CN113550896A - Pump rotor subassembly and oil pump - Google Patents

Abstract

A pump rotor assembly and an oil pump are provided, the pump rotor assembly comprises an inner rotor and an outer rotor, and the outer rotor is sleeved on the periphery of the inner rotor; the central axis of the inner rotor is offset from the central axis of the outer rotor; a volume cavity is arranged between the inner peripheral surface of the outer rotor and the outer peripheral surface of the inner rotor; the inner circumferential surface of the outer rotor comprises a plurality of first protruding portions and a plurality of first concave portions, the outer circumferential surface of the inner rotor comprises a plurality of second protruding portions and a plurality of second concave portions, at least one of the outer rotor and the inner rotor comprises a connecting portion, when the outer rotor comprises the connecting portion, the connecting portion corresponding to the outer rotor is defined as a first connecting portion, and the first protruding portions and the first concave portions adjacent to the first protruding portions are connected through the first connecting portions; when the inner rotor comprises the connecting part, the connecting part corresponding to the inner rotor is defined as a second connecting part, and the second convex part and a second concave part adjacent to the second convex part are connected through the second connecting part; this is advantageous for increasing the displacement of the oil pump.

Description

Pump rotor subassembly and oil pump

Technical Field

The invention relates to the field of vehicles, in particular to parts of a vehicle lubricating system and/or a vehicle cooling system.

Background

The oil pump mainly provides a power source for a lubricating system and/or a cooling system of the vehicle; the oil pump comprises a pump rotor component, and the structure of the pump rotor component is closely related to the discharge capacity of the oil pump; in some systems, a large displacement oil pump is generally required to meet system requirements, and therefore how to optimize the pump rotor assembly to increase the displacement of the oil pump is a problem to be considered in the design process.

Disclosure of Invention

The invention aims to provide a pump rotor assembly which is beneficial to improving the discharge capacity of an oil pump.

In order to achieve the above purpose, one embodiment of the present invention adopts the following technical solutions:

a pump rotor assembly characterized by: the pump rotor assembly comprises an inner rotor and an outer rotor, and the outer rotor is sleeved on the periphery of the inner rotor; the central axis of the inner rotor is offset from the central axis of the outer rotor; a volume cavity is arranged between the inner peripheral surface of the outer rotor and the outer peripheral surface of the inner rotor; the inner circumferential surface of the outer rotor comprises a plurality of first convex parts and a plurality of first concave parts, the first convex parts are convexly arranged close to the central axis of the outer rotor along the radial direction of the outer rotor, and the first concave parts are concavely arranged in the direction far away from the central axis of the outer rotor; two adjacent first protruding portions have the first recess along the circumferential direction of the outer rotor;

the outer peripheral surface of the inner rotor comprises a plurality of second protruding parts and a plurality of second concave parts, the second protruding parts are arranged in a protruding mode towards the central axis of the outer rotor along the radial direction of the inner rotor, and the first concave parts are arranged in a concave mode towards the direction far away from the central axis of the inner rotor; along the circumferential direction of the inner rotor, two adjacent second protruding parts have the second concave parts;

at least one of the outer rotor and the inner rotor comprises a connecting part, when the outer rotor comprises the connecting part, the connecting part corresponding to the outer rotor is defined as a first connecting part, the first protruding part and the first concave part adjacent to the first protruding part are connected through the first connecting part, and the ratio of the tooth bottom circle diameter (D2) of the outer rotor to the tooth top circle diameter (D1) of the outer rotor satisfies the following relational expression: D2/D1 > 1.14;

when the inner rotor comprises the connecting part, the connecting part corresponding to the inner rotor is defined as a second connecting part, the second protruding part and the second concave part adjacent to the second protruding part are connected through the second connecting part, the inner rotor is orthographically projected in a direction parallel to the end face of the inner rotor, and in the projection of the inner rotor, the distance from the center of the inner rotor to each part of the second connecting part is smaller than the distance from the center of the inner rotor to each part of the second protruding part.

In this technical solution, at least one of the outer rotor and the inner rotor includes a connection portion, when the outer rotor includes the connection portion, the connection portion corresponding to the outer rotor is defined as a first connection portion, the first protruding portion and the first concave portion adjacent to the first protruding portion are connected by the first connection portion, and a ratio of a tooth bottom circle diameter (D2) of the outer rotor to a tooth top circle diameter (D1) of the outer rotor satisfies the following relational expression: D2/D1 > 1.14; through the mode, the distance between the outer rotor addendum circle and the outer rotor dedendum circle is favorably increased, so that the distance between the first concave part and the first convex part is favorably and relatively increased, and the volume cavity is formed between the first concave part and the outer peripheral surface of the inner rotor, so that the volume of the volume cavity between the first concave part and the outer peripheral surface of the inner rotor is favorably increased, and the displacement of the oil pump is favorably improved; when the inner rotor includes connecting portion, the connecting portion that the definition inner rotor corresponds are the second connecting portion, connect through the second connecting portion between second bellying and the second concave part adjacent with the second bellying, with inner rotor to the direction orthographic projection that is on a parallel with the inner rotor terminal surface, in the projection of inner rotor, the center of inner rotor is less than the center of inner rotor to the distance everywhere of second bellying to the center of second connecting portion everywhere, through the mode, make the partial profile of inner rotor outer peripheral face can be close to the central axis direction of inner rotor relatively through setting up the second connecting portion, because have the volume chamber between the inner peripheral surface of second connecting portion and outer rotor, thereby be favorable to increasing the volume in volume chamber between the outer peripheral face of second connecting portion and inner rotor, and then be favorable to improving the discharge capacity of oil pump.

Drawings

FIG. 1 is a schematic cross-sectional view of an oil pump of the present application;

FIG. 2 is a front view schematically showing a partial structure of the oil pump of FIG. 1 without the pump cover;

FIG. 3 is a perspective view of the pump rotor assembly of FIG. 1 or FIG. 2;

FIG. 4 is a front view of the pump rotor assembly of FIG. 3;

FIG. 5 is a perspective view of the outer rotor of FIG. 3 or FIG. 4;

FIG. 6 is a schematic front view of the outer rotor of FIG. 5;

FIG. 7 is an enlarged view of portion A of FIG. 6;

fig. 8 is a schematic perspective view of the inner rotor of fig. 3 or 4;

FIG. 9 is an enlarged view of portion B of FIG. 4;

FIG. 10 is a front view schematic of the inner rotor of FIG. 3 or FIG. 4;

fig. 11 is an enlarged view of the portion C of fig. 10.

Detailed Description

The invention will be further described with reference to the following figures and specific examples:

the oil pump in the embodiment can mainly provide flowing power for the working medium of the vehicle lubricating system and/or cooling system, and particularly can provide flowing power for the working medium of the lubricating system and/or cooling system in the vehicle transmission system; the oil pump in the present embodiment may be a mechanical oil pump or an electric oil pump, and the electric oil pump will be described in detail below as an example.

Referring to fig. 1, the oil pump 100 includes a pump housing, a pump rotor assembly 1, a stator assembly 4, a motor rotor assembly 2, a pump shaft 3, and an electric control board assembly 5; the pump rotor assembly 1, the motor rotor assembly 2 and the electric control board assembly 5 are arranged along the axial direction of the oil pump 100, the motor rotor assembly 2 is positioned between the pump rotor assembly 1 and the electric control board assembly 5, the stator assembly 4 is positioned at the periphery of the motor rotor assembly 2, the pump rotor assembly 1 is close to one end of the pump shaft 3, the motor rotor assembly 2 is close to the other end of the pump shaft 3, and the motor rotor assembly 2 drives the pump rotor assembly 1 to rotate through the pump shaft 3; the oil pump 100 further comprises a first accommodating cavity 80 and a second accommodating cavity 90, the pump rotor assembly 1 is located in the first accommodating cavity 80, and the stator assembly 4 and the motor rotor assembly 2 are located in the second accommodating cavity 90; referring to fig. 1, the stator assembly 4 includes a stator core 41 and a coil 42, when the oil pump 100 works, the electric control board assembly 5 controls the current passing through the coil 42 of the stator assembly 4 to change according to a predetermined rule, so as to control the stator assembly 4 to generate a changing excitation magnetic field, the motor rotor assembly 2 rotates under the action of the excitation magnetic field, the motor rotor assembly 2 can directly or indirectly drive the pump rotor assembly 1 to rotate, when the pump rotor assembly 1 rotates, the volume of a volume cavity between the pump rotor assemblies 1 changes, so that the working medium is pressed out to the outflow channel 62 to generate flowing power.

Referring to fig. 1, the pump housing includes a pump cover 6, a first housing 7 and a second housing 8, the pump cover 6 is connected to the first housing 7 by screws or bolts, and of course, the pump cover 6 and the first housing 7 may be connected by other methods, such as inserting, clamping, etc.; the first housing 7 and the second housing 8 are connected by a screw or a bolt, specifically, in this embodiment, the oil pump 100 further includes a spacer 9, the spacer 9 can prevent the working medium in the second accommodating cavity 90 from flowing into the cavity where the electronic control board assembly 5 is located, and further is beneficial to preventing the working medium in the second accommodating cavity 90 from affecting the performance of the electronic control board assembly 5, referring to fig. 1, the screw or the bolt sequentially passes through the second housing 8, the spacer 9 and the first housing 7, so that the first housing 7 and the second housing 8 are indirectly fixedly connected, of course, the first housing 7 and the second housing 8 can also be directly fixedly connected by the screw or the bolt without passing through the spacer 9, the structure of the spacer 9 is changed accordingly, and at this time, the spacer 9 can be positioned by being tightly fitted with the inner peripheral side wall of the first housing 7; the first shell 7 and the second shell 8 are connected through screws or bolts, so that the oil pump is more convenient to disassemble and assemble, in the embodiment, the electric control board assembly 5 is arranged in the cavity between the second shell 8 and the partition 9, so that the maintenance of the electric control board assembly 5 in the oil pump is facilitated, and the first shell 7 and the second shell 8 can be connected through splicing, clamping or other connection modes; in addition, in this embodiment, the first accommodating chamber 80 and the second accommodating chamber 90 are formed by the pump housing, specifically, the first accommodating chamber 80 is formed between the pump cover 6 and the first housing 7, and the second accommodating chamber 90 is formed between the first housing 7 and the second housing 8, but it is also possible to directly assemble other parts except the pump housing with the transmission of the automobile without the pump housing, and at this time, a partition may be provided to support the pump rotor assembly 1 on the one hand, and on the other hand, the partition may also serve as a boundary between the first accommodating chamber 80 and the second accommodating chamber 90.

Referring again to fig. 1 and 2, the oil pump 100 further includes an inlet passage 61 and an outlet passage 62, the inlet passage 61 is used for inflow of the working medium, the outlet passage 62 is used for outflow of the working medium, specifically, the working medium can enter the volume chamber 801 through the inlet passage 61, and the working medium can leave the volume chamber 801 through the outlet passage 62; in this embodiment, the inlet channel 61 and the outlet channel 62 are both formed on the pump cover 6, and certainly, when the pump cover 6 is not included, other parts except the pump cover 6 can be directly assembled with a gearbox of an automobile or other parts on the automobile, and at this time, the inlet channel 61 and the outlet channel 62 can be correspondingly arranged on the gearbox or other parts on the automobile; referring to fig. 2, during one rotation of the pump rotor assembly 1, the volume of the volume chamber formed between the outer circumferential surface of the inner rotor 11 and the inner circumferential surface of the outer rotor 12 is changed, and, in particular, in the process that the pump rotor assembly 1 rotates to a certain angle from the beginning, the volume of a part of the volume cavity formed between the outer circumferential surface of the inner rotor 11 and the inner circumferential surface of the outer rotor is gradually increased to form partial vacuum, at this time, the working medium is sucked into the volume cavity 801 from the inflow channel 61, in the process of continuing to rotate the inner rotor 11 and the outer rotor 12, along the rotation direction of the pump rotor assembly 1, the volume between partial volume chambers in the volume chambers formed between the outer circumferential surface of the inner rotor 11 and the inner circumferential surface of the outer rotor 12 is gradually reduced, the working medium is squeezed, so that the working medium entering the volume 801 is pressed out to the outflow channel 62 to generate the motive force for flow.

Referring to fig. 2 to 4, in the present embodiment, the pump rotor assembly 1 includes an inner rotor 11 and an outer rotor 12, the inner rotor 11 is connected to the pump shaft 3 in fig. 1, in the present embodiment, the outer rotor 12 is located at the outer periphery of the inner rotor 11, the inner rotor 11 and the outer rotor 12 are in inner engagement, and a plurality of volume cavities 801 are formed between the outer peripheral surface of the inner rotor 11 and the inner peripheral surface of the outer rotor 12, of course, the outer rotor 12 and the inner rotor 11 may also be in outer engagement, and at this time, the inner rotor 11 and the outer rotor 12 are arranged side by side; in this embodiment, the central axis of the inner rotor 11 and the central axis of the outer rotor 12 are offset, that is, a certain eccentricity e exists between the central axis of the inner rotor 11 and the central axis of the outer rotor 12; referring to fig. 5 and 6, the inner circumferential surface of outer rotor 12 includes a plurality of first protrusions 121 and a plurality of first recesses 122, and in the radial direction of outer rotor 12, first protrusions 121 are convexly disposed toward central axis C1 near outer rotor 12, and first recesses 122 are concavely disposed away from central axis C1 of outer rotor 12; along the circumferential direction of the outer rotor 12, two adjacent first protrusions 121 have one first recess 122, or one first protrusion 121 is located between two adjacent first recesses 122, that is, the first protrusions 121 and the first recesses 122 are spaced apart; referring to fig. 8, the outer circumferential surface of the inner rotor 11 includes a plurality of second protruding portions 111 and a plurality of second recesses 112, the second protruding portions 111 are convexly disposed away from the central axis C2 of the inner rotor 11 in the radial direction of the inner rotor 11, the second recesses 112 are concavely disposed close to the central axis of the inner rotor 11, and one second recess 112 is disposed between two adjacent second protruding portions 111 or one second protruding portion 111 is disposed between two adjacent second recesses 112 in the circumferential direction of the inner rotor 11, that is, the second protruding portions 111 and the second recesses 112 are disposed at intervals; referring to fig. 4, the second protrusion 111 is disposed corresponding to the first recess 122, and the second recess 112 is disposed corresponding to the first protrusion 121; referring to fig. 1, 2 and 4 in combination, when the inner rotor 11 rotates, the second convex portion 111 of the inner rotor 11 meshes with the first concave portion 122 of the outer rotor 12 and/or the second concave portion 112 of the inner rotor 11 meshes with the first convex portion 121 of the outer rotor 12, so that the inner rotor 11 can drive the outer rotor 12 to rotate.

Referring to fig. 5 to 7, in the present embodiment, the first protrusion 121 and the first recess 122 adjacent to the first protrusion 121 are connected by the first connection portion 123, and referring to fig. 6, a ratio of a tooth bottom circle diameter D2 of the outer rotor to an tooth top circle diameter D1 of the outer rotor satisfies the following relation: D2/D1 > 1.14, where the value "1.14" may be a definite value or a rounded value; the distance between the outer rotor addendum circle and the outer rotor dedendum circle is increased, so that the distance between the first concave part and the first convex part is increased, and the volume cavity is formed between the first concave part and the outer peripheral surface of the inner rotor, so that the volume of the volume cavity between the first concave part and the outer peripheral surface of the inner rotor is increased, and the displacement of the oil pump is increased; in addition, the ratio of the tooth bottom circle diameter D2 of the outer rotor to the tooth top circle diameter D1 of the outer rotor also satisfies the following relation: D2/D1<1.32, where the value "1.32" may be a definite value or a rounded value, which is advantageous for preventing the addendum circle of the outer rotor from crossing the outer peripheral boundary of the outer rotor; referring to fig. 6 and 7, for ease of description, a hypothetical reference is introduced here: the first virtual concave portion 124, the first virtual concave portion 124 directly connects with one end of two adjacent first convex portions 121, the first concave portion 122 is closer to the outer peripheral surface of the outer rotor than the first virtual concave portion 124, that is, the first concave portion 122 is relatively moved outward, in the embodiment, the root circle diameter D3 of the first virtual concave portion 124 satisfies the following relation: d3 ═ 1.14D 1; through the manner, the first concave part 122 is closer to the outer peripheral surface of the outer rotor 12, and the volume cavity is formed between the first concave part 122 and the outer peripheral surface of the inner rotor, so that the volume of the volume cavity between the first concave part 122 and the outer peripheral surface of the inner rotor is facilitated, and the displacement of the oil pump is further facilitated to be improved; in addition, referring to fig. 5 to 7, here, for convenience of illustrating the first connecting portion 123 and the first virtual recess 124, the first connecting portion 123 is indicated by a thick solid line, and the first virtual recess 124 is indicated by a broken line, in this embodiment, the main body of the first connecting portion 123 is planar, and there are two cases, the first case is: the surface of the first connecting portion 123 is entirely planar, so that an edge is formed at the connecting position of the first connecting portion 123 with the first protruding portion 121 and the first concave portion 122, and of course, the edge formed at the connecting position of the first connecting portion 123 with the first protruding portion 121 and the first concave portion 122 may also be polished to be a smooth surface by a polishing process; the second case is: the connection part of the first connection part 123 and the first protrusion part 121 is in smooth transition connection through an arc or a curved surface, and/or the connection part of the first connection part 123 and the first recess part 122 is in smooth transition connection through an arc or a curved surface; in this embodiment, the main body of the first connecting portion 123 is planar, but the first connecting portion 123 may be concave, and when the first connecting portion 123 is concave, the first connecting portion 123 is recessed toward the outer peripheral surface of the outer rotor 12; of course, a small protrusion may be provided at a part of the first connection portion 123, or the first connection portion 123 is in a convex shape, in this case, the convex surface of the first connection portion 123 is relatively gentle, the cross section of the convex first connection portion may be an arc, the arc may be formed by point description, or may be an arc, and the first connection portion 123 may be in a curved shape, a planar shape, or a combination of any two or more than three kinds of shapes of a convex shape. Referring to fig. 5 and 6, the minimum distance of the first recess 122 from the outer circumferential surface 120 of the outer rotor 12 is 1mm or more, where "the outer circumferential surface 120 of the outer rotor 12" does not include an outer circumferential surface formed by chamfering of the outer rotor 12; this is advantageous to ensure the structural strength of the first recess 122, and in addition, "1 mm" is a theoretical distance, and all errors in the manufacturing process are within the protection scope of the present application because there are errors in the manufacturing process.

Referring to fig. 6 and 7, at least one of at least a part of the outer surface of the first protrusion 121 and at least a part of the outer surface of the first recess 122 has an arc shape, which includes the following three cases:

in the first case, of the outer surfaces of the first protruding portions 121, the outer surface corresponding to the portion where the first protruding portion 121 and the first connecting portion 123 are directly connected is arc-shaped, and the first connecting portion 123 is tangent to the outer surface of the first protruding portion 121, so that when the working medium flows from the first connecting portion 123 to the first protruding portion 121 or flows from the first protruding portion 121 to the first connecting portion 123, the smoothness of the working medium at the connection portion of the first connecting portion 123 and the first protruding portion 123 is favorably improved; in the first case, the outer surface corresponding to the portion of the first protruding portion 121 not directly connected to the first connecting portion 123 may be arc-surface-shaped, where the outer surface corresponding to the portion of the first protruding portion 121 not directly connected to the first connecting portion 123 may be an arc surface formed by one arc segment, or an arc surface formed by more than two arc segments, where the arc surface formed by one arc segment and the arc surface corresponding to the portion of the first protruding portion 121 directly connected to the first connecting portion 123 may be the same arc segment, or different arc segments with different diameters; of course, the portion of the first protrusion 121 not directly connected to the first connection portion 123 may be a curved surface formed by a fitting curve to which a plurality of points are fitted;

in the second case: in the outer surface of the first concave portion 122, the outer surface corresponding to the portion where the first concave portion 122 is directly connected with the first connecting portion 123 is arc-shaped, and the first connecting portion 123 is tangent to the outer surface of the first concave portion 122, so that when the working medium flows from the first connecting portion 123 to the first concave portion 122 or flows from the first concave portion 122 to the first connecting portion 123, the smoothness of the working medium at the connection position of the first connecting portion 123 and the first concave portion 122 is improved; in the second case, the outer surface corresponding to the portion of the first concave portion 122 not directly connected to the first connection portion 123 may be an arc surface, where the outer surface corresponding to the portion of the first concave portion 122 not directly connected to the first connection portion 123 may be an arc surface formed by one arc segment, or may be an arc surface formed by more than two arc segments, where the arc surface formed by one arc segment and the arc surface corresponding to the portion of the first concave portion 122 directly connected to the first connection portion 123 may be the same arc segment, or may be different arc segments with different diameters; of course, the portion of the first concave portion 122 that is not directly connected to the first connection portion 123 may be a curved surface formed by a fitting curve to which a plurality of points are fitted;

in the third case: referring to fig. 6 and 7, of the outer surfaces of the first protrusions 121, the outer surface corresponding to the portion where the first protrusion 121 is directly connected to the first connection portion 123 is arc-shaped; of the outer surfaces of the first concave portions 122, the outer surface corresponding to the portion where the first concave portion 122 is directly connected to the first connection portion 123 is arc-shaped; one end of the first connecting portion 123 is tangent to the outer surface of the first protrusion 121, which is in the shape of an arc, and the other end of the first connecting portion 123 is tangent to the outer surface of the first recess 122, which is in the shape of an arc, so that when the working medium flows from the first connecting portion 123 to the first recess 122 or flows from the first recess 122 to the first connecting portion 123, the smoothness of the working medium at the connection between the first connecting portion 123 and the first recess 122 is improved, and when the working medium flows from the first connecting portion 123 to the first recess 122 or flows from the first recess 122 to the first connecting portion 123, the smoothness of the working medium at the connection between the first connecting portion 123 and the first recess 122 is improved; in the third case, the outer surface of the first protrusion part 121 corresponding to the portion not directly connected to the first connection part 123 may be arc-shaped, here, the outer surface of the first protruding portion 121 corresponding to the portion not directly connected to the first connection portion 123 may be an arc surface formed by one arc, or an arc surface formed by more than two arcs, wherein, the arc surface formed by a section of arc and the arc surface corresponding to the part of the first protrusion 121 directly connected with the first connection part 123 may be the same section of arc or different sections of arcs with different diameters, of course, the portion of the first protrusion portion 121 not directly connected to the first connection portion 123 may also be a curved surface formed by a fitted curve to which a plurality of points are fitted, specifically, referring to fig. 6 and 7, in the present embodiment, the outer surfaces of the first protruding portions 121 are arc-surface-shaped, and all the outer surfaces of the first protruding portions 121 are arc surfaces formed by a section of arc; in the third case, the outer surface of the first recess 122 corresponding to the portion not directly connected to the first connection portion 123 may be arc-shaped, here, the outer surface of the first concave portion 122 corresponding to the portion not directly connected to the first connection portion 123 may be an arc surface formed by one arc, or may be an arc surface formed by two or more arcs, wherein, the arc surface formed by a section of arc and the arc surface corresponding to the part of the first concave part 122 directly connected with the first connecting part 123 can be the same section of arc or different sections of arcs with different diameters, of course, the portion of the first concave portion 122 that is not directly connected to the first connection portion 122 may also be a curved surface formed by a fitted curve to which a plurality of points are fitted, specifically, referring to fig. 6 and 7, in the present embodiment, the outer surfaces of the first concave parts 122 are arc-surface-shaped, and all the outer surfaces of the first concave parts 122 are arc surfaces formed by a section of arc; the third case will be described in detail below as an example.

Referring to fig. 5 to 7, in the present embodiment, the area of the first protrusion 121 is larger than the area of the outer surface of the first recess 122; for one of the first protruding portions 121 and two first connecting portions 123 respectively connected to two ends of the first protruding portion 121, the two adjacent first connecting portions 123 are symmetrically distributed about a central plane of the first protruding portion 121.

Referring to fig. 4 and 9, the flow area of at least a part of the minimum volume chamber 8010 between the inner peripheral surface of the outer rotor 12 and the outer peripheral surface of the inner rotor 11 is gradually reduced along the rotation direction of the pump rotor assembly 1, in this embodiment, the rotation direction of the pump rotor assembly 1 is counterclockwise, where "counterclockwise" is viewed from a top view when the electric pump without a cross section is placed as in the state of fig. 1; for convenience of description of the minimum volume chamber 8010, referring to fig. 4, a region where the volume chamber between the inner peripheral surface of the outer rotor 12 and the outer peripheral surface of the inner rotor 11 is located is divided into a first region 101 and a second region 102, and for better distinction of the first region 101 and the second region 102 in the drawing, referring to fig. 4, the first region 101 and the second region 102 are distinguished by two different hatching lines, respectively; in the first region 101, the volume of the volume chamber formed by the outer peripheral surface of the inner rotor 11 and the inner peripheral surface of the outer rotor 12 gradually increases from the head of the first region 101 to the tail of the first region 101 along the rotation direction of the pump rotor assembly 1, so that a partial vacuum can be formed in the first region 101, and in conjunction with fig. 1, the working medium is sucked into the first region 101 from the inflow channel 61; in the second region 102, the volume of the volume chamber formed by the outer peripheral surface of the inner rotor 11 and the inner peripheral surface of the outer rotor 12 gradually decreases from the head of the second region 102 to the tail of the second region 102 along the rotation direction of the pump rotor assembly 1, so that the working medium is pressed in the second region 102, and the pressure of the working medium in the second region 102 gradually increases, wherein the minimum volume chamber 8010 is located at the tail of the second region 102, and the minimum volume chamber 8010 can communicate with the volume chamber in the first region 101.

Referring to fig. 4-9, in the present embodiment, the minimum volume cavity 8010 is located between one of the first raised portions 121 of the outer rotor 11 and one of the second recessed portions 112 of the inner rotor; defining a first projecting portion 121 corresponding to one side wall constituting the minimum volume cavity 8010 as a first reference projecting portion 1211, defining a second recessed portion corresponding to the other side wall constituting the minimum volume cavity 1121 as a second reference recessed portion 1121, orthographically projecting the pump rotor assembly 1 in a direction parallel to an end face of the pump rotor assembly 1, defining a first reference line L1 and a second reference line L2, the first reference line L1 being a connecting line of a center O2 of the inner rotor and a tooth bottom tangent point of the second reference recessed portion 1121, the second reference line L1 being a connecting line of a center O2 of the inner rotor and a center of the first reference projecting portion 1211, the first reference line L1 being disposed at an angle to the second reference line L2; specifically, the offset direction of the second reference line L2 with respect to the first reference line L1 is the same as the rotation direction of the pump rotor assembly 1, so that the flow area of at least a part of the volume cavity in the minimum volume cavity 8010 can be gradually reduced along the rotation direction of the pump rotor assembly 1, and thus compared with the case that the volume of the minimum volume cavity is not changed, when the pump rotor assembly 1 is in operation, on one hand, the flow rate of the working medium flowing to the first region 101 at the tail of the second region 102 is favorably reduced, so that the pump efficiency is favorably improved, on the other hand, the smoothness of the working medium flowing in the minimum volume cavity 8010 is favorably improved, so that the pressure fluctuation of the working medium is favorably reduced, so that the noise is favorably reduced; in addition, in the present embodiment, the angle α between the first reference line L1 and the second reference line L2 is greater than 0 ° and equal to or less than 2.5 °, which is advantageous in preventing the first reference projection 1211 and the second reference recess 1121 from causing structural interference.

Referring to fig. 10 and 11, the inner rotor 11 includes a second connection portion 113, the second protrusion 111 and a second recess 112 adjacent to the second protrusion 111 are connected by the second connection portion 113, the inner rotor 11 is orthographically projected in a direction parallel to the end face of the inner rotor 11, and in the projection of the inner rotor 11, a distance L3 from a center O2 of the inner rotor 11 to each of the second connection portions 113 is smaller than a distance from a center O2 of the inner rotor 11 to each of the second protrusion L4; through the mode, the partial outline of the outer peripheral surface of the inner rotor can be close to the central axis direction of the inner rotor relatively by arranging the second connecting part, and the volume cavity is formed between the second connecting part and the inner peripheral surface of the outer rotor, so that the volume of the volume cavity between the second connecting part and the outer peripheral surface of the inner rotor is increased, and the displacement of the oil pump is increased. Referring to fig. 10 and 11, for one of the second protruding portions 111 and two second connecting portions 113 respectively connected to both ends of the second protruding portion 111, the two adjacent second connecting portions 113 are symmetrically distributed about a central plane of the second protruding portion 111.

Referring to fig. 10 and 11, in the present embodiment, the main body of the second connecting portion 113 is planar, and there are two cases: the first case is: the surface of the second connecting portion 113 is entirely planar, so that a ridge is formed at the connection between the second connecting portion 113 and the second protruding portion 111 and the second recessed portion 112; the second case is: the joint of the second connecting part 113 and the second convex part 111 is in smooth transition connection through an arc or a curved surface, and/or the joint of the second connecting part 113 and the second concave part 112 is in smooth transition connection through an arc or a curved surface; referring to fig. 10 and 11, for ease of description, a hypothetical reference is introduced here: the virtual extension portion 114 is an extension section of the second protrusion portion 111, the second connection portion 113 is closer to the central axis of the inner rotor 11 than the virtual extension portion 114, that is, the second connection portion 113 is disposed closer to the inner side than the virtual extension portion 114, the second connection portion 113 is disposed so that a partial contour of the outer peripheral surface of the inner rotor 11 can be closer to the central axis direction of the inner rotor 11, and a volume cavity is formed between the second connection portion 113 and the inner peripheral surface of the outer rotor, so that the volume of the volume cavity between the second connection portion 113 and the outer peripheral surface of the inner rotor is increased, and the displacement of the oil pump is increased; referring to fig. 10 and 11, for convenience of illustrating the second connecting portion 113 and the extension portion 114 of the second protrusion 111, the second connecting portion 113 is marked by a thick solid line, and the extension portion 114 of the second protrusion 111 is marked by a dotted line; in the present embodiment, the second connection portion 113 is planar, but of course, the second connection portion 113 may be concave, and when the second connection portion 113 is concave, the second connection portion 113 is recessed in a direction close to the central axis of the inner rotor 11; of course, the second connection portion 113 may have a combination of a planar shape and a concave shape; here, as to the shapes of the second protruding portion 111 and the second concave portion 112, reference may be made to the description of the first protruding portion 111 and the second concave portion 112, respectively, which is not repeated herein.

In addition, referring to fig. 3 to 11, in the present embodiment, the outer rotor 12 has the first connecting portion 123, and the inner rotor 11 has the second connecting portion 113, that is, the outer rotor 12 and the inner rotor 11 are both provided with connecting portions, but only one of the outer rotor 12 and the inner rotor 11 may include a connecting portion, so that the displacement of the oil pump may also be increased.

It should be noted that: although the present invention has been described in detail with reference to the above-mentioned embodiments, it should be understood by those skilled in the art that the present invention may be modified and equivalents may be substituted for those skilled in the art, and all technical solutions and modifications that do not depart from the spirit and scope of the present invention should be covered by the claims of the present invention.

Claims (11)

1. A pump rotor assembly characterized by: the pump rotor assembly comprises an inner rotor and an outer rotor, and the outer rotor is sleeved on the periphery of the inner rotor; the central axis of the inner rotor is offset from the central axis of the outer rotor; a volume cavity is arranged between the inner peripheral surface of the outer rotor and the outer peripheral surface of the inner rotor; the inner circumferential surface of the outer rotor comprises a plurality of first convex parts and a plurality of first concave parts, the first convex parts are convexly arranged close to the central axis of the outer rotor along the radial direction of the outer rotor, and the first concave parts are concavely arranged in the direction far away from the central axis of the outer rotor; two adjacent first protruding portions have the first recess along the circumferential direction of the outer rotor;

the outer peripheral surface of the inner rotor comprises a plurality of second protruding parts and a plurality of second concave parts, the second protruding parts are arranged in a protruding mode towards the central axis of the outer rotor along the radial direction of the inner rotor, and the first concave parts are arranged in a concave mode towards the direction far away from the central axis of the inner rotor; along the circumferential direction of the inner rotor, two adjacent second protruding parts have the second concave parts;

at least one of the outer rotor and the inner rotor comprises a connecting part, when the outer rotor comprises the connecting part, the connecting part corresponding to the outer rotor is defined as a first connecting part, the first protruding part and the first concave part adjacent to the first protruding part are connected through the first connecting part, and the ratio of the tooth bottom circle diameter (D2) of the outer rotor to the tooth top circle diameter (D1) of the outer rotor satisfies the following relational expression: D2/D1 > 1.14;

when the inner rotor comprises the connecting part, the connecting part corresponding to the inner rotor is defined as a second connecting part, the second protruding part and the second concave part adjacent to the second protruding part are connected through the second connecting part, the inner rotor is orthographically projected in a direction parallel to the end face of the inner rotor, and in the projection of the inner rotor, the distance from the center of the inner rotor to each part of the second connecting part is smaller than the distance from the center of the inner rotor to each part of the second protruding part.

2. The pump rotor assembly of claim 1, wherein: the ratio of the outer rotor root circle diameter (D2) to the outer rotor tip circle diameter (D1) also satisfies the following relationship: D2/D1< 1.32; the main body of the first connecting part is planar or concave, and when the main body of the first connecting part is concave, the first connecting part is sunken towards the direction close to the outer peripheral surface of the outer rotor.

3. A pump rotor assembly according to claim 1 or 2, wherein: the main part of second connecting portion is planar or concave surface form, works as when the main part of second connecting portion is concave surface form, the second connecting portion is to being close to the central axis direction sunken setting of inner rotor.

4. A pump rotor assembly according to claim 2 or 3, wherein: when the main body of the first connecting part is planar, in the outer surface of the first protruding part, the outer surface corresponding to the part of the first protruding part directly connected with the first connecting part is arc-shaped, and the outer surface of the first connecting part, which is arc-shaped, is tangent to the outer surface of the first protruding part.

5. A pump rotor assembly according to claim 2 or 3, wherein: when the main body of the connecting part is planar, in the outer surface of the first concave part, the outer surface corresponding to the part of the first concave part directly connected with the first connecting part is arc-shaped, and the first connecting part is tangent to the outer surface of the first concave part in the arc-shaped.

6. A pump rotor assembly according to claim 2 or 3, wherein: when the main body of the first connecting part is planar, the outer surface of the first protruding part corresponding to the part of the first protruding part directly connected with the first connecting part is arc-planar; in the outer surface of the first concave part, the outer surface corresponding to the part of the first concave part directly connected with the first connecting part is in an arc surface shape; one end of the first connecting part is tangent to the outer surface of the first protruding part in an arc shape, and the other end of the first connecting part is tangent to the outer surface of the first concave part in an arc shape.

7. The pump rotor assembly of claim 6, wherein: the outer surface of the first convex part is an arc surface formed by a section of circular arc, and the outer surface of the first concave part is an arc surface formed by a section of circular arc; aiming at one of the first protruding parts and two first connecting parts respectively connected with two ends of the first protruding part, the two adjacent first connecting parts are symmetrically distributed around the central plane of the first protruding part.

8. A pump rotor assembly according to any one of claims 1 to 7, wherein: the flow area of at least part of the minimum volume cavity between the inner peripheral surface of the outer rotor and the outer peripheral surface of the inner rotor is gradually reduced along the rotation direction of the pump rotor assembly.

9. The pump rotor assembly of claim 8, wherein: the minimum volume cavity is located between one of the first lobes of the outer rotor and one of the second recesses of the inner rotor; defining the first convex part corresponding to one side wall forming the minimum volume cavity as a first reference convex part, defining the second concave part corresponding to the other side wall forming the minimum volume cavity as a second reference concave part, orthographically projecting the pump rotor assembly to the direction parallel to the end face of the pump rotor assembly, and defining a first reference line and a second reference limit, wherein the first reference line is a connecting line of the center of the inner rotor and the tooth bottom tangent point of the second reference concave part, the second reference line is a connecting line of the center of the inner rotor and the center of the first reference convex part, and the first reference line and the second reference line are arranged in an angle.

10. The pump rotor assembly of claim 9, wherein: the offset direction of the second reference line relative to the first reference line is the same as the rotating direction of the pump rotor assembly, and the angle between the first reference line and the second reference line is greater than 0 degrees and smaller than or equal to 2.5 degrees.

11. An oil pump, the oil pump includes pump shaft, pump rotor subassembly, stator module, motor rotor subassembly, first chamber and the second chamber of holding, the pump rotor subassembly set up in first chamber of holding, stator module and motor rotor subassembly set up in the second chamber of holding, the pump rotor subassembly is close to one end of pump shaft, the motor rotor subassembly is close to the other end of pump shaft and is connected with the pump shaft, the pump rotor subassembly be claim 1 to 10 any one the pump rotor subassembly.

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