Motor vehicle cooling system and method of inserting an electric coolant pump into the system

Abstract

The invention relates to a motor vehicle cooling system having an electric coolant pump (5) and a method for inserting an electric coolant pump into the system, the motor vehicle cooling system having a housing (1) with a pump shaft (2) and the electric coolant pump (5) having an electric motor arranged in a motor housing (6), the electric coolant pump (5) being at least partially accommodated in the pump shaft (2) and a clamping device (9) being fastened on an upper side (7) of the motor housing (6), the clamping device (9) having at least two clamping arms (12) which are supported with their free ends (18) on an inner side (10) of the pump shaft and clamp the electric coolant pump (5) to the housing (1).

Description

TECHNICAL FIELD

[0001] The invention relates to a motor vehicle cooling system with an electric coolant pump and to a method for inserting an electric coolant pump into a motor vehicle cooling system. BACKGROUND

[0002] In motor vehicles, motor vehicle cooling systems are used for temperature- increasing devices, in particular drive batteries, preferably for electric or hybrid vehicles.

[0003] These coolant pumps are usually radial centrifugal pumps. A distinction is made between plug-in pumps and additional pumps in terms of installation. For plug-in pumps, parts of the structure, such as the spiral channel and the inlet, are located in the housing of the cooling system.

[0004] The plug-in pump is inserted into a pump shaft formed in the housing. So far, the pump has been mounted in the pump shaft by means of a clamp in combination with a resilient ring. However, this only serves to fix the pump in the housing to a limited extent, and this fixation has a large radial space requirement. Furthermore, with this form of fixation, a defined position cannot be set, and only in combination with soft lines can the function be ensured, otherwise part of the pump load must be taken up by the lines connected to the pump. SUMMARY

[0005] It is therefore an object of the invention to give a suitable device for connecting a plug-in pump to a housing, which has a simple assembly form, while at the same time having a defined mounting position and a reduced radial space requirement.

[0006] The above object is achieved by a motor vehicle cooling system with an electric coolant pump and by a method for inserting an electric coolant pump into a motor vehicle cooling system.

[0007] It is therefore proposed that a motor vehicle cooling system with an electric coolant pump is provided, which has a housing, which has a pump shaft, and which has an electric coolant pump, which has an electric motor arranged in an electric motor housing. The electric coolant pump is at least partially inserted into the pump shaft, that is to say, this coolant pump is a plug-in pump. Preferably, an inlet and an outlet are formed in the housing, as well as a pump chamber provided with an impeller. A clamping device is fixed on the upper side of the electric motor housing, which has at least two clamping arms, which are supported with their free ends on the inside of the pump shaft, preferably embedded in order to form a press-on, and which clamp the electric coolant pump to the housing, which is made of plastic, for example, in an electric vehicle.

[0008] The clamping device allows a simple installation to be achieved. Furthermore, a position of the coolant pump in the pump shaft determined in the axial direction can be achieved. Furthermore, the clamping device has a small radial installation space. Preferably, the upper side of the motor housing is a housing cover which covers the installation opening.

[0009] Preferably, a wedge-shaped protrusion is formed on the peripheral surface of the motor housing, each of the at least two clamping arms is supported on one of the wedge-shaped protrusions, and the height of the wedge-shaped protrusions from the peripheral surface increases in the longitudinal direction downwards, such that when the clamping device is installed on the upper side of the motor housing, the clamping arms slide over the wedge-shaped protrusions and splay outwards away from the longitudinal axis of the electric coolant pump.

[0010] In addition to the press fit, a form fit can also be formed, the free end of the clamping arm engaging in a corresponding recess in the inner side of the pump shaft in the form fit. The recess can be window-like. It is advantageous here that the clamping arm is wedge-shaped in an end region, the height of the end region decreasing in the radial direction outwards, whereby the clamping arm can slide into the window-like recess above the wedge and engage there.

[0011] Preferably, the clamping device has a central fixing region from which the clamping arms extend radially outwards substantially parallel to the upper side of the motor housing, the clamping arms being uniformly spaced in the circumferential direction relative to the longitudinal axis of the electric coolant pump.

[0012] Preferably, the motor vehicle cooling system has a circumferential gap between the electric coolant pump and the pump shaft, the clamping arm has a first bend in order to extend in a first region substantially parallel to the peripheral surface of the motor housing, the first region adjoining the region in which the clamping arm extends parallel to the upper side of the motor housing, and the clamping arm has a second bend which defines a second region between the second bend and the free end, the second region of the clamping arm passing over the gap. Preferably, the second region is a wedge-shaped end region. Preferably, the clamping arm is supported on the wedge-shaped protrusion of the motor housing with the lower side or inner side of the second bend.

[0013] If the wedge-shaped protrusion of the motor housing forms a slide angle with the normal to the outer surface of the motor housing, and the slide angle is significantly smaller than the angle of the wedge-shaped end region of the clamping arm, the clamping can be achieved particularly simply.

[0014] In order to secure the clamping device on the upper side of the motor housing, the motor housing can have a threaded pin on its upper side, which has an external thread, on which the central securing region of the clamping device is pushed on and secured by a nut. It is also conceivable, however, that the motor housing has an opening on its upper side, which has an undercut, into which the clamping device is engaged by being pressed in in the axial direction.

[0015] Furthermore, a method for inserting an electric coolant pump into a motor vehicle cooling system is proposed, which has a housing, which has a pump shaft, and which has an electric motor arranged in a motor housing, and which comprises the following steps:

[0016] a) inserting the electric coolant pump into the pump shaft;

[0017] b) pushing a clamping device towards the upper side of the motor housing, which has at least two clamping arms, which are thereby supported on the outer cover surface of the motor housing;

[0018] c) securing the clamping device on the upper side of the motor housing and moving the clamping device axially towards the upper side of the motor housing, wherein the clamping arms are spread apart from one another relative to the longitudinal axis by sliding on the outer cover surface of the motor housing and thereby press with their free ends against the inner side of the pump shaft, so that a press fit with axial holding force is produced between the clamping device and the housing.

[0019] This method is particularly simple, since in step c) only a longitudinal force has to be exerted on the motor housing.

[0020] Preferably, in step c) the clamping device is secured on the upper side of the motor housing by a threaded connection, or the upper side of the motor housing has an opening into which the clamping device is engaged in step c).

[0021] Advantageously, in step c) the free ends of the clamping arms are engaged into corresponding grooves on the inner side of the pump shaft in order to produce a form fit.

[0022] It can furthermore be provided that the clamping arms have wedge-shaped end regions, which in step c) slide along the upper edges of the grooves and achieve the form fit and the press fit.

[0023] It is also conceivable that during assembly the clamping device is first placed on the motor housing, as described in step b), then it is inserted into the pump shaft, and finally it is secured, as described in step c).

[0024] The clamping device and / or the housing are preferably configured as described above. BRIEF DESCRIPTION OF DRAWINGS

[0025] Two embodiments of the present application are explained in detail below with reference to the drawings. Identical components or components having the same function are provided with the same reference numerals. In which:

[0026] Figure 1 a top view of a pump shaft of a motor vehicle cooling system with an inserted coolant pump is shown,

[0027] Figure 2 a top view of a pump shaft of a motor vehicle cooling system with an inserted coolant pump is shown,

[0028] Figure 3 a longitudinal sectional view of the arrangement of Figure 2

[0029] Figure 4 a top view of a pump shaft of a motor vehicle cooling system with an inserted coolant pump is shown,

[0030] Figure 5 a longitudinal sectional view of the arrangement of Figure 4

[0031] Figure 6 a schematic view of a coolant pump inserted into a pump shaft is shown. DETAILED DESCRIPTION

[0032] Figures 1 to 5 A part of a housing 1 of a motor vehicle cooling system is shown. The housing 1 has a pump shaft 2 which comprises an opening 3 and an elongated tubular region 4 adjoining the opening 3. In this region 4 an electric coolant pump 5 in the form of a plug-in pump is inserted. The plug-in pump is a radial flow centrifugal pump whose impeller is preferably a closed impeller. The inlet, the pump working chamber and the outlet of the electric coolant pump 5, for example in the form of a spiral channel, are formed in the housing 1 (not shown). The electric coolant pump 5 has an electric motor which is mounted in a motor housing 6 and drives a not shown impeller. The motor housing 6 has a mounting opening on the side opposite the impeller which is closed by a housing cover 7. In the housing cover 7 an electrical interface 8 is formed into which a plug connector for operating the electric motor can be inserted.

[0033] ​​The electric coolant pump 5 is held in the center of the pump shaft 2 by a clamping device 9. An annular gap 11 is provided between the coolant pump 5 and the inner side 10 of the pump shaft 2. The clamping device 9 is held centrally and positionally fixed on the upper side of the housing cover 7 and has three clamping arms 12 starting from the housing cover, which extend in the radial direction and are uniformly spaced apart in the circumferential direction. The clamping arms 12 project outward beyond the housing cover 7 and the gap 11. The clamping arms 12 have a substantially right-angled bend 13, which has an outer diameter that corresponds to the inner diameter of the outer surface of the motor housing 6 with a slight clearance. The clamping arms 12 thus extend in a first region 14 parallel to the outer surface of the motor housing 6. A substantially right-angled second bend 15 adjoins the first region 14, which forms a bearing face 16 on the inner side or lower side. An adjoining second region 17 extends in the radial direction beyond the gap 11 and has a free end 18. The second region 17 of the clamping arms 12 is wedge-shaped in the longitudinal section, the height of which decreases in the radial direction and the lower side is substantially perpendicular to the longitudinal axis of the pump. In a side view, the s-shaped course of the clamping arms 12 makes it possible to clamp the coolant pump 5 in the pump shaft 2 purposefully.

[0034] To this end, the clamping arms 12 are supported at their free outer ends 18 on the inner side 10 of the pump shaft 2. In the pump shaft 2, in the region of the contact area with the clamping arms 12, a longitudinal groove 19 is provided, which constitutes a guide structure for the end of the clamping arms 18 in the longitudinal direction. The groove 19 defines the position of the clamping arms 12 in the pump shaft 2 and constitutes a form fit with the clamping arms.

[0035] On the outer cover surface of the motor housing 6, a wedge-shaped protrusion 20 is provided for supporting the clamping arms, the height of which from the outer cover surface increases in the longitudinal direction downward (from the housing cover side). The wedge-shaped protrusion 20 forms a sliding angle β with the normal to the side surface of the motor housing 6 (see Fig. 2). Figure 6 During assembly, the lower or inner side of the second bend 15 of the clamping arms 12 is supported on the upper side of the wedge-shaped protrusion 20 of the motor housing 6 when the clamping arms 12 are expanded and slides downward as a result of the sliding angle. The upper side or free end 18 of the wedge-shaped second region 17 of the clamping arms 12 slides on the inner side 10 of the pump shaft 12. It can be provided that the groove 19 is only window-like in the region of the inner side 10 of the pump shaft 2 and the upper side of the wedge-shaped second region 17 is guided along the upper edge of the window-like groove 19 when the clamping arms 12 are expanded. In this case, the sliding angle β of the protrusion 20 of the motor housing 6 is significantly smaller than the angle α of the wedge-shaped upper side of the clamping arms, whereby a mutual clamping of the components is achieved, as is shown in Fig. 3. Figure 6 However, the sliding angle β of the wedge-shaped protrusion cannot be too small, in order to avoid self-locking.

[0036] When the clamping device is installed, the clamping device is pushed in the longitudinal direction towards the upper side of the housing cover. This causes the clamping arms to be elastically deformed. The clamping arms slide over the wedge-shaped protrusions of the motor housing and open in the radial direction. The clamping arms thereby exert an axial force on the element to be clamped and the components are clamped to one another in a press fit. The forces acting on the coolant pump can be absorbed by the clamping device, so that tilting of the coolant pump in the pump shaft can be prevented.

[0037] It is also possible to provide that the wedge-shaped protrusions are a circumferential protrusion, so that the electric coolant pump can be installed independently of the angle.

[0038] Compared to conventionally used clamps, the clamping device has a smaller radial space requirement. The installation in the final system is also particularly simple, since the clamping device only needs to be acted upon in the axial direction. The connection to the pipe can be achieved since the coolant pump has a defined position in the pump shaft.

[0039] In Figures 2 to 5 Two different ways of attaching the clamping device 9 to the housing cover 7 are shown.

[0040] Figure 2 and Figure 3 A centrally threaded pin 21 with external thread is shown, which protrudes in the longitudinal direction upwards from the top of the housing cover 7. The clamping device 9 is mounted to the threaded pin 21. For this purpose, the clamping device 9 has a ring-shaped area 22 in the centre thereof, which has a centrally arranged through-going hole 23. The clamping arms 12 extend from the ring-shaped area 22. The clamping device 9 is placed on the threaded pin 21 so that the threaded pin 21 passes through the hole 23. A nut 24 is again placed on the threaded pin 21 and screwed onto the threaded pin 21, pushing the clamping device 9 downwards towards the top of the housing cover, so that the clamping arms 12 slide over the wedge-shaped protrusions of the motor housing 20 and clamp the coolant pump in the pump shaft. This threaded connection also provides protection against the clamping device becoming loose due to vibrations.

[0041] In Figure 4 and Figure 5A second embodiment of the fastening of the clamping device 9 on the upper side of the housing cover 7 is shown. The housing cover 7 has a central opening 25 with an undercut 26, which is preferably configured as a circumferential shoulder, whereby the rotational position can be freely chosen. The clamping device 9 has at least one hook-like protrusion 27 on the lower side in the respective central annular region 22 of the lead-out clamping arm 12, which is configured to be elastic and, upon mounting, is bent inwards and, at the end of the insertion portion, springs outwards and snaps behind the undercut 26, whereby the hook-like protrusion is snapped to the housing cover 7. The pressing-in force required for this is provided by the pressing tool. In order to achieve a seal, an O-ring 28 is provided, which is arranged between the lower side of the clamping device 9 and the upper side of the housing cover 7 and, circumferentially, around the central annular region 22 of the clamping device and seals the two components 9, 7 between the hook-like protrusion 27 and the opening 25.

Claims

1. Motor vehicle cooling system having an electric coolant pump (5), having a housing (1) with a pump shaft (2) and having an electric motor pump (5) with an electric motor arranged in a motor housing (6), which is at least partially accommodated in the pump shaft (2), characterized in that On the upper side (7) of the motor housing (6) a clamping device (9) is fixed, which comprises at least two clamping arms (12) which are supported with their free ends (18) on the inner side (10) of the pump shaft (2) and clamp the electric coolant pump (5) to the housing (1), on the side surface of the motor housing (6) wedge-shaped protrusions (20) are formed, each of the at least two clamping arms (12) is supported on one of the wedge-shaped protrusions (20) and the height of the wedge-shaped protrusions (20) from the side surface increases in the longitudinal direction downwards, so that when the clamping device (9) is mounted on the upper side (7) of the motor housing (6) the clamping arms (12) slide on the wedge-shaped protrusions (20) and open outwards away from the longitudinal axis of the electric coolant pump (5).

2. Motor vehicle cooling system according to claim 1, characterized in that The free ends (18) of the clamping arms (12) engage into corresponding grooves (19) on the inner side (10) of the pump shaft (2) to form a form fit.

3. Motor vehicle cooling system according to claim 2, characterized in that The grooves (19) are window-like.

4. The motor vehicle cooling system of claim 3, wherein, The clamping arms (12) are wedge-shaped in the end region, the height of which decreases radially outwards.

5. The motor vehicle cooling system of claim 1, wherein, The clamping device (9) has a central fixing region (22) from which the clamping arms (12) extend radially outwards substantially parallel to the upper side (7) of the motor housing (6), the clamping arms (12) are uniformly spaced in the circumferential direction relative to the longitudinal axis of the electric coolant pump (5).

6. The motor vehicle cooling system of claim 1, wherein, The motor vehicle cooling system has a circumferential gap (11) between the electric coolant pump (5) and the pump shaft (2), the clamping arms (12) have a first bend (13) so as to extend in a first region (14) substantially parallel to the peripheral surface of the motor housing (6), and the clamping arms (12) have a second bend (15) which defines a second region (17) between the second bend (15) and the free end (18), the second region (17) of the clamping arms (12) passes over the gap (11).

7. The motor vehicle cooling system of claim 4, wherein, The wedge-shaped protrusions (20) of the motor housing (6) form a slide angle (β) with the normal to the side surface of the motor housing (6), which is significantly smaller than the angle (α) of the wedge-shaped region of the clamping arms (12).

8. The motor vehicle cooling system of claim 5, wherein, The motor housing (6) comprises on the upper side (7) a threaded pin (21) having an external thread, the central fixing region (22) of the clamping device (9) is placed on the threaded pin (21) and is fixed on the threaded pin (21) by means of a nut (24).

9. The motor vehicle cooling system of claim 1, wherein, The motor housing (6) has on its upper side (7) an opening (25) which has an undercut (26), the clamping device (9) engages into the opening (25) by being pressed in in the axial direction.

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