JP3371499B2 - Rotating electric machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating electric machine such as an induction motor, and more particularly, to a relatively small-capacity general-purpose induction motor using an iron-based jacket. Related to rotating electric machines. 2. Description of the Related Art As a rotating electric machine such as a general-purpose induction motor having a relatively small capacity, an induction motor having a structure shown in FIG. 6 has been widely used. As shown in FIG. 6, a housing 1 is formed in a cylindrical shape with both ends in the axial direction open, and a plurality of radiation fins 1a are provided on the outer peripheral portion in a vertical or horizontal direction (or radially).
Having. A stator 2 is attached to the housing 1 and a shaft 5 is rotatably supported. The stator 2 has a stator coil 3 mounted and wound on the inner peripheral wall of the housing 1. End brackets 4a and 4b each having a spigot fitting portion are attached to fitting portions at both ends of the housing 1, and are screwed to the housing 1 with bolts. The shaft 5 includes the end bracket 4a,
4b are supported via respective bearings, one end of which is inserted through the end bracket 4b to form an output shaft, and the other end of the other end is inserted with an end bracket 4a to form an external cooling fan 9 (hereinafter referred to as an external fan). Fan). Next, the outer fan 9 and the end bracket 4a are larger than the outer diameter of the outer fan 9 in the axial direction.
A cover 10 (hereinafter referred to as an end cover) that covers up to the outer diameter portion or the vicinity of the outer peripheral portion of the housing 1 is screwed from a direction perpendicular to the axis of the rotating electric machine to the outer periphery of a plurality of seats provided on the outer periphery of the end bracket 4a. Or it is fixed with bolts.
One end of the end cover 10 is connected to the outside fan 9
Are provided with a plurality of air holes 10a (hereinafter, referred to as ventilation inlets). On the other hand, the other end is formed in an open cylindrical shape or an irregular cylindrical shape, and a ventilation passage is formed by a radial gap between the end bracket 4a and the outer diameter portion of the housing 1. The motor is the end bracket 4
a and 4b close the openings at both ends of the housing 1, and the motor draws in the outside air from the ventilation inlet 10a of the end cover 10 by the outer fan 9, and the end bracket 4a, the housing 1 and the end. The outside air is passed through the outer surface of the bracket 4b to cool it. A rotor 6 is provided at an intermediate position of the shaft 5 in the housing 1 so as to face the stator 2, and the rotor 6 has a secondary conductor bar (not shown) and an endrin 7 (not shown). Internal cooling fan 8 (hereinafter referred to as inner fan)
Is composed of a plurality of blade blades protruding from both end surfaces of the end ring 7 of the rotor 6 along the axial direction to cool the inside of the motor. When the shaft 5 rotates by the magnetic action formed by the rotor 6 and the stator 2, the inner fan 8 and the outer fan 9 also rotate.
The outside air flows from the ventilation inlet 10a of the end cover 10 to the outer surfaces of the end bracket 4a, the housing 1, and the end bracket 4b as shown by the arrow A, and is cooled. On the other hand, the inside passes through the inner fan 8 and the rotor 6,
After passing while cooling the end ring 7, the stator coil 3 side and both end faces of the stator 2, compared with the housing 1, the structure is cooled when passing through the end brackets 4a and 4b where the temperature rise is relatively low. I have. As a known example, there is JP-A-61-251440. [0009] In recent years, rotating electric machines such as general-purpose induction motors are often operated in a variable speed manner by a variable frequency power source such as an inverter. The frequency or the higher-order frequency n times the operating frequency coincided, and vibration and noise increased due to resonance. An object of the present invention is to provide a rotating electric machine which has a structure which can be automatically assembled and which solves the disadvantages of the prior art and has low vibration and noise. An object of the present invention is to provide a structure in which when the end cover is mounted on the end bracket, the end cover and the end bracket can be mounted and assembled in an axial direction. And fixing the two. In general, the main frame components, the housing and the end bracket which constitute the rotating electric machine are fastened to the rotating electric machine in the axial direction by using tack screws such as bolts. Therefore, when the end cover is fixed to the end bracket, if the same is assembled and mounted from the axial direction of the rotating electric machine, the tightening method can be unified, and as a result, the assembly can be easily automated. In addition, by forming vibration insulation between the end cover and the end bracket, it is possible to prevent an increase in vibration and noise due to resonance. An embodiment of the present invention will be described with reference to FIG. FIG. 1 shows an external side view of a motor according to the present invention. As shown in FIG. 1, a housing 1 is formed in a cylindrical shape having both ends in the axial direction open, and a plurality of radiation fins 1 are provided on an outer peripheral portion in a vertical, horizontal, or radial direction (or radially).
a. The stator 2 has a stator coil 3 wound around the inner peripheral wall of the housing 1. End brackets 4a and 4b each having a spigot fitting portion are attached to fitting portions at both ends of the housing 1, and fastened to the housing 1 by bolts from the axial direction. The shaft 5 is supported via the end brackets 4a and 4b and respective bearings, and one end of the shaft 5 is connected to the end bracket 4b.
To form an output shaft, and the other end of the other end is inserted through the end bracket 4a, and the outer fan 9 is fixedly mounted. Further, a plurality of seats 11 are provided on the outer periphery of the end bracket 4a, and further, a cylindrical projection 11a extending in the axial direction from the non-load side end face of the seat 11 is provided. Next, the end cover 10 is configured to be larger than the outer diameter of the outer fan 9 and to cover the outer peripheral portion of the outer fan 9 and the end bracket 4a or the outer peripheral portion of the housing 1 in the axial direction. I do. The end cover 10 has an inner diameter smaller than the outer diameter of the end cover 10 and larger than the outer diameter of the outer fan 9 at a position facing the projection 11a provided on the seat 11 of the end bracket 4a. The same number of notches 10b having an arbitrary width in the direction are provided, and the cylindrical projections 11a are attached to the cylindrical projections 11a from the axial direction of the rotating electric machine by using screws or bolts 14 (hereinafter referred to as bolts) via rubber bushes 12 in a configuration described later. One end of the end cover 10 is provided with a plurality of air holes 10a (hereinafter, referred to as ventilation openings) for taking in the outside air by the outside fan 9. On the other hand, the other end is formed in an open cylindrical shape or an irregular cylindrical shape, and a ventilation path is formed by a radial gap provided between the end bracket 4a and the outer diameter portion of the housing 1. The motor is the end bracket 4
a and 4b close the openings at both ends of the housing 1, and the motor sucks in the outside air from the ventilation inlet 10a of the end cover 10 by the outer fan 9 and the end bracket 4a, the housing 1, and the end bracket 4b. The outer surface is configured to ventilate outside air. A rotor 6 is provided at an intermediate position of the shaft 5 in the housing 1 so as to face the stator 2, and the rotor 6 has a secondary conductor bar and an endrin 7 which are not shown. The inner fan 8 in the inside is composed of a plurality of blade blades protruding from both end surfaces of the end ring 7 of the rotor 6 along the axial direction to cool the inside of the motor. When the shaft 5 rotates due to the magnetic action formed by the rotor 6 and the stator 3, the inner fan 8 and the outer fan 9 also rotate.
The outside air flows from the ventilation inlet 10a of the end cover 10 to the outer surfaces of the end bracket 4a, the housing 1, and the end bracket 4b as shown by the arrow A, and is cooled. On the other hand, the inside passes through the inner fan 8 and the rotor 6,
After passing through the end ring 7, the stator coil 3 side, and both end faces of the stator 2 while cooling, the cooling is performed when passing through the end brackets 4 a and 4 b where the temperature rise is relatively low compared to the housing 1. The mounting structure of the end cover 10 according to the present invention will be described in detail with reference to FIG. A plurality of seats 11 are provided at arbitrary positions on the outer periphery of the end bracket 4a and larger than the outer diameter of the end bracket 4a and smaller than the inner diameter of the end cover 10. The seats 11 have a thickness in the axial direction of the rotating electric machine. A cylindrical projection 11a is provided in the axial direction of the end cover 10 side,
The projection is provided with a screw hole 11b from the end cover 10 side toward the load side. On the other hand, the end cover 10 has a notch 10b at a position facing the seat 11 having an inner diameter smaller than the outer diameter of the end cover 10 and larger than the outer diameter of the outer fan 9 and having an arbitrary width in the circumferential direction. Is provided in the axial direction from the end surface on the side opposite to the end bracket to the end surface on the end bracket side, or from the end surface of the end cover 10 to an intermediate position from the end surface on the latter side. The end face of the notch 10b on the end bracket side is connected to the seat 11 and the rivet 14 of the end bracket 4a.
The notch 10b is made of the same material as that of the end cover 10 so that the end cover 10 can be held by the notch 10b, and the notch 10b has a notch end face portion 10c (constituting a mounting plate).
Is provided. The notch end face portion 10c is provided with a cylindrical projection 11a provided on the seat 11 of the end bracket 4a.
Is provided so that the hole can be sufficiently penetrated. Next, a cylindrical end bracket having an inner diameter that can be inserted into the cylindrical projection 11a of the seat 11 and an outer diameter that can penetrate the hole 10d provided in the cutout end face portion 10c of the end cover 10 is provided. A rubber bush 12 having an outer diameter on the side in contact with the seat 11 having a flange shape larger than the outer diameter and having a length in the axial direction of the cylinder longer than the cylindrical protrusion 11a is inserted into the cylindrical protrusion 11a of the end bracket. Subsequently, the notch end face portion 10c of the end cover 10 is fitted and attached to the cylindrical projection 11a. To mount the screw, a screw or bolt 14 (hereinafter referred to as a bolt) via a washer 13 is first inserted into the inner diameter portion of the rubber bush 12 toward a screw hole 11b provided in the cylindrical projection 11a of the end bracket. 13 is the end bracket seat 1
Then, the bolt 14 is screwed until it comes into contact with the end surface 11c of the cylindrical projection. At this time, the end portion of the rubber bush is pushed by the washer 13 and is pushed out to the surface of the cut end surface portion 10c of the end cover 10 so that the petals are spread outward. , End cover 10
Is mounted on the end bracket 4a. Further, the vibration isolation structure according to the present invention will be described in detail with reference to FIGS. FIG. 3 shows a state in which a rubber bush 12 is inserted into a cylindrical projection 11a provided on the seat 11 of the end bracket.
The state where the notched end face portion 10c of the end cover 10 is inserted into the cylindrical projection 11a is shown. The rubber bush 12
The side of the end bracket 4a in contact with the seat 11 has a flange 12a having an outer diameter larger than the through hole 10d provided in the notch end face portion 10c of the end cover 10, and has a cylindrical outer diameter capable of penetrating the through hole 10d. And is configured to be longer in the axial direction than the cylindrical projection. Also, the inner diameter portion 12 on the opposite side of the collar.
b may be configured to expand in a tapered shape in the outer diameter direction. Next, as shown in FIG. 4, a bolt 14 via a washer 13 is screwed into a screw hole 11b provided in the cylindrical projection 11a.
At this time, the rubber bush 12 is screwed so that the opposite brim side of the rubber bush 12 is in contact with the surface of the end plate of the end cover so that the petals are spread outward by the washer 13. The bolt is made to complete the tightening by the washer 13 hitting the cylindrical projection end face 11c of the cylindrical projection 11a. That is, the end cover 10 is attached to the end bracket 4a via the rubber bush 12, but for the above-described reason, a tightening torque suitable for the bolt diameter can always be applied. On the other hand, the rubber bush 12 can always maintain a constant spring constant because a constant reaction force acts on the washer. In other words, the motor body and the end cover 10 are insulated and mounted on the vibration transmission path. Therefore, the vibration caused by the electromagnetic vibration generated when the motor is shifted by the inverter and the vibration caused by the mechanical imbalance is not transmitted to the end cover 10, thereby preventing the vibration and noise from increasing. Further, since all parts constituting the motor are mounted in the axial direction, automation of assembly can be easily realized. This will be described with reference to FIG. In this embodiment, the seat 11 is also used as a bolt seat for mounting the end bracket 4a to the housing 1. As can be easily understood from FIG. 5, all the main frame parts constituting the motor are attached using tack screws from the axial direction of the motor. Therefore, if the end cover 10 is also mounted in the axial direction, the mounting method can be unified, so that there is no problem in automation of assembly and automation can be easily realized. On the other hand, an example of the prior art is shown in FIG. 7, but as shown in the figure, the bolts for attaching the end cover 10 are mounted at right angles to the motor shaft 5, so that the tightening method cannot be unified and automation is difficult. Was. As described above, according to this embodiment, the following effects can be obtained. 1. By mechanically insulating the end bracket and the end cover, vibration and noise generated from the rotating electric machine can be prevented from propagating to the end cover. 2. As a result, it is possible to suppress an increase in vibration and noise caused by vibration and noise generated from the rotating electric machine resonating at the end cover. 3. As a result, a low-vibration and low-noise rotating electric machine can be provided. In addition, a similar rotating electric machine can be provided even when a speed change operation is performed by the inverter. 4. Since the mounting method of the main components constituting the rotating electric machine can be unified, automation of assembly can be easily realized. As a result, the manufacturing cost can be reduced, and an inexpensive rotating electric machine with a short delivery time can be provided. According to the present invention, it is possible to prevent the vibration and noise generated from the rotating electric machine from being transmitted to the end cover, and to unify the mounting method of the main components constituting the rotating electric machine.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an external partial cross-sectional side view of a rotating electric machine showing one embodiment of the present invention. FIG. 2 is an external partial cross-sectional side view of an end cover and an end bracket showing one embodiment of the present invention. FIG. 3 is a cross-sectional view of a vibration isolation structure showing one embodiment of the present invention. FIG. 4 is a cross-sectional view of a vibration isolation structure showing one embodiment of the present invention. FIG. 5 is an exploded view of a rotating electric machine showing one embodiment of the present invention. FIG. 6 is a partial cross-sectional side view showing the appearance of a conventional rotary electric machine. FIG. 7 is an exploded view of a conventional rotating electric machine. [Description of Signs] 1 ... housing, 1a ... heat dissipation rib, 2 ... stator
3 ... stator coil, 4a, 4b ... end bracket,
5 ... shaft, 6 ... rotor, 7 ... end ring,
8 ... cooling fan, 9 ... outside fan, 10 ... end cover,
10a: ventilation opening, 10b: notch, 10c: notch end face portion, 10d: mounting hole, 11: end bracket seat, 11a: cylindrical projection, 11b: screw hole,
11c: cylindrical projection end face, 12: rubber bush, 1
2a: collar, 12b: inner diameter of end, 13: washer, 1
4 ... bolts.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Asabuki 7-1-1 Higashi Narashino, Narashino City, Chiba Prefecture Hitachi, Ltd. Industrial Equipment Division (72) Inventor Sumio Imai 7-1-1 Higashi Narashino, Narashino City, Chiba Prefecture No. 1 Hitachi, Ltd. Industrial Equipment Division (56) References JP-A 2-65076 (JP, U) JP-A 2-14264 (JP, U) JP-A 56-141556 (JP, U) 1979-43359 (JP, U) Actually open 1981-56965 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02K 9/06 H02K 5/24

Claims (1)

(57) Claims 1. A housing accommodating a stator, end brackets attached to both ends of the housing, and a rotation supported by a rotating shaft inserted through the end bracket. Child, an outer fan mounted on the non-load side of the rotating shaft,
An end cover that covers the outer fan from the outside, wherein at an arbitrary position on the outer periphery of the end bracket, the outer diameter of the end bracket is larger than the outer diameter of the end cover, and the end cover is smaller than the inner diameter of the end cover. A plurality of seats having a thickness in the direction, formed as cylindrical projections toward the axial direction on the end cover side, and provided with screw holes from the end cover side toward the load side on the projections;
At a position opposed to the seat, having an inner diameter smaller than the outer diameter of the end cover and larger than the outer diameter of the outer fan,
An end cover having an arbitrary width in the circumferential direction and provided with a notch in the axial direction from the end surface on the side opposite to the end bracket on the end cover to at least a position halfway on the end surface on the end bracket side, and the end bracket side of the notch A hole formed in the end face portion and through which the cylindrical projection provided on the seat of the end bracket can sufficiently penetrate is provided,
The end bracket has a notch end face portion that can be held with a tack screw in the seat, an inner diameter that can be inserted into a cylindrical protrusion of the seat before mounting, and an outer diameter that can penetrate the hole provided in the notch portion of the end cover. The end portion of the end cover has a cylindrical portion having an axial dimension longer than the seat, and a flange portion having an outer diameter on the side of the end bracket in contact with the seat larger than the outer diameter of the cylindrical portion. A rubber bush fitted with the notch is provided, and a washer screw is inserted through a washer inserted into the inner diameter portion of the bush toward the screw hole provided in the seat of the end bracket in the axial direction of the rotating electric machine. When the screw is screwed in until the washer contacts the cylindrical projection end surface of the end bracket seat, the rubber bush is pressed against the cylindrical portion by the washer, and the rubber bush is brought into contact with the notch end surface. Rotating electric machine, characterized in that in and out state mounting the end cover to the end bracket.