Expansible chamber devices – With fluid purifying means
Patent
1980-06-23
1982-08-24
Therkorn, Ernest G.
Expansible chamber devices
With fluid purifying means
92 87, 92121, 210222, F15B 2104, F01C 900
Patent
active
043455093
DESCRIPTION:
BRIEF SUMMARY
DESCRIPTION
1. Technical Field
This invention relates generally to rotary actuators for effecting limited controlled rotational movement of one element relative to another and more particularly to fluid pressure operated rotary actuators.
2. Background Art
Controlled changes of the rotational position of one component of a machine relative to another component are often provided for by connecting a fluid pressure operated rotary actuator between the components. For example, backhoe attachments for excavating earth and which are supported on a vehicle typically include a rotary hydraulic actuator which enables pivoting of the excavating elements relative to the vehicle about a vertical axis. Essentially similar rotary actuators are used in diverse other types of apparatus.
Rotary actuators of this type have a housing and an actuator shaft which jointly define an annular internal chamber. A divider fixed to the housing extends to the shaft within the chamber and a pivotal vane fixed to the shaft extends to the housing. By directing pressurized fluid into the chamber at one side of the divider while draining fluid at the other side, the vane and shaft may be caused to turn a desired amount relative to the housing. Seals are usually provided along the lines of contact of the vane and divider with the interior walls of the chamber and along the line of contact of the divider with the actuator shaft to avoid a loss of efficiency and precision from fluid leakage.
Durability has been reduced and maintenance problems have been complicated as a result of internal damage from abrasive metallic particles which accumulate in the actuator chamber. The harder and more abrasive particulate contaminants arise from the grinding of metal elements of the system and tend to be predominately ferromagnetic. Particles which accumulate at the bottom of the actuator chamber are repetitively moved back and forth by the motion of the actuator vane and damage the seals and walls of the actuator chamber. This ultimately requires replacement of actuator components and, in the interim, makes costly cleaning procedures advisable.
Damage from metallic contaminants tends to be relatively severe in rotary actuators as compared with other forms of fluid motors. The flushing effect of the fluid flow in a rotary actuator is often relatively low. In the backhoe usage discussed above, much larger volumes of fluid are typically applied to the piston and cylinder actuators which also manipulate portions of the mechanism. Further, it is a common practice to use a separate fluid source for the rotary actuator. Because of the low flow requirements, no filter may be provided in the flow circuit.
To minimize damage by particulate contaminants, it has been heretofore necessary to disassemble and clean the rotary actuator periodically. This includes draining and preferably replacing the actuator fluid. These maintenance procedures are undesirably complicated, costly and time consuming and at best do not avoid abrasion damage as effectively as would be desirable.
The present invention is directed to overcoming one or more of the problems as set forth above.
DISCLOSURE OF THE INVENTION
In one aspect of the present invention, a rotary actuator has housing means for defining a vane chamber, an actuator shaft extending within the vane chamber and being rotatable relative to the housing means, a vane extending radially from the actuator shaft within the vane chamber, and port means for transmitting pressurized fluid to and from the vane chamber to pivot the vane and turn the actuator shaft relative to the housing means. The actuator is further provided with trapping means for retaining particulate contaminants of the fluid in the chamber at a location which is away from the path of movement of the vane.
In another aspect of the present invention the actuator includes magnetic means for holding ferromagnetic particles at the location away from the path of movement of the vane.
In still another aspect of the present invention, the trapping means includes a su
REFERENCES:
patent: 2854956 (1958-10-01), Hager
patent: 3049102 (1962-08-01), Reimer et al.
patent: 3696713 (1972-10-01), Ragard
patent: 3731598 (1973-05-01), Brignon
patent: 3869391 (1975-03-01), Kramer
Bridwell John W.
Doyle James R.
Caterpillar Tractor Co.
Therkorn Ernest G.
LandOfFree
Contaminant trap for fluid operated rotary actuator does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Contaminant trap for fluid operated rotary actuator, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Contaminant trap for fluid operated rotary actuator will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1432476