Cooling jacket and deflection unit for cooling jackets

Abstract

A cooling jacket (14) for cooling an electric motor, in particular a stator (23), wherein a first spiral line (16) for transporting a coolant is formed at least partially on the cooling jacket (14). The aim of the invention is to provide a cooling system that is optimized in terms of mounting space and ensures axially equalized cooling. This aim is achieved in that a second spiral line (17) for transporting coolant is formed at least partially, and in that based on a common spiral axis R, both spiral lines (16, 17) form an axially integrated double spiral, wherein the first spiral line (16) is an inflow line and the second spiral line (17) is a return flow line. The invention further relates to a deflection unit (12) for the return into the second line (17), which substantially prevents the static pressure from dropping.

Claims

1. A cooling jacket for cooling an electric motor, comprising a first spiral line for transporting a coolant formed at least partially on the cooling jacket, a second spiral line for transporting the coolant at least partially formed on the cooling jacket, the two spiral lines form an axially integrated double spiral in relation to a common spiral axis (R), the first spiral line is a feed flow line and the second spiral line is a return flow line, wherein the first spiral line is connected to the second spiral line on a first axial side of the cooling jacket by a deflection unit which conducts the coolant, the deflection unit including at least one blade element for separating the coolant flow into at least two partial flows and subsequently combining the partial flows, the at least one blade element includes a plurality of blade elements arranged in a cascaded manner in a circumferential direction.

2. The cooling jacket as claimed in claim 1, wherein the first spiral line and the second spiral line are covered by a cover in a radial direction.

3. The cooling jacket as claimed in claim 1, wherein an inflow to the first spiral line and an outflow from the second spiral line are arranged on a second axial side of the cooling jacket.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be described and explained in greater detail below with reference to the exemplary embodiments which are illustrated in the figures, in which:

(2) FIG. 1 shows a hollow-cylindrical cooling jacket comprising an annular deflection unit of which a detail is shown in enlarged form,

(3) FIG. 2 shows a longitudinal section in relation to the rotation axis of the cooling arrangement, comprising the cooling jacket, deflection unit and cover,

(4) FIG. 3 shows a side of the cooling jacket from FIG. 1 which is opposite the deflection unit,

(5) FIG. 4 shows a sectional illustration of the multiple line system of the deflection unit in the circumferential direction, and

(6) FIG. 5 shows adjacent blade elements of the multiple current system from FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(7) FIG. 1 shows a hollow-cylindrical cooling jacket 14 comprising an annular deflection unit 12 which is shown in a detail A in enlarged form.

(8) The deflection unit 12 is in the form of a ring and connects the diametrically opposite openings in the first and second lines 16, 17. Therefore, the deflection unit is arranged on the first axial side in relation to the rotation axis R of the motor (not depicted), which rotation axis coincides with the spiral axis, and avoids additional connections on the first axial side.

(9) The spiral lines 16 and 17 which are designed as slots form helical lines on the hollow-cylindrical cooling jacket 14 and are open radially toward the outside. The radial flange 13 is used to support and fasten a cover 18 (see FIG. 2).

(10) FIG. 2 and FIG. 3 showed a longitudinal section in relation to the rotation axis of the cooling arrangement comprising the cooling jacket 14, deflection unit 12 and cover 18.

(11) The cover 18 is fastened to the annular flange 13 by means of at least one screw (not depicted) and a hole 20 and therefore radially closes off the cooling system. The number of screws can be varied depending on the required retaining and/or sealing force. This cooling system now has an inflow 41 and an outflow 42 on the radial flange 13 only on the vehicle side (second axial side) and can be connected solely from this side, thus saving installation space. Furthermore, the first line and second line which are arranged alternately in the axial direction lead to uniform heat dissipation.

(12) The stator 23 is cooled over a large area by the cooling jacket 14, wherein said cooling jacket can be easily installed on the stator 23 on account of the annular jacket base 15. Furthermore, the deflection unit 12 is also pressed axially against the cooling jacket 14, and therefore fixed, by the cover 18. Since a coolant is supplied to the cooling system, a sealing ring 22 between the cover 18 and the cooling jacket 14 is expedient. A sealing ring can also be arranged at other points, such as on the first axial side in the vicinity of the deflection unit 12, between the cover 18 and the cooling jacket 14 or else between the annular jacket base 15 and the cooling jacket 14 for example, wherein the jacket base 15 can be integrally formed with the cover 18.

(13) A side of the cooling jacket 14 from FIG. 1, which side is opposite the deflection unit 12, and the line which is routed from the diametrically opposite opening to the deflection unit 12, are shown.

(14) The first line and/or second line advantageously form/forms a fluting or wrinkling which creates a turbulent flow (in contrast to a laminar flow), and ensures better distribution of the coolant and therefore also of the absorbed energy. As an alternative, rotation of the coolant (usually a fluid) about a flow longitudinal axis can be caused, for example by virtue of a helical design within the line.

(15) It is also advantageous to implement an inlet or outlet by means of a blind hole, wherein a material-removing tool is radially supplied or discharged on the cooling jacket 14 in the radial direction. This interrupts the line in the circumferential direction in order to make it axially accessible by means of an axial hole.

(16) As an alternative, an inlet or outlet can also be implemented an opening slot in which the also the opening runs over a wide portion of the circumference and does not necessarily exhibit a round shape.

(17) FIG. 4 shows a sectional illustration of the multiple line system of the deflection unit 12 from FIG. 1 in the circumferential direction. The blade elements 19 are arranged in a cascaded manner and split the total flow into a plurality of slowly flowing partial flows 40. In comparison to the inlet 38, which is connected to line 16, the partial flows have a total throughflow cross section which is approximately four times larger than the throughflow cross section of the inlet 38. The same applies in relation to the throughflow cross section of the outlet 39.

(18) The blade elements 19 are arranged in the circumferential direction U and deflect the cooling liquid along the circumference in the opposite direction.

(19) FIG. 5 shows adjacent blade elements 19 of the multiple line system from FIG. 4. The blade arms 33 form, in each case in pairs, a blade inlet 31 and blade outlet 34, as a result of which the size of the partial flow 40 is defined. The largest throughflow cross section 30 is arranged between a blade base 32 and an adjacent blade rear area 35. In this exemplary embodiment, the largest throughflow cross section 30 is oriented along the circumferential direction U.

(20) A widening in volume accordingly occurs along the blade arms 33 along the flow direction, said widening in volume being greatest at the largest throughflow cross section and correspondingly reducing again downstream of said throughflow cross section.

(21) In summary, the invention relates to a cooling jacket 14 for cooling an electric motor, in particular a stator 23, wherein a first spiral line 16 for transporting a coolant is at least partially formed on the cooling jacket 14. This cooling jacket should exhibit cooling which is optimized in respect of installation space and ensures axially compensated cooling by a second spiral line 17 for transporting the coolant being at least partially formed on the cooling jacket 14, and the two spiral lines 16, 17 forming an axially integrated double spiral in relation to a common spiral axis R, wherein the first spiral line 16 is provided in the form of a feed flow line and the second spiral line 17 is provided in the form of a return flow line. Also specified is a deflection unit 12 for returning coolant to the second line 17, which deflection unit for the most part prevents a drop in the static pressure.

LIST OF REFERENCE SYMBOLS

(22) 10 Stop 11 Line transition 12 Deflection unit 13 Radial flange 14 Cooling jacket 15 Annular jacket base 16 First line 17 Second line 18 Cover 19 Blade element 20 Holes 22 Sealing ring 23 Stator 30 Blade passage 31 Blade inlet 32 Blade base 33 Blade arms 34 Blade outlet 35 Blade rear area 36 First axial side 37 Second axial side 38 Inlet 39 Outlet 40 Partial flow 41 Inflow 42 Outflow R Spiral axis A Detail U Circumferential direction X Axial direction