Automotive fluid pump arrangement with a mounting device for an automotive fluid pump arrangement

The invention is directed to an automotive fluid pump arrangement, in particular to an automotive fluid pump arrangement with a vibration-decoupling mounting device for mounting an automotive fluid pump unit onto a motor vehicle mounting structure.

Such a pump arrangement comprises a pump unit, preferably an electric pump unit, for circulating a fluid within a motor vehicle fluid circuit for water circulation. The pump arrangement further comprises a mounting arrangement for mounting the pumping unit to a motor vehicle frame or to an internal combustion engine. The mounting arrangement is provided with a vibration-decoupling body, which is attachable to the motor vehicle frame and which supports the pump unit. The vibration-decoupling body is made of a relatively flexible material, so that relevant vibrations of the pump unit are not transferred to the motor vehicle frame or to the internal combustion engine and viceversa, resulting in relatively low noise emission levels. Typically, the decoupling body is ring-shaped and radially encloses as well as supports the pump unit.

Such a pump arrangement is, for example, disclosed in DE 10 2016 209 204 Al. Here, the ring opening of the vibration-decoupling body is press-fitted to a corresponding peripheral surface of a pump unit housing, so that the pumping unit is supported by the decoupling body in a force-locked manner. Since the decoupling body has to be relatively flexible to provide an efficient vibrational decoupling, the force-locked connection can only support relatively small axial forces. Therefore, the pump unit housing is provided with radially protruding support protrusions which are in axial contact with the decoupling body to provide an additional form-locked axial support of the pump unit at the decoupling body. The support protrusions are arranged on both axial sides of the decoupling body to provide a support in both axial directions. However, the decoupling body has to be mounted to the pump unit during the assembly of the pump unit housing and, in particular, cannot be mounted to a completely assembled pumping unit. As a result, the decoupling body mounting step has to be integrated into the pump unit assembly process causing a complex assembly of the pump arrangement.

WO 2020/083495 Al discloses a mounting arrangement with a flexible decoupling body to mount a completely assembled pump unit to a motor vehicle mounting structure. The pump unit is inserted into the decoupling body and is axially fixed by a form-locked connection using an axial stop surface at the decoupling body and a corresponding stop surface at the pump unit. This form-locked connection secures the pump unit in the first axial mounting direction. In the second axial dismounting direction, the pump unit is additionally fixed by a separate retainer clip.

However, all of these fixation methods known from prior art require additional fixation elements and/or a complex mounting process to attach the pump unit to the decoupling body.

It is an object of the invention to provide an automotive fluid pump arrangement, which provides a reliable and cost-efficient vibration-decoupled mounting of the pump unit to a motor vehicle frame and which can be assembled in a simple way.

This object is achieved with motor vehicle pump arrangement with the features of claim 1. The motor vehicle pump arrangement according to the invention is provided with a pump unit for circulating a working fluid in a motor vehicle fluid circuit. Preferably, the pump unit is electrically driven by an electric motor and is not mechanically driven by an internal combustion engine. The pump unit can, in particular, be an electric water pump for circulating water within a motor vehicle heating or cooling circuit.

The automotive fluid pump arrangement according to the invention is also provided with a mounting device for mounting the pump unit to a motor vehicle frame. The mounting device comprises a ring-shaped vibration-decoupling support part, which extends substantially in a transversal pumping unit plane. The support part radially encloses and supports the pumping unit. The support part is provided with a transversal ring opening, which corresponds with the shape of a pumping unit mounting section, so that the pumping unit is radially supported by the support part substantially along the entire circumference.

Preferably, the support part radially encloses the electric motor of the electric pump unit, so that the centre of mass of the pumping unit is located substantially within the support part. The mounting device further comprises a mounting part for attaching the mounting device to a motor vehicle mounting structure. The pump unit is supported at the motor vehicle frame only via the mounting device and is, in particular, not in direct contact with the motor vehicle frame. Preferably, the support part is made of a relatively soft and elastic material, for example made of rubber, silicone, SEBS, EPDM or any other elastomer, so that the vibration-decoupling support part can compensate vibrations of the motor vehicle frame.

The support part is provided with an axial stop surface, which is oriented substantially perpendicular to a pump unit rotation axis. The pump unit is provided with a corresponding stop surface, which cooperates with the support body's axial stop surface to secure the pump in a first axial pump unit inserting direction, namely in the mounting direction. The support part is also provided with a tensioned friction-enhancing longitudinal lip ring, which is acting in a pressure sleeve-type manner. The elastic lip ring is surrounding the pump unit utricularly and exerts a normal force at an outer pump unit mounting section, so that a friction force is applied between the lip ring and the pump unit, which is fictionally locking the pump unit in an axial dismounting direction.

Preferably, before the pump unit is assembled with the mounting device, the inside perimeter of the lip ring is at least 5% smaller than the outside perimeter of the pump unit mounting section. In this pre-assembled state, the lip ring extends substantially radially inwards from the opening of the support part and is preferably slightly conical. The conical lip ring tapers in mounting direction, so that the pump unit is guided during the insertion process. Due to the smaller inside diameter of the lip ring compared to the outside diameter of the pump unit mounting section, the lip ring flips over in mounting direction during the assembly of the pump unit with the support part and adapts gapless to the pump unit mounting section. This deformation tensions the lip ring, so that a relatively high normal force acting at the mounting section is provided by the lip ring, which is substantially higher than the normal force of a conventional press-fitted connection. The resulting friction force is sufficient to axially secure the pump unit within the support part against any usual axial displacement force. As a result, the support part secures the pump unit in both axial directions, namely the mounting direction and the dismounting direction without any additional fixing means, like clips or screws. Accordingly, in the assembled state, the lip ring is substantially completely axially oriented and contacts the outer surface of the pump unit as well as at the inner surface of the ring opening. Due to the higher friction forces between the tensioned lip ring and the pump unit mounting section compared to the friction forces between the lip ring and the inner surface of the ring opening, the lip ring does not slip at the outer surface of the pump unit mounting section, if the pump unit is displaced in dismounting direction, but slips at the inner surface of the ring opening. The utricular lip ring stays in contact with the pump unit and is thereby folded in a bellow-type manner, so that the lip ring jams inside the ring opening of the support body and blocks a further displacement of the pump unit. As a result, the jamming of the friction-locked lip ring provides a kind of form-locked connection in dismounting direction without the necessity of any undercuts at the pump unit housing.

In a preferred embodiment of the automotive fluid pump arrangement according to the invention, the lip ring is an integral part of the elastomeric support part. The lip ring is, for example, integrally formed onto the elastomeric support body at the inner surface of the ring opening. Thereby, the pump unit is radially supported and axially fixed, both in mounting direction and in dismounting direction by one single part, so that no additional fixation means are needed for connecting the lip ring to the support part. This integral design results in relatively low production costs, because no additional assembly step is required for axially securing the pump unit with a clip or with screws. The integral lip ring allows a relatively compact design of the support part and thereby allows a compact design of the mounting device, which is particularly favourable for an automotive application of the pump arrangement.

In a preferred embodiment of the invention, the ring-shaped supporting body and the corresponding mounting section of the pump unit are circular. The circular shape generally allows a free adaption of the orientation of the tangentially oriented pump outlet, even after the pump unit has been mounted to the motor vehicle. Thereby the mounting device and thus the pump unit can be applicated to different motor vehicles at different mounting positions, so that a kind of all-purpose mounting device is provided. Further, the circular shape simplifies the mounting process of the pump unit with the support part. Due to the friction forces between the lip ring and the pump unit, the rotation of the pump unit during the mounting process simplifies the insertion of the pump unit into the ring-shaped support part.

In a preferred embodiment of the invention, the axial supporting body stop surface is provided with a castellated structure comprising several axially extending merlons. The merlons of the castellated structure are, preferably, disposed along the circumference of the support part in an equiangular arrangement and define several pump receptacles between them. The stop surface of the pump unit is provided with a corresponding castellated structure, which is, for example, defined by the screw sockets of the pump unit housing. In the mounted state of the pump arrangement, the screw sockets of the pump unit housing engage the pump receptacles, so that the pump unit cannot rotate within the support part. As a result, the pumping unit is provided with a defined and stable rotational orientation with respect to the support part and, as a result, with respect to the motor vehicle frame. The castellated structure thereby defines a simple anti-rotation protection of the pump unit.

In a preferred embodiment of the invention, the electrical plug socket of the electrical pump unit is axially extending from the axial front-end surface of the pump unit. The axial front-end surface is defined at the end of the pumping unit axially opposite to the volute of the pump housing. The pump is inserted into the ring opening of the support part with the front-end first, so that the axial front-end surface is oriented in the mounting direction. The electrical plug socket is arranged such that it is not radially exceeding the pump unit mounting section, and is more preferably arranged with a radial distance to the pump unit mounting section, so that the lip ring cannot be damaged by the plug socket during the assembly of the pump unit with the support part. Generally, the lip ring provides enough friction force to the pump unit to avoid a displacement of the pump unit during the axial plugging of the electrical plug to the plug socket.

In a preferred embodiment of the invention, the diameter of the circular lip ring is at least 5% smaller than the diameter of the pump unit mounting section, before the pump unit is assembled with the mounting device. The resulting tensioning of the circular lip ring resulting from the radial expansion allows a homogenous normal force distribution along the complete circumference of the circular pump unit mounting section, which results in a reliable axial fixation of the pump unit. Further, the useful jamming of the lip ring caused by an axial displacement of the pump unit in dismounting direction is more effective with a circular lip ring.

In a preferred embodiment of the invention, the mounting part for attaching the mounting device to the motor vehicle mounting structure is an integral part of the ring-shaped support part. The complete mounting device is thereby defined by one single low-cost piece reducing the manufacturing effort as well as the assembling effort compared to a multi-piece mounting device. The mounting device is, for example, attached to the motor vehicle mounting structure by a screw joint using integrally formed screw holes within the mounting part, so that no additional machining is required for manufacturing the screw holes of the mounting device. Further, no additional assembly step is required for connecting the mounting part with the support part. The integral design provides a very compact and simple mounting device with a reliable and sufficient fixation of the pump unit in combination with an efficient vibration-decoupling of the pump unit from the motor vehicle mounting structure.

An embodiment of the invention is described with reference to the enclosed drawings, wherein figure la shows a perspective view of an automotive fluid pump arrangement with a pump unit and a mounting device in a disassembled state, figure lb shows a perspective view of the automotive fluid pump arrangement of figure 1 in an assembled state, figure 2a shows a cross-sectional top view of the automotive fluid pump arrangement of figure 1 in a disassembled state, and figure 2b shows a cross-sectional top view of the automotive fluid pump arrangement of figure 1 in an assembled state.

The figures la, lb, 2a and 2b show an embodiment of an automotive fluid pump arrangement 10 according to the invention. The automotive fluid pump arrangement 10 comprises an electric water circulation pump unit 15 and a mounting device 20 for attaching the pump unit 15 to a motor vehicle mounting structure 50. The mounting device 20 comprises a circular ring-shaped vibration-decoupling support part 22 with a circular ring opening 35, shown in figures la and 2a.

The electric pump unit 15 comprises a cylindrical pump unit mounting section 18, which is inserted into the circular ring opening 35 of the support part 22 for axially and radially fixing the pump unit 15. The cylindrical support part body 23 radially encloses the inserted pump unit mounting section 18 and thereby radially supports the pump unit 15, shown in figure lb and 2b.

The support part 22 is made of an elastomer to provide a vibration-decoupling of the pump unit 15 from the motor vehicle mounting structure 50. The mounting device 20 further comprises a mounting part 27, which is an integral part of the circular ring-shaped support part 22. The mounting part 27 is provided with a flat rectangular mounting surface 28 being arranged perpendicularly to the pump unit centre line and contacting the motor vehicle mounting structure 50, shown in figure la and lb. The mounting part 27 is also provided with two screw holes 26 for attaching the mounting device 20 to the motor vehicle mounting structure 50 via a screw joint. For reinforcing the mounting device, the transition zone between the support part 22 and the mounting part 27 is provided with reinforcement ribs 24 extending laterally in a transversal pump unit plane, the ribs 24 being tangentially formed onto to the cylindrical support part 22 and being connected to the connection flange 29 of the mounting part 27 at both sides of the screw holes 26.

Figure la and 2a showing the automotive fluid pump arrangement 10 in a disassembled state show the inner side of the support part ring opening 35 being provided with a slightly conical and substantially radially inwards extending circular lip ring 30', which is integrally connected with the support part 22. The lip ring 30' extends radially inwards from the radial inside of the support part 22 and extends axially in mounting direction M of the pump unit, so that the lip ring 30' tapers in mounting direction M referring to its connection zone 32 with the support part 22. The inside diameter dL of the lip ring 30' is 10% smaller than the outer diameter dP of the pump unit mounting section 18, shown in figure 2a. An axial front-end surface 16 is defining the axial end of the pump opposite to the pump volute or the tangentially oriented fluid outlet 19. When the pump unit 15 is inserted in mounting direction M with the axial front-end surface 16 first, the lip ring 30' is flipped over in mounting direction M and changes from a substantially radial orientation to a pure axial and longitudinal orientation. Due to the conical shape of the lip ring 30' and the tapering in mounting direction, the pump unit mounting section 18 is guided into the ring opening 35 and the lip ring 30' deforms into an utricular pressure sleeve, which adapts gapless to the outer shell surface of the pump unit mounting section 18. As a result of the radial expansion of the inside diameter dL to the outer diameter dP of the pump unit mounting section 18, shown in figure 2b, the utricular lip ring 30 extends axially in mounting direction M and is tensioned.

Due to the tensioning of the lip ring 30, the free end 34 of the lip ring 30 provides a radially inwards oriented and relatively high normal force to the pump unit mounting section 18 compared to a conventional pure press-fitted connection. The longitudinal extension of the lip ring 30 in axial mounting direction M in combination with the relatively high friction forces between the lip ring 30 and the pump unit 15 provides a blocking effect, which additionally secures the pump unit 15 in dismounting direction D. If the pump unit 15 is displaced in dismounting direction D, the lip ring 30 deforms in a bellow-type manner and jams between the support part 22 and the pump unit mounting section 18, so that the displacement of the pump unit 15 in dismounting direction is effectively blocked.

The support part 22 is provided with an axial stop surface 25 at the axial end of the support part 22 being orientated in the dismounting direction D. The axial support part stop surface 25 cooperates with a corresponding axial stop surface 17 at the pump unit 15. This pump unit stop surface 17 is oriented opposite to the support part stop surface 25, namely in mounting direction M, so that the pump unit 15 is axially stopped by a form fitted connection, securing the pump unit 15 axially in mounting direction M, shown in figure 2b.

The axial stop surface 25 of the support part 22 is provided with a castellated structure 21, which comprises several arc-shaped merlons 38 extending axially in dismounting direction D and being equiangularly arranged over the circumference of the support part body 23, shown in figure la. The merlons 38 are concentrically arranged to the support part ring opening 35 and define a first member of a rotation-blocking structure of the substantially cylindrical pump unit 15. The castellated structure 21 defines several axial receptacles 39 between the merlons 38 for accommodating the cylindrical and axially oriented screw sockets 14 being equiangularly arranged over the circumference of the pump unit 15 and radially exceeding the pump unit mounting surface 18. The corresponding castellated structure 21 of the support part 22 locks the screw sockets 14 and thereby prevents the pump unit 15 from rotating within the support part ring opening 35, shown in figure lb.

The pump unit 15 is provided with an electrical plug socket 40, which is axially extending from the front-end surface 16 of the pump unit 15 in mounting direction M. The plug socket 40 is radially offset referring to the centreline of the pump unit 15, but is also offset from the outer edge of the front-end surface 16, so that the plug socket cannot damage the radially inwards extending lip ring 30' during the insertion of the pump unit 15 into the support part 22, shown, for example, in figure la.

The electrical plug (not shown) is plugged in axial dismounting direction D. The friction enhancing lip ring 30 provides a sufficient axial fixation of the pump unit 15 in dismounting direction D resulting from the relatively high friction force between the lip ring 30 and the pump unit mounting section 18 and from the jamming of the lip ring 30 caused by a slight displacement of the pump unit 15 in axial direction, so that the axial plugging does not relevantly displace the pump unit 15.