JP7559643B2 - Electric pump - Google Patents

Description

The present invention relates to an electric pump.

Conventionally, electric pumps are known in which the motor section and the pump section are fastened together with bolts or the like.

For example, Patent Document 1 shows a structure in which a bearing plate is disposed between a pump housing and a motor housing, and they are integrally assembled with bolts. In addition, an attachment plate for hydraulic equipment, etc. is formed integrally with the pump housing on the side of the pump housing.

JP 2003-269345 A

However, in the structure of Patent Document 1, the points on the pump housing that are fastened with bolts protrude significantly outward, resulting in an increase in the size of the pump housing.

One way to deal with this issue is to reverse the bolt orientation and fasten the bolt from the pump housing to the motor housing, thereby preventing the pump housing from becoming too large. However, because it is difficult to pass a bolt through the mounting plate from the pump housing, the strength of the fixation is reduced, reducing rigidity, and there are concerns that this could lead to increased vibration.
SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to improve the rigidity of a pump housing while preventing the size of the pump housing from increasing.

One aspect of the electric pump according to the present invention includes a motor section having a drive shaft rotatably supported by a motor housing and rotating the drive shaft, and a pump section located on one side of the motor section in the axial direction along the drive shaft and sucking in and discharging a fluid. The pump section rotates by the driving force of the drive shaft to send the fluid from the suction side to the discharge side, a pump body surrounding the pump rotor in the rotational direction of the pump rotor, a pump cover having a mounting plate section that extends in the axial direction and has a mounting surface that contacts a mounting target and protrudes in a plate-like manner to the one side, covering the one side of the pump rotor, a first connecting member that connects the pump cover to another member located on the other side relative to the one side and passes from the one side to the other side, and a second connecting member that connects the pump cover to another member located on the other side at a location where the pump cover overlaps with the mounting plate section when viewed in the axial direction and passes from the other side to the one side.

The present invention prevents the pump housing from becoming too large and improves its rigidity.

FIG. 1 is a diagram conceptually showing the structure of an oil pump. FIG. 2 is a diagram showing the appearance of the oil pump as viewed from one axial side. FIG. 3 is a diagram showing the appearance of the oil pump as viewed from the mounting surface side. FIG. 4 is a view showing the pump cover as viewed from one axial side. FIG. 5 is a view showing the pump cover as viewed in a direction perpendicular to the axial direction and parallel to the mounting surface. FIG. 6 is a diagram showing the pump cover as viewed in a direction perpendicular to both the axial direction and the mounting surface.

Hereinafter, embodiments of the motor and electric pump of the present disclosure will be described in detail with reference to the accompanying drawings. However, in order to avoid the following description becoming unnecessarily redundant and to facilitate understanding by those skilled in the art, more detailed description than necessary may be omitted. For example, detailed description of already well-known matters and duplicated description of substantially the same configuration may be omitted. Furthermore, elements shown in the previously described figures may be appropriately referenced in the description of the later figures.
FIG. 1 is a diagram conceptually showing the structure of an oil pump.
The oil pump 100 corresponds to one embodiment of the electric pump of the present invention.
The oil pump 100 includes a motor section 110, a sensor section 120, and a pump section 130.
The motor unit 110 receives power and generates a rotational driving force.
The sensor unit 120 detects the rotation of the motor unit 110 .
The pump unit 130 is driven by the motor unit 110 and sucks and discharges oil.
The motor unit 110 includes a motor housing 111 , a drive shaft 112 , a rotor 113 , a stator 114 , and a bearing 115 .

The drive shaft 112 is a member that transmits the rotational driving force of the motor unit 110, and is rotatably supported by the motor housing 111 via a bearing 115. In other words, the motor unit 110 has a drive shaft 112 that is rotatably supported by the motor housing 111, and the drive shaft 112 is driven to rotate.

In the following description, the drive shaft 112 is used as the directional reference, and the direction along the drive shaft 112 may be referred to as the axial direction. Furthermore, in the following description, regardless of the direction shown, the lower side in FIG. 1 may be referred to as one axial side, and the upper side in FIG. 1 may be referred to as the other axial side. Furthermore, in the following description, the direction perpendicular to the rotation centerline of the drive shaft 112 may be referred to as the radial direction, and the side closer to the drive shaft 112 may be referred to as the radial inner side, and the side farther from the drive shaft 112 may be referred to as the radial outer side.

The motor housing 111 is a structure that supports the motor section 110 and the oil pump 100 as a whole, and is formed, for example, by pressing a metal plate. The motor housing 111 has a cylindrical section 111a that extends in the axial direction and a flange section 111b that spreads outward from one axial end of the cylindrical section 111a, and the motor housing 111 has its maximum outer shape at the outer edge of the flange section 111b. The motor housing 111 accommodates a rotor 113 and a stator 114 inside.
The rotor 113 is fixed to the drive shaft 112, has a permanent magnet incorporated therein, and rotates together with the drive shaft 112 by the action of a rotating magnetic field.

The stator 114 is housed in the motor housing 111 facing the rotor 113 and generates a rotating magnetic field. Note that in this embodiment, an inner rotor type structure in which the stator 114 is arranged radially outside the rotor 113 is shown, but the motor of the present invention may have an outer rotor type structure in which the stator 114 is arranged radially inside the rotor 113.

The bearing 115 is, for example, a ball bearing, and supports the drive shaft 112 so that it can rotate freely. The bearing 115 may be a roller bearing, a sliding bearing, or the like. The bearings 115 are arranged on one axial side and the other axial side of the rotor 113, with the bearing 115 on the other axial side fixed to the housing 111 and the bearing 115 on the one axial side held by, for example, the pump section 130.

The sensor unit 120 includes a circuit board case 121, to which the ends of the conductor wires drawn from the coil of the stator 114 are guided. In this embodiment, the circuit board case 121 is used as a space for drawing out the wiring to the motor unit 110. The circuit board case 121 also houses and holds a sensor board 122 therein, for example. The sensor board 122 has a magnetic sensor, and detects, for example, the rotational position and rotational speed of the drive shaft 112. The circuit board case 121 may house a control board or an inverter board together with the sensor board 122 or instead of the sensor board 122. The electric pump of the present invention may not have the sensor unit 120.

The pump section 130 corresponds to an example of a pump section according to the present invention, and includes a pump rotor 131, a pump body 132, and a pump cover 133. The pump section 130 is disposed on one axial side of the motor housing 111. In other words, the pump section 130 is located on one axial side along the drive shaft 112 with respect to the motor section 110, and sucks in and discharges a fluid (oil as an example). In this embodiment, the fluid will be described as oil, but the following description can be applied to any general fluid.
The pump rotor 131 is rotated by the driving force of the drive shaft 112 to send oil from the suction side to the discharge side.

The pump body 132 surrounds the pump rotor 131 in the rotational direction of the drive shaft 112. In other words, the pump body 132 surrounds the pump rotor 131 in the orbital direction of the rotation of the pump rotor 131.

The pump body 132 houses the pump rotor 131 and is fixed to the motor housing 111. In this embodiment, the pump body 132 has a space for housing the pump rotor 131, and the pump cover 133 covers the space and one axial side of the pump rotor 131.

The pump cover 133 has a plate-shaped mounting plate 134 for mounting the oil pump 100 to a mounting body, such as an oil pan of an automobile. The mounting plate 134 has a mounting surface 134a that spreads in the axial direction, and the oil pump 100 is fixed to the mounting body by a fixing member with the mounting surface 134a in contact with the mounting body. In other words, the pump cover 133 has a mounting plate 134 that has a mounting surface 134a that spreads in the axial direction and contacts the mounting body, and protrudes in a plate shape to one axial side. For example, bolts, press-fit pins, rivets, etc. can be used as the fixing member, but in this embodiment, bolts are used as the fixing member in consideration of ease of disassembly, etc.
FIG. 2 is a diagram showing the appearance of the oil pump 100 as viewed from one axial side, and FIG. 3 is a diagram showing the appearance of the oil pump 100 as viewed from the mounting surface 134a side.

The pump cover 133 is connected to the pump body 132 by being screwed to the pump body 132 with a number of bolts 181. The bolts 181 correspond to an example of the first connecting member as defined in the present invention. Note that in addition to bolts, press-fit pins, rivets, etc. may also be used as the first connecting member as defined in the present invention, but in this embodiment, bolts are used as the first connecting member in consideration of ease of disassembly, etc.

The bolt 181, which is the first connecting member, is passed from the pump cover 133 side to the pump body 132 side to fasten the pump cover 133 and the pump body 132 together. In other words, the bolt 181, which is the first connecting member, connects the pump cover 133 to another member (in this embodiment, the pump body 132 is used as an example) located on the other axial side, and passes through the pump cover 133 from one axial side to the other axial side. Note that the bolt 181, which is the first connecting member, may also pass through the pump body 132 to connect the pump cover 133 to the motor housing 111.

The pump cover 133 is connected to the motor housing 111 by, for example, being screwed in place with a single bolt 182. The single bolt 182 corresponds to an example of the second connecting member referred to in the present invention. Note that, in addition to bolts, press-fit pins, rivets, etc. may also be used as the second connecting member referred to in the present invention, but in this embodiment, bolts are used as the second connecting member in consideration of ease of disassembly, etc.

The bolt 182, which is the second connecting member, is passed from the motor housing 111 side to the pump cover 133 side to fasten the pump cover 133 and the motor housing 111. Also, as shown in FIG. 2, the bolt 182, which is the second connecting member, is located within the range of the mounting plate portion 134 when viewed in the axial direction. In other words, the bolt 182, which is the second connecting member, connects the pump cover 133 to another member located on the other axial side (the motor housing 111 as an example in this embodiment) at a location where the bolt 182 overlaps with the mounting plate portion 134 when viewed in the axial direction, and passes from the other axial side to one axial side. Note that the bolt 182, which is the second connecting member, may connect the pump cover 133 to the pump body 132.

The use of the first connecting member that passes from one axial side to the other axial side prevents the pump cover 133 from becoming too large, and the mounting plate portion 134 is connected with the second connecting member, improving rigidity. In addition, the improved rigidity reduces vibration of the oil pump 100, and improves resistance to vibration, preventing damage.

As shown in FIG. 3, the tip 182a of the bolt 182, which is the second connecting member, reaches within the range of the mounting surface 134a. In other words, the bolt 182, which is the second connecting member, reaches a position where it overlaps with the mounting surface 134a when viewed from the mounting surface 134a side. By the second connecting member reaching the mounting surface, the mounting plate portion is firmly connected, improving rigidity.

The pump body 132 is connected to the motor housing 111 by being screwed to the flange portion 111b of the motor housing 111 with a number of bolts 183. In other words, the pump portion 130 is provided with a third connecting member that connects the pump body 132 to the motor housing 111, and the bolts 183 correspond to an example of the third connecting member as defined in the present invention. Note that, in addition to bolts, press-fit pins, rivets, etc. may also be used as the third connecting member as defined in the present invention, but in this embodiment, bolts are used as the third connecting member in consideration of ease of disassembly, etc.

As shown in FIG. 2, flange portion 111b protrudes outward beyond pump cover 133, and the location where bolt 183, the third connecting member, is connected is a different location in the axial direction from the location where bolt 181, the first connecting member, is connected. In other words, bolt 181, the first connecting member, is located at a different connecting location in the axial direction from the connecting location of bolt 183, the third connecting member. In detail, the connecting location of bolt 181, the first connecting member, is located radially inward compared to the connecting location of bolt 183, the third connecting member. The use of the third connecting member improves the rigidity of the electric pump as a whole.

The bolt 183, which is the third connecting member, is passed from the motor housing 111 side to the pump body 132 side to fasten the pump body 132 and the motor housing 111. That is, the bolt 183, which is the third connecting member, passes from the other axial side to one axial side. Because the first connecting member and the third connecting member are oriented in opposite directions, their heads do not interfere with each other, and the connecting points can be close to each other, which prevents the size from increasing.

2, the mounting surface 134a is located closer to the center line of rotation of the drive shaft 112 than the outer shapes of the motor housing 111 and the pump body 132 in the direction perpendicular to the mounting surface 134a. In other words, the mounting surface 134a is not located outside the outer shapes of the motor housing 111 and the pump body 132 in the direction perpendicular to the mounting surface 134a. The surface extended from the mounting surface 134a overlaps with the motor housing 111 and the pump body 132 when viewed from one axial side. With this configuration, the distance that the motor section 110 and the pump section 130 protrude from the mounting body in the direction perpendicular to the mounting surface 134a is shorter than when the mounting surface 134a is located outside the outer shapes of the motor housing 111 and the pump body 132. Because the protruding distance of the motor section 110 and the pump section 130 is short, the moment associated with the protruding distance and the weight of the oil pump 100 is small, reducing vibration and noise when the oil pump 100 is operating.

The pump cover 133 has an internal flow path through which oil flows, and has an intake port 141, which is the opening of the flow path on the intake side, and an exhaust port 151, which is the opening of the flow path on the exhaust side, on the mounting surface 134a.

On the mounting surface 134a, there are provided a plurality of (for example, four) fixing points 161, 162, 163, 164 that are fixed to the mounting body by bolts, which are an example of fixing members. The first fixing point 161 of the four fixing points 161, ..., 164 is a through hole through which a bolt passes from the back side to the front side in FIG. 2 (i.e., from the oil pump 100 side to the mounting body side), and the second to fourth fixing points 162, 163, 164 are bottomed holes that are recessed from the mounting surface 134a side and have a bottom. The second fixing point 162 of the four fixing points 161, ..., 164 is a female threaded hole into which a bolt is screwed from the front side to the back side in FIG. 2 (i.e., from the mounting body side to the oil pump 100 side). Of the four fixing points 161, ..., 164, the third and fourth fixing points 163, 164 are stepped holes that are wider on the opening side and narrower on the back side, and the narrower parts 163b, 164b on the back side are female threaded holes.

The wide opening portions 163a, 164a of the third and fourth fixing points 163, 164 are used for positioning by contacting the inner walls with a ring-shaped positioning protrusion provided on the object to be attached. Therefore, positioning and fixing are concentrated in one fixing point, further suppressing the increase in size of the mounting plate portion 134.

As described above, in this embodiment, the size of the pump cover 133 is reduced and vibration is also reduced. However, since the mounting plate portion 134 of the pump cover 133 has a plate-like structure that protrudes to one side in the axial direction, it is desirable to have a further structure that reduces noise and damage due to vibrations caused by the operation of the motor portion 110 and the pump portion 130.

Figure 4 shows the pump cover 133 as seen from one side in the axial direction, Figure 5 shows the pump cover 133 as seen from a direction perpendicular to the axial direction and parallel to the mounting surface 134a, and Figure 6 shows the pump cover 133 as seen from a direction perpendicular to both the axial direction and the mounting surface 134a.

One axial side of the pump cover 133 is formed with a combination of multiple types of ribs, which increase the rigidity of the pump cover 133. Each rib protrudes in a plate-like manner toward one axial side and extends along the paper surface of FIG. 4. Specifically, orthogonal ribs 171 and 172 extending perpendicular to the mounting surface 134a, parallel ribs 173, 174 and 175 extending parallel to the mounting surface 134a, a diagonal rib 176 extending diagonally relative to the mounting surface 134a, and arc-shaped ribs 177 and 178 extending in an arc are provided.

In other words, the pump cover 133 has orthogonal ribs 171, 172 that protrude in a plate-like shape toward one side in the axial direction and extend in a direction intersecting with the mounting surface 134a (for example, in a perpendicular direction). The orthogonal ribs 171, 172 improve the rigidity of the pump housing and suppress vibration.

The pump cover 133 also has parallel ribs 173, 174, and 175 that protrude in a plate-like shape toward one side in the axial direction and extend in a direction along the mounting surface 134a (for example, in a parallel direction). The parallel ribs also improve the rigidity of the pump cover 133 and suppress vibration.

The pump cover 133 also has a diagonal rib 176 that protrudes in a plate-like shape to one side in the axial direction and extends in a direction connecting the bolt 181, which is the first connecting member, to the fixed point 161. The diagonal rib improves the rigidity of the pump cover 133 and suppresses vibration. The bolt 181, which is the first connecting member, can also be used functionally as part (extension) of the rib.

The pump cover 133 further includes arc-shaped ribs 177, 178 that protrude in a plate shape to one side in the axial direction and extend in the circumferential direction around the drive shaft 112 and in the direction connecting the bolts 181, which are the first connecting members. The arc-shaped ribs improve the rigidity of the pump housing and suppress vibration. The bolts 181, which are the first connecting members, can also be used functionally as part of the ribs (extensions).

It is desirable for the pump cover 133 to have multiple types of ribs among the above-mentioned orthogonal ribs 171, 172, parallel ribs 173, 174, 175, diagonal rib 176, and arcuate ribs 177, 178, as this synergistically improves the rigidity.

The first orthogonal rib 171 extends from the mounting plate 134 and directly supports the mounting plate 134, increasing the rigidity of the pump cover 133. The second orthogonal rib 172 protrudes in a plate shape to one side in the axial direction and extends in a direction connecting the bolts 181, which are the first connecting members. The second orthogonal rib 172 increases the rigidity of the pump cover 133 and suppresses vibration. The bolts 181, which are the first connecting members, can also be functionally used as part (extension) of the rib.

As shown in FIG. 5, the ridges of each of the orthogonal ribs 171, 172 are inclined at an angle, and the height of each of the orthogonal ribs 171, 172 is higher on the mounting plate portion 134 side (right side in FIG. 5) than on the opposite side. This improves rigidity while also preventing the ribs from becoming too large. Also, when comparing the heights of the parallel ribs 173, 174, 175, the mounting plate portion 134 side (right side in FIG. 5) is higher than the opposite side (left side in FIG. 5). This also improves rigidity while preventing the ribs from becoming too large.

The first parallel rib 173 extends from the mounting plate portion 134 in a direction along the mounting surface 134a. The first parallel rib 173 increases the rigidity of the pump cover 133 and suppresses vibration. The first parallel rib 173 also extends toward the bolt 181, which is the first connecting member, and a portion of the first parallel rib 173 surrounds the bolt 181. This allows the bolt 181 to be effectively used as part (extension) of the rib, further increasing the rigidity of the pump cover 133.

As shown in FIG. 6, the parallel ribs 173, 174, and 175 have ridges that are inclined at an angle, and the side facing the mounting plate 134 (the left side in FIG. 6) is higher than the opposite side. This improves rigidity while preventing the ribs from becoming too large.

Note that, although an oil pump is given here as an example of a use of the electric pump of the present invention, the use of the electric pump of the present invention is not limited to the above. The electric pump of the present invention can be used as a pump that sucks in and expels water, air, etc.

The above-described embodiments should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not by the above-described embodiments, and is intended to include all modifications within the meaning and scope of the claims.

100: Oil pump 110: Motor section 111: Motor case 112: Drive shaft 113: Rotor 114: Stator 115: Bearing 120: Sensor section 121: Board case 122: Sensor board 130: Pump section 131: Pump rotor 132: Pump body 133: Pump cover 134: Mounting plate section 134a: Mounting surface 141: Intake port 151: Discharge port 161, 162, 163, 164: Fixing points 171, 172: Orthogonal ribs 173, 174, 175: Parallel rib 176: Oblique ribs 177, 178: Arc-shaped rib 181: Bolt as first connecting member 182: Bolt as second connecting member 183: Bolt as third connecting member

Claims (11)

a motor section having a drive shaft rotatably supported by a motor housing and rotating the drive shaft;
a pump section that is located on one side of the motor section in an axial direction along the drive shaft and that draws in and discharges a fluid,
The pump unit is
a pump rotor that rotates by the driving force of the drive shaft to send the fluid from a suction side to a discharge side;
a pump body surrounding the pump rotor in a circumferential direction of the rotation of the pump rotor;
a pump cover having a mounting plate portion extending in the axial direction and having a mounting surface that contacts a mounting body and protruding in a plate-like shape toward the one side, the pump cover covering the one side of the pump rotor;
a first connecting member that connects the pump cover to another member located on the other side of the one side and passes from the one side to the other side;
a second coupling member that couples the pump cover to another member located on the other side at a portion where the pump cover overlaps with the mounting plate portion as viewed in the axial direction and passes from the other side to the one side;
An electric pump having The pump portion further includes a third connecting member that connects the pump body to the motor housing,
The electric pump according to claim 1 , wherein the first connecting member is located at a connecting location different from a connecting location of the third connecting member when viewed in the axial direction. The electric pump according to claim 2, in which the third connecting member passes from the other side to the one side. The electric pump according to any one of claims 1 to 3, wherein the second connecting member reaches a position overlapping the mounting surface when viewed from the mounting surface side. The electric pump according to any one of claims 1 to 4, wherein the pump cover further comprises a first rib that protrudes in a plate-like shape toward the one side and extends in a direction intersecting with the mounting surface. The electric pump according to claim 5, wherein the height of the first rib is higher on the mounting plate side than on the opposite side. The electric pump according to any one of claims 1 to 6, wherein the pump cover further includes a second rib that protrudes in a plate-like shape toward the one side and extends in a direction along the mounting surface. The mounting plate portion has a fixing portion that is fixed to the mounting body by a fixing member,
The electric pump according to claim 1 , wherein the pump cover further comprises a third rib that protrudes in a plate shape toward the one side and extends in a direction connecting the first connecting member and the fixing point. the pump portion includes a plurality of the first coupling members,
The electric pump according to claim 1 , wherein the pump cover further comprises a fourth rib protruding in a plate shape toward the one side and extending in a direction connecting the first connecting members to each other. the pump portion includes a plurality of the first coupling members,
10. The electric pump according to claim 1, wherein the pump cover further includes a fifth rib that protrudes in a plate shape toward the one side and extends in a circumferential direction around the drive shaft and in a direction connecting the first connecting members to each other. The electric pump according to any one of claims 1 to 10, wherein the pump cover further includes a sixth rib that protrudes in a plate shape toward the one side and extends from the mounting plate portion in a direction along the mounting surface.

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