Electric pump

Abstract

The present invention provides an electric pump comprising: a housing; a gear portion disposed in the housing; a stator disposed corresponding to the gear portion; and a support member disposed between the gear portion and the housing, wherein the gear portion comprises a first gear, a second gear disposed corresponding to the first gear, and a magnet disposed on the second gear, and the support member comprises a first region supporting the first gear and a second region protruding from the first region and inserted into the first gear.

Description

Technology Field

[0001] The present invention relates to an electric pump. Background Technology

[0002] An electric oil pump (EOP) serves to discharge a flow rate at a constant pressure. Such an oil pump includes a housing, a gear unit positioned within the housing, and a motor that drives the gear unit. However, conventional electric oil pumps have a problem in that the gear unit and the motor unit are mechanically separated, resulting in an increased axial length.

[0003] In addition, since the housing is made of plastic, thermal deformation may occur due to heat generated in the gear section during operation. Consequently, play may develop between the housing and the gear section, or axial misalignment may occur between multiple gears included in the gear section, leading to a problem where the efficiency of the electric oil pump is reduced. The problem to be solved

[0004] The present invention aims to provide an oil pump that enables the miniaturization of the housing, prevents axial play in the gear section caused by thermal deformation of the housing, and stabilizes the driving of the gear section. means of solving the problem

[0005] An embodiment may provide an electric pump comprising: a housing; a gear portion disposed in the housing; a stator disposed corresponding to the gear portion; and a support member disposed between the gear portion and the housing, wherein the gear portion comprises a first gear, a second gear disposed corresponding to the first gear, and a magnet disposed on the second gear, and the support member comprises a first region supporting the first gear and a second region protruding from the first region and inserted into the first gear.

[0006] Preferably, the second region can penetrate the first gear.

[0007] According to an embodiment, an electric pump may be provided comprising: a housing; a gear portion disposed in the housing; a stator disposed corresponding to the gear portion; a cover disposed on the upper side of the gear portion; and a support member disposed on the lower side of the gear portion, wherein the support member includes a second region that passes through the gear portion in an axial direction and is coupled to the cover.

[0008] The above housing can be combined with the above cover.

[0009] The above housing may include a lower surface that supports the gear portion and the support member, and a side wall that extends upward from the lower surface.

[0010] An embodiment may provide an electric pump comprising: a mold member; a gear portion disposed within the mold member; a stator disposed corresponding to the gear portion; and a metal support member disposed between the gear portion and the mold member, wherein the gear portion comprises a first gear, a second gear disposed corresponding to the first gear, and a magnet disposed on the second gear, and at least a portion of the support member is disposed between the lower surface of the gear portion and one surface of the mold member.

[0011] The above stator can be embedded in the above mold member.

[0012] The above mold member includes a receiving portion in which the gear portion is disposed, and the upper surface of the mold member may be disposed higher than the top of the stator.

[0013] It includes a cover disposed on the upper side of the gear portion, and at least a portion of the cover may be disposed in the receiving portion.

[0014] An embodiment may provide an electric pump comprising: a housing; a gear portion disposed in the housing; a driving portion for driving the gear portion; and a support member disposed between the gear portion and the housing, wherein the gear portion includes a first gear and a second gear that rotates in correspondence with the first gear, the driving portion includes a magnet disposed on the second gear and a coil disposed in correspondence with the magnet, and the support member includes a first region coupled to the housing and a second region fixed to the first gear.

[0015] The above housing may include a receiving portion in which the gear portion is disposed.

[0016] The above support member may include aluminum.

[0017] One region of the support member penetrates the gear portion in the axial direction, and another region can support the gear portion in the axial direction.

[0018] The upper end of the support member may be positioned higher than the upper surface of the gear part.

[0019] The maximum diameter of the above support member may be greater than or equal to the outer diameter of the above gear part.

[0020] The above gear portion may have a through hole formed in which the support member is disposed, and the gear portion may have a protrusion formed on the inner circumference where the through hole is formed, protruding toward the axis center.

[0021] The support member includes a side facing radially with respect to the inner surface of the gear portion, and some of the sides of the support member may be in contact with the protrusion, while other parts may be spaced apart from the inner surface of the gear portion. Effects of the invention

[0022] According to the present invention, axial play in the gear section caused by thermal deformation of the housing can be prevented, and the axial error of the gears included in the gear section can be reduced, thereby enabling stable operation of the electric pump.

[0023] According to the present invention, by utilizing the electrical interaction between the gear unit and the stator to provide the power required for pumping into oil, a separate motor unit can be omitted. Accordingly, the axial length of the electric pump can be reduced, and the electric pump can be miniaturized. Brief explanation of the drawing

[0024] FIG. 1 is a cross-sectional view schematically illustrating an electric pump according to one embodiment of the present invention. FIG. 2 is a cross-sectional view schematically illustrating an electric pump according to another embodiment of the present invention. FIG. 3 is a cross-sectional view illustrating an electric pump according to another embodiment of the present invention. FIG. 4 is an exploded perspective view illustrating an electric pump according to another embodiment of the present invention. FIG. 5 is a cross-sectional perspective view showing the cross-section of the housing and the stator. FIG. 6 is a perspective view illustrating the state in which the gear part and the support member are combined. FIG. 7 is an exploded perspective view illustrating the first gear, the second gear, and the support member. FIG. 8 is a plan view illustrating the state in which the gear part and the support member are combined. FIG. 9 is a perspective view illustrating a support member. FIG. 10 is a plan view illustrating a support member. FIG. 11 is a side view illustrating a support member. Figure 12 is an enlarged view of a part of Figure 11. FIG. 13 is a plan view illustrating the state in which the first gear and the support member are combined. Figure 14 is a partial cross-sectional view of the electric pump shown in Figure 3. Figure 15 is a graph comparing the comparative example and the example with respect to the oil flow rate relative to the oil pressure. Specific details for implementing the invention

[0025] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0026] Regarding the rotational motion of the gear section, the direction parallel to the reference axis of rotation is called the axial direction, the direction perpendicular to the axial direction with respect to the axis of rotation is called the radial direction, and the direction following a circle with a radius in the radial direction with respect to the axial direction is called the circumferential direction.

[0027] FIG. 1 is a cross-sectional view schematically illustrating an electric pump according to one embodiment of the present invention.

[0028] Referring to FIG. 1, the electric pump (10) includes a housing (110), a gear section (120), a stator (130), a support member (140), a cover (150), and a power supply section (160).

[0029] The housing (110) and the cover (150) can form the outer shape of the electric pump (10). A stator (130) and a gear section (120) can be placed inside the housing (110). The housing (110) can be formed of resin or plastic material.

[0030] The housing (110) may include a bottom surface (111) and a side wall (112). At this time, the bottom surface (111) may support the stator (130) and the gear section (120) in the axial direction. The side wall (112) may surround the stator (130) from the outside. At this time, the gear section (120) may be positioned on the inside of the stator (130).

[0031] The gear unit (120) rotates through electrical interaction with the stator (130). The gear unit (120) can be positioned corresponding to the stator (130) and can be positioned inside. The gear unit (120) serves to pump fluid and provides the power required for pumping.

[0032] The stator (130) is positioned to correspond to the gear section (120). A coil forming a rotating magnetic field is wound on the stator (130) to induce electrical interaction with the gear section (120), thereby inducing rotation of the gear section (120).

[0033] A support member (140) may be positioned between the gear section (120) and the housing (110). At this time, the support member (140) may be fixed to the lower surface (101). Additionally, the end of the support member (140) may pass through the gear section (120) and be coupled to the cover (150). The support member (140) may be made of a metal material. This support member (140) may rub against the lower surface of the gear section (120) while the gear section (120) rotates. The support member (140) can reduce rotational friction of the gear section (120) and prevent axial play of the gear section (120). Furthermore, one side of the support member (140) may pass through the gear section (120) axially to fix the rotational axis of the gear section (120).

[0034] The cover (150) may be positioned on the upper side of the gear portion (120). The cover (150) may be coupled with the housing (110). The cover (150) may be formed of a metal material. In this case, the cover (150) may be made of the same material as the support member (140). The cover (150) may include aluminum.

[0035] A power supply unit (160) may be positioned on one side of the housing (110). The power supply unit (160) may be electrically connected to the stator (130) to supply current to the stator (130). The power supply unit (160) may include a printed circuit board and electronic components mounted on the printed circuit board.

[0036] FIG. 2 is a cross-sectional view schematically illustrating an electric pump according to another embodiment of the present invention, FIG. 3 is a cross-sectional view illustrating an electric pump according to another embodiment of the present invention, and FIG. 4 is an exploded perspective view illustrating an electric pump according to another embodiment of the present invention.

[0037] Referring to FIGS. 2 to 4, the electric pump (20) may include a mold member (210), a gear part (220), a stator (230), a support member (240), a cover (250), and a power supply part (260).

[0038] The mold member (210) covers the stator (230). At this time, the mold member (210) may be injection-formed into the stator (230). Additionally, the mold member (210) may include a receiving portion inside. A gear portion (220) is disposed in the receiving portion. The receiving portion may be cylindrical in shape. The diameter of the receiving portion may be larger than the outer diameter of the gear portion (220).

[0039] The gear portion (220) may be disposed in the receiving portion of the mold member (210). The gear portion (220) may include a first gear (221), a second gear (222), and a magnet (223). The second gear (222) is disposed on the outside of the first gear (221). The magnet (223) may be disposed on the outer surface of the second gear (222). There may be multiple magnets (223). The magnets (223) may be disposed along the circumferential direction.

[0040] The stator (230) is positioned inside the mold member (210). The stator (230) is positioned corresponding to the gear part (220). The stator (230) is electrically connected to the power supply unit (260), so that when current is supplied from the power supply unit (260), electrical interaction with the magnet (223) can be induced.

[0041] A support member (240) is positioned between the gear section (220) and the mold member (210). One side of the support member (240) is in contact with the mold member (210). At this time, one side of the support member (240) can be fixed to the mold member (210). The end of the support member (240) can penetrate the gear section (220). Also, the end of the support member (240) can be coupled with the cover (250). The support member (240) may be made of a metal material. The support member (240) can slide with the gear section (220) when the gear section (220) is driven by the electrical interaction between the stator (230) and the gear section (220). Since this support member (240) is formed of a metal material, it has excellent sliding properties with the gear section (220). In addition, it can prevent axial play between the gear part (220) and the mold member (210). Furthermore, the support member (240) fixes the rotational axis of the gear part (220), allowing the gear part (220) to operate more stably.

[0042] The cover (250) is positioned above the gear portion (220) and can be coupled with the upper end of the mold member (210). The cover (250) may be formed of a metal material. The cover (250) may include an intake port (not shown) and an exhaust port (not shown). The intake port (not shown) and the exhaust port (not shown) can guide fluid to be smoothly sucked in and discharged by the gear portion (220).

[0043] A power supply unit (260) may be positioned on one side of a mold member (210). The power supply unit (260) may be electrically connected to a stator (230) to supply current to the stator (230). The power supply unit (260) may include a printed circuit board and an electronic component mounted on the printed circuit board.

[0044] FIG. 5 is a cross-sectional perspective view showing the cross-section of the mold member and the stator.

[0045] Referring to FIG. 5, the stator (230) may include a stator core (231), a coil (232) wound on the stator core (231), and an insulator (233) disposed between the stator core (231) and the coil (232). At this time, the coil (232) may be connected to a power supply unit (260). The stator (230) is embedded in a mold member (210).

[0046] The mold member (210) can cover the stator core (231), coil (232), and insulator (233). At this time, the mold member (210) can be combined with the stator (230) by an injection molding method. An insert injection molding method may be used as the injection molding method. At this time, the mold member (210) may be formed from a resin or plastic material. For example, the mold member (210) may be formed from a thermally conductive plastic material. Thermally conductive plastics may include pellet-type resin, heat dissipation resin, PPA (Polyphtalamide) resin, CNT (Carbon NanoTube), etc.

[0047] A cover (250) may be disposed on the upper surface (210A) of the mold member (210). At this time, the upper surface (210A) of the mold member (210) may be disposed higher than the top of the stator (230). At least one fastening hole (210H) may be formed on the upper surface (210A) of the mold member (210). A screw thread may be formed in the fastening hole (210H) for connecting a fastening member. At this time, the fastening hole (210H) may be connected to the cover (250) by the fastening member.

[0048] The mold member (210) can form a receiving portion (S). A gear portion (220) can be disposed in the receiving portion (S). The receiving portion (S) may be cylindrical in shape. The axial length of the receiving portion (S) may be greater than the axial length of the gear portion (220). Also, the diameter of the receiving portion (S) may be greater than the outer diameter of the gear portion (220).

[0049] And, the upper side of the receiving portion (S) can be closed by a cover (250).

[0050] The edge of the cover (250) is attached to the upper surface (210A) of the mold member (210). The central part of the cover (250) may protrude toward the gear part (210) and be placed in the receiving part (S). At this time, the central part of the cover (250) may secure the upper end of the gear part (220). Also, the receiving part (S) may be connected to the suction port (not shown) and discharge port (not shown) of the cover (250). At this time, the suction port (not shown) and discharge port (not shown) may be formed by partitioning the space.

[0051] FIG. 6 is a perspective view showing the state in which the gear part and the support member are combined, FIG. 7 is an exploded perspective view showing the first gear, the second gear and the support member, and FIG. 8 is a plan view showing the second gear and the support member.

[0052] In this embodiment, for convenience of explanation, the gear part (220) and support member (240) shown in FIG. 3 have been described with reference, but the shape and function of the gear part (220) and support member (240) described in this embodiment can also be applied to the gear part (120) and support member (140) shown in FIG. 1 and FIG. 6.

[0053] Referring to FIG. 6, the support member (240) supports the gear portion (220) in the axial direction. Additionally, the support member (240) can penetrate the gear portion (220) to fix the rotational axis of the gear portion (220). To this end, the support member (240) may include a first region (241) and a second region (242).

[0054] The first region (241) is positioned on the lower side of the gear section (220). At this time, the first region (241) can support the lower surface of the gear section (220). Also, the first region (241) can be fixed to the mold member (210). The first region (241) may be in the shape of a disc. The diameter (D2) of the first region (241) may be greater than or equal to the outer diameter (D1) of the gear section (220). Meanwhile, although not shown in the drawing, the diameter of the first region may be formed smaller than the outer diameter of the gear section, and the edge of the gear section may be spaced apart from the mold member.

[0055] The second region (242) may protrude from the first region (241). The second region (242) may penetrate the first gear (221). At this time, the second region (242) may be positioned at the axis of rotation of the first gear (221). The second region (242) may be a cylindrical member extended in the axial direction. At this time, the diameter of the second region (242) may be smaller than the diameter of the inner surface of the first gear (221).

[0056] Referring to FIG. 7, the first gear (221) is positioned inside the second gear (222), and a second region (242) may be positioned inside the first gear (221). The second region (242) may penetrate the first gear (221) in the axial direction. At this time, the axial length of the second region (242) may be greater than the axial length of the gear portion (220). The end of the second region (242) may be positioned higher than the upper surface of the first gear (221). Also, the end of the second region (241) may be coupled to the cover (250).

[0057] Referring to FIG. 8, N outer lobes (2211) may be formed along the circumferential direction, extending radially outward with respect to the axis center on the first gear (221). Meanwhile, N+1 inner lobes (2221) may be formed inwardly, extending radially in the second gear (222). At this time, the outer lobes (2211) may be formed to engage with the inner lobes (2221). As the first gear (221) rotates, the second gear (222) rotates at a rotation ratio of (N+1) / N. The gear section (220) has a certain eccentric structure when the first gear (221) rotates, and due to this eccentricity, a space capable of transporting fluid (oil) is created between the first gear (221) and the second gear (222). That is, when the first gear (221) rotates, the part with increased volume sucks in surrounding fluid due to a pressure drop, and the part with decreased volume discharges fluid due to an increase in pressure.

[0058] The gear unit (220) generates electrical interaction with the stator (330) to pump oil and simultaneously provide the power required for pumping. Accordingly, the electric pump according to the present invention can reduce the axial length of the electric pump by omitting a separate motor unit.

[0059] FIG. 9 is a perspective view illustrating a support member, FIG. 10 is a plan view illustrating a support member, FIG. 11 is a side view illustrating a support member, and FIG. 12 is an enlarged view illustrating a part of FIG. 11.

[0060] Referring to FIG. 9, the support member (240) may include a first region (241) and a second region (242) protruding upward from the upper surface of the first region (241). In this case, the first region (241) and the second region (242) may be formed integrally. The support member (240) may include aluminum. In this case, the cover (250) may be made of the same material as the support member (240).

[0061] The first region (241) may include a first surface (241A) and a second surface (241B). The first surface (241A) and the second surface (241B) may be arranged axially. At this time, the first surface (241A) is arranged toward the gear portion (220). And, the second surface (241B) is arranged toward the mold member (210). The first surface (241A) is in contact with the gear portion (220), and the second surface (241B) is in contact with the mold member (210). At this time, while the gear portion (220) rotates, the contact portion between the first surface (241A) and the gear portion (200) may be frictionally contacted. The diameter (D2) of the first region (241) may be greater than or equal to the outer diameter of the gear portion (220).

[0062] The first region (241) may have a disc shape. At this time, the first region (241) may have a first thickness (T1) in the axial direction. At this time, the first thickness (T1) may be equal to the value obtained by subtracting the axial length of the gear part (220) from the distance between the mold member (210) and the cover (250) placed in the receiving part (S). At this time, the axial height of the gear part (220) can be adjusted according to the first thickness (T1) of the first region (241). In addition, by adjusting the first thickness (T1) of the first region (241), play between the mold member (210), the gear part (220), and the cover (250) placed in the axial direction can be prevented.

[0063] The second area (242) extends from the first area (241). The second area (242) may be placed on the first surface (241A). The second area (242) may be placed eccentrically at the center of the first surface (241A). The shortest distance from one point (P1) on the edge of the first surface (241A) to the second area (242) may differ from the shortest distance from another point (P2) on the edge of the upper surface of the first area (241) to the second area (242).

[0064] The second region (242) may include the first part (2421) and the second part (2422). The first part (2421) may extend from the first region (241). The first part (2421) may be positioned inside the first gear (221). In this case, the diameter (D3) of the first part (2421) may be smaller than or equal to the diameter of the inner circumference of the first gear (221). Thus, the first part (2421) is positioned on a rotation axis that serves as a reference for the rotational movement of the first gear (221), and can support the radial movement of the gear part (220).

[0065] The second part (2422) may extend from the end of the first part (2421). The second part (2422) may be positioned above the upper surface of the first gear (221). Additionally, the second part (2422) may be coupled with a cover (250). At this time, a groove corresponding to the shape of the second part (2422) is formed in the cover (250), so that the second part (2422) may be positioned in the groove. The diameter (D4) of the second part (2422) may be smaller than the diameter (D3) of the first part (2421). According to an embodiment, the ratio of the diameter of the second part (2422) to the diameter (D3) of the first part (2421) may be 0.5 to 0.8. These support members (240) can support the radial movement of the gear unit (220) while the gear unit (220) is driven, and can be combined with the cover (250) to increase the fixing force.

[0066] The axial length (L) of the second region (242) is equal to the sum of the axial lengths of the first part (2421) and the second part (2422). At this time, the first part (2421) may have a first length (L1) in the axial direction, and the second part (2422) may have a second length (L2) in the axial direction. At this time, the first length (L1) may be greater than the second length (L2). According to an embodiment, the ratio of the second length (L2) to the first length (L1) may be 0.15 to 0.4.

[0067] Meanwhile, according to another embodiment of the present invention, although not illustrated in the drawings, the axial length (L) of the second region (242) may be smaller than the axial length of the gear portion (220). In this case, the upper end of the second region (242) may be positioned lower than the upper surface of the gear portion (220). Also, the upper end of the second region (242) may be spaced apart from the cover (250).

[0068] Referring to FIG. 12, the upper edge of the first part (2421) may be formed tapered. Additionally, the upper edge of the second part (2422) may be formed tapered. Furthermore, the second region (242) may include a step (2423) connecting the first part (2421) and the second part (2422).

[0069] FIG. 13 is a plan view illustrating the state in which the support member (140) and the first gear are combined.

[0070] Referring to FIG. 13, the first gear (211) may have a first width (W) which is the minimum width with respect to the radial direction. In this case, the first width (W) may be the shortest distance between the inner diameter of the first gear (211) and the dedendum circle of the first gear (211). The first width (W1) may be smaller than the diameter (D3) of the first part (2421). For example, the first width (W1) may be 2 to 4.5 mm, and the diameter (D3) of the first part (2421) may be 4.5 to 6.5 mm. In this case, the first width (W1) and the diameter (D3) of the first part (2421) may vary depending on the size of the electric pump. The ratio of the first width (W1) to the diameter (D3) of the first part (2421) may be 0.3 to 1. At this time, as the ratio of the first width (W1) to the diameter (D3) of the first part (2421) decreases, the mechanical strength of the first gear (211) may decrease. On the other hand, if the ratio of the first width (W1) to the diameter (D3) of the first part (2421) increases, the diameter of the first part (2421) may not be sufficiently secured, and thus the mechanical strength of the support member (240) may decrease.

[0071] Figure 14 is a partial cross-sectional view of the electric pump shown in Figure 3.

[0072] Referring to FIG. 14, the first gear (221) may include a lower surface facing the support member (240) and an upper surface facing the cover (250). Additionally, a through hole (221H) may be formed in the first gear (221) that penetrates the upper and lower surfaces. At this time, a rotation axis (RA) serving as a reference for the rotational movement of the first gear (221) may be disposed in the through hole (221H). Additionally, a first part (2421) may be disposed in the through hole (221H). At this time, the first part (2421) may include a side surface (2421A) facing the inner circumferential surface of the first gear (221). The diameter of the through hole (221H) may be formed larger than the diameter of the first part (2421), so that the side surface (2421) may be spaced apart from the inner circumferential surface of the first gear (221).

[0073] The first gear (221) may include a protrusion (2212) that protrudes toward the rotation axis (RA). The protrusion (2212) may be disposed on the inner circumference of the first gear (221). At this time, the protrusion (2212) may include a protruding surface (221A) that contacts the side (2421A) of the first part (2421).

[0074] The side (2421A) of the first part (2421) may include a first part (2421A1), a second part (2421A2), and a third part (2421A3).

[0075] The first part (2421A1) may be in contact with the protruding surface (221A). The first part (2421A1) may be spaced apart from the first area (241). Also, the second part (2421A2) may be positioned between the first area (241) and the first part (2421A1). At this time, the second part (2421A2) may be spaced apart from the first gear (221). The second part (2421A2) may have a greater axial length than the first part (2421A1). Additionally, the third part (2421A3) may be positioned between the first part (2421A1) and the second part (2422). At this time, the third part (2421A3) may be spaced apart from the first gear (221). Meanwhile, the cover (250) may include a third part (2421A3) that protrudes between the first gears (221). Additionally, a groove (250G) may be formed on the inner side of the projection (251) of the cover (250). At this time, a second part (2422) may be disposed in the groove (250G). The axial length of the groove (250G) may be formed to be longer than the axial length of the second part (2422). At this time, the upper end of the second part (2422) may be spaced apart from the cover (250).

[0076] The cover (250) may include a seating surface (252) positioned between the groove (250G) and the projection (251). At this time, the seating surface (252) may come into contact with the step (2423). In this way, the cover (250) may include a structure for being coupled and fixed with the support member (240) to increase the fixing force of the support member (240).

[0077] Figure 15 is a graph comparing the comparative example and the example with respect to the oil flow rate relative to the oil pressure.

[0078] In the embodiment of FIG. 15, the change in oil flow rate with respect to oil pressure of an electric pump including a housing, gear section, stator, support member, and cover, similar to the structure of FIG. 3, was measured. The electric pump of the embodiment has a structure in which power is generated through the gear section and oil is pumped from the gear section.

[0079] In Comparative Example 1, the change in oil flow rate with respect to oil pressure was measured in a conventional electric pump in which the motor part and the pump part are mechanically separated. The electric pump of Comparative Example 1 has a structure in which power generated in the motor part is transmitted to the pump part so that the pump part operates.

[0080] In Comparative Example 2, the change in oil flow rate with respect to oil pressure was measured for an electric pump in which the support member was omitted from the structure of Fig. 3. At this time, the electric pump of Comparative Example 2 may have the same configuration as the electric pump used in the embodiment, except that the support member was omitted.

[0081] Referring to FIG. 15, it can be seen that in Comparative Example 2, the oil flow rate decreases rapidly as the oil pressure increases compared to Comparative Example 1. Therefore, it can be seen that the oil flow rate value according to oil pressure in the electric pump of Comparative Example 2 decreases rapidly compared to a conventional electric pump in which the motor part and the pump part are mechanically separated. Through this, it can be confirmed that while the axial length of the electric pump including the gear part acting as the motor part and the pump part can be reduced, hydraulic pressure loss occurs due to axial play between the gear part and the housing.

[0082] On the other hand, compared to Comparative Example 2, it can be seen that the oil flow rate in the Example decreases relatively little even when the oil pressure increases. At this time, it can be seen that the magnitude of the decrease in flow rate in the Example is similar to that of Comparative Example 1. That is, it can be seen that the Example has a structure similar to Comparative Example 2, and there is no significant difference in oil pumping performance compared to Comparative Example 1. In this way, the electric pump according to the present invention can maintain oil pumping performance by reducing the axial length to miniaturize the size while preventing axial play from occurring between the gear part and the housing.

[0083] The aforementioned embodiments have been described using an electric pump as an example, but are not limited thereto. They can be used in various devices, such as vehicles or home appliances. Explanation of the symbols

[0084] 10, 20: Electric pump 110: Housing 120, 220: Gear section 130, 230: Status 140, 240: Support member 150, 250: Cover 160, 260: Power supply 210: Mold member 221: 1st gear 222: 2nd Gear 223: Magnet 241: First Zone 242: Second Zone 2421: Part 1 2422: Part 2

Claims

Claim 1 An electric pump comprising a housing, a gear portion disposed in the housing, a stator disposed in the housing, a cover disposed on the upper side of the gear portion, and a support member, wherein the support member comprises a first region having a predetermined thickness between a first surface facing the gear portion and a second surface facing the housing, and a second region protruding axially from the first surface of the gear portion, and the second region comprises a first portion extending from the first region and penetrating the gear portion, and a second portion extending from the end of the first portion and coupled to the cover. Claim 2 In claim 1, the cover is an electric pump comprising a groove that accommodates the second part. Claim 3 An electric pump according to paragraph 2, wherein the diameter of the first part is larger than the diameter of the second part, the second region includes a step connecting the first part and the second part, and the cover includes a seating surface in contact with the step. Claim 4 In paragraph 3, the cover includes a projection protruding between the first part and the inner circumferential surface of the gear part, and the seating surface is positioned between the groove and the projection, forming an electric pump. Claim 5 In claim 1, the housing comprises a mold member formed by injection molding to cover the stator, the mold member comprises a receiving portion for receiving the gear portion, and the first region is an electric pump disposed between the mold member and the gear portion within the receiving portion. Claim 6 In paragraph 2, the upper part of the second section is an electric pump spaced apart from the groove. Claim 7 An electric pump according to claim 1, wherein the inner surface of the gear portion through which the second region penetrates includes a protrusion, the first portion of the second region includes a first part in contact with the protrusion, and a second part disposed between the first region and the first part and spaced apart from the inner surface of the gear portion. Claim 8 In claim 7, the electric pump in which the axial length of the second part is longer than the axial length of the first part. Claim 9 An electric pump according to claim 7, wherein the first part is positioned on the opposite side of the second part with the first part in between, and further comprises a third part spaced apart from the inner surface of the gear part. Claim 10 In claim 1, the first region is disc-shaped, and the second region is an electric pump eccentrically positioned with respect to the center of the first surface. Claim 11 An electric pump according to claim 1, wherein the gear portion comprises a first gear, a second gear disposed outside the first gear, and a magnet disposed on the outer surface of the second gear, and the diameter of the first region is greater than or equal to the diameter of the first gear. Claim 12 In claim 11, the first gear has a first width which is the shortest distance between the inner diameter of the first gear and the root circle of the first gear with respect to the radial direction, and the first width is smaller than the diameter of the first part of the electric pump.

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