Abstract
A hydraulic cylinder for a drive unit assembly for a reciprocating floor slat conveyor system has a single tubular barrel divided into two chambers by a center head or plug. The center head is held in position by shrink fitting it into the barrel.
Claims
1. A hydraulic cylinder for use in a reciprocating floor conveyor system, comprising a barrel portion having a single barrel tube that is divided into two chambers by a central center head member, wherein the center head member is held in place inside said barrel tube by an interference fit, and wherein said interference fit comprises creating a temperature difference between said barrel tube and said center head member, with said center head member being cooler than said barrel tube, in a manner so that said temperature difference enables said center head member to be positioned within said barrel tube, followed by allowing said center head member to warm and said barrel tube to cool so that said center head is fixed in position inside said barrel tube.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The following is a general description of the attached images and drawings:
(2) FIG. 1 is a pictorial image of three milled aluminum cross drives for a drive unit, with each cross-drive having an integrated cylinder clamp with grooves that our machined into the cross-drive. The side or stiffening ribs are also milled or extruded into the cross drive. Bolt openings or other openings can be drilled at any location needed for drive shoes;
(3) FIG. 2 is a pictorial image of an aluminum drive unit with cross-drives missing. The hydraulic cylinders have grooves that are machined to match the aluminum cross-drives;
(4) FIG. 3 is a pictorial image of the underside of the aluminum cross-drives shown in FIG. 1 and show cross-drive wear plates;
(5) FIG. 4 is a pictorial image of the aluminum cross drives integrated in a drive unit system;
(6) FIG. 5A is a bottom view of the drive unit system shown in FIG. 4;
(7) FIG. 5B is an end view of the drive unit system shown in FIG. 4;
(8) FIG. 5C is a top view of the drive unit shown in FIG. 4;
(9) FIG. 6 is a bottom view of the frame portion of the drive unit system shown in FIG. 4;
(10) FIG. 7 illustrates the hydraulic drive package for the drive unit system shown in FIG. 4, and illustrates the drive unit's cylinders, valve assemblies, pressure filter, and tubing;
(11) FIG. 8 is an exploded view of control and switching valve assembly;
(12) FIG. 9 is an exploded view of an integrated valve assembly;
(13) FIG. 10 is an exploded view of a switching valve assembly;
(14) FIG. 10A is an exploded view of the left-hand portion of the switching valve assembly shown in FIG. 10;
(15) FIG. 10B is an exploded view of the central portion of the switching valve assembly shown in FIG. 10;
(16) FIG. 10C is an exploded view of the right-hand portion of the switching valve assembly shown in FIG. 10;
(17) FIG. 11 is an exploded view of a speed round valve body assembly;
(18) FIG. 12 is a side cross-sectional view of a barrel assembly;
(19) FIG. 13A is a side cross-sectional view of a check valve cartridge assembly;
(20) FIG. 13B is a pictorial view of the check valve cartridge assembly;
(21) FIG. 13C is another pictorial view of the check valve cartridge assembly;
(22) FIG. 14A is an exploded view of the aluminum cross-drive, with the drive shoes exploded from the cross-drive;
(23) FIG. 14B is an unexploded side view of the aluminum cross-drive;
(24) FIG. 15 is a hydraulic control valve schematic for the drive unit;
(25) FIG. 16 is a hydraulic control valve schematic for the drive unit; and
(26) FIG. 17 is a hydraulic control valve schematic for the drive unit.
DETAILED DESCRIPTION
(27) Referring now to FIG. 1 in the illustrations, reference number 10 generally points to three side-by-side cross-drive members that are typically connected to a series of three hydraulic cylinders in a drive unit that is used in a reciprocating floor conveyor system. A person skilled in the art would be familiar with the nature and operation of the drive unit in the context of reciprocating floor conveyor systems.
(28) In this case, the cross-drive member 10 is extruded or milled from a single piece of aluminum. It has opposite side ribs 12, 14 on a lower side thereof (the lower side is generally indicated by number 16. A series of bolt holes (generally indicated by number 18 can be drilled through the body of the cross-drive member 10 for the attachment of drive shoes (number 20 in FIG. 4).
(29) Also, in the embodiment illustrated in FIG. 1, it can be seen that a hydraulic cylinder cradle 22 is also integrated into the cross-drive member 10. In this particular embodiment, the cradle 22 has grooves in the region generally indicated by 24 that mate with similar grooves on the outer surfaces of the hydraulic cylinders (see, generally, arrows 38, 40, 42 in FIG. 2), with the grooves on the cylinders generally indicated by arrows 32 in FIG. 2.
(30) Referring now to FIG. 3, the lower side 16 of the cross-drive members 10 may have steel wear plates 34, attached to the ribs 12, 14. This assists in wear prevention should the cross-drives 10 slide against underlying support beams 36.
(31) FIGS. 5A-5C provide the various views of the arrangement described above. FIG. 6 illustrates the drive unit frame without the hydraulic cylinders and other drive units. FIG. 7 illustrates the hydraulic cylinders 38, 40, 42 and related hydraulic components. FIGS. 8-10 and FIGS. 10A-10C illustrate various valve assembly components that are used to operate the drive unit. FIG. 12 illustrates a cross-section of the hydraulic cylinders. FIGS. 13A-13C illustrate a valve cartridge assembly that is used to operate the drive unit. FIGS. 14A-14B illustrate various components of the cross-drive members 10 described above. With respect to FIG. 14B, in particular, reference 44 illustrates how the hydraulic cylinders 38, 40, 42 are clamped to the drive unit 10. Last, FIGS. 15-17 provide control valve schematics for operating the drive unit.
(32) The valve assembly includes a 6-way neutral center control valve. This eliminates need for a ball valve. It has two coils, one to enable unload, and one to enable load. This means that if there is an electrical failure in the coils, the control valve will default to the neutral position, shutting the drive off. There is also a vent to shift switching valve (VTS) that can shift at very low and very high speeds. The valve shifts when one of the vent lines is opened to tank, meaning that there should be less hydraulic shock to the system when switching from the conveying stroke (all together) to the restage stroke (1-2-3). Finally, a 2-speed valve is included in the assembly. This valve allows the drive to be switched from normal operation to a high speed mode. The valve allows the hydraulic oil in the #3 cylinder to loop to itself and tank. The hydraulic pressure is applied to only 2 cylinders instead of 3, increasing the speed of travel by a theoretical 16%. The #3 cylinder is pushed mechanically by the cross-drives.
(33) Referring again to FIG. 12, the hydraulic cylinders described above have a barrel portion 46 that is divided into two chambers 48, 50 by a central barrier or plug 52 (also called a center head). The plug 52 is held in place by shrink-fitting it into the barrel (also called an interference fit). This enables the hydraulic cylinder to be made from a single barrel tube in lieu of two separate tubes that are welded together.
(34) As discussed above, the cylinder barrel has machined grooves for the cross-drive clamps along with the interference fit center head described above. The interference fit is made as follows: The center head is cooled and the barrel is heated to create clearance between the two parts, and then the center head is placed into the barrel. As the barrel cools and the head expands, the interference fit is created, which holds the center head in place, and eliminates the need for welding the barrel together from two pieces. Cross-over tubes 54 are welded into the barrel.
(35) The foregoing description is not intended to limit the scope of the patent right. The patent right is to be limited only by the patent claim or claims that follow. The disclosure of unclaimed matter is reserved for other patent claims in subsequent patent applications.
