Electrical generator or motor structure – Dynamoelectric – Oscillating
Reexamination Certificate
2000-03-20
2001-02-06
Ramirez, Nestor (Department: 2834)
Electrical generator or motor structure
Dynamoelectric
Oscillating
C277S407000, C092S125000
Reexamination Certificate
active
06184598
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an oscillating motor employed in particular in the aircraft and vehicle industry.
An oscillating motor of this type consists in general of a stator with a housing having covers on both ends. One or more stator wings are arranged in the housing. A drive shaft which is equipped with an identical number of rotor wings, is supported in the covers. This stator wings and the rotor wings form several chambers having adjustable volumes. The chambers are formed as pressure and discharge chambers, respectively, and are therefore connected with respective supply and the discharge connections.
To provide internal leak-tightness, the pressure chambers and the discharge chambers are separated from each other by a respective frame scaling element which encloses the stator ring and the rotor wing, respectively.
To provide leak-tightness to the outside, a respective annular sealing clement is arranged in the region of the drive shaft between the rotor and each cover. The sealing element is preferably located in the cover.
2. Description of the Related Art
U.S. Pat. No. 3,195,421 describes an oscillating motor which has an annular scaling element in the form of a flexible diagonal sealing ring. The flexible diagonal sealing ring is inserted into an annular groove of the cover and is supported by the wall of the annular groove. Its diagonal sealing edge is oriented against the direction of the pressure towards the circumferential scaling gap located between the end faces of the cover and the rotor wing.
The diagonal scaling ring is subjected to considerable wear due to the frequent change in the relative movement between the diagonal scaling ring affixed in the cover and the rotor wings. This arrangement causes leaks at an early stage of the operation.
An oscillating motor with a similar sealing arrangement is described in U.S. Pat. No. 3,426,654, wherein the diagonal sealing ring is pre-tensioned by a flexible O-ring through a support element. This arrangement attempts a trade-off between leak-tightness and sliding characteristics by carefully dimensioning the force components which act on the diagonal sealing ring.
In this modified sealing arrangement, the sliding and sealing properties are therefore not optimized. Because of the occurring leakage, an additional cylinder seal is required on the journal of the rotor to prevent oil from leaking out. This additional cylinder seal, however, entraps the leaked material and therefore applies in the non-operating state a pressure on the diagonal sealing ring as well as on the rotation bearing, which is adversely affects the start-up characteristics of such an oscillating motor. This arrangement also shortens the service life and limits the possible application for oscillating motors of this type.
Instead of a diagonal scaling ring, a sliding sealing ring may be disposed in the cover to improve the running characteristics.
This modified sealing arrangement, however, is typically rejected because of its poor sealing properties.
Moreover, the sliding sealing ring is in constant contact with the frame sealing element of the rotor and stator wings. Since it is difficult to eliminate a relative movement between the sliding sealing ring and the frame sealing element, the frame sealing element is highly stressed, which results in a short service life.
Is therefore an object to develop a radial oscillating motor of the aforedescribed type which incorporates static sealing points between the rotor and the annular sealing elements.
SUMMARY OF THE INVENTION
This object is solved by the characterizing features of claim
1
. Advantageous embodiments are described in the dependent claims
2
to
10
.
The invention eliminates the aforedescribed disadvantages of the prior art. Particularly advantageous is the high leak-tightness of the pressure chambers to the outside, a wear-resistant design of the sealing elements and, at the same time, an extremely quiet running characteristics of the rotor.
Advantageously, the sealing points in the region of the rotor wings are removed away from the sliding surfaces between the rotor and the covers and instead moved to a region where this sealing point is formed by components which run relatively quiet. In this way, approximately 50% of the dynamic seals found in prior art devices are converted into static seals. Accordingly, the sliding function of the sliding sealing ring on the radial sealing gap is spatially separated from the sealing function of the sliding sealing ring on the axial sealing gap, so that the sliding sealing ring can be optimized for specific applications.
The sealing properties are also improved because the soft sealing ring, in particular a soft sealing ring in the form of a diagonal sealing ring, is exposed to the pressure of the leaking oil inside the mounting space and is therefore pressed against the scaling gaps in opposite directions. The leakage therefore remains entrained and can no longer leak out, which would otherwise be possible due to the play between the bearing journal and the cover. This arrangement eliminates additional high-pressure seals. Conversely, the increased pressure on the diagonal sealing ring improves the sealing characteristics at the sealing gap which faces the pressure chamber.
The sealing characteristics is also improved because a pressure, which represents the pressure in the pressure chamber and an identical pressure in the mounting space of the diagonal sealing ring, is applied across the entire annular surface of the sliding sealing ring. The sliding sealing ring is thereby pressed against the cover uniformly and with greater force.
To attain a quiet running characteristics, the radial sliding and sealing surface of the sliding sealing ring advantageous is greater in the radial direction than the sliding ring. In this was, the system can be adapted to specific applications.
Advantageously, a locking arrangement for preventing rotation may be provided between the rotor and the sliding sealing ring to ensure that the sliding sealing ring does not move relative to any other sealing element, i.e., neither relative to the frame sealing element nor relative to the diagonal sealing element. This locking arrangement preserves the static characteristics of the sealing point.
In a simple and cost-effective embodiment, the locking arrangement includes at least one recess in the form of an axial groove located on the sliding sealing ring and at least one driver clement on the rotor wing, wherein the recess and the driving element are in engagement with each other.
The driver element may be formed of the existing end face of one of the two legs or of both legs of the rotor wing, in which case the axial grooves would have to be provided as pairs. With such a rotation locking arrangement, the marginally sealed axial sealing gap may then be sealed with an additional soft sealing ring. This arrangement advantageously improves the leak-tightness to the outside, while at the same time ensuring a long service life of the soft sealing ring.
Advantageously, the end faces of the covers and the housing may be formed as continuous planar surfaces, wherein the covers and the housing may be secured in the radial direction by a centering element, for example a tension ring. The end faces can then be machined more accurately and the radial sealing gap better optimized, which in turn improves the leak-tightness and the hydraulic efficiency of the oscillating motor.
The invention the described hereinafter in greater detail with reference of an embodiment.
REFERENCES:
patent: 3128679 (1964-04-01), Trendle
patent: 3195421 (1965-07-01), Rumsey et al.
patent: 3207047 (1965-09-01), O'Connor
patent: 3426654 (1969-02-01), Laughman
patent: 4809590 (1989-03-01), Naumann et al.
patent: 5560621 (1996-10-01), Zutz
patent: 5791444 (1998-08-01), Schiffler
patent: 5996523 (1999-12-01), Fox
Beetz Stefan
Reichel Klaus
Darby & Darby
Jones Judson H.
PNP Luftfedersysteme GmbH
Ramirez Nestor
LandOfFree
Sealing ring for an oscillating motor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sealing ring for an oscillating motor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sealing ring for an oscillating motor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2590844