JP2002044926A - Dc brushless motor for pump unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a DC brushless motor for a pump unit that enables exchanges of bearings on site, rather than in a specialized factory. SOLUTION: The DC brushless motor for a pump unit has a constitution, such that a bearing cover 19 for controlling bearing is fixed to a motor bracket 3 with a small screw 20 that is inserted from the surface side of an end bracket 3 and locked with a nut passing through the end bracket 3, and with a stud screw 21, that extends from the bearing cover 19 and is locked with a nut at the surface side of the end bracket 3 passing through the end bracket 3. When the end bracket 3 is removed from a body unit 2 by releasing the small screw 20 and the nut 25, the bearing 10a is so disconnected from the motor bracket 3 as to appear in drawable manner from a motor shaft 8a, at the end side of the body unit 2. Then, the bearing 10a can be exchanged, by drawing it from the motor shaft 8a using a drawing tool.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC brushless motor for a pump device having a bearing cover for regulating a bearing for supporting a motor shaft.

[0002]

2. Description of the Related Art A DC brushless motor, which is more efficient than an induction motor, is being used for a pump device used in a water supply device in order to save energy.

[0003] A DC brushless motor has a motor case,
Specifically, inside a motor case composed of a body and a board-shaped motor bracket detachably attached to the body end,
In this structure, a stator is installed, a rotor having permanent magnets is housed in the stator, and a motor shaft extending in the axial direction from the rotor is rotatably supported by bearings installed on the inner surface of a motor bracket.

When a motor is used in a pump device,
Due to the high pushing pressure, a high thrust load acts on the rotor in the load side direction.

For this reason, in the DC brushless motor assembled to the pump device, the bearing on the load side (the bearing supporting the shaft portion to which the pump section is connected) is formed on the opposite surface of the motor bracket so that the bearing does not separate from the motor bracket. Is arranged to suppress the axial movement of the bearing from the rotor side.

[0006] Incidentally, the DC brushless motor uses a permanent magnet for the rotor. Therefore, when disassembly such as extracting the rotor from the motor case, dust such as iron powder adheres to the rotor, and the motor is not used. The problem that cannot be done occurs.

Therefore, in the case of the DC brushless motor, if it is necessary to disassemble the motor, a structure including a motor bracket, a rotor, a bearing, and a bearing cover is conventionally formed as one unit on the premise that the disassembly is performed in a clean room. The structure is such that it can be extracted from the motor case only in units of one unit.

[0008] For this reason, conventionally, after the bearing cover is pulled out, it is fixed with a screw screwed into the back surface of the motor bracket so as to entrust the disassembly to a specialized worker, and the head of the screw is attached to the motor. Uses a structure that is hidden by the case.

[0009]

A pump device frequently used in a water supply device is usually driven by a fully-closed DC brushless motor.

However, the use condition of the DC brushless motor used in the pump device is severe, so that it is necessary to replace a load-side bearing that supports the motor shaft.

That is, the bearing on the load side of the pump device is
As mentioned earlier, they are subject to high thrust loads. In addition, in the case of a fully-closed type, air is sucked in from a fan provided at the end of the motor shaft on the non-load side (the end opposite to the pump), and air is drawn along the outer periphery of the body of the motor case. Since air is blown, the temperature of the bearing on the load side tends to be higher than that of the bearing on the non-load side. For this reason, the degree of damage to the load-side bearing is severe, and it is necessary to replace the load-side bearing during long-term operation.

By the way, the replacement of the bearing is desirably performed locally because the pump device can be operated immediately. However, the conventional DC brushless motor has a structure in which the structure including the motor bracket, the rotor, the bearing, and the bearing cover is handled as one unit as described above. It is necessary to work at a factory that has a facility that takes out the rotor's permanent magnets, that is, a clean room where no foreign matter is attached.

For this reason, in the DC brushless motor for a pump device, the bearing cannot be replaced on site even if the bearing is required to be replaced. Therefore, an improvement in this point is required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a DC brushless motor for a pump device which enables a bearing to be replaced on site, not by a specialized factory. It is in.

[0015]

According to a first aspect of the present invention, there is provided a DC brushless motor for a pump device, wherein a bearing cover disposed inside a motor bracket for restricting movement of the bearing in the axial direction includes: At least one screw of a screw tool inserted from the front side of the motor bracket and screwed through the motor bracket, and a screw tool extending from the bearing cover and penetrating the motor bracket and fastened with a nut on the front side of the motor bracket By using the tool, it is configured to be fastened to the motor bracket, when the fastening with the screw tool is released and the motor bracket is removed from the body,
The bearing comes off from the motor bracket so that the bearing can be pulled out of the motor shaft at the end of the body.

Thus, when replacing the bearing, the fastening by the screw is released, the motor bracket is removed from the body, and the bearing is shown outside the body with the motor shaft assembled, so that the bearing is fixed to the bearing cover. The released bearing may be pulled out of the motor shaft using an extraction jig (gear puller or the like) and replaced with a new bearing.

Accordingly, the bearing can be replaced on site without the need to pull out the rotor having the permanent magnet to the outside.

In the DC brushless motor for a pump device according to the present invention, in addition to the above object, the bearing cover is provided at a plurality of positions so that the bearing cover and the motor bracket can be easily fastened. Concluded with
Adopting a structure in which most of the parts are fastened with screws inserted from the front side of the motor bracket, and the remaining part is fastened with screws extending from the bearing cover,
When the motor bracket is mounted, the motor bracket and the bearing cover are aligned with respect to a screw tool extending from the bearing cover.

According to a third aspect of the present invention, there is provided a DC brushless motor for a pump device, wherein the stopper cover receives the released bearing cover at a position adjacent to the bearing cover so that the bearing cover can be fastened by screws. The fastening work can be started immediately when the motor bracket is mounted.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on one embodiment shown in FIGS.

FIG. 1 shows a pump device A to which the present invention is applied.
FIG. 2 shows a partially cut-away side cross section of a (used for water supply device), in which M is a fully-closed DC brushless motor.

To explain the DC brushless motor M, reference numeral 1 denotes a motor case. The motor case 1 includes, for example, a cylindrical body 2, disc-shaped end brackets 3 and 4 (corresponding to motor brackets) for closing the open ends of the body 2, and attaching and detaching these end brackets 3 and 4 and the body 2. Fasteners to be fastened as possible, for example from the outside each end bracket 3,
4 has a bolt 5 screwed into the peripheral wall 2a of the body 2 through the outer periphery.

An annular stator 6 is provided on the inner surface of the body 2 among them. A rotor 7 having a permanent magnet 7a on its surface is housed inside the stator 6. Motor shafts 8a, 8b extending from both ends of the rotor 7 along the axial direction penetrate both end brackets 3, 4. Annular concave portions 9a, 9b are formed on the inner surfaces of both end brackets 3, 4 around the axis of the motor shafts 8a, 8b. Then, one motor shaft 8a
Is inserted (by press-fitting) into the load-side bearing 10a housed in the recess 9a and protrudes out of the motor case 1. The other motor shaft 8b is inserted into the non-load bearing 10b housed in the recess 9b and protrudes outward. The rotor 7 is rotatably supported by the bearings of the motor shafts 8a and 8b by the bearings 10a and 10b. Thus, when a motor drive current is applied to the stator 6 from the outside, the rotor 7 is rotated. The motor shaft 8 protruding from the bearing 10b
A fan 11 is attached to the end b, and the motor is cooled by wind sent from the non-load side to the load side following the outer peripheral surface of the body 2. Here, reference numeral 12 denotes a fan cover attached to the end bracket 4 so as to surround the fan 11.

Motor shaft 8 projecting from bearing 10a
For example, impellers 13 serving as pump constituent parts are assembled in multiple stages at the tip end of a. A discharge casing 15, an intermediate casing 16, and a suction casing 17 in which a guide vane 14 is incorporated are disposed around the impeller 13, and a pump unit P around the motor shaft 8a.
Is formed. Thereby, the DC brushless motor M
A pump device A of a direct connection type capable of performing a water pumping operation by the pump section P using the power source as a power source. Reference numeral 27 denotes a discharge side connecting pipe, and reference numeral 28 denotes a maintenance valve on the suction / discharge side.

A bearing cover 19 is fixed to the rear surface (inner surface) of the end bracket 3 so as to sandwich the bearing 10a on the load side from the rotor 7 side. The bearing cover 19 is
The bearing 10a is formed of an annular plate member that covers the upper end of the bearing 10a, and regulates the bearing 10a that is to be moved by the thrust load applied from the pump unit 18 so as not to shift upward in the axial direction.

The mounting of the bearing cover 19 is designed so that it can be fixed or disassembled by work from outside the end bracket 3.

For this purpose, a long small screw 20 (corresponding to a screw) inserted from a surface side of the end bracket 3 is inserted into a plurality of positions around the axis of the bearing cover 19, for example, four points at equal intervals. A structure is used in which the end bracket 3 is fastened to the end bracket 3 or the stud screw 21 (corresponding to a screw tool) extending from the bearing cover 19 and penetrating the end bracket 3 is used.

Specifically, through holes 23 are formed at four points corresponding to the fastening points of the end bracket 3 so as to penetrate in the thickness direction. A screw hole 24 is formed at most of the fastening points of the bearing cover 19, for example, at three points.
A stud screw 21 is connected to one of the fastening points of the remaining bearing cover 19 so as to protrude along the axial direction of the end bracket 3. The distal end of the small screw 20 inserted into the through hole 23 is screwed into each screw hole 24 from the front side of the end bracket 3. Also stud screw 2
Numeral 1 is inserted into the remaining through hole 23, and the front end portion is fixed (fastened with a nut) on the surface side of the end bracket 3 by fastening with a nut 25. With such a fastening structure, if the screws and nuts are released outside the end bracket 3 and the fastening of the bearing cover 19 is released, the fixing of the bolts 5 holding the end bracket 3 is only released and the end bracket 3 The system that can be removed from the body 2 is ready, and if the end bracket 3 is removed from the body 2 from the system,
The bearing 3a comes out of the end bracket 3, and the bearing 3a is made to appear on the end side of the body 2 in a posture that can be pulled out from the motor shaft 8a.

With this structure, the load-side bearing 10a can be replaced without being pulled out of the rotor 5 from inside the motor case 1.

As another contrivance, a stopper 26 for receiving the disengaged bearing cover 19 in a horizontal position is provided on the motor shaft portion adjacent to the bearing cover 19.
Are formed. The stopper portion 26 is formed, for example, by an annular step. The stopper portion 26 is formed at a position where the tip of the stud screw 21 is held in a position protruding from the surface of the motor bracket 3 or where the tip of the small screw 20 reaches the screw hole 24. The fastening work necessary for the replacement work of the bearing 10a on the side is configured to be started immediately.

With the above arrangement, the replacement operation of the DC brushless motor M for the pump device can be smoothly performed on site.

That is, it is assumed that in this DC brushless motor M, replacement of the load-side bearing 10a is required.

At this time, the DC brushless motor M is separated from the pump section P, and the separated DC brushless motor M is placed on a flat surface 27 such as a worktable as shown in FIG. Place vertically to face.

Next, the small screw 20 and the nut 25 on the surface of the end bracket 3 are removed. Thus, the fastening of the bearing cover 19 is released, and the bearing cover 19 falls downward, and FIG.
As shown in (b), it is held in a horizontal state by the stopper portion 26. At this time, the tip of the stud screw 21 slightly protrudes from the surface of the end bracket 3.

Thereafter, the bolt 5 holding the end bracket 3 is removed. Thereby, the end bracket 3
, A system is established that can be pulled out of the bearing 10a alone.

Then, as shown in FIG. 2B, the end bracket 3 is extracted using an extraction jig, for example, a gear puller 27. Then, the bearing 10a comes out of the concave portion 9a of the end bracket 3 and remains on the motor shaft 8a.

Here, the bearing 10a is already mounted on the bearing cover 1
9 is disconnected from the motor shaft 8a.
And appears on the end side of the trunk 2.

Here, the bearing 10a is connected to the motor shaft 8a.
As shown in FIG. 2 (c), if the bearing 10a pressed into the outer periphery of the shaft is pulled out of the motor shaft 8a using the gear puller 27 as shown in FIG. Can be removed.

Then, as shown in FIG. 3A, a new bearing 10c is press-fitted into the original motor shaft portion using a press-fitting jig 29 instead.

Subsequently, the end bracket 3 is returned. At this time, for example, as shown in FIG. 3B, the end bracket 3 is
In the state where 0 is inserted, in the remaining one through hole 23,
While passing the stud screw 21 connected to the bearing cover 19, the bearing 10a is set at the end of the body 2 so that the bearing 10a is housed in the recess 9a.

At this time, the bearing cover 19 is received by the stopper 26 at the point where the tip of the small screw 20 inserted into the end bracket 3 reaches, so that, for example, each small screw 20 If the tip of the end bracket 3 is moved to a point where it is hooked on each screw hole 24, the remaining three through holes 23 of the end bracket 3 and the screw holes 24 are aligned. When the small screw 20 is not inserted, the position of the remaining three through holes 23 and the screw holes 24 is adjusted by adjusting the end bracket 3 based on the stud screws 21.

When the end bracket 3 is placed at the end of the body 2 (when the end bracket is mounted), the tip of the stud screw 21 from the bearing cover 19 slightly protrudes from the front side of the end bracket 3. The leading end h of each of the small screws 20 inserted from the front side of the end bracket 3 reaches each of the screw holes 24 and is in a position where it can be fastened, so that the fastening work is immediately started.

However, as shown in FIG. 3 (c), the nut 25 is set on the tip of the stud screw 21 and tightened, and the small screws 23 are screwed into the screw holes 24. It is fastened to the end bracket 3 while being positioned so as to sandwich it.

Thereafter, the end bracket 3 is fastened to the end of the body 2 with the bolts 5 and the mounting of the end bracket 3 is completed, and the replacement of the bearing 10a is completed.

As described above, the replacement of the bearing 10a does not require the rotor 7 having the permanent magnet 7a to be pulled out.
Not a specialized factory with clean room facilities,
The bearing 10a on the load side can be replaced on site without any problem.

In addition, of the plurality of fixing points, one of the plurality of fixing points is fixed by the stud screw 21 connected to the bearing cover 19, and the other is a small screw 20 inserted from the surface side of the end bracket 3. Therefore, the positioning of the through hole 23 and the screw hole 24 of the end bracket 3 with reference to the stud screw 21 can be easily performed, and the bearing cover 19 and the end bracket 3 can be easily fastened.

In addition, the bearing cover 1 whose fastening has been released
9 has the advantage that the bearing cover 19 and the end bracket 3 can be quickly fastened because the stopper 26 holds the fastening work immediately.

In the embodiment, the stopper 26 is formed as an annular step slightly larger than the inner diameter of the bearing cover 19, but as shown by a two-dot chain line in FIG. May be enlarged so that the rotor 7 is not exposed to the outside during disassembly.

In one embodiment, a fastening structure using small screws and stud screws is used together, but the invention is not limited to this, and only one of the structures may be used.

[0050]

As described above, according to the first aspect of the present invention, when replacing the bearing, the fastening with the screw is released, the motor bracket is removed from the body, and the bearing is attached to the motor shaft. After appearing outside the body as it is assembled, pull out the bearing that has been fixed with the bearing cover from the motor shaft and replace it with a new bearing.
Bearings can be replaced on site without any problems, without the need to pull out the rotor with the permanent magnets to the outside, and not at a specialized factory with clean room facilities.

According to the second aspect of the present invention, in addition to the above effects, the positioning between the end bracket and the bearing cover can be performed with reference to the screw extending from the bearing cover, so that the bearing cover and the end can be easily formed. This has the effect that the bracket can be fastened.

According to the third aspect of the present invention, in addition to the above-described effects, the bearing cover having been released is held by the stopper portion in a state where the fastening operation can be started immediately, so that the bearing can be quickly mounted. This has the effect that the fastening work between the cover and the end bracket can be completed.

[Brief description of the drawings]

FIG. 1 is a partially sectional side view for explaining a structure of a DC brushless motor for a pump device according to an embodiment of the present invention.

FIG. 2 is a view for explaining an operation when removing a bearing on the load side of the DC brushless motor.

FIG. 3 is a view for explaining an operation when a new bearing is installed in place of the removed bearing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Motor case 2 ... Body part 3 ... End bracket (motor bracket) 7 ... Rotor 5 ... Bolt 6 ... Stator 7a ... Permanent magnet 7 ... Permanent magnet 8a ... Motor shaft 9a ... Depression 10a ... Bearing 19 ... Bearing cover 20 ... Small Screw (screw) 21: stud screw (screw) 23: through hole 24: screw hole 26: stopper portion.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (Reference) H02K 15/14 H02K 15/14 A F term (Reference) 5H019 AA10 CC03 DD02 FF01 FF03 5H605 AA08 BB05 BB07 CC04 DD05 EB10 GG06 5H607 AA12 BB01 BB07 BB09 BB14 CC01 DD03 DD09 FF06 GG01 GG08 JJ05 5H615 AA01 BB01 BB07 BB14 PP25 SS20

Claims (3)

[Claims] A stator is installed in a motor case having a body and a motor bracket detachably attached to an end of the body, and a rotor having a permanent magnet in the stator is provided. A bearing cover in which a motor shaft extending from the rotor in the axial direction is rotatably supported by a bearing housed on the inner surface of the motor bracket, and the axial movement of the bearing is arranged inside the motor bracket. A DC brushless motor for a pump device, wherein the bearing cover is inserted from a surface side of the motor bracket and is screwed through the motor bracket; and the motor bracket extends from the bearing cover. Through at least one of the screws that pass through and are fastened with nuts on the front side of the motor bracket. When the fastening with the screw is released and the motor bracket is removed from the body, the bearing comes off from the motor bracket and is pulled out from the motor shaft to the end of the body. A DC brushless motor for a pump device, characterized in that it appears as possible. 2. The bearing cover is fastened to the motor bracket at a plurality of locations, most of the locations are fastened with screws inserted from the front side of the motor bracket, and the remaining portions are partially secured. The DC brushless motor for a pump device according to claim 1, wherein the motor is fastened by a screw extending from the bearing cover. 3. The motor shaft portion adjacent to the bearing cover has a stopper portion for receiving the unfastened bearing cover in a position in which the screw can be fastened by the screw. A DC brushless motor for a pump device according to claim 1.