JPS5959034A - Frameless rotary electric machine - Google Patents

Abstract

PURPOSE:To improve the cooling effect of a frameless rotary electric machine by providing the position for providing a heat transfer rib and the position for providing a stator coil slot at 1:1 and forming the shape approximately to a triangular shape. CONSTITUTION:The shape of the bottom 13A of a vent hole 13 is formed substantially in semicircular shape having approx. r in radius in such a manner that the center is disposed on the extension line of the radius passing the intermediate of the two adjacent coil slots 2. Further, the width l5 at the position nearest to the slot of a heat transfer rib 14 corresponding to the slots 2 on the extension of the radius R passing the slots 2 is selected to become l5=2r. On the other hand, the width l6 of the other end of the rib 14 is slightly reduced as compared with the width l5 so that the product of the sectional area of the vent hole of the hole 13 and the thermal transfer efficiency of the rib 14 carried by the rib 14 becomes maximum, thereby forming the shape of the rib 14 approximately to a triangular shape.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a structure that improves the cooling effect of the iron core of a stator (hereinafter referred to as stator) of a frameless type (hereinafter referred to as frameless) rotating electric machine.

Conventionally, this type of structure has been constructed as shown in FIG. FIG. 1 is a plan view of a portion showing the structure of a stator core that has been commonly used in the past.
) indicates one quarter of the stator core, and four of the same shape are
The shape of the entire area can be obtained by arranging the sheets radially. (2) is a stator winding groove (hereinafter referred to as a slot) in which the stator winding (not shown) is buried; (3) is an air hole for passing cooling air (generally air); (4)
is a heat transfer rib-like portion (hereinafter referred to as lip) provided between two adjacent air holes (3).

Next, the functional operation of the stator core of this structure will be explained. After the stator core (1) is laminated and fixed in a direction perpendicular to the drawing, the stator windings are buried in the slots in the same way as in general frameless rotating electric machines, and the arms on the load side and the anti-load side are (hereinafter referred to as a bracket) and a rotor (hereinafter referred to as a loaf) (not shown) are assembled and completed. In the rotating electric machine configured as described above, copper loss and iron loss occur from the stator portion, and this becomes lost thermal energy and is transmitted and radiated to the outer peripheral portion of the stator core (1). -The outer periphery of this stator core (11) is provided with heat transfer ribs (4) and air holes (3) for efficiently cooling the transferred lost heat energy. Cooling air is radiated by a separately excited fan (not shown) installed externally.

However, in conventional rotating electric machines, the heat transfer ribs (
4) and each position of the stay winding slot (2) were provided completely unrelated to each other. Therefore, the magnetic path of the stator core pack is located at the bottom of the air hole (3) (
3A) and the bottom of the stator winding slot (2) (2A
) can be used effectively, and the maximum width of the cross-sectional area of the magnetic path through which the lines of magnetic force pass is limited to the range ill and cannot be made larger than that. Furthermore, the width of the heat transfer rib (4) has conventionally been approximately
2:;Ara, and there was a drawback that the shape of the ribs could not be said to be selected in an optimal relationship from the viewpoint of heat transfer effect.

This invention was made in order to eliminate the drawbacks of the conventional stator core due to lack of consideration given to the rationalization of the structure of the stator core. In addition, by making the shape approximately triangular, it is possible to make the width of the magnetic path cross-sectional area of the stator core shaft as large as possible on average, and to improve the heat transfer effect. The purpose of this invention is to provide a frameless rotating electrical machine with a good rib shape and improved cooling effect.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 shows a partial view of the stator core according to the present invention. In the figure, Qll is a plan view showing one quarter of the stator core. α Teng is the position and shape of the wind hole according to this invention,
It is the position and shape of the heat transfer rib according to the invention of Q-anatomy C.

Next, the function and operation of the stator core C will be explained.

The shape of the bottom (13A) of the air hole α3 is a semicircle with a radius r, and the center of the circle (radius r) is on the extension line of the radius passing between the two adjacent winding slots, as shown in the figure. Leave it behind. Furthermore, the heat transfer rib 04 is located on an extension line of radius R passing through the winding slot and corresponds to the slot.
The width (15) at the position closest to the slot is 15
= 2r. Therefore, when the number of stator winding slots (2) is S,
Select the radius r so that the following relational expression is satisfied.

2rr (R + r ) / 5 = 4r - 10,000, the width 16 of the other end of the heat transfer rib α (the part near the outer periphery of the stator core) is the cross-sectional area of the air passage of the air hole (to) and the heat transfer The width 16 is made slightly smaller than the width 15 so that the product of heat transfer efficiency carried by the transfer rib Q41 is maximized.

That is, the shape of the heat transfer rib a→ is selected to approximate a triangle so as to satisfy the condition 16<15.

Also, considering the magnetic path cross-sectional area of the stator core back, compared to the conventional one shown in FIG. 1, the magnetic path width I! If you need the same magnetic path width as 1, 14+r/3=ll
It is sufficient to set the magnetic path width 14 (14<ll) so that
The radius of curvature of the bottom portion (3A) of the conventional example shown in FIG. 1 can be made smaller, and the cross-sectional area of the air passage can be increased, thereby improving the cooling effect. Conversely, if the radius R of the circle in contact with the bottom of the air hole αJ is the same as the conventional example of ill, the width of the magnetic path cross-sectional area should be increased by IJl-14 (= r/3). This has the advantage that it can be washed away.

In the above embodiments, the outer shape of the stay core is rectangular, but it goes without saying that the same effect can be obtained even when the outer shape is round.

Although it is obvious that the above explanation is correct, if the invention of B is used, the air holes and air holes provided on the outer periphery of the stator core and C
Heat transfer lips between lJ and U] are placed one-to-one at the positions of the stator winding slots provided on the circumference of the stator iron.
The heat transfer ribs are provided correspondingly to each other, and the shape of the heat transfer ribs is approximated to a triangle, which is advantageous in that the V-frameless rotating electric machine has a high cooling effect.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the structural shape of a stake core of a conventional hummless rotating electric machine, and FIG. 2 is a plan view showing the structural shape of a stator core according to the (:I/J invention. In each figure, (11 is the iron core, (2) is the winding slot 1
(3) is the air hole, (4) is the heat transfer rib, ki is the stator core, α-ply air hole, u4) is the heat transfer rib, R is the radius of the circle that touches the bottom of the air hole, r is the radius of the circle that touches the bottom of the air hole in C. The radius of the circle that determines the shape, S indicates the number of winding slots. Patent r+s *F+ person Mitsubishi Electric Corporation agent Makoto Kuzuno - 1 other person

Claims (1)

[Scope of Claims] +1) In a frameless rotating electric machine having a large number of air holes for cooling ventilation on the outer periphery of the stator core, a heat transfer lip separating the air holes is provided on the inner periphery of the stator core. 1. A frameless rotating electric machine characterized by C, wherein the heat transfer ribs are provided corresponding to each position of the winding grooves, and the shape of the heat transfer ribs is a square triangle. (2) Assuming a circumference connecting the bottoms of the air holes in the stator core, the radius of the central force s is R1, the width of the side closest to the winding slot of the heat transfer lip is 2r, and the width of the side of the heat transfer lip closest to the winding slot is 2r. A 7-frameless rotating electrical machine according to claim 1, characterized in that the width of the heat transfer rib is selected to satisfy the following equation 9: 2π(R+r)÷5=4r, where S is the number of . .