MEGENS PETER (NL)
TSAI CHANG (US)
US5615595A | 1997-04-01 | |||
US7997393B2 | 2011-08-16 | |||
US20080014101A1 | 2008-01-17 | |||
CN202732536U | 2013-02-13 | |||
US8393686B2 | 2013-03-12 |
We claim: 1. A method of assembling a hydraulic cylinder comprising: positioning a cylindrical housing portion of an intermediate hydraulic head assembly between a first piston and a second piston, the first piston and the second piston being spaced apart and adjacently arranged on a piston rod; positioning a split bearing assembly around the piston rod between the first piston and second piston on the piston rod in a coaxial radial overlapping arrangement with the cylindrical housing portion of the intermediate hydraulic head assembly; positioning a first cylindrical body housing portion around the first piston and connecting the first cylindrical body housing poriion to the cylindrical housing portion of the intermediate hydraulic head assembly; and positioning a second cylindrical body housing portion around the second piston and connecting the second cylindrical body housing portion to the cylindrical housing portion of the intermediate hydraulic head assembly. 2. The method of claim 1 , wherein at least one of the steps of either connecting the first cylindrical body housing to the cylindrical housing portion of the intermediate hydraulic head assembly or connecting the second cylindrical body housing to the cylindrical housing portion of the intermediate hydraulic head assembly occurs after the step of positioning the split bearing assembly around the piston rod between the first piston and second piston on the piston rod in a coaxial radial overlapping arrangement with the cylindrical housing portion of the intermediate hydraulic head assembly. 3. The method of claim 1, further comprising: positioning a cylindrical housing portion of an auxiliary -intermediate hydraulic head assembly between the second piston and a third piston, the second piston and the third piston being spaced apart and adjacently arranged on a piston rod; positioning a split bearing assembly around the piston rod between the second piston and third piston on the piston rod in a coaxial radial overlapping arrangement with the cylindrical housing portion of the auxiliary intermediate hydraulic head assembly; positioning a third cylindrical body housing poriion around the third piston and connecting the third cylindrical body housing to the cylindrical housing portion of the auxiliary intermediate hydraulic head assembly; and connecting the second cylindrical body housing to the cylindrical housing portion of the auxiliary intermediate hydraulic head assembly. 4. The method of claim 3, further comprising connecting a first end hydraulic head cap to the first cylindrical body housing portion; and connecting a second end hydraulic head cap to the third cylindrical body housing portion. 5. The method of claim 1 , wherein the step of positioning a split bearing assembly around the piston rod between the first piston and second piston on the piston rod in a coaxial radial overlapping arrangement with the cylindrical housing portion of the intermediate hydraulic head assembly includes aligning a fluid channel on an exterior of the split bearing assembly with a fluid aperture in the cylindrical housing portion. 6. A hydraulic piston comprising: a cylinder body including at least a first intermediate head assembly and a second intermediate head assembly, wherein each intermediate head assembly is configured to enable hydraulic fluid to flow into and out of the cylinder body; a piston rod extending through the cylinder body; an intermediate piston internally formed on the piston rod and positioned between the first and second intermediate head assemblies; and wherein each of the first and second intermediate head assemblies inclu de split bearing assemblies positioned around the piston rod. 7. The hydraulic piston of claim 6, wherein each of the first and second intermediate head assemblies include a hydraulic fluid line interface, the hydraulic line interface including a first hydraulic port and a second hydraulic port, wherein each of the first and second intermediate head assemblies is configured to facilitate delivery of a hydraulic fluid into the cylinder body from the first hydraulic port and simultaneously facilitate the escape of hydraulic fluid from the cylinder body from the second hy draulic port. 8. The hydraulic piston of claim 7, wherein the first hydraulic port directs hydraulic fluid to flow through a first hydraulic fluid channel, wherein the second hydraulic port directs hydraulic fluid to flow through a second hydraulic fluid channel, wherein the split bearing assemblies include a first annular hydraulic fluid channel on an exterior surface of the split bearing assembly that is in fluid communication with at least one hydraulic fluid aperture, which is in fluid communication with a second annular fluid channel, and wherein the first and second intermediate head assemblies are configured such that hydraulic fluid can flow from outside of the cylinder body into the cylinder body via a flow path that includes the hydraulic fluid channel of the intermediate head assemblies, the first annular hydraulic fluid channel of the split bearing assembly, the at least one hydraulic fluid aperture of the split bearing assembly and the second annular hydraulic fluid channel of the split bearing assembly. 9. The hydraulic piston of claim 6, wherein each of the first intermediate head assembly and a second intermediate head assembly include a shoulder and recess configuration that secures the split bearing assemblies at least in a fixed longitudinal position relative to the cylinder body. 10. The hydraulic piston of claim 6, wherein the split bearing assemblies are configured to limit fluid flow within the cylinder body from a first side of the split bearing to a second side of the split bearing. 1 1. The hydraulic piston of claim 6, wherein each of the first intermediate head assembly and a second intermediate head assembly is a separate component that is connected to the cylinder body via fasteners. 12. The hydraulic piston of claim 6, wherein each of the first intermediate bead assembly and a second intermediate head assembly include portions that are integral to different adjacent portions of the cylinder body. 13. The hydraulic piston of claim 6, wherein a first hydraulic fluid port of the first intermediate head assembly is integral to a first cylinder body portion and a second hydraulic fluid port of the first intermediate head assembly is integral a second cylinder body portion that abuts the first cylinder body portion. 14. The hydraulic piston of claim 6, wherein at least one of the split bearing assemblies includes a first portion and a second portion that are configured to be joined together around the piston rod without the need to access an end of the piston rod, wherein the split bearing assembly includes a first outer diameter thai is sized to fit the inside of a body portion of the intermediate head assembly, a second outer diameter that is less than the first outer diameter thereby defining a first annular fluid channel between an exterior surface of the split bearing and an interior surface of the body portion of the intermediate head assembly, a first inner diameter thai is sized to fit around the piston rod, a second inner diameter that is less than the first inner diameter thereby defining a second annular fluid channel between an exterior surface of the piston rod and an interior surface of the split bearing assembly, and wherein the split bearing assembly includes at least one fluid channel that extends between the first annular fluid channel and the second annular fluid channel. 15. A hydraulic piston comprising: a cylinder body including a first end and a second end; a first head cap connected to the first end of the cylinder body, the first head cap configured to enable hydraulic fluid to flow into and out of the cylinder body; a second head cap connected to the second end of the cylinder body, the second head cap configured to enable hydraulic fluid to flow into and out of the cylinder body; at least one intermediate head assembly connected to the cylinder body between the first and second head caps, the intermediate head configured to enable hydraulic fluid to simultaneously flow into and out of the cylinder body; a piston rod assembly coaxially arranged with the cylinder body and extending through the cylinder body, the piston rod assembly including: a piston rod extending through the cylinder body, the piston rod including a first end and a second end; a first piston integrally formed on the piston rod between the first head cap and the at least one intermediate head, the first piston slidably engaged with the cylinder body; a second piston integrally formed on the piston rod between the second head cap and the at least one intermediate head, the second piston slidably engaged with the cylinder body; wherein the at least one intermediate head assembly includes an outer housing portion and an inner split bearing portion, wherein the outer housing portion includes inner cross-sectional configurations that enable the first and second piston to extend therethrough and wherein the inner split bearing portion includes at least a first portion and a second portion that connect together around the piston rod and extend between the outer housing portion of the intermediate head assembly and the piston rod. 16. The hydraulic piston of claim 15, wherein the at least one intermediate head assembly connected to the cylinder body between the first and second head cap includes a first intermediate head assembly between the first and second head cap and a second intermediate head assembly between the first and second head cap, wherein the first piston is located between the first head cap and the first intermediate head assembly, wherein the second piston is located between the second intermediate head assembly and second head cap, wherein the piston rod assembly includes a third piston integrally formed on the piston rod between the first intermediate head assembly and the second intermediate head assembly. 17. The hydraulic piston of claim 15, wherein the inner split bearing portion includes a first half and a second half, wherein each half being substantially identical. 18. The hydraulic piston of claim 15, wherein the piston rod extends through the entire cylinder body and includes a unitary construction. 19. The hydraulic piston of claim 15, wherein the inner split bearing assembly- includes a first ou ter diameter that is sized to fit the inside of the outer housing portion of the intermediate head assembly, a second outer diameter that is less than the first outer diameter thereby defining a first annular fluid channel between an exterior surface of the split bearing and an interior surface of the outer housing portion of the intermediate head assembly, a first inner diameter that is sized to fit around the piston rod, a second inner diameter that is less than the first inner diameter thereby defining a second annular fluid channel between an exterior surface of the piston rod and an interior surface of the split bearing assembly, and wherein the split bearing assembly includes at least one fluid channel that extends between the first annular fluid channel and the second annular fluid channel. 20. The hydraulic piston of claim 15, wherein the at least one intermediate head assembly includes portions that are integral to different adjacent portions of the cylinder body. |
This application is being filed on July 21, 2014, as a PCT International Patent application and claims priority to Indian Patent Application Serial No.
887/KOL/2013 filed on July 24, 2013, the disclosure of which is incorporated herein by reference in its entirety.
Technical Field
The present disclosure provides a compact high-output piston assembly that includes multiple pistons.
Background
Hydraulic pistons are used for mechanical actuation in many applications. The hydraulic pistons are arranged such that extending and retracting a piston rod connected to pistons housed in a cylinder body causes a desired mechanical action.
Pressurized hydraulic fluid is directed into and out of the cylinder thereby causing the piston rod to extend and retract. Improved high performance pistons are desirable.
The present disclosure provides a method of assembling and disassembling a hydraulic cylinder. In addition it provides a hydraulic cylinder that includes a modular intermediate head construction that enable the assembly thereof between two adjacent pistons without removing the piston from the piston rod.
Brief Description of the Figures
FIG. 1 is an isometric view of a hydraulic cylinder according to an embodiment of the present disclosure;
FIG. 2 is a top elevation view of the hydraulic cylinder of FIG. 1 ;
FIG. 3 is a cross-sectional view of the hydraulic cylinder of FIG . 1 ;
FIG, 4 is an isometric view of a component of the hydraulic cylinder of
FIG. 1 ;
FIG. 5 is an enlarged view of a portion of FIG. 3; and FIG. 6 is a cross-sectional view of an alternative embodiment of a hydraulic cylinder according to the present disclosure. Detailed Description
Referring to the FIGS. 1 -5, a first embodiment of a hydraulic piston according to the present disclosure is described below in further detail. In the depicted embodiment, the hydraulic cylinder 10 includes a cylinder body 12, a first intermediate head assembly 14, and a second intermediate head assembly 16. In the depicted embodiment, each intermediate head assembly 14, 16 is configured to enable hydraulic fluid to
simultaneously flow into and out of the cylinder body through hydraulic ports 18, 20, 22, 24 on the intermediate head assemblies 14, 16. In the depicted embodiment the hydraulic cylinder 10 further includes a first head cap 26 located at a first end 28 of the cylinder body 12, and a second head cap 30 located at a second end 32 of the cylinder body 12. Each of the first and second head caps 26, 30 are configured to enable hydraulic fluid to flow into and out of the cylinder body. It should be appreciated that many other alternative hydraulic piston configurations are possible.
In the depicted embodiment the hydraulic piston includes a piston rod 34 that extends coaxially into the cylinder body 12, which in the depicted embodiment is generally cylindrical. Pistons 36, 38, 40 are supported on the piston rod 34 and slide within the cylinder body 12 in response to hydraulic pressure due to the flow of hydraulic fluid into and out of the heads 26, 14, 16 and 30. The pistons in the depicted embodiment are cylindrical member that interface with the inside surface of the cylinder body 12. In the depicted embodiment end piston 36 is positioned between the first head cap 26 and the first intermediate head assembly 14, end piston 40 is positioned between the second head cap 30 and the second intermediate head assembly 16, and intermediate piston 38 is positioned between the first intermediate head assembly 14 and the second intermediate head assembly 16. It should be appreciated that many other alternative configurations are possible.
During normal operations to move the piston to the left, hydraulic fluid would be allowed to escape through the first head cap 26 and be delivered to the hydraulic cylinder through the second head cap 30. Simultaneously, ports 18 and 22 of the intermediate head assemblies 14, 16 would deliver hydraulic fluid, and ports 20 and 24 would allow for the escape of hydraulic fluid from the cylinder body 12. Conversely, to move the piston to the right, hydraulic fluid would be allowed to escape through the second head cap 30 and be delivered through the first head cap 26. Simultaneously, ports 20 and 24 of the intermediate head assemblies 14, 16 would deliver hydraulic fluid and ports 18 and 22 would allow for the escape of hydraulic fluid from the cylinder body 12. It should be appreciated that many other alternative hydraulic piston configurations and modes of operation are possible (for example, the piston can be moved to the left by delivering fluid to the cylinder body only via the second head cap 30).
In the depicted embodiment, each of the pistons 36, 38 and 40 are all integrally formed on the piston rod 34 (includes a unitary construction). The depicted configuration provides a system that can withstand high forces as it minimizes stress concentration within the piston rod and piston assembly. It also facilitates quick and easy assembly and disassembly, it should be appreciated that many other alternative configurations are possible (e.g., embodiments where at least some of the pistons are not integrally formed on the piston rod).
Assembly of the hydraulic piston 10 of the depicted embodiment can include the following steps: positioning a cylindrical housing portion 54 of the intermediate hydraulic head assembly 14 between a first piston 36 and a second piston 38, the first piston and the second piston being spaced apart and adjacently arranged on a piston rod 34; positioning a split bearing assembly 56 around the piston rod between the first piston 36 and second piston 38 on the piston rod 34 in a coaxial radial overlapping arrangement with the cylindrical housing portion 54 of the intermediate hydraulic head assembly 14; positioning a first cylindrical body housing portion 58 around the first piston 36 and connecting the first cylindrical body housing portion 58 to the cylindrical housing portion 54 of the intermediate hydraulic head assembly 14; and positioning a second cylindrical body housing portion 60 around the second piston 38 and connecting the second cylindrical body housing portion 60 to the cylindrical housing portion 54 of the intermediate hydraulic head assembly 14. It should be appreciated that many other methods of assembling hydraulic pistons according to the present disclosure are possible including some that including a different combination of steps some of the steps being ones that are identified above as well as some other steps.
As discussed above, it should be appreciated that the above-identified assembly steps are only one of a number of assembly methods. Also, the sequence in the above recitation can vary as well. In one embodiment at least one of the steps of either connecting the first cylindrical body housing portion 58 to the cylindrical housing portion body housing portion 60 to the cylindrical housing portion 54 of the intermediate hydraulic head assembly 14, occurs after the step of positioning the split bearing assembly 56 around the piston rod 34 between the first piston 36 and second piston 38 on the piston rod 34 in a coaxial radial overlapping aiTangement with the cylindrical housing portion 54 of the intermediate hydraulic head assembly 14. For easy assembly, the split bearing assembly 56 can be positioned between the adjacent pistons 36 and 38 before the section of piston rod 34 between the pistons 36, 38 are enclosed by the combination of the cylindrical housing portion 54 and the adjacent cylindrical body housing portions 58, 60. In other embodiments the sequence of steps is not as described above.
As already discussed above the assembly method can also include more, less, as well as different steps, and the sequence of the steps can also vary. For example, the method of assembly can also include the additional steps of: positioning a cylindrical housing portion 62 of an auxiliary intermediate hydraulic head assembly (second intermediate head assembly 16) between the second piston 38 and a third piston 40, the second piston 38 and the third piston 40 being spaced apart and adjacently arranged on a piston rod 34 as depicted in FIG. 3; positioning a second split bearing assembly 64 (in the depicted embodiment the second split bearing assembly 64 has the same construction of the first split bearing assembly 56) around the piston rod 34 between the second piston 38 and third piston 40 on the piston rod 34 in a coaxial radial overlapping arrangement with the cylindrical housing portion 62 of the auxiliary intermediate hydraulic head assembly 16; positioning a third cylindrical body housing portion 66 around the third piston 40 and connecting the third cylindrical body housing 66 to the cylindrical housing portion 62 of the auxiliary intermediate hydraulic head assembly 16; and connecting the second cylindrical body housing 60 to the cylindrical housing portion 62 of the auxiliary intermediate hydraulic head assembly 16.
The method of assembly can also, for example, include the additional step of: connecting a first end hydraulic head cap (first head cap 26) to the first cylindrical body housing portion 54, and connecting a second end hydraulic head cap (second head cap 30) to the third cylindrical body housing portion 66 of the cylinder body 12.
In some embodiments the above-identified step of positioning a split bearing assembly 56 around the piston rod 34 in a coaxial radial overlapping arrangement with the cylindrical housing portions 54, 62 of the intermediate hydraulic head assemblies 14, 16 includes aligning a fluid channel (a first annular hydraulic fluid channel 68) on an exterior of the split bearing assembly with a fluid aperture (a hydraulic fluid channel 70) in the cylindrical housing portion 54 of the intermediate hydraulic head assembly 14.
It should be appreciated that the first and second intermediate hydraulic head assemblies 14, 16 can share the same construction or have differences. In the depicted embodiment the first and second intermediate hydraulic head assemblies share similar features and therefore these similar features will not be described herein separately.
As discussed above, in the depicted embodiment each of the first and second intermediate head assemblies includes a first hydraulic port and a second hydraulic port. In the depicted embodiment the first hydraulic port 18 directs hydraulic fluid to flow through a first hydraulic fluid channel 70, The second hydraulic port 20 directs hydraulic fluid to flow through a second hydraulic fluid channel 72. The split bearing assembly 56 includes a first annular hydraulic fluid channel 68 on an exterior surface of the split bearing assembly that is in fluid communication with at least one hydraulic fluid aperture 74, which is in fluid communication with a second annular fluid channel 76. The first and second intermediate head assemblies 14, 16 are configured such that hydraulic fluid can flow from outside of the cylinder body 12 into the cylinder body via a flow path that includes the hydraulic fluid channel 70 of the intermediate head assemblies, the first annular hydraulic fluid channel 68 of the split bearing assembly, and the at least one hydraulic fluid aperture 74 of the split bearing assembly, and the second annular hydraulic fluid channels 76 of the split bearing assembly. It should be appreciated that many other alternative embodiments of the intermediate heads are possible.
In the depicted embodiment each of the first intermediate head assembly and a second intermediate head assembly include a shoulder 78 and recess 80
configuration that secures the split bearing assemblies at least in a fixed longitudinal position relative to the cylinder body 12. In the depicted embodiment the recess 80 in the inner surface of the cylindrical housing portion 54 of the intermediate hydraulic head assembly 14 is sized to receive the exterior surface 82 of the split bearing assembly 56. When the cylindrical housing portion 54 of the intermediate hydraulic head assembly 14 is secured to the cylindrical body portion 58 via bolts 84, the split bearing assembly 56 is fixed laterally with respect to the cylinder body 12. The alternative intermediate heads may or may not share some of the features of the embodiment of the intermediate head that are described above.
In the depicted embodiment the split bearing assembly 56 is configured to limit fluid flow within the cylinder body 12 from a first side of the split bearing to a second side of the split bearing. In the depicted embodiment the split bearing assembly 56 includes a fluid blocking portion 86 with an outer diameter Dl and an inner diameter D2 that limits flow of the hydraulic fluid from traveling from adjacent fluid channels 70, 72 of the intermediate head assembly. The diameter Dl is slightly smaller than the inner diameter of the cylindrical housing portion 54 of the intermediate hydraulic head assembly 14, and the diameter D2 is slightly larger than the diameter of the piston rod 34. Ring seals 88 provide further sealing at the interface between the surface of the split bearing assembly 56 and the cylindrical housing portion 54 of the intermediate hydraulic head assembly 14. It should be appreciated that many alternative split bearing configuration are possible.
In the depicted embodiment the first annular hydraulic fluid channel 68 is located in a center portion of the generally cylindrical split bearing assembly and is defined by an exterior surface that has a diameter D3 that is smaller than Dl and larger than D2. In the depicted embodiment D3 varies, thereby forming a radiuses surface on the split bearing assembly that cooperates with the inner surface of the cylindrical housing portion 54 to form an annular fluid channel. In the depicted embodiment the second annular fluid channel 76 is defined between an interior surface of the split bearing assembly that has a radius of D4 which is greater than D2 and the exterior surface of the piston rod 34. In the depicted embodiment, two apertures 74 and 90 connect the first and second annular fluid channels 68, 76. It should be appreciated that many other alternative configurations are possible.
In the depicted embodiment the split bearing assembly 56 includes a first portion and a second portion that are configured to be joined together around the piston rod without the need to access an end of the piston rod 34. In the depicted embodiment the split bearing portion includes a first half and a second half and each half is substantially identical. It should be appreciated that many other configurations are possible.
As described above, in one embodiment in accordance with the present disclosure the hydraulic piston comprises a cylinder body 12 including a first end and a second end; a first head cap 26 is connected to the first end of the cylinder body, the first head cap is configured to enable hydraulic fluid to flow into and out of the cylinder body 12; a second head cap 30 is connected to the second end of the cylinder body, the second head cap is configured to enable hydraulic fluid to flo w into and out of the cylinder body; at least one intermediate head assembly 14, 16 is connected to the cylinder body between the first and second head caps, the intermediate head configured to enable hydraulic fluid to simultaneously flow into and out of the cylinder body; a piston rod assembly is coaxiaiiy arranged with the cylinder body 12 and extends through the cylinder body, the piston rod assembly including: a piston rod 34 that extends through the cylinder body 12, the piston rod including a first end and a second end; a first piston 36 is integrally formed on the piston rod between the first head cap 26 and the at least one intermediate head 14, 16, the first piston slidably engaged with the cylinder body ; a second piston 38 integrally formed on the piston rod between the second head cap 30 and the at least one intermediate head 14,16; wherein the at least one intermediate head assembly 14, 16 includes an outer housing portion 54 and an inner split bearing portion 56, wherein the outer housing portion 54 includes inner cross-sectional configurations that enable the first and second piston to extend therethrough and wherein the inner split bearing portion includes at least a first portion 92 and a second portion 94 that connects together around the piston rod and extends between the outer housing portion 54 of the intermediate head assemblies 14, 16 and the piston rod 34. Many alternative embodiment that are in accordance with the present disclosure are also possible.
Referring to FIG. 6, an alternative embodiment is shown. In the depicted embodiment the intermediate head assembly includes portions 100, 102 that are integral to different adjacent portions 104, 106 of the cylinder body. In the embodiment of FIG. 6, unlike the embodiments disclosed in FIGS. 1-5, the intermediate head is not a separate component that is connected to the cylinder body via fasteners. In particular, the first hydraulic fluid port and channel 108 of the first intermediate head assembly is integral to a first cylinder body portion 100, and a second hydraulic fluid port and channel 1 10 of the first intermediate head assembly is integral to a second cylinder body portion 102 that abuts the first cylinder body portion.
In both depicted embodiments the hydraulic cylinder 10 also includes a preload assembly that includes end caps 42, 44 and tensioning members 46 that extend therethrough that are configured to apply tension to the piston rod 34. In the depicted embodiment the tension member of the preloading assembly includes a multi-jackbolt tensioner type bolt. The multi-jackbolt is configured such that the bolt applies tension (tightens) by torqueing multiple smaller bolts 48 located at the bolt head 52 that press against a washer 50 and thereby together pull on the larger center bolt. It should be appreciated that many alternative embodiments of the tensioning members 46 exist including, for example, standard type bolts. The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.
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