JP5372649B2 - Electric pump - Google Patents

Description

  The present invention relates to an electric pump that drives a liquid pump by an electric motor.

  For example, Patent Document 1 discloses a small conventional electric pump used as a supply source of hydraulic oil for a clutch of an automatic transmission of a vehicle or cooling oil for an electric motor of a hybrid vehicle.

  In this electric pump, a trochoid oil pump and a brushless DC motor, which is an electric motor for rotating the oil pump, are integrally accommodated in a housing.

  The housing is divided into a plurality of parts on the oil pump side and the electric motor side, and a driver portion such as a substrate is integrally attached to the accommodation space of the upper end portion on the brushless DC motor side. As a result, the dead space can be effectively used and the entire housing can be reduced in size.

Japanese Patent No. 4042050

  However, in the conventional electric pump, since the peripheral wall of the housing, in particular, the partition wall between the brushless DC motor and the oil pump is formed to be relatively thick, the overall weight increases. There are technical issues such as.

  The present invention has been devised in view of the technical problem of the conventional electric pump, and a recess or the like recessed toward the inner peripheral side is formed in the outer peripheral portion between the pump structure of the housing and the electric motor. It aims at providing the electric pump reduced in weight.

According to the first aspect of the present invention, in particular, a concave portion that is recessed toward the inner peripheral side is formed in the outer peripheral portion of the housing between the liquid pump and the electric motor, and the outer peripheral surface of the concave portion is directed forward of the vehicle. It is characterized by providing a plurality of linear protrusions extending toward the surface.

According to a second aspect of the invention, between the liquid pump and the electric motor in the housing, Rutotomoni a plurality recess disposed circumferentially on the outer peripheral surface of the recess, extends toward the forward direction of the vehicle A plurality of linear protrusions are provided .

According to a third aspect of the present invention, a recessed portion is provided in the outer peripheral portion between the liquid pump and the electric motor in the metal housing, and the outer peripheral surface of the recessed portion extends toward the front of the vehicle. A plurality of heat dissipating fins are provided.

According to a fourth aspect of the present invention, a recessed portion is formed in the outer peripheral portion of the metal housing between the liquid pump and the electric motor, and the outer peripheral surface of the recessed portion extends toward the front of the vehicle. It is characterized by providing a plurality of reinforcing ribs.

  According to the first aspect of the present invention, the weight of the housing can be reduced by the recessed portions, and the strength of the housing can be improved by being reinforced by the plurality of linear protrusions.

  According to the second aspect of the present invention, the weight of the housing can be reduced by the recess.

  According to the third aspect of the present invention, the weight of the housing can be reduced by the recess, and the heat generated from the electric motor or the like can be absorbed and radiated by the radiating fins to effectively cool the housing.

  According to the invention described in claim 4, the weight of the housing can be reduced, and the strength of the housing can be improved by the reinforcing rib.

It is a longitudinal section showing the electric pump of a 1st embodiment of the present invention. It is the sectional view on the AA line of FIG. It is the BB sectional view taken on the line of FIG. It is CC sectional view taken on the line of FIG. It is CC sectional view taken on the line of FIG. 1 which shows the electric pump of 2nd Embodiment.

Hereinafter, an embodiment in which an electric pump according to the present invention is applied as a supply source of hydraulic oil for a clutch of an automatic transmission (transmission), for example, will be described with reference to the drawings.
[First Embodiment]
As shown in FIG. 1, the electric pump includes a housing 1 disposed and fixed in an engine room of a vehicle, an oil pump 2 that is a liquid pump accommodated in the housing 1, and the oil pump 2. It is mainly composed of an electric motor 3 to be driven and a driver unit 4 that operates the electric motor 3.

  The housing 1 is formed in a substantially cylindrical shape by an aluminum alloy material. A pump housing chamber 1a for housing a pump component of the oil pump 2 is formed on the inner lower end side in FIG. A motor housing chamber 1b for housing a motor component of the electric motor 3 is formed. The driver unit 4 is disposed and fixed on the upper end side of the motor housing chamber 1b of the housing 1. Further, as will be described later, the housing 1 is integrally cast by molding that can be divided into three.

  As shown in FIG. 2, the oil pump 2 is a trochoid pump, and the lower part of the pump housing chamber 1 a (the lower surface of the housing 1) is also fixed by a bolt 6 via a seal member 5. It is blocked by an alloy material pump cover 7. The pump structure housed in the motor housing chamber 1a includes a drive shaft 8 disposed along the inner central axis direction of the housing 1, an inner rotor 9 fixed to a lower end portion of the drive shaft 8, And an outer rotor 10 that rotates while the inner teeth 10 a mesh with the outer teeth a of the inner rotor 9.

  The drive shaft 8 extends along the inner axial direction of the housing 1, and also serves as the motor shaft of the electric motor 3.

  The inner rotor 9 is rotatably supported by a bearing portion 1c whose cylindrical convex portion 9b is eccentric from the pump housing chamber 1a. On the other hand, the outer rotor 10 has an outer peripheral surface rotatably supported on an inner peripheral surface of the pump housing chamber 1a. Further, the number of teeth of the outer teeth 9a of the inner rotor 9 is one less than the number of teeth of the inner teeth of the outer rotor 10, and the rotation between the outer teeth 9a and the inner teeth 10a with rotation. A plurality of pump chambers 11 whose volumes are changed accordingly are formed.

  A suction chamber 12, which is a suction portion having a shape along the volume increase of the pump chamber 11, is formed on the bottom surface of the pump storage chamber 1 a and the inner end surface of the pump cover 7, and the volume of the pump chamber 11 is decreased. A discharge chamber 13 which is a discharge portion having a shape along the line is formed. On the outer end surface side of the pump cover 7, a suction hole 12a for introducing hydraulic oil into the suction chamber 12 and a discharge hole 13a for discharging the hydraulic oil from the discharge chamber 13 are formed. Hydraulic fluid is supplied to the transmission via an external discharge passage.

  Further, as shown in FIG. 1, a seal chamber and a bearing storage chamber coaxial with the bearing portion 1c are formed between the pump storage chamber 1a and the motor storage chamber 1b. An oil seal 14 is provided for fluid-tightly sealing between the pump housing chamber 1a and the motor housing chamber 1b, while the bearing housing chamber has a pair of upper and lower portions that rotatably support the drive shaft 9. The ball bearings 15a and 15b are accommodated.

  The seal housing chamber and the suction chamber 12 are communicated with each other by a low pressure passage 16 so that excessive oil pressure does not act on the oil seal 14.

The pair of ball bearings 15a and 15b has upper end portions of a plate-like retainer 18 whose inner races are press-fitted and fixed to the outer peripheral surface of the drive shaft 8 and whose one end portions are fixed to the housing 1 by bolts 17. There has been pressed in the axial direction downwards. As a result, the outer race of the lower ball bearing 15b is pressed against the stepped portion 1d of the housing 1 toward the pump side, thereby positioning the entire shaft in the axial direction.

  As shown in FIG. 3, the electric motor 3 is a brushless DC motor, and includes a rotor 19 fixed to the outer peripheral surface of the drive shaft 8, a stator 20 disposed on the outer peripheral side of the rotor 19, Is mainly composed of

  The rotor 19 includes a cylindrical rotor core 19a formed of a plurality of magnetic laminates, and a cylindrical magnet 19b bonded and fixed to the outer peripheral surface of the rotor core 19a. It is press-fitted and fixed to the drive shaft 8 via the inner peripheral surface of the hole and the outer peripheral surface of the drive shaft 8.

  The stator 20 has a stator core 20a formed in a cylindrical shape by a laminated plate of magnetic materials, an insulator slot 20b fixed via an insulator coated on the outer periphery of the stator core 20a, and wound around the insulator slot 20b. Coil 20c.

  The stator 20 is entirely fixed to the housing 1 by a pair of bolts 21 inserted through bolt insertion holes formed in the axial direction of the outer peripheral portion of the stator core 20a, and at the fixed position, the stator 20 has an axial length. The substantially equal inner circumferential surface of the stator core 20a and the outer circumferential surface of the magnet 19b are opposed to each other through a cylindrical air gap C having a predetermined width.

  The driver section 4 is mainly composed of a connector mold 22 made of a synthetic resin material, a substrate 23 provided with electronic components, and a heat sink 24 made of an aluminum alloy material that protects the substrate 23 and the like.

  The connector mold 22 includes a substrate mounting portion 22a in which a substrate 23 is fixed to an upper end surface with bolts 25, and a connector portion 22b in which a connector terminal 26 connected to an electronic circuit of the substrate 23 is molded. Yes. The entire connector mold 22 is fastened together with the stator 20 together with the stator 20 by the pair of bolts 21, and is interposed between the lower surface of the board mounting portion 22 and the upper end surface of the housing 1. The motor housing chamber 1 b is liquid-tightly sealed by the seal ring 27.

  The connector portion 22b is formed with a vent hole 28 that allows the inside of the driver portion 4 and the electric motor 3 to communicate with each other. The vent hole 28 controls the pressure change due to the internal temperature change by allowing air to flow through the vehicle connector and the harness (not shown) that are liquid-tightly fitted to the connector portion 22b. . The connector portion 22b is formed to face downward so that water or the like is difficult to enter inside.

  The board 23 is configured to rotate the drive shaft 8 by energizing the coil 20c via a terminal 29 with a current supplied to the connector terminal 26 from an electronic controller (not shown).

  The heat sink 24 is liquid-tightly fixed to the upper surface of the connector mold 22 through a seal ring 31 with a plurality of bolts 30, and a plurality of protrusions 24a for increasing the exposed area to the outside are formed on the outer surface. Is provided.

  A cooling sheet 32 that covers the heat generating part of the substrate 23 is interposed between the inner surface of the heat sink 24 and the substrate 23, and the heat of the heat generating part is transferred by the cooling sheet 32 to the heat sink 24. The substrate 23 is cooled by dissipating heat to the outside via the.

  Between the upper end of the drive shaft 8 and the substrate 23, a sensor 50 for detecting the rotational speed of the drive shaft 8 is provided. The sensor 50 has a target protrusion 52 to be detected fixed to the upper end portion of the drive shaft 8 via a holding portion 51, and protrudes from a lower portion of the substrate 23 to sense the target protrusion 52. The rotation information signal detected by the detection unit 53 is output to an electronic controller (not shown).

  In the partition wall 1e between the pump storage chamber 1a and the motor storage chamber 1b of the housing 1, excess oil discharged from the discharge chamber 13 is supplied to the suction chamber 12, as shown in FIGS. A relief valve 33 for inflow is arranged.

  The relief valve 33 includes a valve hole 34 formed in the partition wall 1 e, a columnar valve body 35 slidably provided in the valve hole 34, and an open end of the valve hole 34. And a coil spring 37 that is elastically mounted between the inner end surface of the plug 36 and the rear end surface of the valve body 35 and biases the valve body 35 toward the distal end portion of the valve hole 34. It is configured.

  A relief passage 38 having a small diameter coaxial with the valve hole 34 is formed at the distal end side of the valve hole 34, and the relief passage 38 is connected to the discharge chamber 13 and the suction chamber via the valve hole 34. An opening is formed so that 12 communicates.

  The valve body 35 is formed in a cylindrical shape with a lid, and a distal end portion 35a opens and closes the relief passage 38 according to the sliding position, and is biased in a direction to close the relief passage 38 by the spring force of the coil spring 37. Has been.

  The plug 36 is screwed into a female screw portion formed at the opening end of the valve hole 34 via a male screw portion formed on the outer periphery of the cylindrical tip portion 36a, and a flange portion and a valve integral with the head portion. A seal washer 54 is interposed between the opening edge of the hole 34.

  The coil spring 37 is compressed and deformed when the discharge force in the relief passage 38 exceeds a predetermined value, and the valve spring 35 is moved backward so that the discharge chamber 13 and the suction chamber 12 communicate with each other. Is set to Thus, the discharged surplus oil is caused to flow into the suction chamber 12 to adjust the discharge flow rate.

  A recess 39 (a recess) recessed toward the inner periphery is formed on the outer periphery of the partition wall 1 e between the oil pump 2 and the electric motor 3 of the housing 1. A plurality of first to third reinforcing ribs 40, 41, 42 that are linear protrusions are provided on the outer peripheral surface so as to project integrally with the housing 1.

  That is, as shown in FIGS. 1 and 4, the recess 39 is formed in a deep groove shape around the partition wall 1 e, and in particular, the vicinity of the valve hole 34 is partially and relatively shallowly formed. However, the first and second recesses 39a and 39b on both sides in the axial direction of the valve hole 34 and the third recess 39c positioned in the direction perpendicular to the axis are notched in a deep groove shape. In FIG. 4, the housing 1 is disposed such that the recess 39a side is the vehicle front position and the recess 39b side is the vehicle rear position.

  The reinforcing ribs 40 to 42 are formed in a plate shape and project from the outer peripheral surface of each of the recesses 39a to 39c in a substantially vertical direction, and are provided on the first recess 39a side and the second recess 39b side. The first and second reinforcing ribs 40 and 41 extend in the axial direction of the valve hole 34, that is, along the longitudinal direction of the vehicle body, while the third reinforcing rib 42 on the third recess 39c side is in the longitudinal direction of the vehicle. It extends along the direction perpendicular to. The extending length L of the reinforcing ribs 40 to 42 is set to be substantially the same as the length of each arcuate tip edge to the outer peripheral edge of the housing 1, that is, the outer diameter of the housing 1.

  Further, three first reinforcing ribs 40 are formed, whereas two second reinforcing ribs 41 and four third reinforcing ribs 42 are formed.

  Further, each of the reinforcing ribs 40 to 41 has a relatively thin wall thickness and is set to substantially the same thickness, so that the surface area of the reinforcing ribs 40 to 41 functions as a heat radiating fin that obtains effective heat dissipation. It has become.

  Note that the casting mold for molding the housing 1 is divided into three in the axial direction both sides of the relief valve 33 and the direction perpendicular to the axial direction. 40, 41, and 42 are extended directions.

  As described above, according to the electric pump of the present embodiment, since the deep groove-shaped recess 39 (39a to 39c) is formed around the partition wall 1e of the housing 1, the housing 1 can be sufficiently reduced in weight.

  Further, since the strength of the housing 1 is sufficiently increased by the reinforcing ribs 40 to 41, even if the sectional area of the partition wall 1e is reduced by the recess 39, the strength of the entire housing 1 can be maintained high. In particular, vibrations associated with the rotation of the drive shaft 9 can be effectively suppressed by the unique arrangement in which the reinforcing ribs 40 to 41 extend in the radial direction of the drive shaft 9.

  Further, each of the reinforcing ribs 40 to 41 is provided at the partition wall portion 1e of the housing 1, that is, at a portion where the oil pump 2 side and the electric motor 3 side are coupled, so that the strength of the housing 1 is further increased. be able to.

Since the sectional area of the partition wall 1e is reduced by the recess 39 as described above, the heat transfer area from the oil pump 2 to the electric motor 3 can be reduced, so that the heat of the hydraulic oil received by the oil pump 2 can be reduced. The heat transfer to the electric motor 3 can be sufficiently suppressed.

  Moreover, in addition to the heat of the hydraulic oil, heat generated in the coil 20 of the electric motor 3 is transmitted from the housing 1 to the reinforcing ribs 40 to 41, and is effectively radiated from here. A decrease in performance can be suppressed.

  That is, in the electric motor 3, since each stator 20 is covered with a connector mold 22 made of a synthetic resin material having low heat transfer properties, heat is trapped inside the electric motor 3 due to heat generated by the coil 20c, etc. The internal temperature rises, the resistance value of the coil 20c rises, or the magnetic characteristics of the magnet 19b are lowered, so that the motor performance is lowered.

  Therefore, in the present embodiment, since the reinforcing ribs 40 to 41 function as heat dissipating fins having a large surface area, a temperature increase of the coil 20c and the like can be suppressed by a high heat dissipating effect inside the electric motor 3. As a result, a reduction in motor performance can be suppressed and power consumption can be suppressed.

  In particular, since the first reinforcing rib 40 protrudes in the traveling direction of the vehicle and receives the traveling wind directly from the front end side, the heat dissipation effect is further enhanced, and the second reinforcing rib 41 also has the traveling direction of the vehicle. Since the protrusion protrudes in the opposite direction, the heat dissipation is also good from this structure.

  Moreover, in this embodiment, since the said electric motor 3 is comprised by the brushless DC motor and this motor generate | occur | produces comparatively more heat than a motor with a brush, the cooling effect by each said reinforcement ribs 40-41 is more. validate.

  In addition, since the said housing 1 and each reinforcement rib 40-41 are formed with the aluminum alloy material, the heat absorption from an inside is high.

  In addition, since the axial direction of the valve hole 34 and the extending direction of the first and second reinforcing ribs 40 and 41 are the same direction, the die-cutting direction when the housing 1 is molded is the same. The 33 valve holes 34 and the first and second reinforcing ribs 40 and 41 can be molded together.

[Second Embodiment]
FIG. 5 shows a second embodiment in which the structure of the reinforcing rib is changed.

  That is, the third reinforcing rib provided at right angles to the valve hole 34 is eliminated, and only the first reinforcing rib 40 and the second reinforcing rib 41 extending in the same direction along the axial direction of the valve hole 34 are used. In addition, six first reinforcing ribs 40 in the front direction of the vehicle body and three second reinforcing ribs 41 in the rear direction of the vehicle body are provided.

  Further, the thickness of the first reinforcing rib 40 is substantially the same as that of the first embodiment, but the thickness of the second reinforcing rib 41 is formed thicker than that of the first reinforcing rib 40. . Other configurations are the same as those of the first embodiment.

  Therefore, according to this embodiment, since the number of the first reinforcing ribs 40 that directly receive the traveling wind is increased, the heat absorbed by the housing 1 can be radiated more effectively, and the second reinforcing rib 41 The heat dissipation effect is further enhanced by increasing the number of the heat sinks.

  In addition, by increasing the thickness of the second reinforcing rib 41, the high strength of the housing 1 can be maintained even if the third reinforcing rib is eliminated.

  Further, as described above, each of the reinforcing ribs 40 and 41 protrudes along the axial direction of the valve hole 34, so that the molding die of the housing 1 is arranged on the first reinforcing rib 40 side and the second reinforcing rib 41. It can be a two-sided type.

  For this reason, when the housing 1 is molded, the two molding dies can be released from side to side along the axis of the valve hole 34 and the extending direction of the reinforcing ribs 40 and 41, so that the molding operation is easy. is there. Further, since there are only two molds, the cost of the casting apparatus can be reduced.

Hereinafter, technical ideas other than the invention described in the above-mentioned claims ascertained from the embodiment will be described below.
(a)
The electric pump according to claim 1,
The electric pump, wherein the linear protrusion extends in an axial direction of the drive shaft.

The linear convex portion improves the strength of the housing, and vibrations associated with the rotation of the drive shaft can be effectively suppressed particularly by its unique arrangement configuration.
(b)
In the electric pump described in (a),
The linear convex part is provided in the site | part which combined the said pump structure side and electric motor side of the said housing, The electric pump characterized by the above-mentioned.

According to this invention, the strength of the housing can be further increased by the unique arrangement of the linear protrusions.
(c)
In the electric pump described in (a),
Forming the housing by molding,
A relief valve is disposed in the vicinity of the recess to allow excess fluid discharged from the pump structure to flow out to the low pressure part,
The relief valve includes a valve hole provided linearly in the housing, and a valve body that slides in the valve hole,
An electric pump characterized in that at least the linear convex portion provided in the axial direction of the valve hole is formed so as to extend along the axial direction of the valve hole.

According to the present invention, since the axial direction of the valve hole and the extending direction of the linear convex portion are the same direction, the die-cutting direction at the time of molding the housing is the same, so the valve hole of the relief valve is linear. It becomes possible to mold the convex portions together.
(d)
In the electric pump described in (c),
An electric pump characterized in that all of the linear protrusions are arranged so as to extend along the axis of the valve hole.

The mold releasability at the time of mold forming of the housing is improved.
(e)
In the electric pump described in (d),
The linear pump is disposed on both sides of the valve hole in the axial direction.

Because it is on both sides, heat dissipation is improved.
(f)
In the electric pump described in (e),
The electric pump is characterized in that the housing is formed by a two-part mold.

At the time of molding the housing, the two molding dies can be released to the left and right along the axis of the valve hole and the extending direction of the linear convex portion, so that the molding operation is easy.
(g)
The electric pump according to claim 1,
An electric pump characterized in that the housing is made of an aluminum alloy material.

By forming the aluminum alloy material, the heat absorption from an electric motor or the like is improved.
(h)
The electric pump according to claim 1,
The electric pump characterized in that the housing is mounted in an engine room of a vehicle, and at least a part of the linear convex portion extends in a vehicle traveling direction.

When the vehicle travels, the linear projecting portion directly receives the traveling wind, so the heat dissipation effect is increased.
(i)
In the electric pump described in (h),
The linear convex portions are provided at front and rear positions in the vehicle traveling direction, and the linear convex portions provided on the front side in the vehicle traveling direction are formed more than the linear convex portions provided on the rear side in the vehicle traveling direction. An electric pump characterized by

Since a large number of front linear protrusions are provided, the heat dissipation effect is further improved.
(j)
The electric pump according to claim 1,
The electric motor is constituted by a brushless motor, and a stator around which a coil is wound is fixed to the inner periphery of the housing.

  Since the brushless motor generates a relatively large amount of heat as compared with the motor with the brush, the cooling effect by the linear protrusion becomes more effective.

  The present invention is not limited to an electric pump for transmission, but can be applied to an electric pump for other purposes.

DESCRIPTION OF SYMBOLS 1 ... Housing 1a ... Pump accommodation chamber 1b ... Motor accommodation chamber 1e ... Partition part 2 ... Oil pump 3 ... Electric motor 4 ... Driver part 8 ... Drive shaft 9 ... Inner rotor 10 ... Outer rotor 12 Inhalation chamber (intake part)
13: Discharge chamber (discharge section)
33 ... Relief valve 34 ... Valve hole 39a-39c ... 1st-3rd recessed part (recessed part)
40-42 ... 1st-3rd reinforcement rib (linear convex part)

Claims (4)

A liquid pump that discharges the fluid sucked from the suction portion to the outside from the discharge portion by rotating the rotor;
An electric motor that rotates the drive shaft by energization and transmits a rotational force to the rotor via the drive shaft;
A housing made of an aluminum alloy material that houses the liquid pump and the electric motor inside,
In the outer periphery between the liquid pump and the electric motor in the housing, a recess recessed on the inner periphery side is formed,
An electric pump characterized in that a plurality of linear convex portions extending toward the front of the vehicle are provided on the outer peripheral surface of the concave portion. A liquid pump that discharges the fluid sucked from the suction portion through the discharge portion by transmitting the rotational force;
An electric motor that rotates the drive shaft by energization and transmits a rotational force to the rotor via the drive shaft;
A housing made of an aluminum alloy material that houses the liquid pump and the electric motor inside,
Between the liquid pump and the electric motor in the housing, provided with a plurality of recesses arranged in the circumferential direction,
An electric pump characterized in that a plurality of linear convex portions extending toward the front of the vehicle are provided on the outer peripheral surface of the concave portion . A liquid pump that discharges the fluid sucked from the suction portion through the discharge portion by transmitting the rotational force;
An electric motor that rotates the drive shaft by energization and transmits a rotational force to the rotor via the drive shaft;
A housing made of an aluminum alloy material that houses the liquid pump and the electric motor inside,
In the outer periphery between the liquid pump and the electric motor of the housing, forming a recessed portion,
An electric pump characterized in that a plurality of heat dissipating fins extending toward the front of the vehicle are provided on the outer peripheral surface of the recess. A liquid pump that discharges the fluid sucked from the suction portion through the discharge portion by transmitting the rotational force;
An electric motor that rotates the drive shaft by energization and transmits a rotational force to the rotor via the drive shaft;
A housing made of an aluminum alloy material that houses the liquid pump and the electric motor inside,
In the outer periphery between the liquid pump and the electric motor of the housing, forming a recessed portion,
An electric pump comprising a plurality of reinforcing ribs extending toward the front of the vehicle on an outer peripheral surface of the recess.

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