, when the inner rotor 2 rotates in the direction of the arrow P1 by the power of the engine, the outer rotor 3 rotates in the same direction as the inner rotor 2 rotates. As a result, as shown in FIGS. 4A to 4D, the volume of each working chamber 5 changes, and oil is sucked into the suction chamber 41 from the suction port due to the volume change of the working chamber 5. . The oil flowing into the suction chamber 41 is sent out to the discharge chamber 42 side by the working chamber 5 and further discharged from the discharge chamber 42 to the discharge port.

  By the way, when the pumping operation of the oil pump 1 as described above is repeated, the pressure in the discharge chamber 42 becomes higher than the pressure in the suction chamber 41, and the working chamber 5, which is the above-described dead space, communicates with the discharge chamber 42. At this time, a reverse flow of oil from the discharge chamber 42 to the working chamber 5 occurs. For this reason, there is a concern that the pressure in the working chamber 5 rapidly increases and oil pulsation occurs.

  In this embodiment, as a countermeasure against the above-described oil pulsation, the oil pump 1 is provided with an oil storage space 6 capable of communicating with the working chamber 5 (hereinafter referred to as “working chamber 5A”) that has become the above-described dead space. ing. Hereinafter, this point will be described.

  As shown in FIG. 1, the oil storage space 6 is provided in the region between the suction chamber 41 and the discharge chamber 42 in the body 4, and is provided so as to overlap the working chamber 5A. In this embodiment, the oil storage space 6 is provided as a recess formed in the side wall 44 of the body 4 as shown in FIGS.

  The oil storage space 6 is provided at a position where it can communicate with the discharge chamber 42 via the working chamber 5A. On the other hand, the oil storage space 6 is provided at a position not communicating with the suction chamber 41 via the working chamber 5A. In a state where the oil storage space 6 is not in communication with the working chamber 5A, sealing is performed between the side wall 44 of the body 4 and the inner rotor 2 and the outer rotor 3, whereby the oil storage space 6 is maintained in a sealed state. ing. In this state, the oil storage space 6 is filled with oil, and the pressure in the oil storage space 6 is kept higher than the pressure in the suction chamber 41.

  The operation of the oil storage space 6 during operation of the oil pump 1 will be described with reference to FIG. 4 (a) to 4 (d) show how the communication state of the working chamber 5A, the oil storage space 6, the suction chamber 41, the discharge chamber 42, etc. changes according to the order in which the inner rotor 2 rotates in the direction of the arrow P1. Is shown.

  First, the state of FIG. 4A is a state in which the injection of oil into the working chamber 5A is completed. In this state, the working chamber 5 </ b> A does not communicate with the suction chamber 41 and is blocked. The working chamber 5 </ b> A does not communicate with the oil storage space 6 and the discharge chamber 42 and is blocked.

  4B is a state in which the inner rotor 2 has been rotated by a predetermined angle in the direction of the arrow P1 from the state of FIG. 4A, and at this time, communication between the working chamber 5A and the oil storage space 6 has started. Is done. Then, as the inner rotor 2 rotates in the direction of the arrow P1, an area where the working chamber 5A and the oil storage space 6 communicate with each other in a plan view increases. Due to the communication between the working chamber 5A and the oil storage space 6, the oil in the oil storage space 6 in a higher pressure state than in the working chamber 5A flows into the working chamber 5A. Thereby, the pressure in 5 A of working chambers rises compared with the state of Fig.4 (a).

  4C is a state in which the inner rotor 2 has been rotated by a predetermined angle in the direction of the arrow P1 from the state of FIG. 4B, and the communication between the working chamber 5A and the discharge chamber 42 is started. Then, as the inner rotor 2 rotates in the direction of the arrow P1, the area where the working chamber 5A and the discharge chamber 42 communicate with each other in plan view increases. Due to the communication between the working chamber 5A and the discharge chamber 42, oil in the discharge chamber 42 that is in a higher pressure state than in the working chamber 5A flows into the working chamber 5A. Thereby, the pressure in 5 A of working chambers rises compared with the state of FIG.4 (b).

  4D is a state in which the inner rotor 2 is rotated by a predetermined angle in the direction of the arrow P1 from the state of FIG. 4C, and the oil storage space 6 and the discharge chamber 42 are connected via the working chamber 5A. It is communicated. In this state, all areas of the oil storage space 6 overlap with the working chamber 5A in plan view, and the area where the working chamber 5A and the oil storage space 6 communicate with each other is the largest. When the inner rotor 2 rotates by a predetermined angle in the direction of the arrow P1 from the state of FIG. 4D, the next (adjacent) working chamber 5A is in the state shown in FIG. In this state, as described above, the oil storage space 6 is maintained in a sealed state, and the pressure in the oil storage space 6 is maintained at a higher pressure than the pressure in the suction chamber 41 (working chamber 5A).

  According to this embodiment, since the oil storage space 6 is provided in the oil pump 1, oil pulsation when the working chamber 5 </ b> A communicates with the discharge chamber 42 can be suppressed.

  Specifically, before the working chamber 5A communicates with the discharge chamber 42, the working chamber 5A and the oil storage space 6 are communicated (see FIG. 4B). Thereby, the oil in the oil storage space 6 in a higher pressure state than in the working chamber 5A flows into the working chamber 5A, and the pressure in the working chamber 5A increases. For this reason, compared with the case where the oil storage space 6 is not provided, the pressure difference in the working chamber 5A before and after the working chamber 5A and the discharge chamber 42 communicate with each other is reduced.

  Specifically, when the working chamber 5A communicates with the discharge chamber 42 by an amount corresponding to an increase in the pressure in the working chamber 5A due to the communication between the working chamber 5A and the oil storage space 6 (see FIG. 4C), the operation is performed. The pressure rise in the chamber 5A is suppressed. That is, before the working chamber 5A communicates with the discharge chamber 42, the working chamber 5A is communicated with the oil storage space 6 that is held at an intermediate pressure between the pressure in the suction chamber 41 and the pressure in the discharge chamber 42. The pressure in the working chamber 5A can be increased stepwise. Therefore, when the working chamber 5A communicates with the discharge chamber 42, it is possible to suppress oil pulsation due to a sudden rise in pressure in the working chamber 5A.

  In addition, when the working chamber 5A communicates with the discharge chamber 42 (see FIG. 4C), the oil in the discharge chamber 42 flows into the working chamber 5A and the oil storage space 6. That is, as compared with the case where the oil storage space 6 is not provided, the volume of the space into which the oil in the discharge chamber 42 can flow is increased by the volume of the oil storage space 6. Thereby, when the working chamber 5A communicates with the discharge chamber 42, the pressure rise in the working chamber 5A is suppressed, and oil pulsation due to the sudden rise in pressure in the working chamber 5A can be suppressed.

  In the above embodiment, the case where the oil storage space 6 is provided in the body 4 has been described. However, the present invention is not limited to this, and an oil storage space may be provided in the cover, or an oil storage space may be provided in both the body 4 and the cover.

  The modification of the oil pump of this invention is demonstrated with reference to FIGS. In this modification, when the working chamber 5A communicates with the discharge chamber 42, the volume of the space into which the oil flows in the discharge chamber 42 is increased, so that the oil pulsation caused by the sudden rise in the pressure in the working chamber 5A occurs. We are trying to suppress it. Specifically, by reducing the rigidity of the body 4 or the cover 7 located between the suction chamber 41 and the discharge chamber 42, when the oil in the discharge chamber 42 flows into the working chamber 5A, the body 4 or The cover 7 is elastically deformed. It should be noted that this modification can also be applied to the configuration in which the oil storage space of the above embodiment is provided.

  In the first modification shown in FIG. 5, the notch (recessed portion) 7 a is formed in the cover 7, thereby reducing the rigidity of the portion of the cover 7 where the notch 7 a is formed. In the second modification shown in FIGS. 6 and 7, the notch (recess) 4 a is formed in the body 4, thereby reducing the rigidity of the portion of the body 4 where the notch 4 a is formed.

  Another modification of the oil pump will be described with reference to FIGS. In the third modification shown in FIGS. 8 and 9, in the oil pump 1, a region (flow passage cross-sectional area) where the working chamber 5 </ b> A and the oil storage spaces 6 a to 6 d communicate with each other is limited to be smaller than that in the above embodiment. ing. In the above embodiment, when the flow path cross-sectional area between the working chamber 5A and the oil storage space 6 is maximum, the entire region of the oil storage space 6 is included in the working chamber 5A in plan view (FIG. 4D). In the present modification, only a partial region of the oil storage spaces 6a to 6d is included in the working chamber 5A when the flow path cross-sectional area between the operation chamber 5A and the oil storage spaces 6a to 6d is the maximum. ing.

  Specifically, the body 4 shown in FIG. 8 and the cover 7 shown in FIG. 9 constitute a housing of the oil pump 1. 8 and 9, for convenience, the inner rotor 2 and the outer rotor 3 provided in the oil pump 1 are indicated by two-dot chain lines. 8 and 9 are perspective views of the body 4 and the cover 7 in plan view, and the suction chamber 41, the discharge chamber 42, and the oil storage spaces 6a to 6d are indicated by solid lines.

  As shown in FIGS. 8 and 9, in the oil pump 1 according to the modified example 3, the body 4 is provided with two oil storage spaces 6a and 6b, and the cover 7 is provided with two oil storage spaces 6c and 6d, for a total of four. Two oil storage spaces 6a to 6d are provided. The oil storage spaces 6a and 6c are provided radially inward of the oil storage space 6 (see FIGS. 1 and 2) of the above embodiment, and the oil storage spaces 6b and 6d are the oil storage space of the above embodiment. 6 is provided outside in the radial direction. The oil storage spaces 6a to 6d are formed in a substantially arc shape (or a substantially elliptical shape) in plan view.

  In the oil storage spaces 6a and 6c provided on the inner side, the one end portions 61a and 61c are located on the outer side in the radial direction from the other end portions 62a and 62c. That is, the distance from the center C2 (see FIG. 1) of the inner rotor 2 is larger at the other end portions 62a and 62c than at the one end portions 61a and 61c.

  Moreover, as for the oil storage space 6b, 6d provided in the outer side, one end part 61b, 61d is located inside radial direction rather than the other end part 62b, 62d. That is, the distance from the center C1 (see FIG. 1) of the outer rotor 3 is smaller at the other end portions 62b and 62d than at the one end portions 61b and 61d.

  When the inner rotor 2 rotates in the direction of the arrow P1, the flow path cross-sectional area between the working chamber 5A and the oil storage spaces 6a to 6d changes as shown in FIGS. In FIG. 10, FIG. 11, the one part dashed line L1, L2 shows a part of movement locus | trajectory of the location of the largest diameter of the working chamber 5A when the inner rotor 2 rotates to the direction of arrow P1, and the minimum diameter. The location of the maximum diameter of the working chamber 5A is the location of the maximum diameter of the space between the inner teeth 31 of the outer rotor 3, and the movement locus thereof is an arc shape centered on the center C1 of the outer rotor 3. Become. Also, the minimum diameter portion of the working chamber 5A is the minimum diameter portion of the space between the outer teeth 21 and 21 of the inner rotor 2, and the movement locus thereof is an arc shape centered on the center C2 of the inner rotor 2. Become.

  As shown in FIGS. 10 and 11, the flow path cross-sectional area between the working chamber 5A and the inner oil storage spaces 6a and 6c is larger at the other end portions 62a and 62c than at the one end portions 61a and 61c. . In this case, as the inner rotor 2 rotates in the direction of the arrow P1, the cross-sectional area of the working chamber 5A and the oil storage spaces 6a and 6c increases, but the other end portions 62a and 62c of the oil storage spaces 6a and 6c. Only a part of the region is communicated with the working chamber 5A.

  The flow path cross-sectional area between the working chamber 5A and the outer oil storage spaces 6b and 6d is larger at the other end portions 62b and 62d than at the one end portions 61b and 61d. In this case, as the inner rotor 2 rotates in the direction of the arrow P1, the cross-sectional area of the working chamber 5A and the oil storage spaces 6b and 6d increases, but the other end portions 62b and 62d of the oil storage spaces 6b and 6d. Only a part of the region is communicated with the working chamber 5A.

  Here, as the flow path cross-sectional area between the working chamber 5A and the oil storage space increases, the amount of oil flow per unit time between the working chamber 5A and the oil storage space increases, and the hydraulic pulsation increases accordingly. There is concern. In particular, in a high rotation range, there is a concern about hydraulic pulsation due to bubbling of oil. Therefore, it is not desirable that the hydraulic pulsation due to an increase in the amount of oil flow increases.

  However, in the present modification, the flow passage cross-sectional area between the working chamber 5A and the oil storage spaces 6a to 6d is limited to be small as described above, so the unit time between the working chamber 5A and the oil storage spaces 6a to 6d is The oil circulation amount per hit can be reduced, and the hydraulic pulsation caused by the increase in the oil circulation amount can be suppressed. Further, even in a high rotation range, hydraulic pulsation due to an increase in the amount of oil circulation can be suppressed, and even if hydraulic pulsation due to bubbling of oil occurs, the influence can be suppressed as much as possible.

  Another modification of the oil pump will be described with reference to FIGS. In Modification 4 shown in FIGS. 12 and 13, in the oil pump 1, the oil storage space 6 e provided in the body 4 and the oil storage space 6 f provided in the cover 7 have the same size. That is, in the third modification described above, the oil storage spaces 6a and 6b provided in the body 4 and the oil storage spaces 6c and 6d provided in the cover 7 are different in size (FIGS. 8 and 9). In this modification, the number and size of the oil storage spaces are different from those of Modification 3 described above.

  Specifically, in the oil pump 1 according to this modification, the body 4 shown in FIG. 12 and the cover 7 shown in FIG. 13 constitute a housing of the oil pump 1. 12 and 13, for convenience, the inner rotor 2 and the outer rotor 3 provided in the oil pump 1 are indicated by two-dot chain lines. 12 and 13 are perspective views of the body 4 and the cover 7 in plan view, and the suction chamber 41, the discharge chamber 42, and the oil storage spaces 6e and 6f are indicated by solid lines.

  As shown in FIGS. 12 and 13, in the oil pump 1 according to the modified example 4, the body 4 is provided with one oil storage space 6e, and the cover 7 is provided with one oil storage space 6f. The size of the oil storage space 6e of the body 4 and the size of the oil storage space 6f of the cover 7 are the same. The size of the oil storage spaces 6e and 6f means the area (opening area) of the oil storage spaces 6e and 6f in plan view.

  Here, when the oil storage space is provided only in one of the body 4 and the cover 7, the pressure (surface pressure) of the oil filled in the oil storage space is reduced to one surface of the inner rotor 2 or the outer rotor 3 (for example, 4 (a) and 4 (b), it acts only on the body 4 side surface of the outer rotor 3). For this reason, there is a concern that the inner rotor 2 and the outer rotor 3 are inclined by the pressure of the oil filled in the oil storage space, and oil leakage from the oil storage space to the suction port occurs.

  On the other hand, in this modification, as described above, by providing the oil storage spaces 6e and 6f in the body 4 and the cover 7, respectively, the pressure of the oil filled in the oil storage spaces 6e and 6f is reduced. It acts on both surfaces (the surface on the body 4 side and the surface on the cover 7 side). In addition, since the oil storage spaces 6e and 6f are set to have the same size, the pressure acting on both surfaces of the outer rotor 3 can be made substantially the same. Thereby, it can suppress that the inner rotor 2 and the outer rotor 3 incline with the pressure of the oil with which the oil storage space 6e, 6f was filled, and the clearance between the inner rotor 2 and the outer rotor 3, the body 4 and the cover 7 is reduced. Local expansion can be suppressed, and as a result, oil leakage from the oil storage spaces 6e and 6f to the suction port can be suppressed.

  Embodiment disclosed this time is an illustration in all the points, Comprising: It does not become the basis of limited interpretation. The technical scope of the present invention is not interpreted only by the above-described embodiments, but is defined based on the description of the scope of claims. Further, the technical scope of the present invention includes all modifications within the meaning and scope equivalent to the scope of the claims.

  INDUSTRIAL APPLICABILITY The present invention can be used for an inscribed oil pump that includes an inner rotor and an outer rotor that meshes the inner rotor in an eccentric state.

DESCRIPTION OF SYMBOLS 1 Oil pump 2 Inner rotor 3 Outer rotor 4 Body 41 Suction chamber 42 Discharge chamber 5, 5A Actuation chamber 6 Oil storage space

Claims (1)

An inner rotor having a plurality of external teeth;
An outer rotor having a larger number of inner teeth than the outer teeth and meshing the inner rotor in an eccentric state;
A housing that rotatably accommodates the outer rotor,
An oil pump in which a working chamber is formed between teeth that mesh with each other of the inner rotor and the outer rotor, and a pump operation is performed by a change in the volume of the working chamber,
The housing has a suction chamber formed in an enlarged region of the volume of the working chamber, a discharge chamber formed in a reduced region of the volume of the working chamber, and a space between the suction chamber and the discharge chamber. An oil pump characterized in that an oil storage space communicating with the working chamber is formed in the region.

Images