Patent Application
20220252066
The present disclosure relates generally to a gerotor pump, and more specifically to a split power gerotor pump.
Split power gerotor pumps are known. One example is shown and described in U.S. Pat. No. 10,072,660 titled PUMPING DEVICE FOR PUMPING OIL FROM A STORAGE CONTAINER TO A TRANSMISSION SYSTEM OF A MOTOR VEHICLE to Böhm.
Example embodiments broadly comprise a split power gerotor pump including a rotational axis, a shaft, an inner gerotor, an eccentric pocket, and an outer gerotor. The inner gerotor is rotationally fixed on the shaft, rotatable about the rotational axis, and includes n first lobes. The eccentric pocket is rotatable about the rotational axis, and includes a cylindrical bore with a center radially offset from the rotational axis and an outer surface, disposed radially outside of the cylindrical bore and arranged for direct engagement with a gear or a rotor for an electric motor. The outer gerotor includes a cylindrical outer surface installed in the cylindrical bore and n+1 second lobes.
In some example embodiments, the split power gerotor pump includes a first port plate fixed to the eccentric pocket on a first axial side and a second port plate fixed to the eccentric pocket on a second axial side, opposite the first axial side. The first port plate has a first orifice for directing a hydraulic fluid into a gap between a one of the n first lobes and a one of the n+1 second lobes, and the second port plate has a second orifice for receiving the hydraulic fluid after relative rotation between the inner gerotor and the outer gerotor compresses the gap. In some example embodiments, a one of the first port plate or the second port plate is integrally formed with the eccentric pocket from a same piece of material. In an example embodiment, the split power gerotor pump has a first seal that seals a first annular face of the other one of the first port plate or the second port plate to a second annular face of the eccentric pocket.
In some example embodiments, the split power gerotor pump has a housing with a collection chamber hydraulically connected to the first orifice and arranged for hydraulic connection to a hydraulic sump. In an example embodiment, the shaft extends through an axial entirety of the collection chamber. In some example embodiments, the split power gerotor pump includes an outlet cover fixed to the second port plate and a second seal disposed between the outlet cover and the second port plate for sealing the outlet cover to the second port plate. The outlet cover has a tubular protrusion concentric with the rotational axis for expelling the hydraulic fluid. In an example embodiment, the split power gerotor pump includes a first bearing installed on the tubular protrusion. The outlet cover has a cylindrical protrusion, the second port plate has a cylindrical bore, and the cylindrical protrusion is installed in the cylindrical bore for radially positioning the second port plate relative to the outlet cover.
In some example embodiments, the split power gerotor pump includes a second bearing installed in the eccentric pocket for rotatably supporting the shaft. In some example embodiments, the split power gerotor pump includes a housing and a third bearing installed in the housing for rotatably supporting the eccentric pocket. In an example embodiment, the split power gerotor pump includes a third seal installed in the eccentric pocket axially between the third bearing and the outer gerotor for sealing the eccentric pocket to the housing.
In some example embodiments, the split power gerotor pump includes a housing and an electric motor. In some example embodiments, the electric motor is fixed to the housing and drivingly engaged with the shaft. In an example embodiment, the split power gerotor pump includes a fourth seal for sealing seal the housing to the electric motor. In an example embodiment, the outer surface of the eccentric pocket has a toothed profile arranged for direct engagement with the gear.
In some example embodiments, the electric motor has a stator rotationally fixed to the housing and including a plurality of stator coils, and the rotor rotationally fixed to the outer surface of the eccentric pocket. In an example embodiment, the stator is a magnetic stator and the rotor is a magnetic rotor. In an example embodiment, a straight line extending radially outward from the rotational axis passes through, in order, the inner gerotor, the outer gerotor, the rotor and the stator.
Embodiments of the present disclosure are described herein. It should be appreciated that like drawing numbers appearing in different drawing views identify identical, or functionally similar, structural elements. Also, it is to be understood that the disclosed embodiments are merely examples and other embodiments can take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the embodiments. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures can be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations.
The terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the present disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure belongs. Although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the disclosure, the following example methods, devices, and materials are now described.
The following description is made with reference to
The inner gerotor is rotationally fixed on the shaft by ground flats 114 (ref.
Port plate 128 is fixed to eccentric pocket 110 on axial side 130, and port plate 132 is fixed to eccentric pocket 110 on axial side 134, opposite axial side 130. Port plate 128 includes orifice 136 for directing the hydraulic fluid into gap 138 between lobe 140 and lobe 142, and port plate 132 includes orifice 144 for receiving the hydraulic fluid after relative rotation between the inner gerotor and the outer gerotor compresses the gap. In the embodiment shown in
Seal 146 seals annular face 148 of port plate 132 to annular face 150 of the eccentric pocket. Housing 152 includes collection chamber 154 hydraulically connected to orifice 128 and arranged for hydraulic connection to a hydraulic sump (not shown). As shown in
Outlet cover 156 is fixed to port plate 132 and includes tubular protrusion 158 concentric with the rotational axis for expelling the hydraulic fluid from the port plate. Seal 160 is disposed between the outlet cover and port plate 132 for sealing the outlet cover to the port plate. Bearing 162 is installed on the tubular protrusion. The outlet cover includes cylindrical protrusion 164, port plate 132 includes cylindrical bore 166, and the cylindrical protrusion is installed in the cylindrical bore for radially positioning the second port plate relative to the outlet cover.
Bearing 168 is installed in the eccentric pocket for rotatably supporting the shaft, and bearing 170 is installed in housing 152 for rotatably supporting the eccentric pocket. Seal 172 is installed in the eccentric pocket axially between bearing 170 and the outer gerotor, for sealing the eccentric pocket to the housing.
In the embodiment shown in
The following description is made with reference to
While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments can be combined to form further embodiments of the disclosure that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics can be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes can include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, to the extent any embodiments are described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics, these embodiments are not outside the scope of the disclosure and can be desirable for particular applications.
