The present invention relates to a vane cell pump in accordance with the type more specifically described in the preamble of claim 1.
Mechanical vane cell pumps with adjustable stroke rings are, for example, sufficiently known. With such vane cell pumps, a pressurization of the rear vane chamber is provided, in order to, in ongoing operation, subject the respective vanes to rear vane chamber pressure in such a manner that they are moved radially outwards. However, upon the start of the vane cell pump, the pump pressure initially must be built up, such that no rear vane chamber pressure is initially present. In addition, at low ambient temperatures, the problem arises that, due to the friction conditions, the vanes do not independently extend into the joining gap, and thus no pumping pressure can be generated.
As such, so-called “forced guides” are provided with vane cell pumps. For example, a forced guide ring can be provided in a radially inward manner at the rotor for this purpose, such that this additional component mechanically forces out the vanes. However, due to the radial dimensions of the forced guide ring, an additional need for radial installation space arises, since the forced guide ring is inserted radially inward. In order to obtain the same sealing conditions as with a vane cell pump without a forced guide ring, when viewed radially, a larger installation space is thus required. Otherwise, there is a poorer hydraulic degree of efficiency.
The present invention is subject to the task of proposing a vane cell pump of the type described above, with which a forced guide is ensured without a loss of efficiency and without an additional need for installation space.
In accordance with the invention, this task is solved by the characteristics of claim 1. Additional advantages and advantageous embodiments arise from the subclaims and the description along with the drawings.
Thus, what is proposed is a vane cell pump with a rotor rotatably mounted in an adjustable stroke ring and driven by a drive shaft, with several vanes that are mounted in a radially displaceable manner in radially running slots of the rotor. The vanes are subjected to rear vane chamber pressure, whereas at least one forced guide element is allocated to one vane for the radial movement of the vane in such a manner that the forced guide element is integrated into the rotor and/or into the drive shaft without any effect on installation space.
In this manner, the existing installation space of the rotor and the drive shaft is used to accommodate the forced guide element without any effect on installation space. The integration means that the forced guide element radially passes through the drive shaft and/or the rotor at least in sections.
Thus, with the vane cell pump in accordance with the invention, suction performance is ensured, and losses of efficiency and expansions of installation space are thus prevented in an advantageous manner.
In accordance with one possible embodiment of the present invention, it can be provided that two vanes are coupled with each other through the forced guide element radially passing through the drive shaft and running in sections in the rotor. A rigid or even a non-rigid coupling rod may be provided as a forced guide element.
Upon the use of a rigid coupling rod that is designed to be structurally simple, the forcibly guided vanes are arranged opposite to each other. This ensures that if one of the vanes is retracted, the other is guided radially outwards, in order to build up corresponding pump pressure immediately upon starting the pump. Thus, with the vane cell pump in accordance with the invention, starting performance is generally optimized, without increased leakage occurring due to the reduced length of the axial gap.
With non-opposing vanes, non-rigid coupling rods, such as articulated coupling rods or the like, can be used for forced guidance. An articulated coupling rod includes, for example, a first rod element and a second rod element, which are in an operative connection with each other in an articulated manner. As the articulated connection, a sliding block (for example), but also other structural solutions, can be provided. In this manner, forced guides for vane cell pumps with asymmetrical vanes arrangements are easily possible.
In accordance with an additional embodiment, it is also conceivable that only one vane is forcibly guided. This design is particularly suitable for double-stroke vane cell pumps.
For example, for this purpose, a spring-loaded piston element arranged in a guide groove running radially through the drive shaft is provided as the forced guide element; this is in operative connection with a coupling rod on the rotor side for the forced actuation of the associated vane. With this possible design, the forced guide element is virtually integrated into the drive shaft and partly integrated in the rotor.
Another type of design may provide that a spring-loaded piston element guided into the radially running slot of the associated vane of the rotor is provided as the forced guide element; this is in operative connection with the vane on the side turned away from the spring element. With this design, the forced guide element is integrated only into the rotor.
The present invention is further described below with reference to the drawings. The following is shown:
FIG. 1 a schematic sectional view of a first embodiment of a vane cell pump in accordance with the invention with a rigid coupling rod as a forced guide element for coupling two opposing vanes;
FIG. 1A an additional view of the first embodiment of the vane cell pump in accordance with FIG. 1 with an adjusted stroke ring;
FIG. 1B an alternative arrangement in accordance with FIG. 1 with two rigid coupling rods for coupling respective opposing vanes;
FIG. 1C an additional sectional view in accordance with FIG. 1B
FIG. 2 a schematic sectional view of a second embodiment of the vane cell pump with an articulated coupling rod as a forced guide element;
FIG. 3 a schematic sectional view of a third embodiment of the vane cell pump with a forced guide element for forcibly guiding a vane; and
FIGS. 4 to 6B several schematic sectional views of a fourth embodiment of the vane cell pump with a forced guide element arranged exclusively within the rotor.
FIGS. 1 to 6 show examples of various views and embodiments of a vane cell pump in accordance with the invention. Regardless of the respective embodiments, the vane cell pump comprises a rotor 3 rotatably mounted in an adjustable stroke ring 1 and driven by a drive shaft 2, on which several vanes 4 are provided. The stroke ring 1 is adjustable by an adjusting spring 15 around the pivot point 16 on the housing of the vane cell pump, such that the coaxially arranged rotor 3 in FIG. 1 is not displaceable into the coaxial location shown in FIG. 1A. The vanes 4 are mounted in a radially displaceable manner in radially running slots 12 of the rotor 3, which form the rear vane pressure chamber, and are subjected to rear vane chamber pressure, such that they can be brought into corresponding radial end positions. In order to ensure a corresponding radial movement of each vane 4 upon starting the vane cell pump, it is provided that a forced guide element is allocated to at least one vane 4 for the radial movement of the vane 4. In accordance with the invention, it is provided that the forced guide element is integrated in the rotor 3 and/or in the drive shaft 2 without any effect on installation space.
FIGS. 1 to 1 C show a first possible embodiment, with which two opposing vanes 2 are coupled with each other through a forced guide element running radially through the drive shaft 2 and in sections through the rotors 3. A rigid coupling rod 5 is provided as the forced guide element; this is connected to the opposing vanes 4. The rigid coupling rod 5 runs through a guide groove 9 of the drive shaft, whereas the two ends of the rigid coupling rod 5 are each guided into one slot 12 of the rotor 3.
In FIGS. 1 to 1 C, a symmetrical vane distribution is provided for the vane cell pump. FIG. 1 shows a concentric arrangement of the rotor 3, with which the rigid coupling rod 5 is centrally arranged. In FIG. 1A, the stroke ring 1 is adjusted, such that a single-stroke vane cell pump is provided with vanes 4 that are arranged in a symmetrically distributed manner, FIG. 1B and 1C show an alternative arrangement, for which several rigid coupling rods 5, 5A are provided, with which, in each case, opposing vanes 4 are coupled with each other. FIG. 1C shows a sectional view, from which it is clear that the coupling rods 5, 5A can be arranged in different planes.
A second possible embodiment is shown in FIG. 2, with which an articulated piston rod is provided as the forced guide element, which connects with each other two vanes 4 that are not directly opposing. Thus, this embodiment is intended for an asymmetrical vane arrangement for the vane cell pump. The articulated piston rod comprises a first rod element 6 and a second rod element 7, which are in operative connection with each other in an articulated manner through a sliding block 8. Moreover, with this embodiment, the forced guide element is provided radially through the input shaft 2 and in sections in the slots 12 of the associated vane 4.
The first rod element 6 and the second rod element 7 are, at least in sections, guided into the respectively assigned slot 12 of the rotor 3, whereas the ends of the rod elements 6, 7 turned towards the sliding block 8 are guided into the guide groove 9 of the drive shaft 2. The sliding block 8 is guided into a guide groove 9 running through the drive shaft 2. The respective longitudinal axis of the rod elements 6, 7 are aligned orthogonally with respect to the facing surfaces of the sliding block 8. For example, the associated surfaces of the sliding block 8 are designed to be spherical. Thus, changes in length can be compensated by different contact positions.
In FIGS. 3 and 4, additional embodiments are shown, with which one forced guide element is solely assigned to one vane 4. The forced guide element pushes the corresponding vane in an unpressurized state in a radially outward manner against the stroke ring 1. As soon as the vane cell pump is in operation, the forced guide element is pushed against a spring force into an end position, and the vane 4 is pushed over the rear vane chamber pressure against the stroke ring 1.
FIG. 3 shows a third embodiment, with which a spring-loaded piston element 10 arranged in a guide groove 9 running radially through the drive shaft 2 is provided as the forced guide element; this is in operative connection with a coupling element 11 for the forced actuation of the associated vane 4. The coupling element 11 is guided, on the one hand, into the guide groove 9 and, on the other, into the slot 12 of the vane 4. The guide groove 9 is connected with the slots 12 of the vane 4 in such a manner that, in the ongoing operation of the vane cell pump, the end of the piston element 10 turned towards the coupling element 11 is subjected to rear vane chamber pressure. In this manner, the coupling element 11 is pressed against the associated vane 4, such that the vane is moved in a radially outward manner. On the other hand, due to the pressurization of the rear vane chamber, the piston element 10 is pressed in a radially inward manner against the force of the spring element 13. In this way, a decoupling between the forced guide element and the vanes 4 in the ongoing operation of the vane cell pump is ensured.
FIGS. 4 through 6B show various views and operating states for a vane cell pump in accordance with a fourth embodiment of the invention. In contrast to the third embodiment, with the fourth embodiment, the forced guide element is arranged exclusively in the rotor 3 of the vane cell pump. For this purpose, a piston element 10A is arranged in a radially movable manner in the slot 12 of the associated vane 4. The piston element 10A is arranged in a movable manner through a spring element 13A in a radially outward manner against the associated vane 4. In the ongoing operation of the vane cell pump, the slots 12 of the vane 4 can be subjected to rear vane chamber pressure through an annular channel 14.
FIGS. 4 through 4B show the double-stroke vane cell pump in the operating state with which the forcibly guided vane 4 is fully retracted, such that the piston element 10A is moved against the force of the spring element 13A in a radially inward manner into its final state. This state is shown in several sections.
FIGS. 5 to 5B show an operating state of the vane cell pump, with which the piston element 10A is moved in a radially outward manner through the spring force of the spring element 13A to the associated vane 4, whereas different sectional views are shown.
Finally, FIGS. 6 to 6B show the state with which the vane cell pump is in ongoing operation, since the vanes 4 are subjected to rear vane chamber pressure, such that it is moved in a radially outward manner, and simultaneously the piston element 10A is moved against the force of the spring element 13A in a radially inward manner into its end positions.
REFERENCE SIGNS
1 Stroke ring
2 Drive shaft
3 Rotor
4 Vane
5 Rigid coupling rod
6 First rod element
7 Second rod element
8 Sliding block
9 Guide groove
10,10A Piston element
11 Piston element
12 Slot
13,13A Spring element
14 Annular channel
15 Adjusting spring
16 Pivot point
Patent Application
20160177947
