Guide device for a cooling fluid flowing around winding heads of an electrical machine, and electrical machine

Abstract

A guide device (1) for a cooling fluid flowing around winding heads (28) of an electrical machine (21), including a body (2), with a recess (4) delimited by an inner edge (3) for guiding through a shaft of the electrical machine (21), and a guide element (5), which protrudes from the body (2) in the axial direction and extends in the peripheral direction in a radial position lying between the inner edge (3) and an outer edge (6) of the body (2).

Claims

1. An electrical machine, comprising: a stator having stator windings, and a guide device for a cooling fluid flowing around winding heads of the electrical machine, the guide device being secured to an end plate of the electrical machine, and comprising: a body, with a recess delimited by an inner edge for guiding through a shaft of the electrical machine, and a first guide element, which protrudes from the body in an axial direction and extends in a peripheral direction in a first radial position lying between the inner edge and an outer edge of the body, the first guide element being arranged inside of the winding heads of the stator windings in a radial direction, and a second guide element formed separately from the first guide element, the second guide element protruding from the body in the axial direction and extending in the peripheral direction in a second radial position lying between the first radial position and the outer edge of the body, the second guide element being arranged outside of the winding heads in the radial direction, wherein the first guide element and the second guide element form two overlap regions extending in the peripheral direction.

2. The electrical machine according to claim 1, wherein centers in the peripheral direction of the guide elements are arranged so as to be connectable by a line traversing a center point of the recess.

3. The electrical machine according to claim 2, wherein an outlet opening for the cooling fluid is formed in a region of the center in the peripheral direction of the second guide element.

4. The electrical machine according to claim 3, wherein the second guide element has a radial indentation, which opens into the outlet opening formed in the second guide element.

5. The electrical machine according to claim 1, wherein a radially outwardly pointing elevation is formed at a free end of the first guide element and/or a radially inwardly pointing elevation is formed at a free end of the second guide element.

6. The electrical machine according to claim 1, wherein the guide device is formed from a plastics material.

7. The electrical machine according to claim 1, further comprising a rotor arranged inside the stator so as to form an air gap, wherein a radially outermost portion is positioned at a free end of the first guide element radially further outwardly than the air gap.

8. The electrical machine according to claim 1, further comprising a coolant feed, which is arranged in such a way that the cooling fluid is conducted to the first guide element in order to flow around the first guide element in the peripheral direction.

9. The electrical machine according to claim 1, wherein the stator windings are formed as hairpin windings.

10. The electrical machine according to claim 1, wherein an outlet opening is formed at a bottom inside the second guide element so that the cooling fluid flows around the first guide element enters an inside of the second guide element through gaps, and exits from the outlet opening.

11. The electrical machine according to claim 1, wherein the first guide element extends substantially half of the recess, and the second guide element extends substantially another half of the recess to form the two overlap regions extending in the peripheral direction.

12. The electrical machine according to claim 1, wherein the body has a flat plate shape having an inner portion with the recess therein, and an outer portion inclined with respect to the inner portion, the first guide element being located between the inner portion and the outer portion, the second guide element being located in the outer portion.

13. The electrical machine according to claim 12, wherein the first guide element is secured between the inner portion and the outer portion by radially inwardly pointing reinforcement elements, and the second guide element is secured to the outer portion by radially outwardly pointing reinforcement elements.

Description

(1) Further advantages and details of the present invention will become clear from the exemplary embodiments described hereinafter and also with reference to the drawings. These are schematic representations and show:

(2) FIG. 1 a perspective view of an exemplary embodiment of the guide device according to the invention;

(3) FIG. 2 an axial plan view of the guide device shown in FIG. 1;

(4) FIG. 3 a perspective sectional illustration of an exemplary embodiment of the electrical machine according to the invention;

(5) FIG. 4 a perspective detailed view of the electrical machine in the region of a first guide element of the guide device; and

(6) FIG. 5 a perspective detailed view of the electrical machine in the region of a second guide element of the guide device.

(7) FIG. 1 is a perspective view of an exemplary embodiment of a guide device 1.

(8) The guide device comprises a body 2, with a recess 4 delimited by an inner edge 3, and also a first guide element 5, which protrudes from the body in the axial direction and extends in the peripheral direction in a first radial position lying between the inner edge 3 and an outer edge 6 of the body 2. The guide device 1 additionally also comprises a second guide element 7, which protrudes from the body 2 in the axial direction and extends in the peripheral direction in a second radial position lying between the first radial position and the outer edge 6. The entire body 2 is formed from an electrically insulating material, in this particular case from a plastics material.

(9) The body 2 to this end has an inner portion 8a, which is delimited by the edge 3 and which extends along a radial plane, and a second portion 8b, which is delimited by the outer edge 6 and is axially angled relative to the first portion 8a. On a first side of the body 2 visible in FIG. 1, the first guide element 5 is arranged in a transition region between the first portion 8a and the second portion 8b and is secured to the first portion 8a by means of additional radially inwardly pointing reinforcement elements 9. The second guide element 7 protrudes axially from the second portion 8b of the body and is reinforced by additional radially outwardly pointing reinforcement elements 10.

(10) An outlet opening 11 is formed in the body 2 in the region of the middle of the second guide element. The outlet opening 11 passes through the second portion 8b of the body 2. In addition, a radially outwardly pointing indentation 12 is formed in the second guide element 7 and opens into the outlet opening 11.

(11) At a free end of the first guide element 5 there is formed a radially outwardly pointing elevation 13, which will be explained later in greater detail with reference to FIG. 4. At a free end of the second guide element 7 there is formed a radially inwardly pointing elevation 14, which will be explained later in greater detail with reference to FIG. 5.

(12) In addition, the body 2 has a plurality of through-openings 15 formed in the peripheral direction in its second portion 8b, which are usable in order to secure the guide device 1 in position or to introduce a cooling fluid to the first guide element.

(13) FIG. 2 is an axial plan view of the side of the guide device 1 shown in FIG. 1.

(14) The first guide element 5 extends in the peripheral direction over an angular range of 180°. By contrast, the second guide element 7 extends over an angular range of approximately 195°, such that the guide elements 5, 7 form two overlap regions 16a, 16b. The centres 17, 18 of the guide elements 5, 7 are arranged such that a line 19 connecting them traverses the centre point 20 of the recess 4.

(15) FIG. 3 is a perspective sectional illustration of an exemplary embodiment of an electrical machine 21 in the region of a first end face.

(16) The electrical machine 21 comprises a stator 22 and a rotor 23, between which there is formed an air gap 24, and also a machine housing 25, and an end plate 26. In FIG. 3 an A end plate is shown. The electrical machine 21 has, on its second end face, a further end plate (B end plate). A guide device 1 according to the previously described exemplary embodiment is arranged on each of these end plates 26. The electrical machine 21 is a prime mover for an electrically drivable vehicle.

(17) The stator 22 has stator windings 27, which are formed as hairpin windings. Winding heads 28 of the stator windings 27 protrude from the stator 22 in the direction of the end plate 26. The first guide element 5 is arranged radially inside of the winding heads 28, and the second guide element 7 is arranged radially outside of the winding heads 28.

(18) The electrical machine 21 also has a coolant feed 29, which is arranged in such a way that a cooling fluid is conducted to the first guide element 5 in order to flow around the first guide element in the peripheral direction. In the overlap regions 16a, 16b (see FIG. 2), the cooling fluid flows down from the first guide element 5 to the second guide element 7 as a result of the force of gravity acting in the direction of a machine bottom 30. From there, the cooling fluid flows around the other winding heads 28 and passes at the lowest point of the second element 7 into the outlet opening 11 (see FIG. 1).

(19) FIG. 4 is a perspective detailed view of the electrical machine 21 in the region of the first guide element 5. As can be seen, a radially outermost portion of the first guide element 5 lies radially further outwardly than the air gap 24. The elevation 13 prevents cooling fluid from escaping axially from the guide device 1 and entering the air gap 24.

(20) FIG. 5 is a perspective detailed view of the electrical machine 21 in the region of the second guide element 7. Here, the elevation 14 prevents cooling fluid from escaping axially from the guide device 1 and from leaving the guide device 1 other than through the outlet opening 11 (see FIG. 1).