JP2543126Y2 - Fully enclosed fan-type rotating electric machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to a totally enclosed fan-type rotary electric machine, and more particularly to a structure for reducing a rise in temperature of a load-side bearing.

(Prior Art) The configuration of a conventional fully-closed external fan-type rotating electric machine is, for example, as shown in the upper half longitudinal front view of FIG. Stator core 2 on the wall
Insert A rotor core is inserted into the rotating shaft 4 to form a rotor 5, and bearings 6 and 6B are fitted to both ends of the rotating shaft 4, respectively, and are rotatably supported by bearing brackets 3 and 3A.
A plurality of cooling fins 8 extending in the axial direction are provided around the stator frame 1, and an outer fan 9 is fitted on the non-load side of the rotating shaft 4, and a fan cover 10 having a suction port 11 is provided on the outer periphery. Provide.

The ventilation cooling of the fully enclosed fan-shaped rotary electric machine will be described. The cooling air is sucked in from the suction port 11 of the fan cover 10 by the suction and exhaust action of the outer fan 9 accompanying the rotation of the rotor 5, flows between the cooling fins 8 around the stator frame 1 in the load side direction, and is fixed. Heat is taken from heat transfer from the child core 2 to the stator frame 1 and the cooling fins 8 to perform cooling. In the ventilation cooling by the outer fan 9, since the cooling air is blown from the non-load side to the load side, the inside air 12 on the non-load side near the outer fan 9 can pass through the bearing bracket 3 on the non-load side. Since the cooling is performed, the temperature rise of the bearing 6 on the non-load side is low.

(Problems to be solved by the invention) However, the stator frame 1 and the bearing bracket 3A on the load side
Is located far from the outer fan 9, so that the cooling effect is inferior and the temperature of the indoor air 13 on the load side increases. In addition, the temperature rise of the bearing 6B on the load side due to radiant heat in the machine becomes higher than the temperature caused by the heat generated by the bearing itself. In particular, in recent years, when a rotating electric machine is downsized and an insulator having high heat resistance is used, the rotor core and the stator core
2. Since the temperature of the stator windings 14 and the like becomes high, the temperature of the bearing 6B also becomes high via the load side inside air 13, and there is a disadvantage that the life of the bearing and the lubricating oil is shortened.

As a countermeasure, Japanese Utility Model Publication No. 59-36129 discloses a heat shield air chamber formed in a space between a heat shield slinger and a load-side bearing bracket. That is, an annular bowl-shaped heat shield cover is provided inside the bearing bracket on the load side, and a disk-shaped heat shield slinger larger than the inner diameter of the heat shield cover and having a gap in the axial direction is fitted to the rotating shaft. A heat shield air chamber is formed in the space between the bearing bracket and the load side bearing bracket so as to cover the load side bearing.
This heat shield air chamber reduces the heat inflow from the load side inside air and the radiant heat from the rotor core, stator core, and stator windings to reduce the temperature rise, and furthermore, to the bearing fitted to the rotating shaft. This facilitates the insertion and assembly of the bearing bracket.

In the case of the structure of Japanese Utility Model Publication No. 59-36129, this is an effective method since a small-sized hermetically sealed bearing is used in a small fully enclosed outer fan type rotating electric machine. However, in the case of medium-sized and large-sized fully-enclosed fan-type rotary electric machines, the bearings have a large diameter, and therefore cannot be adopted because open-type rolling bearings are used due to lubrication problems.

The present invention is intended to solve the above-mentioned drawbacks, and reduces the temperature rise by reducing the inflow from the inside air and radiant heat to an open-type rolling bearing used on the load side of a medium-sized or large-sized fully-enclosed external fan-type rotary electric machine. It is another object of the present invention to provide a fully enclosed fan-shaped rotary electric machine that facilitates insertion and assembly of a bearing bracket into a bearing fitted to a rotary shaft.

(Means for Solving the Problems) The present invention provides a fully enclosed external fan type rotary electric machine having an internal oil drain for supplying lubricating oil to an open type bearing housed in a housing of a load-side bearing bracket, and has a low heat ray absorption rate. A bowl-shaped heat-shielding cover made of material with a trapezoidal cross section and a hole at the bottom, and a substantially shaft-shaped tubular through-hole that projects vertically from the inner and outer surfaces at the center and has a grease reservoir inside. An inner oil drain having a grease reservoir side facing the inside of the housing to fix the inner oil drain, and having one end of the heat shield cover in contact with an annular rib formed on the inner surface of the bearing bracket. The end is attached and fixed to the end face of the shaft through-hole of the inner oil drain, and a heat insulating air chamber is formed in a space between the inner surface of the bearing bracket, the outer surface of the inner oil drain and the heat shield cover.

Thus, by forming the heat insulating air chamber in the space between the heat shield cover and the inner surface of the bearing bracket and the outer surface of the inner oil drain, the load side inside air is shut off by the heat shield cover, and the temperature of the heat insulating air chamber is reduced. The temperature of the inside oil drainer becomes lower.
Then, the temperature rise of the open-type bearing and the lubricating oil surrounded by the inner oil drain is reduced. Also, the spring function of the heat shield cover facilitates the mounting and assembly of the heat shield cover to the bearing bracket.

(Embodiment) An embodiment of the present invention will be described below with reference to FIG. 1 and FIG. Note that the same reference numerals are used for the same parts as in the related art. FIG. 1 is an enlarged cross-sectional view of a main part of a load-side bearing portion of a large-sized fully-closed external fan-type rotary electric machine according to an embodiment of the present invention. The fully enclosed outer fan type rotary electric machine according to the present invention has the same configuration as the conventional configuration except for the periphery of the load-side bearing.Since the load-side bearing employs the open-type bearing 6C, the structure of the bearing bracket 3B is different. I will explain only.

That is, in the drawing, the bearing bracket 3B is fitted to the load-side end face of the stator frame 1 having the stator core 2 having the stator windings 14 therein and having the cooling fins 8 on the outer periphery. The bearing bracket 3B has a housing 22 for accommodating the through-hole through which the rotating shaft 4 penetrates and the open-type bearing 6C at the center, and an injection passage (grease injection) through which lubricating oil (grease) passes. Road) and grease inlet. On the inner surface of the bearing bracket 3B, an annular annular rib 17 is formed between the housing 22 and the outer periphery of the bearing bracket 3B.

Next, there is a cylindrical shaft through-hole 7a which is substantially in the shape of a hat and projects vertically from the inner and outer surfaces of the shade at the center, and the inner side between the side surface of the shaft through-hole 7a and the outer periphery of the shade. Grease injection path between
An inner oil drainer 7 having a grease reservoir 7c and a grease reservoir 7c is formed.
Then, an outer surface 7d is formed by an outer surface of the inner oil drainer 7 and an outer surface of the shaft through-hole 7a projecting vertically from the outer surface. Next, the inner oil drainer 7 is fixed to the end face of the housing 22 inside the bearing bracket 3B while the grease injection path 7b faces the grease injection path of the housing 22 and the grease reservoir 7c faces the open type bearing 6C. .

It is made of a material having a low heat ray absorption rate (for example, aluminum or nickel plating plate), has a trapezoidal cross section, and has a bottom portion 15.
A bowl-shaped heat shield cover 15 having an opening in a is provided, and one end (outer diameter side) is an annular rib formed on the inner surface of the bearing bracket 3B.
17, and the other end (inner diameter side) is fixed to the end face of the shaft through-hole 7 a of the inner oil drainer 7 with the mounting screw 16.
The inner surface and the outer surface 7d of the inner oil drainer 7 and the heat shield cover 15
A heat-insulated air chamber 18 is formed in the space. The grease inlet of the housing 22 of the bearing bracket 3B is
Is installed. A grease receiver 20 for storing old grease is attached to the lower side surface of the bearing bracket 3B.

 Next, the operation will be described.

First, the grease injected from the grease pipe 19 passes through the grease injection port of the housing 22 of the bearing bracket 3B and the grease injection path 7b of the inner oil drainer 7, enters the grease reservoir 7c, and is supplied to the open type bearing 6C. Then, when the rotating electric machine, which is a fully-closed external fan-type rotating electric machine, is rotated by turning on the power, the inside of the machine is stirred by the fins 5a of the rotor 5 and the outside fan 9 of the outside of the machine counters the cooling fins 8 of the stator frame 1. Heat is dissipated by blowing heat exchange from the load side. Therefore, the inside air 13 on the load side has a higher temperature than the inside air 12 on the non-load side. However, the bottom 15 of the heat shield cover 15
Since the distance between the a and the tip of the fin 5a of the rotor 5 is small, the wind speed by the fin 5a becomes strong, and this strong wind hits the coil end 14, so that the coil end 14 is cooled better than the conventional state without the heat shield cover 15. Is done.

On the other hand, the heat shield cover 15 is made of a material having a small heat ray absorption rate, so that heat intake is small, and heat is reflected because the reflectance is large. Therefore, the heat-insulating air chamber 18 formed between the heat shield cover 15, the inner surface of the bearing bracket 3 </ b> B, and the outer surface 7 d of the inner oil drainer 7 is substantially insulated from the load-side internal air 13 and the load-side internal air 13. Lower temperature.

As a result, the temperature rise of the inner oil drainer 7 is reduced, and the lubricating oil stored in the low temperature state of the inner oil drainer 7 is maintained at a low temperature. Then, the open bearing 6C surrounded by the inner oil drain 7 keeps the temperature rise low, in addition to the surrounding and lubrication of the lubricating oil in a low temperature state, and furthermore, the open bearing 6C radiates heat from the outer surface of the bearing bracket 3B. be able to. By maintaining these low temperatures, the open bearing 6C and the lubricating oil have a long life.

In addition, the heat shield cover 15 has one end serving as an inner diameter having an inner oil drain 7.
The other end of the outer diameter is fixed to the end face of the shaft through-hole 7a with the mounting screw 16, and the other end of the outer diameter is abutted against the annular rib 17 of the bearing bracket 3B on the load side. Since it is integrally held by the bearing bracket 3B and has a trapezoidal bowl shape in cross section, the outer diameter side is bent by a spring action, and the assemblability of attaching the heat shield cover 15 to the load side bearing bracket 3B becomes easy.

As described above, in this embodiment, since the heat is effectively cooled from the outer surface of the bearing bracket while reducing the flow of heat into the open-type bearing on the load side, the temperature rise of the bearing on the load side is kept low and the service life is extended. A fully-closed external fan-type rotary electric machine employing an open-type bearing that facilitates assemblability can be provided.

[Effects of the Invention] As described above, according to the present invention, heat from the inside air to the load side bearing is reduced by reflecting and blocking the inside air on the load side with the heat shield cover, and the temperature rise of the bearing is reduced. And at the same time, have an effect of extending the life, and at the same time, facilitate the assemblability of the rotating electric machine. Also, the spring function of the heat shield cover facilitates the mounting and assembly of the heat shield cover to the bearing bracket.

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view of a main part of a load-side bearing portion of a fully-closed external fan-type rotary electric machine according to the present invention, and FIG. 2 is a front view including an upper half vertical cross-section of a conventional fully-closed external fan-type rotary electric machine. 3,3A, 3B… Bearing bracket, 6C… Open type bearing, 7… Inner oil drain, 7a… Shaft through-hole, 7c… Grease reservoir, 7d… Inner oil drain outer surface, 15… Heat shield cover, 15a… Bottom , 17 ... annular rib, 18 ... heat insulating air chamber, 22 ... housing.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References Japanese Utility Model Showa 50-108020 (JP, U) Japanese Utility Model Showa 48-41930 (JP, U) Japanese Utility Model Showa 52-22108 (JP, U) Japanese Utility Model Showa 60- 162954 (JP, U) Japanese Utility Model Showa 53-53511 (JP, U) Japanese Utility Model Showa 56-4361 (JP, U) Japanese Utility Model Showa 62-88446 (JP, U) Japanese Utility Model Utility Model 59-36129 (JP, Y2)

Claims (1)

(57) [Scope of request for utility model registration] 1. A fully-closed external fan-type rotary electric machine having an internal oil drain for supplying lubricating oil to an open-type bearing housed in a housing of a load-side bearing bracket, wherein the cross-sectional shape is made of a material having a low heat ray absorption rate and having a trapezoidal shape. A bowl-shaped heat shield cover having a hole at the bottom, an inner oil drain having a substantially shaft shape, a cylindrical shaft through-hole that projects vertically from the inner and outer surfaces in the center, and a grease reservoir inside, The grease reservoir side faces the inside of the housing to fix the inner oil drain, the heat shield cover has one end in contact with an annular rib formed on the inner surface of the bearing bracket, and the other end has the shaft of the inner oil drain. A fully enclosed outer fan-type rotating electric machine, wherein a heat insulating air chamber is formed in a space between an inner surface of a bearing bracket, an outer surface of an inner oil drainer, and the heat shield cover.