CN113279934A

CN113279934A - Pump unit with pump and electric motor

Info

Publication number: CN113279934A
Application number: CN202110193538.9A
Authority: CN
Inventors: 马塞尔·格拉尔杜斯·玛丽亚·尼乌文赫伊斯
Original assignee: North American Dynamic Packer Co
Current assignee: North American Dynamic Packer Co
Priority date: 2020-02-20
Filing date: 2021-02-20
Publication date: 2021-08-20
Also published as: EP3869038A1

Abstract

The present disclosure relates to a pump unit having a pump and an electric motor. A pump unit (26) for pressurizing a hydraulic actuation system (21) comprises a pump housing (261) having a pump chamber (264) for accommodating the pump and an electric motor (3) for driving the pump. The electric motor is a brushless DC motor comprising a motor rotor (31) having a number of magnets (33) at an outer surface and field coils positioned opposite the magnets to rotationally drive the motor rotor. The pump unit further comprises a control unit (29) comprising a Printed Circuit Board (PCB) for controlling the electric motor. The control unit (29) and the closure (265) form a subassembly that can be mounted as a module to close the pump chamber. The control unit comprises at least one hall sensor (34) to detect the rotational position of the motor rotor. The at least one hall sensor is positioned on a printed circuit board, the printed circuit board positioned opposite a motor rotor end face (612).

Description

Pump unit with pump and electric motor

Technical Field

The present invention relates to a pump unit for pressurizing a hydraulic actuation system.

Background

The pump unit comprises a pump housing comprising a pump chamber for accommodating the pump. It is desirable to provide a pump unit design that provides a greater degree of compactness while maintaining the same pump flow rate, or in other words, an increase in pump flow rate while maintaining the same compactness. Such a compact pump unit would be beneficial in a variety of applications including hydraulic actuation systems for moving parts.

The compact pump unit is particularly suitable for use in automotive applications, more particularly for actuating a convertible top system or wheel suspension, because of its narrow built-in space and the required dynamic performance in any orientation of the pump unit.

In addition to automotive applications, such a compact pump unit would also be beneficial in other fields, for example in the marine field, the medical field or the domestic field. For example, in the field of marine vessels, compact pump units may be beneficial in hydraulic actuation systems for operating marine equipment such as marine doors, hatches, lifts, gantries (balconies), bulwarks, masts, mooring gangways, and the like. For example, in the medical field, a compact pump unit may be beneficial in a hydraulic actuation system for operating a medical device, such as a medical tool, a lift, a trolley, a chair or a stretcher, for example an ambulance stretcher or a dental chair or a medical table, for example an operating table, a treatment table or a scanning table. For example, in the civilian field, a compact pump unit may be beneficial in a hydraulic actuation system for operating a building door or hatch (e.g., a sliding garage door, porthole, skylight, or shutter).

EP2.662.568 discloses an electric pump device including a housing for integrally housing a pump that generates oil pressure, a brushless motor that drives the pump, and a control device that controls the operation of the motor. A cylindrical motor housing is placed behind the pump housing, and a cover closes the rear open end. The cover is fixed to the motor case by welding. The three-phase driving electric power is supplied by the control device. The control device includes a circuit board. The circuit board is mounted to the insulator. The motor coil of the motor is sandwiched between the circuit board and the insulator. The voltage sensor serving as the voltage detection means is connected to a microcomputer embedded on the circuit board. The microcomputer estimates a rotational position of the motor rotor based on an induced voltage of the motor coil detected by the voltage sensor.

US6.168.393 entitled Hoerbiger discloses a conventional motor driven radial piston pump assembly. The pump assembly is configured for transportable purposes or for generating small forces, for example for hydraulic actuation of a folding-lid roof of a motor vehicle. The main requirement for such a pump assembly is that the assembly is as small as possible, so that the pump assembly can be built in a narrow installation space, for example, in a narrow chassis compartment of a vehicle.

The pump assembly includes a radial piston pump supported on one side thereof by a base section. The base section serves to mount the pump together with all its connecting lines, control elements and electric motor. An electric motor is operatively connected to the pump and is coaxially supported on the base section relative to a central axis of the motor output shaft along the pump propulsion axis.

The electric motor is typically a conventional DC motor for operating the pump. The electric motor comprises a motor housing, which can be closed by a cover. The motor housing accommodates the motor. The motor is supported at the pump end and at the opposite end. The motor has an output motor shaft at its pump end. Electrical components are provided at opposite ends. The output motor shaft is connected to the pump rotor by a coupling. The coupling includes a flange-shaped body and a beam-shaped connecting rod.

The electric motor is connected to the base section by a motor housing such that all supporting forces, bearing forces and moments are carried by the base section. The base section may be configured for attaching the entire motor-driven radial piston pump assembly. The base section takes the reaction forces and the weight of the motor and transmits those forces directly on the base section, which also supports the pump, which affects the compact construction.

A disadvantage of the known pump assembly is that its outer dimensions are still not sufficiently small. This type of pump assembly is particularly desirable with small outer dimensions.

GB 812.812a discloses a pump comprising a housing for a stator, a rotor with a piston and a movable stator ring. The rotor and stator ring are disposed in a cylindrical recess of the housing. The rotor has a rotor shaft which is received in a bore provided with an anti-friction bearing, for example of the needle roller type, on which the rotor shaft rotates. The rotor shaft is further supported at its outer end by a further anti-friction bearing. The rotor may be driven by coupling a motor to the outer end of the motor shaft.

The disadvantage of this pump is that the pump flow is limited. Further, the pump requires excessive built-in space for use in an automotive actuation system.

EP 0544.856 discloses a pump unit comprising a hydraulic piston pump driven by an electric motor. The piston pump and the electric motor are accommodated in a common cylindrical pump housing which is closed at both ends by cover-shaped parts. The electric motor and the piston pump form a first module and a second module coupled to each other.

The electric motor includes a motor rotor. The motor rotor supports a number of magnets at its outer circumference. At one side the motor rotor is journalled to the shaft by ball bearings and at the opposite side the motor rotor is supported by the piston pump. The motor rotor can be driven by actuating a radially positioned coil opposite the magnet. The motor rotor is rotationally connected to the pump rotor of the piston pump so that the pump rotor rotates together with the motor rotor.

The piston pump has a pump rotor body supported by a pump stator. The pump stator, which is an elongated stator body, is fixed to the pump housing at one end. The pump rotor body has a projection that is received in a recess of the motor rotor body. The pump rotor body is rotationally fixed to the motor rotor.

A disadvantage of the disclosed pump unit is that its outer dimensions are still not sufficiently small. A relatively compact pump unit is desired.

Another disadvantage is that the disclosed pump unit has poor dynamic performance. In particular, such pump units will become unstable when driving at high rotational speeds and in any orientation, as is desired in automotive applications.

Disclosure of Invention

It is a general object of the present invention to at least partly obviate the above disadvantages and/or to provide a useful alternative. More specifically, it is an object of the present invention to provide a pump unit having a compact configuration and, in addition, providing a stable dynamic behavior when operating at high rotational speeds, as required in e.g. automotive applications, such as operating a convertible top system.

More particularly, the present invention aims to provide a hydraulic actuation system comprising a compact pump unit that can be built into a narrow installation space, such as a chassis compartment of a vehicle. Furthermore, it is a further object to provide a pump unit having a high dynamic performance allowing to build in the pump unit in any orientation.

According to the invention, this object is achieved by a pump unit according to the following.

According to the invention, a pump unit is provided for pressurizing a hydraulic actuation system, in particular for actuating a convertible top system. The pump unit comprises a pump housing comprising a pump chamber for receiving a pump. The pump unit further comprises an electric motor for driving the pump.

The electric motor comprises a motor rotor having a longitudinal motor rotor body comprising a number of magnets. The motor rotor body defines an axial axis. The magnet is positioned at an outer surface of the motor rotor body. Further, the electric motor includes an excitation coil positioned to oppose the magnet of the motor rotor body to rotationally drive the motor rotor body.

In particular, the pump is a piston pump, which comprises a pump stator immovably positioned inside the pump chamber. The pump stator has a longitudinal pump stator body comprising at least two channels serving as inlet or outlet channels, respectively. Further, the piston pump includes a pump rotor positioned about the pump stator body. The pump rotor has a pump rotor body which is drivable in a direction of rotation about an axial axis. The pump rotor body comprises several cylinder bores for each receiving a piston, which is slidable in radial direction with respect to the pump rotor body. Further, the piston pump comprises an eccentric ring positioned around the pump rotor body. The eccentric ring is eccentrically positioned with an eccentricity relative to the pump rotor body to provide a pump flow rate.

The pump unit further comprises a control unit for controlling the pump flow. The pump flow rate can be controlled by controlling the rotational speed of the electric motor. Preferably, however, in operation, the motor rotor is driven at a constant rotational speed. The pump flow of the pump can then be controlled by the control unit by adjusting the eccentricity of the eccentric ring of the piston pump.

The pump housing of the pump unit comprises a closure for closing the pump chamber. In particular, the closure is a cap comprising a seal that can be fitted to an opening of the pump chamber to seal the pump chamber. In particular, the closure has an alignment member to rotationally position the closure relative to the pump chamber.

The control unit of the pump unit comprises a printed circuit board connected to the closure member. The control unit forms a subassembly with the closure. The subassembly of the control unit and the closure forms a module that can be mounted to the pump housing as a separate item.

The control unit is configured to control the electric motor. In an embodiment, the control unit is further configured to control an actuator for actuating an eccentric ring of the pump. The electric motor of the pump unit is a brushless DC motor. The control unit comprises at least one hall sensor for detecting the angular position of the motor rotor. The hall sensor provides a sensor signal to determine the angular position of the motor rotor to accurately energize the field coils of the electric motor. Thus, the hall sensor may be used to optimize the control of the brushless DC motor of the pump unit.

An improvement is provided by positioning at least one hall sensor on a printed circuit board of a control unit. At least one hall sensor is positioned opposite an end face of the motor rotor to detect an angular position of the motor rotor. A printed circuit board mounted to the enclosure is positioned opposite an end face of the motor rotor to properly align the at least one hall sensor with the motor rotor.

In particular, a printed circuit board of the control unit holding the at least one hall sensor is aligned with a rotor mark of the motor rotor of the pump unit. In particular, the closure includes a closure recess for receiving and positioning the printed circuit board. The printed circuit board is centered by the closure recess. In assembly of the pump unit, positioning of the printed circuit board in the closure recess aligns and positions the hall sensor relative to the rotor index of the motor rotor. Preferably, the printed circuit board comprises two hall sensors, more preferably three hall sensors, which are circularly equally spaced on the printed circuit board opposite the end face of the motor rotor.

In an embodiment of the pump unit according to the invention, the printed circuit board is positioned outside the pump chamber at an outer surface of the closure. The printed circuit board is positioned outside of the pump chamber. The closure is positioned between the printed circuit board and the pump chamber. The closure may include a passage to guide electrical wires from the printed circuit board to the excitation coil inside the pump chamber. At least one hall sensor is positioned outside of the pump cavity, and the closure includes a non-ferrous material (non-ferrite) to conduct the generated magnetic field such that the at least one hall sensor detects the angular position of the motor rotor.

In another embodiment, the module may hold the field coil of the electric motor. Preferably, the excitation coil is positioned between the closure and the control unit. The excitation coil is connected to the closure at the outer front side. The enclosure comprises a non-ferrous material to conduct the generated magnetic field to magnets on a motor rotor provided behind the enclosure. Advantageously, the pump unit has a modular structure, which allows to reduce the assembly time in the production of the pump unit.

According to an embodiment of the invention, an improvement is provided in that the motor rotor and the pump rotor are incorporated into a common rotor. The common rotor is an article. The common rotor is positioned inside the pump chamber. The pump chambers house a common rotor. The common rotor includes a motor rotor portion and a pump rotor portion. Functionally, the common rotor serves both as a rotor of the electric motor and as a rotor of the pump. The improvement according to the first aspect provides that the common rotor is fully supported by the pump stator.

The pump unit according to this embodiment has no motor stator. No separate motor stator is provided to support the motor rotor. The motor rotor and the pump rotor are incorporated into a common rotor that is supported solely by the pump stator. A separate motor stator is superfluous since the common rotor is fully supported by the pump stator.

In other words, it can also be said that according to this aspect the motor stator is incorporated into the pump stator, which results in a common stator. Advantageously, the pump unit according to the first aspect may have a compact configuration. Furthermore, the pump unit may have a stable dynamic performance allowing a high rotational speed and mounting of the pump unit in any orientation.

In contrast to the prior art pump unit from EP 0.544.856, the pump unit according to the first aspect of the present invention is supported only by the pump stator and not by a separate second shaft, motor stator, positioned on the opposite side of the common rotor. According to the first aspect, only one component (pump stator) is provided for supporting the common rotor. Advantageously, a possible misalignment between the individual components is prevented, which contributes to an improved dynamic performance of the pump unit according to the invention. The potential unbalance is minimized, which allows a high rotational speed of the common rotor to achieve a relatively high pump flow rate by a relatively small sized pump unit.

In an embodiment of the pump unit according to the invention, the pump stator is fixed to the pump housing as a cantilever. The pump stator has a proximal end fixed to the pump housing and a free distal end. The pump stator is connected to the pump housing at only one end. Thus, instead of support at both sides of the common stator, the common rotor is supported to the pump housing at only one side (i.e. the proximal end of the pump stator). Advantageously, by providing a single-sided support for the common rotor, the pump unit may have a more compact configuration in the axial direction.

In an embodiment of the pump unit according to the invention, the pump stator extends through the common rotor over at least half the length of the common rotor. The length of the common rotor in the axial direction is at most twice the length of the pump stator. Advantageously, the length of the pump stator helps to stabilize the dynamic performance. Especially at high speeds, it provides a rigid support for the common rotor to counteract the forces generated in operation.

In an embodiment of the pump unit according to the invention, the common rotor is an article manufactured from solid parts (solid parts) by lathe operation. The solid part may be a piece of rough bar material from a single material, which is subsequently machined by a turning operation to obtain a common rotor. Alternatively, the solid part may be provided by a moulding operation. The solid part may be a piece of prefabricated bar material. The solid part may be a so-called hybrid comprising a first material and a second material in combination, for example aluminium and steel, wherein the first material is positioned adjacent to the second material as seen in the longitudinal direction. The common rotor, which is made of a hybrid material, includes a first material that forms the motor rotor portion that is different from a second material that forms the pump rotor portion. Starting from a hybrid as input material, a common piece of rotor is obtained after the turning operation has been performed. The common rotor formed from the hybrid piece may include a motor rotor portion made of a first material (e.g., aluminum or plastic) and a pump rotor portion made of a second material (e.g., steel). Advantageously, a common rotor formed from solid parts by a turning operation may contribute to a precisely balanced common rotor that contributes to a stable dynamic behavior.

The prior art pump unit from EP 0.544.856 discloses a common rotor as one item, which is manufactured by assembling two prefabricated parts. The two parts are welded together. In an embodiment according to the invention, the pump unit has as one item a common rotor made of a single solid part. Instead of assembling two separately prefabricated parts, the manufacture of a single solid part may provide improved dynamic performance. Manufacturing the common rotor by a turning operation may minimize any weight imbalance about the central axis of the common rotor. Minimizing the unbalance advantageously contributes to a more stable dynamic behavior of the common rotor at high rotational speeds. The wobbling motion can be reduced. In addition, minimizing imbalance facilitates quieter operation. The pump unit is therefore particularly suitable for use in automotive hydraulic actuation systems. For example, in a highly dynamically controlled vehicle wheel suspension, a pump unit is advantageous because of its stable dynamic behavior at high rotational speeds. For example, in a convertible top system, the pump unit is advantageous because it operates quietly.

In an embodiment of the pump unit according to the invention, the motor rotor comprises magnets positioned at an outer circumferential motor rotor surface of the motor rotor. An excitation coil for generating a magnetic field is positioned opposite the magnet. The field coil is radially spaced from the magnet. Preferably, the excitation coil is positioned inside the pump chamber of the pump housing. The exciting coil may be attached to the inner circumferential surface of the pump chamber.

In an embodiment of the pump unit according to the invention, the common rotor comprises a motor rotor recess which is open at a motor rotor end face. The motor rotor recess is adapted to receive an excitation coil of the electric motor. The motor rotor recess has an inner circumferential surface and an inner bottom surface, wherein the magnets of the motor rotor are positioned at the inner circumferential surface or the inner bottom surface. Preferably, the magnets are positioned at the inner circumferential surface and the field coil is positioned at a location spaced radially inwardly from the magnets inside the motor rotor recess. The field coil is arranged to generate a fluctuating magnetic field in the radial direction to actuate the magnet to drive the motor rotor in the radial direction.

In an embodiment of the pump unit according to the invention, the magnets of the motor rotor are positioned at a motor rotor end face of the common rotor. The field coil is positioned opposite to the magnet of the motor rotor in the axial direction. Preferably, the excitation coil is positioned outside the pump chamber. The pump chamber may be closed by a closure, wherein the excitation coil is connected to the closure. Advantageously, the axial arrangement of the magnetic field and the excitation coil may further contribute to a compact configuration of the common rotor. The total weight of the common rotor may be reduced compared to the radial arrangement of the magnets and the excitation coils, and the common rotor may have an increased balance that may contribute to improved dynamic performance.

According to a further aspect of the invention, the reservoir of the pump unit is formed by a pump chamber in the pump housing. The pump stator of the piston pump has an inlet passage in fluid communication with the pump chamber. The reservoir formed by the pump chamber makes the seal positioned between the canister and the pump chamber superfluous compared to conventional arrangements comprising a separate canister as a reservoir positioned at or outside the pump housing. Advantageously, the risk of leakage, which is present in particular at high pressures of more than 100 bar, is minimized.

Further, the invention relates to a hydraulic actuation system comprising a pump unit according to the invention. Advantageously, the hydraulic actuation system is adapted to be built into a narrow space, such as a frame compartment. Furthermore, the compact configuration of the integrated pump-motor pump unit allows the hydraulic actuation system to be mounted behind movable parts that are not visible from the outside, for example in medical equipment behind furniture accessories such as hospital beds.

The pump unit according to the invention may be beneficial to be mounted in a movable hydraulic actuation system, since the pump unit may have a very compact, light weight construction.

The pump unit may advantageously be battery powered. A movable hydraulic actuation system comprising a battery allows operation of relatively heavy loads by at least one hydraulic actuator controlled by an electrically driven pump unit. The pump unit according to the invention may therefore be very beneficial in mobile applications requiring small and light-weight actuation systems, but at the same time requiring the movement of large loads. In particular, a pump unit is provided for pressurizing an automotive actuation system, for example configured as a convertible top system, trunk lid, hood (hood cover) system or wheel suspension of a vehicle. Typically, the pump unit is set to a compact size to be installed at a narrow installation space, for example, within a compartment of a vehicle chassis. Examples of such applications in the medical, marine and civil fields are mentioned above. The actuation system of an ambulance stretcher is a prominent example of such a movable actuation system that should be both lightweight and powerful. The lightweight is because the ambulance stretcher should be carried by personnel, and the strength is because it should move the patient's load on the stretcher.

The hydraulic actuation system is in particular a hydraulic actuation system of a motor vehicle comprising a pump unit according to the invention. Advantageously, the pump unit comprises a rotary piston pump adapted for quiet operation and reliable at high rotational speeds. The pump unit is in particular a pump unit of a motor vehicle configured for operating a vehicle part such as a convertible top, a sunroof, a trunk lid, an engine hood, an air deflector or a vehicle wheel suspension linkage. Advantageously, the automotive pump unit has a compact configuration that allows mounting the pump unit in a narrow vehicle compartment (such as a chassis compartment) that is located close to the movable vehicle part.

In an embodiment of the vehicle actuation system, the vehicle actuation system is a convertible top system comprising a convertible top comprising a top part which is movable relative to the remaining top parts. The convertible top to be operated serves for selectively covering or opening a passenger space of the vehicle and may comprise several roof sections which are pivotally connected to each other. The first roof section is movable relative to the second roof section to place the convertible top in a closed state or an open state, respectively.

Further, the present invention relates to a vehicle comprising such an automotive hydraulic actuation system (such as a convertible top or a vehicle wheel suspension).

Further embodiments are defined in the dependent claims.

Drawings

The invention will be explained in more detail with reference to the drawings. The drawings illustrate possible embodiments according to the invention and are not to be construed as limiting the scope of the invention. Specific features may also be considered as separate from the illustrated embodiments and may be considered in a broader context not only as delimitation features for the illustrated embodiments but also as common features for all embodiments falling within the scope of the appended claims, wherein:

fig. 1 shows a schematic side view of a vehicle provided with a convertible top system;

fig. 2 shows a schematic view of the convertible top system outside fig. 1 including a hydraulic actuation system comprising a pump unit for pressurizing a number of cylinders;

fig. 3 shows a first embodiment of the pump unit in a schematic sectional view in relation to the axial axis, wherein the pump unit comprises an electric motor and a piston pump, both being received in a pump chamber of the pump housing, and wherein the electric motor comprises radially arranged magnets and an excitation coil, wherein the excitation coil is positioned on the outside with respect to the magnets;

fig. 4 shows a second embodiment of the pump unit as in fig. 3, wherein the magnet coil is positioned on the inside with respect to the magnet;

fig. 5 shows a third embodiment of the pump unit as in fig. 3, in which the field coils of the electric motor are arranged axially with respect to the magnets.

In the drawings, the same reference numerals are used to designate the same or similar components.

Detailed Description

Fig. 1 discloses a schematic view of a vehicle 1. The vehicle 1 comprises a car actuation system for hydraulic actuation of movable vehicle components like sunroofs, engine hoods, trunk lids, air deflectors, convertible tops or wheel suspensions. As shown herein, a vehicle 1 is provided with a convertible top system 2 for selectively opening or covering a passenger space. The convertible top system 2 has a well-known mechanical structure.

Here, the convertible top system 2 has a convertible top 20, which convertible top 20 comprises a front top section 200. The roof part 200 is pivotally connected to the remaining roof part 201 of the convertible top 20 about a pivot axis. Herein, the front roof portion 200 is shown released from the front window frame 11. In the closed configuration of the convertible top, the front roof portion 200 is connected to the front window frame 11 and locked by the locking member 12.

Fig. 2 shows an embodiment of the convertible top system 2 in more detail. The general mechanical structure of such convertible roof systems is well known in the art. Fig. 2 further shows a hydraulic actuation system 21. The hydraulic actuation system 21 is arranged to actuate the convertible top 20, the locking member 12 and furthermore the cover plate 202. The cover 202 is provided to cover a compartment of the vehicle 1 configured to receive the convertible top 20 when shifted to the open configuration.

The hydraulic actuation system 21 comprises two pairs of hydraulic cylinders 23, 23' for moving the

roof portions

200, 201 of the convertible top 2; 24. 24'. The hydraulic cylinder 25 is arranged to move the cover plate 202 and the hydraulic cylinder 22 is arranged to actuate the locking member 12. A cylinder 22; 23. 23'; 25. 25' are hydraulically connected to a hydraulic pump unit 26 via hydraulic conduits.

The pump unit 26 has a pump housing 261. The pump housing 261 is block-shaped. A control unit 29 is provided to control the pump unit 26. The control unit 29 is electrically connected to the electric motor 3 for driving an internally located pump, here a piston pump 4. The electric motor 3 is connected to the front side of the pump housing 261. The piston pump 4 is arranged internally in the pump chamber 264 inside the pump housing. The pump chamber 264 is an internal space configured to accommodate the piston pump 4. The arrangement of the piston pump 4 in the pump chamber 264 is further illustrated by fig. 3-5, which show a sectional view of the pump unit 26 in relation to the longitudinal axis.

As shown in fig. 2, the pump unit 26 includes a valve unit 28. The valve unit is mounted to a mounting face, which herein is positioned at a top side of the pump housing. Further, the pump unit 26 comprises a reservoir 263 for accumulating hydraulic liquid. The reservoir 263 is herein positioned at the rear side of the pump housing 261.

According to an aspect of the invention, improvements are provided by combining an electric motor 3 and a piston pump 4. In particular by incorporating the motor rotor 31 of the electric motor 3 and the pump rotor 46 of the piston pump 4 into a common rotor 6 as shown in fig. 3-5. The common rotor 6 is an item. The common rotor 6 is a separately mountable part of the assembled pump unit 26. The common rotor 6 as a whole can be mounted to the rest of the pump unit 26.

The common rotor 6 is positioned inside the pump chamber 264. The common rotor 6 defines an axial axis a. The axial axis a is the axis of rotation of the common rotor 6. The common rotor 6 includes a motor rotor portion 61 serving as the motor rotor 31 and a pump rotor portion 62 serving as the pump rotor 46.

The electric motor 3 is a brushless DC motor. DC motors are advantageous because of their relatively long life without intervention. The electric motor 3 has a motor rotor 31 forming a motor rotor portion 61 of the common rotor 6. The motor rotor 31 has a motor rotor main body 610. The motor rotor body 610 is cylindrical and elongated. The motor rotor body 610 has an outer circumferential surface 611 and a motor rotor end surface 612.

Further, the electric motor 3 includes a plurality of field coils 32. The excitation coil 32 is a DC excitation coil that generates a magnetic field in operation. The field coil 32 is positioned opposite to the magnet 33 at the motor rotor body 610. Several embodiments comprising a rotor with magnets and oppositely positioned field coils are possible and are further illustrated in fig. 3-5.

According to an aspect of the present invention, both the motor rotor 31 and the pump rotor 46 are supported by the pump stator 42. In contrast to conventional motors, the electric motor 3 according to the invention does not have a separate component serving as a motor stator. The electric motor 3 has a motor rotor 31 supported by a pump stator 42, which makes the motor stator superfluous.

The piston pump 4 is a rotary piston pump. Piston pumps of this type are well known in the art. Such a rotary piston pump 40 comprises a piston 41 which in operation rotates together with the pump rotor.

Such a rotary piston pump 40 has a pump rotor 46 and a pump stator 42. The pump stator 42 has an elongated stator body 420 extending in the axial direction. The pump stator body 420 is beam-shaped. The pump stator body 420 is immovably fixed to the pump housing 261. The pump stator body 420 is fixed to be cantilever. The pump stator body 420 has a proximal stator end 421 that is secured to a bottom surface 2641 of the pump cavity 264. The pump stator body 420 extends along an axial axis of the pump unit 26. The pump stator body 420 has a free distal stator end 422 positioned in the interior space provided by the pump cavity 264. The pump stator body 420 comprises at least two channels for the transport of hydraulic liquid, which form at least one inlet channel 43 and at least one outlet channel 44.

The pump rotor 46 has a pump rotor body 460 that is rotationally connected to the pump stator body 420 of the pump stator 42. The pump rotor body 460 is coaxially positioned with respect to the pump stator 42. The pump stator 42 supports a pump rotor 46. The pump rotor 46 is supported from one side. The pump stator 42 provides unilateral support to the pump rotor 46, as the pump stator 42 is secured to the pump housing only at the proximal stator end 421.

The pump rotor body 460 includes several cylinder bores for respectively receiving the pistons 41. The piston 41 has a longitudinal piston body 410. The piston body 410 has a proximal piston end directed towards the stator body 420 and a distal piston end directed radially outwards towards an annular element surrounding the rotor body 460. The annular element is a so-called eccentric ring 48. The rotor body 460 is positioned inside the eccentric ring 48.

To reduce wear, the eccentric ring 48 is formed as a bearing. The bearing may be a plain bearing. The eccentric ring 48 is herein formed by a ball bearing having an inner ring and an outer ring, wherein the inner ring is carried by the ball bearing relative to the outer ring. The outer ring is immovably positioned and fixed to the pump housing 261 and the inner ring is rotatably positioned. The inner ring of the eccentric ring 48 is movable in rotation with the pump rotor 46 positioned inside.

The eccentric ring 48 includes an inner bearing surface that serves as a running surface 481 for the distal end of the piston 41. Running surface 481 is located opposite outer circumferential rotor surface 621 of pump rotor body 460. The eccentric ring 48 is eccentrically positioned with respect to the pump rotor body 460. An annular intermediate space between the outer circumferential rotor surface 461 and the inner running surface 481 is provided to allow the piston 41, which is held by the pump rotor body 460 in operation, to move in a radial direction. Due to the existing eccentricity E, the height of the intermediate space between the outer circumferential rotor surface 621 and the running surface 481 varies, which will cause the piston 41 to move in the radial direction when the pump rotor body 460 is rotationally driven. Moving the piston 41 radially inwards will provide pressure to the hydraulic liquid and will push the hydraulic liquid through the outlet channel 44, and moving the piston 41 radially outwards will provide a low pressure to the hydraulic liquid, which will suck the hydraulic liquid through the inlet channel 43. Thus, moving the piston 41 radially produces pumping work on the hydraulic circuit.

Fig. 3-5 show schematic cross-sectional views in relation to the longitudinal axis of several embodiments of the pump unit, in which several aspects of the invention are shown.

According to one aspect of the invention, reservoir 263 is formed from pump chamber 264. The inlet channel 43 of the pump stator 42 is in fluid communication with the pump chamber so that hydraulic liquid can be transferred from the pump chamber 264 as reservoir 263.

Fig. 3-5 schematically show three alternative embodiments of such an improved pump unit 26 comprising a common rotor 6 supported by only one single stator. The illustrated embodiment includes the same or similar components, but the components are positioned differently in space.

The pump unit 26 includes a pump housing 261 including a pump chamber 264 for housing the electric motor 3 and the piston pump 4, and a closure 265 for closing the pump chamber 264. In fig. 3 and 4, the electric motor 3 and the piston pump are completely received in the pump chamber 264. In fig. 5, a portion of electric motor 3 is positioned outside pump chamber 264.

The pump housing 261 has a compact configuration. Here, the pump housing 261 is cylindrical. The pump housing 261 has at least one outer mounting face at an outer surface for mounting, for example, the valve unit 28, the control unit 29, the power source and/or the reservoir 263.

The pump cavity 264 inside the pump housing 261 defines an axial axis a that extends from the front side F to the rear side B of the pump housing. The pump chamber 264 is open at the front side F of the pump housing 261. Pump chamber 264 is formed by a cylindrical interior space. Pump cavity 264 has a bottom surface 2641 and an inner circumferential surface 2642. The pump chamber 264 is adapted to at least partially receive both the electric motor 3 and the piston pump 4.

In the assembled configuration of the pump unit 26, a closure 265 is provided for closing the pump chamber 264. The closing member 265 is plate-shaped. Herein, the closure 265 is a cap fitted to the pump chamber opening. The closure 265 is sealably connected to the pump housing 261 to hydraulically seal the pump chamber 264.

Further, the pump unit 26 comprises a control unit 29. The control unit 29 has a compact configuration. The control unit 29 comprises a printed circuit board PCB designed for controlling the pump unit 26. The operating principle diagram of the controllable movement of the special hydraulic actuation system 21, which is in particular the convertible top system 2, is embedded in the design of the printed circuit board of the control unit 29. The control unit 29 is plate-shaped and can be connected to the outer surface of the closing member 265. The control unit 29 is adapted such that the closure 265 forms a module of the pump unit. The control unit 29 is dimensioned to correspond to the diameter of the closure 265. According to one aspect of the invention, the control unit 29 and the closure 265 form a subassembly. The subassembly of the control unit 29 and the closure 265 forms a separately mountable module of the pump unit 26.

As shown in fig. 3, the motor rotor body 610 includes several magnets 33 positioned on the outer circumferential rotor surface 621. The exciting coil 32 is positioned opposite to the magnet 33. The excitation coil 32 is positioned radially with respect to the magnet 33. The field coil 32 is positioned to surround the motor rotor 31. The field coil 32 is spaced radially outward from the magnet 33 supported by the motor rotor body 610. The excitation coil 32 is positioned inside the pump cavity 264 at the inner circumferential surface 2642.

Fig. 3-5 show a subassembly of the closure 265 and the printed circuit board PCB of the control unit 29. The printed circuit board PCB holds at least one hall sensor 34. At least one hall sensor 34 is positioned at a radial distance from the axial axis a. The hall sensor 34 is embedded in circuitry on the printed circuit board. The hall sensor 34 cooperates with a rotor mark 35 positioned on the motor rotor end surface 612 to detect the angular position of the motor rotor body 610. The rotor mark 35 may be formed by the magnet 33 of the rotor.

The printed circuit board is aligned with the closure 265, for example by receiving the printed circuit board in the closure recess, to obtain alignment of the hall sensor 34 with the rotor mark 35 of the motor rotor. Here, at least one hall sensor 34 is located outside of the pump chamber 264. The enclosure 265 contains at least a portion of a non-ferrous material to conduct magnetic flux to detect the rotor mark 35 by the hall sensor 34. Embedding the at least one hall sensor 34 on the printed circuit board is beneficial for obtaining a more compact configuration of the pump unit.

Fig. 3 shows the pump stator 42 extending through the rotor 6. Here, the pump stator 42 extends substantially up to the motor rotor end face 612 of the rotor 6.

Fig. 4 shows different spatial arrangements of the excitation coil 32 and the magnet 33. The excitation coil 32 is positioned radially with respect to the magnet 33. The motor rotor 31 includes a rotor recess 613. The rotor recess 613 opens at a motor rotor end surface 612 of the motor rotor portion 61. The rotor recess 613 is configured to receive the field coil 32. An excitation coil 32 for generating a magnetic field is positioned opposite the magnet 33.

The magnet 33 is positioned at an inner surface (particularly an inner bottom or circumferential surface) of the rotor recess 613. Here, the magnet 33 is positioned at an inner circumferential surface of the rotor recess 613.

The field coil 32 is positioned inside the rotor recess 613. The excitation coil 32 is positioned radially inward with respect to the magnet 33, which magnet 33 is herein positioned at the inner circumferential surface of the rotor recess 613. The excitation coil 32 is positioned inside the pump chamber 264. The excitation coil 32 is connected to the closure 265. The excitation coil 32 is centrally located and connected to the inner surface of the closure 265.

Fig. 4 shows the pump stator 42 extending through the rotor 6. Here, the pump stator 42 extends substantially up to the bottom surface of the rotor recess 613. The pump stator 42 extends for about at least half the length of the common rotor 6.

Fig. 5 shows a further different spatial arrangement of the excitation coil 32 and the magnet 33. The magnet 33 is positioned at the motor rotor end surface 612 of the rotor 6. The exciting coil 32 is positioned opposite to the magnet 33. The excitation coil 32 is located outside the pump chamber 264. The excitation coil 32 is connected to an enclosure 265 that covers the pump chamber 264. The closure 265 is positioned between the field coil 32 and the magnets 33 on the rotor 6. The control unit 29 is connected to the closure 265 via an excitation coil. Advantageously, the rotor 6 of the pump unit in fig. 5 comprising axially arranged field coils and magnets has a very compact configuration compared to the radially arranged field coils and magnets shown in fig. 3 and 4.

Fig. 5 shows the pump stator 42 extending through the rotor 6. Here, the pump stator 42 extends up to the motor rotor end face 612 of the rotor 6.

In addition to the shown embodiment of the pump unit according to the invention, several variants are possible without departing from the scope.

The present invention thus provides several aspects that allow for a compact configuration of the pump unit. Such a compact pump unit, which is installed in a hydraulic actuation system for automotive applications (like a convertible top system), is particularly advantageous, wherein the pump unit has to be built into a narrow chassis compartment.

The above aspects of the invention are to be considered independent of each other. In particular, the aspects relating to the arrangement of the magnet coils and magnets are considered technically independent of the aspects of a common piece of rotor supported only by the pump stator and of the pump chamber housing the piston pump and the electric motor and serving as a reservoir for the pump unit.

Specific embodiments according to the invention are defined in the following clauses:

1. pump unit (26) for pressurizing a hydraulic actuation system (21), in particular for pressurizing an automotive actuation system, such as a convertible top system (2), a trunk lid, a hood system or a wheel suspension of a vehicle (1), wherein the pump unit comprises a pump housing (261), which pump housing (261) comprises a pump cavity (264) for accommodating a piston pump (4), and wherein the pump unit (26) further comprises an electric motor (3) for driving the piston pump,

wherein the electric motor (3) comprises:

-a motor rotor (31), wherein the motor rotor comprises a longitudinal motor rotor body (610), which longitudinal motor rotor body (610) comprises several magnets (33) at an outer surface, wherein the motor rotor body (610) defines an axial axis;

-an excitation coil (32), the excitation coil (32) being positioned opposite the magnet of the motor rotor body (610) to rotationally drive the motor rotor body (610);

wherein the piston pump (4) comprises:

-a pump stator (42) immovably positioned inside the pump chamber (264), the pump stator having a longitudinal stator body (420), wherein the pump stator body (420) comprises at least two channels serving as an inlet channel (43) or an outlet channel (44), respectively;

-a pump rotor (46) positioned around the pump stator body (420), the pump rotor having a pump rotor body (620), the pump rotor body (620) being drivable in a direction of rotation about the axial axis, wherein the pump rotor body (620) comprises several cylinder bores for each receiving a piston (41), the pistons (41) being slidable in a radial direction with respect to the pump rotor body (620);

-an eccentric ring (48) positioned around the pump rotor body (620), wherein the eccentric ring (48) is eccentrically positioned with respect to the pump rotor body (620) with an eccentricity E to provide a pump flow rate;

wherein the motor rotor (31) and the pump rotor (46) are incorporated into a common rotor (6), the common rotor (6) being one item comprising a motor rotor portion (61) and a pump rotor portion (62), and wherein the common rotor (6) is supported solely by the pump stator (42).

2. Pump unit (26) for pressurizing a hydraulic actuation system (21), in particular for pressurizing an automotive actuation system, such as a convertible top system (2), a trunk lid, a hood system or a wheel suspension of a vehicle (1), wherein the pump unit comprises a pump housing (261), which pump housing (261) comprises a pump cavity (264) for accommodating a piston pump (4), and wherein the pump unit (26) further comprises an electric motor (3) for driving the piston pump,

wherein the electric motor (3) comprises:

wherein the piston pump (4) comprises:

wherein the motor rotor (31) and the pump rotor (46) are incorporated into a common rotor (6), the common rotor (6) being a one-piece item comprising a motor rotor portion (61) and a pump rotor portion (62), and wherein the magnet (33) of the motor rotor (31) is positioned at an outer circumferential motor rotor surface (611).

3. Pump unit (26) for pressurizing a hydraulic actuation system (21), in particular for pressurizing an automotive actuation system, such as a convertible top system (2), a trunk lid, a hood system or a wheel suspension of a vehicle (1), wherein the pump unit comprises a pump housing (261), which pump housing (261) comprises a pump cavity (264) for accommodating a piston pump (4), and wherein the pump unit (26) further comprises an electric motor (3) for driving the piston pump,

wherein the electric motor (3) comprises:

wherein the piston pump (4) comprises:

wherein the motor rotor (31) and the pump rotor (46) are incorporated into a common rotor (6), the common rotor (6) being a one-piece item comprising a motor rotor portion (61) and a pump rotor portion (62), and wherein the common rotor (6) has a motor rotor recess (613), the motor rotor recess (613) being open at a motor rotor end face (612), wherein the motor rotor recess (613) has an inner circumferential surface (614) and an inner bottom surface (615), wherein the magnet is positioned at the inner circumferential surface or the inner bottom surface.

4. Pump unit (26) for pressurizing a hydraulic actuation system (21), in particular for pressurizing an automotive actuation system, such as a convertible top system (2), a trunk lid, a hood system or a wheel suspension of a vehicle (1), wherein the pump unit comprises a pump housing (261), which pump housing (261) comprises a pump cavity (264) for accommodating a piston pump (4), and wherein the pump unit (26) further comprises an electric motor (3) for driving the piston pump,

wherein the electric motor (3) comprises:

wherein the piston pump (4) comprises:

wherein the motor rotor (31) and the pump rotor (46) are incorporated into a common rotor (6), the common rotor (6) being a one-piece item comprising a motor rotor portion (61) and a pump rotor portion (62), and wherein the magnet (33) of the motor rotor (31) is positioned at a motor rotor end face (612) of the common rotor (6).

5. Pump unit (26) for pressurizing a hydraulic actuation system (21), in particular for pressurizing an automotive actuation system, such as a convertible top system (2), a trunk lid, a hood system or a wheel suspension of a vehicle (1), wherein the pump unit comprises a pump housing (261), which pump housing (261) comprises a pump cavity (264) for accommodating a piston pump (4), and wherein the pump unit (26) further comprises an electric motor (3) for driving the piston pump,

wherein the electric motor (3) comprises:

wherein the piston pump (4) comprises:

wherein the motor rotor (31) and the pump rotor (46) are incorporated into a common rotor (6), the common rotor (6) being a piece of goods comprising a motor rotor portion (61) and a pump rotor portion (62), and wherein the pump unit (26) further comprises a control unit (29) for controlling the pump flow, wherein the control unit (29) is connectable to a closure (265) of the pump housing (261) for closing a pump cavity (264), wherein the control unit (29) and the closure (265) form a subassembly mountable as a module to the pump housing.

6. Pump unit (26) for pressurizing a hydraulic actuation system (21), in particular for pressurizing an automotive actuation system, such as a convertible top system (2), a trunk lid, a hood system or a wheel suspension of a vehicle (1), wherein the pump unit comprises a pump housing (261), which pump housing (261) comprises a pump cavity (264) for accommodating a piston pump (4), and wherein the pump unit (26) further comprises an electric motor (3) for driving the piston pump,

wherein the electric motor (3) comprises:

wherein the piston pump (4) comprises:

wherein the motor rotor (31) and the pump rotor (46) are incorporated into a common rotor (6), the common rotor (6) being one piece comprising a motor rotor portion (61) and a pump rotor portion (62), and wherein a reservoir (263) is formed by the pump cavity in the pump housing.

Thus, a pump unit for pressurizing a hydraulic actuation system comprises a pump housing 261 having a pump chamber for accommodating the pump and an electric motor for driving the pump. The electric motor is a brushless DC motor including a motor rotor having a number of magnets at an outer surface and an excitation coil positioned opposite the magnets to rotationally drive the motor rotor. The pump unit further comprises a control unit comprising a printed circuit board for controlling the electric motor. The control unit and the closure form a subassembly that can be mounted as a module to enclose the pump chamber. The control unit comprises at least one hall sensor to detect the rotational position of the motor rotor. The at least one hall sensor is positioned on a printed circuit board positioned opposite the motor rotor end face.

Description of the figures

42 pump stator for 1 vehicle

11 front window frame 420 pump stator body

12 locking member 421 Pump stator proximal end

422 pump stator distal end

2 convertible roof system 43 entryway

20 convertible top 44 exit passage

200 roof part 46 pump rotor

201 remaining roof part

202 cover plate 48 eccentric ring

481 running surface

21 outer circumferential ring surface of hydraulic actuation system 482

23. 23' hydraulic cylinder

24. 24' Hydraulic Cylinder 484 Motor end face

25 hydraulic cylinder 49 connecting rod

22 hydraulic cylinder E eccentricity

26 Pump Unit

261 Pump housing 5 Ring actuator

263 reservoir 53 lever

264 Pump Chamber

2641 bottom surface 6 common rotor

2642 circumferential surface 61 Motor rotor portion

265 enclosure 610 motor rotor body

28 valve unit 611 motor rotor outer circumferential surface

29 control unit 612 motor rotor end face

613 motor rotor recess

614 motor rotor inner circumferential surface

3 electric motor 615 motor rotor inner bottom surface

31 motor rotor

32 field coil 62 pump rotor section

33 magnet 620 pump rotor body

34 hall sensor 621 outer circumferential rotor surface

35 rotor mark 622 pump rotor end face

4-piston pump

40 rotary piston pump

41 piston

410 piston body

Claims

1. Pump unit (26) for pressurizing a hydraulic actuation system (21), wherein the pump unit comprises a pump housing (261), which pump housing (261) comprises a pump chamber (264) for accommodating a pump, and wherein the pump unit further comprises an electric motor (3) for driving the pump,

wherein the electric motor (3) comprises:

-an excitation coil (32), the excitation coil (32) being positioned opposite the magnet (33) of the motor rotor body (610) to rotationally drive the motor rotor body;

wherein the pump unit (26) further comprises a control unit (29) for controlling the electric motor (3) of the pump unit, wherein the control unit (29) comprises a Printed Circuit Board (PCB) connected to a closure (265) of the pump housing, wherein the control unit (29) and the closure (265) form a subassembly which can be mounted as a module to the pump housing (261) to enclose the pump cavity (264), wherein the electric motor (3) is a brushless DC motor, wherein the control unit (29) comprises at least one Hall sensor (34) to detect the rotational position of the motor rotor (31), wherein the at least one Hall sensor (34) is positioned on the Printed Circuit Board (PCB) of the control unit (29), the Printed Circuit Board (PCB) is positioned opposite the motor rotor end face (612).

2. Pump unit (26) according to claim 1, wherein the closure (265) is plate-shaped, in particular formed as a cover, which fits to a pump chamber opening, wherein the Printed Circuit Board (PCB) is dimensioned to fit in a closure recess to align the at least one Hall sensor (34) with a rotor mark (35) of the motor rotor (31).

3. Pump unit (26) according to claim 1 or 2, wherein the Printed Circuit Board (PCB) of the control unit (29) is positioned outside the pump cavity (264) at an outer surface of the closure (265).

4. Pump unit (26) according to claim 1, wherein the magnet (33) of the motor rotor (31) is positioned at the motor rotor end face (612) of the motor rotor (6).

5. The pump unit (26) of claim 4, wherein the excitation coil (32) is positioned outside of the pump cavity (264) of the pump housing (261).

6. Pump unit (26) according to claim 1, wherein the modules of the control unit (29) and the closure (265) further comprise at least one excitation coil (32) of the electric motor.

7. Pump unit according to claim 3, wherein the closure (265) comprises a non-ferrous material to conduct the generated magnetic field.

8. Pump unit (26) according to claim 1, wherein the motor rotor (6) has a motor rotor recess (613), the motor rotor recess (613) being open at a motor rotor end face (612), wherein the motor rotor recess (613) has an inner circumferential surface (614) and an inner bottom surface (615), wherein the magnet (33) is positioned at the inner circumferential surface or the inner bottom surface.

9. Pump unit (26) according to claim 1, wherein the magnet (33) of the motor rotor (31) is positioned at an outer circumferential motor rotor surface (611).

10. The pump unit (26) of claim 1, wherein a reservoir (263) is formed by the pump cavity in the pump housing.

11. A hydraulic actuation system (21) comprising a pump unit (26) according to any one of the preceding claims.

12. A vehicle suspension comprising a hydraulic actuation system (21) according to claim 11, wherein the vehicle suspension comprises a linkage and at least one hydraulic cylinder for actuating a link of the linkage to allow active control of the vehicle wheel suspension.

13. Convertible roof system (2) comprising a hydraulic actuation system (21) according to claim 11, wherein the convertible roof system (2) comprises a convertible roof (20), the convertible roof (20) comprising a roof part (3), which roof part (3) is movable relative to the remaining roof parts (6).

14. A vehicle (1) comprising a hydraulic actuation system (2) according to claim 11.

15. Use of a pump unit (26) according to any one of claims 1-10 in the marine, medical or civil field, for example in marine equipment such as ship doors, hatches, lifts, telescopes, bulwarks, masts, mooring gangways, etc.; in the medical field, for example, medical tools, lifts, trolleys, chairs or stretchers, for example ambulance stretchers or dental chairs, or medical tables, for example operating, treatment or scanning tables; in the civil sector, for example for operating doors or hatches of buildings, such as sliding garage doors, portholes, skylights or shutters.