Background of the Invention
This invention relates to fluid spray equipment, more particularly it relates to rotary fluid spray apparatus for car washes.
Various rotary fluid spray apparatus have been employed for providing pressurized fluid spray to vehicles in automatic car washes. These apparatus spray fluids under pressure for cleaning, rinsing, waxing or other functions. These mechanisms are particularly appropriate for vehicle washes which do not utilize cloth or other materials which make contact with the exterior of the vehicle. In such "non-contact" automatic car washes a number of such apparatus will be utilized each with one or more spray nozzles directed toward the vehicle with the nozzle being rotated about an axis substantially parallel to the nozzle discharge direction to create a fast moving wide circular spray pattern. The fluid spray mechanism is moved longitudinally along the vehicle, either by moving the spray mechanism or the vehicle such that broad swaths on the vehicle exterior may be covered on each pass. Prior art rotary spray mechanisms have been high maintenance items requiring regular maintenance or replacement with seals being a particularly vulnerable portion of the mechanisms.
Summary of the Invention
A rotary spray fluid apparatus anchored to a carwash structure directs a high pressure discharge in a circular pattern at a vehicle. The apparatus has an elongate body portion with a first end and a second end, has a bore extending from end, to end and has a side inlet communicative with the bore. A rotatable hollow shaft of a second diameter extends through the bore defining an annular space with fluid transfer region, a pair of sealing regions and a pair of bearing regions. The shaft has an intermediate portion with a port extending into an axial passageway in the bore. The shaft has a pair of sealing sections each positioned axially outward from the intermediate portion, and a pair of bearing sections, each positioned axially outward from the sealing regions. A pair of bearings each having a hollow cylindrical section sized for the annular space, and a collar portion to abut an end of body portion. A pair of shaft retaining portions retain the bearings and shaft in the body portion. Each annular sealing region has a pair of sealing rings with engaging faces in a radial plane. One of each pair of sealing rings sealed to the body portion and the other sealed to the rotatable shaft. A spring positioned in the fluid transfer region of the annular space provides an axial compressive force to maintain the engaging faces together. One end of the shaft is coupled to a radially extending spray head with a plurality of nozzles pointing generally in an axially direction. As a pressurized fluid is provided to the apparatus at the side inlet, the shaft is rotated at the end opposite to the end with the radially extending conduit.
A feature of the invention is the relatively simple configuration providing a highly robust design capable of handling high fluid pressures for extended periods of time.
An object and advantage of the invention is that the rotary fluid apparatus is reliable, low in maintenance and highly suitable in the car wash environment.
A feature of the invention is a uniform annular space which contains the bearings, the sealing components and the spring. The uniform annular space facilitates economical manufacture and compact configuration.
A feature of the invention is the advantageous use of ultra high molecular weight plastic bearings which are ideally suited for the high moisture environment associated with car washes. The collared hollow cylindrical design of the bearings facilitates easy manufacture and provides for easy assembly.
Brief Description of the Drawings
FIG. 1 is an elevational view of the rotatable spray wash apparatus positioned over a vehicle.
FIG. 2 is a bottom plan view of the apparatus of FIG. 1.
FIG. 3 is a cross-sectional view through the fluid coupling union of the apparatus taken at 3--3 of FIG. 2.
FIG. 4 is a detail of a sectional view showing the annular space of the fluid coupling union and components therein.
Detailed Specification
Referring to FIGS. 1 and 2 the rotary spray apparatus is shown and is generally designated with the numeral 10. The rotary spray apparatus is connected to a car wash structure 14 such as by U-bolts 15 and is shown positioned above a vehicle 16, although the apparatus is equally suitable for use on the sides of and below vehicles.
The rotary spray apparatus 10 is comprised principally of a fluid coupling union 18 with a body portion 20, a rotatable shaft 24, a spray head 28 having nozzles 30, and a motor 34. A fluid source 36 connects to the body portion 20 by way of a coupling assembly 38. The motor 34 is mechanically coupled to the rotatable shaft by a conventional coupling 42. The spray head 28 has a hub portion 46 and arms 48. The spray head sprays fluid such as water, soap and water, wax solutions and rinse solutions at the vehicle. The nozzle discharge 50 is in a pattern as illustrated by the dashed lines in FIG. 1. The sprays pattern is frusto-conical and at any distance from the spray head has a particular width such as indicated by the diameter of the dashed outer circle 52 in FIG. 2. FIG. 2 also illustrates the circular pattern of the rotatable spray conduits as shown by dashed lines 54.
The motor 34 typically will be an electrically powered motor although other types of motors would also be suitable such as pneumatic or hydraulic. The motor drives the rotatable shaft and thus causes the spray head 28 to revolve as shown by the arrow 56. The direction of rotation is generally not significant. Alternatively, the nozzles 30 may be tilted slightly from parallel to the shaft to provide a rotational force from the nozzle discharge 50.
Referring to FIG. 3, a cross-sectional view of the fluid coupling 18 is shown. The fluid coupling 18 has the body portion 20 with a bore 62, and a side connection portion 67 with a side inlet 68. The side inlet is connected by way of a nipple 69 to the coupling assembly 38 by way of threaded connections. A driven end 70 of the rotatable shaft 24 is connected to the motor connector 42 by way of a key 71. The opposing outlet end 72 of the rotatable shaft 24 connects by way of threads 76 to the hub portion 46 of the spray head 28.
The body portion 20 has an exterior 80, a first end portion 81, a first end 82, and a second end portion 83, a second end 84, an interior 88 formed by the fluid inlet 68 and the bore 62, and an interior surface 90. The bore 62 has a first internal diameter as indicated by the dashed line designated with the numeral 94.
Abutting the ends 82, 84 of the body portion 20 are plastic bearings 98 and 100 formed out of ultra high molecular weight polyethylene, preferably oil impregnated. Such plastic is available from Pobco, Inc., 100 Hope Avenue, Worceter, Mass. 01603. Each bearing has a hollow cylindrical portion 102 and a collar portion 104. The end caps 106, 108 are configured as washers and are adjacent to the bearings 98, 100.
The rotatable shaft 24 extends through the body portion 20 and has a driveable end 112, a narrowed intermediate portion 113 and a fluid outlet end 114. A fluid passageway 118 configured as a bore extends from a fluid inlet 120 axially down the shaft 24 to communicate with a fluid outlet 122. The shaft has a second diameter indicated by the dashed line labelled 124. The shaft 24 and body portion 20 define an annular space 128. The first diameter 94 and second diameter 124 define an annular space 128. The annular space has an intermediate fluid transfer region 130, a pair of sealing regions 132, and a pair of bearing regions 134. Significantly, the annular space 128 is a uniform annular space 136 with uniform diameters at the bearing region and the sealing region. The uniform annular space facilitates assembly and ease of manufacture. At each sealing region 132 there is a set 140 of rings comprising cooperating sealing rings 142 comprising a first sealing ring 144, a second sealing ring 146 and a third spacer ring 148 which also functions as an O-ring retaining ring and also provides a spring engagement surface 149. Extending between the two sets of cooperating sealing rings is a spring 152 which spirals around the shaft 24. The spring 152 is shown as rotating with shaft in the configuration shown in the Figures.
The bore 62 in the body portion 20 has a pair of grooves 156 appropriately sized to accommodate internal conventional spiral spring retaining members configured as rings 158. A pair of shaft retainers 162, 164 on the shaft function to retain the shaft within the body portion 20 and to further generally secure the fluid coupling union 18 assembly together. The shaft retainer 162 at the first end 82 of the body portion 20 is shown configured as a shoulder with the retainer 164 at the second end 84 configured as a snap ring. Two snap rings or other configurations of retainers may also be suitable.
Referring to FIG. 4 details of the sealing region 132 and bearing region 134 of the annular space 128 are shown. The first sealing ring 144 abuts against the internal retaining member ring 158 and has a recess 170 with an O-ring 174. The first sealing ring 144 has an engaging surface 166 which is snugly fitted against the interior surface 90 and also has an inner surface 167 which is loosely fitted relative to the shaft 24. The first sealing ring has a sealing face 168 perpendicular to the shaft 24. The second sealing ring 146 has cut-away edge portions 182 and 184, a cooperating sealing face 186 and a recess 188 for an o-ring 190. The second sealing ring 146 has an inner facing shaft engaging face 192 which is snug against the shaft 24 and an outer surface 194 which is loosely fit relative to the inner surface 90 of the body portion 20. The third spacer ring 148 evenly distributes the spring 152 force, holds the O-ring 190 in place, is snug against the rotatable shaft 24, and is loose with respect to the body portion 20. When the fluid 200 in the inlet 64 and the annular space 128 is pressurized the fluid is retained within the fluid coupling by the set of sealing rings 140 and the O-rings 174, 190. The O-ring 190 seals the path of the fluid between the first sealing ring 144 and the shaft. The other O-ring 174 seals the fluid path between the second sealing ring 146 and the interior surface 90 of the body portion 20. The path between the first sealing ring 144 and the second sealing ring 146 is sealed by the cooperating sealing faces 168, 186. The cut-away edge portions 182, 184 on the second sealing ring 146 provide for even and stable wear of the cooperating sealing faces 186. The first sealing rings are suitably machined from stainless steel and the second sealing rings are suitably formed from high grade graphite such as AXF-5Q grade available from Poco Graphite, Inc., 1601 S. 8th Street, Decatur, Tex. 76234.
The motor 34 suitably drives the shaft at approximately 100 RPM's. The internal fluid pressure in the apparatus may approach 1,000 PSI which traditional seals cannot sustain for extended periods of time. Note that in the fluid coupling union the compressive load on the sealing faces 186, 168 is sustained both by the internal spiral spring retainers 158 and also by the retainers on the shaft.
The apparatus operates as follows: fluid under pressure from the fluid source 36 is provided to the side inlets 68 at the fitting portion 67. The fluid enters the interior 88 of the body portion and is sealed within the annular space 128 by way of the sealing faces as described above. The pressurized fluid enters the fluid passageway 118 and the rotating shaft 24 by way of the fluid inlet 120. The fluid under pressure then flows into the hub portion 46 out the arms 48 and is discharged by way of the nozzles 30. The high pressure spray in conjunction with the rotation of the spray head 28 provides an effective non-contact cleaning. The rotation of the spray head 28 on the shaft provides radial loading well within the range supportable by the UHMW polyethylene bearings 98, 100. Although the spray discharge from the nozzles does provide some axial loading this is readily absorbed by the internal spiral spring retaining rings 158 and the retainers 106, 164 on the shaft 24. Moreover, the motor 34 may be suitable engaged to support some of the axially loading on the shaft 24 due to the fluid spray force.
The center shaft and body portion and end caps may all suitably be machined from stainless steel for corrosion resistance.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention.