Pilot operated bypass valve with reverse check

Abstract

An inner subassembly (297) for assembling a valve assembly (200) includes a spool valve (206) defining a central bore extending axially through a spool annular wall (246) and including a spool tapered tip (248) disposed at a first axial end (240), and a hydraulic actuation spine (250) extending radially outward from the spool annular wall (246) and disposed axially between a second axial end (242) and the first axial end (240). The spool valve (206) can further define a first bypass bore (252). A valve stem (208) defines a first flow bore (264) aligned with the first bypass bore (252).

Description

Technical Field

[0001] This disclosure relates to valves used in hydraulic hammers and the like in the earthmoving, construction, and mining industries. Specifically, this disclosure relates to a valve that provides bypass and reverse check functions within a confined space. The bypass function diverts some fluid flow away from the equipment if the equipment is insufficiently lubricated. Background Technology

[0002] Hydraulic hammer assemblies, hydraulic pumps, and hydraulic motors typically employ valves that provide various functions. One valve prevents unwanted reverse flow of fluid (sometimes called a check valve). Another valve allows flow to bypass the equipment (sometimes called a bypass valve or safety valve). Typically, these valves are separate from each other, occupying space within the equipment.

[0003] U.S. Patent No. 5,992,450A, Parker et al., disclose a pump assembly (33) including a cartridge valve assembly (39) having a lift valve member (69) which, under the influence of an electromagnetic actuator (53), moves toward a closed position when the pilot section (51) is closed. Figure 4 The bias causes the flow entering the inlet port (65) to flow out of the outlet opening (61). When the actuator (53) is not energized ( Figure 1 The pilot lift valve (89) and armature (93) are biased to the open position by the pilot spring (94). Figure 5 This causes fluid in the inlet port (65) to flow through the orifice (71) in the lift valve member (69) and through the pilot section (51) to the system storage chamber (R), thereby creating a pressure differential on the lift valve member (69) and opening the tank port (67). Then, flow continues from the inlet port (65) to the tank port (67), thus operating in "bypass" mode. The pilot section (51) also acts as a pressure relief mechanism in case of excessive inlet pressure.

[0004] It is evident that a bypass valve and a reverse check valve that occupy less space in the equipment are needed. More specifically, in some applications, bypass functionality may be desirable when lubricant is insufficient, without the use of solenoids or other circuit systems. Summary of the Invention

[0005] An outer subassembly for assembling a valve assembly according to embodiments of the present disclosure is provided. The outer subassembly can include a housing including an at least partially annular body and an annular wall defining a first central bore defining a longitudinal axis, a circumferential direction, a radial direction, and a first longitudinal end disposed along the longitudinal axis and a second longitudinal end disposed along the longitudinal axis. The first central bore can extend through the second longitudinal end, and the annular wall can further define a first transverse bore extending radially through the annular wall to the central bore proximate the flange and a second transverse bore extending radially through the annular wall to the first central bore. The second transverse bore can be axially disposed between the second longitudinal end and the first transverse bore. A sleeve can define a through bore forming a sleeve annular wall, and can further define a proximal end configured to mate with the second longitudinal end of the housing and a distal end. The sleeve annular wall can further define a third transverse bore extending radially through the sleeve annular wall in communication with the through bore and disposed proximate the proximal end and a fourth transverse bore extending radially through the sleeve annular wall in communication with the through bore and axially disposed between the third transverse bore and the distal end.

[0006] An inner subassembly for assembling a valve assembly according to embodiments of the present disclosure is provided. The inner subassembly can include a spool defining a central bore extending axially through a spool annular wall including a spool conical tip disposed at a first axial end and a hydraulic actuation spine extending radially outward from the spool annular wall and axially disposed between a second axial end and the first axial end. The spool can further define a first bypass bore extending through the spool annular wall to a second central bore and axially disposed between the hydraulic actuation spine and the first axial end. A valve stem disposed in the central bore can also be provided, the valve stem defining a closed axial end including a valve stem conical tip, an open axial end, and another central bore forming a valve stem annular wall. A first flow bore can extend radially through the valve stem annular wall axially disposed between the closed axial end and the open axial end, and the valve stem can include a stepped body such that the valve stem annular wall bulges radially outward at a location axially disposed between the first flow bore and the open axial end.

[0007] A valve assembly according to embodiments of the present disclosure can include a housing including an at least partially annular body and an annular wall defining a first central bore defining a longitudinal axis, a circumferential direction, a radial direction, and a first longitudinal end disposed along the longitudinal axis and a second longitudinal end disposed along the longitudinal axis. The housing can also include a flange disposed at the first longitudinal end, and the first central bore extends through the second longitudinal end, the annular wall further defining a first transverse bore extending radially through the annular wall to the first central bore proximate the flange and a second transverse bore extending radially through the annular wall to the first central bore, the second transverse bore axially disposed between the second longitudinal end and the first transverse bore. A sleeve can also be provided defining a through bore forming a sleeve annular wall and further defining a proximal end configured to mate with the second longitudinal end of the housing and a distal end including a radially inwardly extending rim that partially axially obstructs the through bore. The sleeve annular wall can further define a third transverse bore extending radially through the sleeve annular wall in communication with the through bore and disposed proximate the proximal end and a fourth transverse bore extending radially through the sleeve annular wall in communication with the through bore and axially disposed between the third transverse bore and the distal end. Further, a spool valve can be disposed in the first central bore and the through bore, the spool valve defining a first axial end, a second axial end, a second central bore extending axially through the spool valve forming a spool annular wall and including a spool tapered tip disposed at the first axial end. A hydraulic actuation spine can extend radially outwardly from the spool annular wall and axially disposed between the second axial end and the first axial end. The spool valve can further define a first bypass bore extending through the spool annular wall to the second central bore and axially disposed between the first axial end and the hydraulic actuation spine. Further, a valve stem can be disposed in the second central bore, the valve stem defining a closed axial end including a valve stem tapered tip, an open axial end, a third central bore forming a valve stem annular wall, and a first flow bore extending radially through the valve stem annular wall axially disposed between the closed axial end and the open axial end. The valve stem can include a stepped body such that the valve stem annular wall projects radially outwardly at a location axially disposed between the valve stem tapered tip and the open axial end. BRIEF DESCRIPTION OF DRAWINGS

[0008] The accompanying drawings incorporated in and forming a part of the specification, illustrate several aspects of the present disclosure, and together with the description serve to explain the principles of the present disclosure. In the drawings:

[0009] Figure 1 is an environmental side view of a hydraulic excavator that can use a hydraulic hammer assembly having a valve assembly constructed in accordance with various embodiments of the present disclosure.

[0010] Figure 2 is Figure 1 is an enlarged detail view of the hydraulic hammer assembly of

[0011] Figure 3 is Figure 2 a perspective view of the power unit assembly of the hydraulic hammer assembly of

[0012] Figure 4 is Figure 3 a partial side sectional view of the power unit showing a valve assembly constructed in accordance with an embodiment of the present disclosure.

[0013] Figure 5 is Figure 4 a perspective view of the valve assembly of

[0014] Figure 6 is Figure 5 a sectional view of the valve assembly showing the internal components and the manner of operation of the valve assembly.

[0015] Figure 7 is Figure 6 a side sectional view of the valve assembly of

[0016] Figure 8 is Figure 5 an exploded assembly view of the valve assembly of

[0017] Figure 9 is Figure 8 a perspective view of the sleeve of the valve assembly of

[0018] Figure 10 is Figure 8 a perspective view of the housing of the valve assembly of

[0019] Figure 11 is Figure 8 a perspective view of the spool of the valve assembly of

[0020] Figure 12 is Figure 8 a perspective view of the valve stem of the valve assembly of

[0021] Figure 13 is Figure 8 a perspective view of the valve stem of the pilot assembly of

[0022] Figure 14 is Figure 5 a sectional view of the valve assembly of

[0023] Figure 15 illustrates Figure 14 the valve assembly of the valve assembly with the spool shifted to the right due to the pilot pressure applied on the spool, thereby opening the bypass port, such that the flow through the outlet port is reduced when the lubricant is insufficient.

[0024] Figure 16 A valve assembly of Figure 14 is illustrated, wherein when the outlet pressure is higher than the inlet pressure, the spool shifts to the right, the valve stem shifts to the right, thereby preventing all fluid flow through the valve assembly (this provides a reverse check function of the valve). DETAILED DESCRIPTION

[0025] Reference will now be made in detail to embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. In some cases, reference numbers will be indicated in the specification by a parenthetical reference to the figure number in which the reference number is first introduced, e.g., 100a, 100b, or 100', 100", etc. It will be understood that the use of a letter or prime notation following a reference number indicates that these features are similarly formed and have similar functionality, as is often the case when geometric shapes are mirrored about a plane of symmetry. For ease of explanation in the specification, the letter and prime notation is not generally included herein, but can be shown in the drawings to indicate the repetition of features having similar or identical functionality or geometry discussed within this written specification.

[0026] Various embodiments of valve assemblies constructed in accordance with the principles of the present disclosure will be discussed, which can provide bypass, check valve, and lubrication protection functions in a compact space. Further, an exemplary machine in which embodiments can be employed, such as a hydraulic excavator, will first be discussed, it being understood that any suitable machine including a swing-to-load backhoe, a backhoe, or other heavy equipment used in the earthmoving, construction, and mining industries can employ these embodiments. It will also be understood that the described valves can be used in another device other than a hydraulic hammer, such as a hydraulic pump or motor, etc.

[0027] From Figure 1 embodiments of the present disclosure will be discussed, which can provide bypass, check valve, and lubrication protection functions in a compact space. Further, an exemplary machine in which embodiments can be employed, such as a hydraulic excavator, will first be discussed, it being understood that any suitable machine including a swing-to-load backhoe, a backhoe, or other heavy equipment used in the earthmoving, construction, and mining industries can employ these embodiments. It will also be understood that the described valves can be used in another device other than a hydraulic hammer, such as a hydraulic pump or motor, etc.

[0028] Reference will now also be made toFigure 2 The hydraulic hammer assembly 110 can be secured to the operating end 112 of the manipulator 108. The hydraulic hammer assembly 110 can include an upper portion 116 including a power unit 118 as shown, and a lower nose portion 122 secured to the power unit 118. A breaking hammer tool 120 having an upper end (not shown) can be retained within the nose portion 122. For example, the breaking hammer tool 120 can be adapted to produce cyclic vibratory movement with sufficient strength to break rock. Functional components of the hydraulic hammer assembly 110 including the breaking hammer tool 120 can be constructed of a wrought or otherwise hardened metal such as a refined steel, for example, to ensure proper strength, although other suitable materials can be used within the scope of the present disclosure such as a diamond bit for an operating portion of the breaking hammer tool 120. Figure 3 The hydraulic hammer assembly 110 can be secured to the operating end 112 of the manipulator 108. The hydraulic hammer assembly 110 can include an upper portion 116 including a power unit 118 as shown, and a lower nose portion 122 secured to the power unit 118. A breaking hammer tool 120 having an upper end (not shown) can be retained within the nose portion 122. For example, the breaking hammer tool 120 can be adapted to produce cyclic vibratory movement with sufficient strength to break rock. Functional components of the hydraulic hammer assembly 110 including the breaking hammer tool 120 can be constructed of a wrought or otherwise hardened metal such as a refined steel, for example, to ensure proper strength, although other suitable materials can be used within the scope of the present disclosure such as a diamond bit for an operating portion of the breaking hammer tool 120.

[0029] Reference is now also made to Figure 3 The hydraulic hammer assembly 110 is shown separately, i.e., apart from the manipulator 108 and with an outer shell cover of the hydraulic hammer assembly 110 removed to reveal the exposed power unit 118, and a plurality of tie rods 124 arranged circumferentially about a cylindrical, piston-containing sleeve structure 126. The sleeve structure 126 can contain a piston (not shown) adapted to drive the breaking hammer tool 120. In this way, the power unit 118 can be effectively utilized with a suitable working fluid such as a hydraulic and / or pneumatic fluid, for example, to reciprocally compress the piston against the upper end (not shown) of the breaking hammer tool 120. It can also be appreciated that the plurality of tie rods 124 can effectively hold or maintain the power unit 118 and the nose portion 122 together under the severe impact loads that can be experienced within the hydraulic hammer assembly 110. Further, a valve assembly 200 can be employed at the top of the hydraulic assembly to provide the various functions described herein.

[0030] The lower nose portion 122 can define an actual nose portion 128 which can function as a structural housing to support the upper end (not shown) of the breaking hammer tool 120. An upper end 130 of each of the tie rods 124 can be secured to an upper structure or upper head 132 of the power unit 118. Each tie rod 124 can have a threaded lower end (not shown) which extends downwardly through a vertically oriented hole or tie rod hole 134 within the nose portion 122. The tie rod hole 134 defines a longitudinal axis of the installed tie rod 124. Each tie rod 124 can be adapted to be threadably secured to a tie rod nut 136 (see Figure 4 ).

[0031] In some cases, hammer mechanisms require hydraulic fluid / oil and lubricants to effectively operate and have a desired life before requiring maintenance.

[0032] Figure 4The valve assembly 200 is shown, which can help monitor the flow of hydraulic fluid / oil and lubricant to the hammer mechanism, thus enabling the valve assembly 200 to work properly. The supply hole 138 introduces hydraulic fluid / oil into the valve assembly inlet 139, and when lubricant is flowing at an appropriate level and the pressure in the hammer mechanism is less than the inlet pressure of the hydraulic fluid / oil, the supply hole 138 allows fluid to exit the valve assembly outlet 142 at full capacity to the hammer mechanism. However, if lubricant is insufficient, then the valve assembly will bypass some of the fluid, reducing the rate at which the hammer mechanism works, to reduce the likelihood of damage or increased wear. If the pressure in the hammer mechanism is greater than the inlet pressure, then the valve closes as a check valve. The structure to accomplish this in a compact space (i.e., via a single valve assembly) will now be discussed in further detail.

[0033] Referring now to Figures 5 to 7 , embodiments of such a valve assembly 200 can include a housing 202, a sleeve 204, a spool 206, and a valve stem 208.

[0034] The housing 202 can include an at least partially annular body having an annular wall 210 and a first central bore 212 defining a longitudinal axis 214, a circumferential direction 216 (best shown in Figure 5 ), and a radial direction 218 (best shown in Figure 6 and Figure 7 ). A first longitudinal end 220 and a second longitudinal end 222 can be disposed along the longitudinal axis 214 (see Figure 6 , Figure 7 and Figure 10 ). Further, a flange 224 can be disposed at the first longitudinal end 222, and the first central bore 212 can extend completely through the second longitudinal end 222. The annular wall 210 can further define a first transverse bore 226 extending radially through the annular wall 210 to the first central bore 212 proximate the flange 224. Likewise, a second transverse bore 228 can extend radially through the annular wall 210 to the first central bore 212. The second transverse bore 228 can be axially disposed between the second longitudinal end 222 and the first transverse bore 226. The functions of these various features will be explained later herein.

[0035] Referring to Figure 6 , Figure 7 and Figure 9The sleeve 204 can define a through-hole 230 forming a sleeve annular wall 229. When assembled, the through-hole 229 of the sleeve 204 can be at least partially concentric or coextensive with the first central bore 212 of the housing 204. The sleeve 204 can also have a proximal end 232 (so named because it is proximal to the housing 202) configured to mate with the second longitudinal end 222 of the housing 202 in a manner to be described in further detail later herein. The distal end 234 of the sleeve 204 can include a radially inwardly extending edge 237 (also referred to as a "lip," "flange," or the like) that partially axially obstructs the through-hole 230, creating a stop for the spool valve 206. The edge can be integral with the main body of the sleeve, or can be a separate component attached to the sleeve or the like. Further, the sleeve annular wall 229 can further define a third transverse bore 236 extending radially through the sleeve annular wall 229, in communication with the through-hole 230 and disposed proximate the proximal end 232. A fourth transverse bore 238 can extend radially through the sleeve annular wall 229, also in communication with the through-hole 230 and axially disposed between the third transverse bore 230 and the distal end 234.

[0036] Turning now to Figure 6 , Figure 7 and Figure 11 , the spool valve 206 can be disposed in the first central bore 212 and the through-hole 230. The spool valve 206 can define a first axial end 240, a second axial end 242, and a second central bore 244 extending axially through the spool valve 26 forming a spool valve annular wall 246. A spool valve tapered tip 248 can be disposed at the first axial end 240, and a hydraulic actuation ridge 250 (so named because it is a hydraulic actuation surface 251 that can receive fluid pressure as a signal if lubricant to the hammer mechanism becomes insufficient) can extend radially outwardly from the spool valve annular wall 246. The ridge 250 can be axially disposed between the second axial end 242 and the first axial end 240. A first bypass bore 252 can extend through the spool valve annular wall 246 to the second central bore 244, and can be axially disposed between the first axial end 240 and the hydraulic actuation ridge 250.

[0037] Looking at Figure 6 , Figure 7 and Figure 12, the valve stem 208 can be disposed in the second central bore 244 of the spool 206. The valve stem 208 can define a closed axial end 254 including a valve stem tapered tip 256 and an open axial end 258. The valve stem 208 can also have a third central bore 260 forming a valve stem annular wall 262. A first flow bore 264 can extend radially through the valve stem annular wall 262 axially disposed between the closed axial end 254 and the open axial end 258. The valve stem 208 can also include a stepped body such that the valve stem annular wall 262 projects radially outward at a location 266 axially disposed between the valve stem tapered tip 256 and the open axial end 258.

[0038] It should be noted that in other embodiments of the present disclosure, any of these components and their features can be configured differently. Also, the cross holes, bypass holes, and flow bores can be part of a circular array of multiple such holes around the longitudinal axis 214, as shown in Figures 9 to 12 Furthermore, multiple seal grooves 268 and seals 270 (see Figure 7 、 Figure 9 and Figure 10 ) can be provided between each of the cross holes to prevent leakage when the valve assembly is installed into the hammer assembly.

[0039] Looking at Figure 7 and Figure 8 , a snap ring 272, a guide 274 (which can also be referred to as an “end cap” or a “spacer,” among others), and a compression spring 276 can also be installed in the spool 206. More specifically, the spool 206 further defines a snap ring groove 278 disposed proximate the second axial end 242 and in communication with the second central bore 244.

[0040] During assembly, the valve stem 208 is inserted into the spool 206, then the compression spring 276 is inserted into the valve stem 208, and then the guide 274 is inserted into the spool 206, thereby capturing the compression spring 276 between the valve stem 208 and the guide 274. The snap ring 272 can then be inserted into the spool 206 and snapped into the snap ring groove 278. The guide 274 can now abut the snap ring 272 due to the spring force pushing the guide 274 and the valve stem 208 in opposite axial directions. The valve stem tapered tip 256 can also abut the spool tapered tip 248 due to the spring force (see Figure 7 As will be discussed in greater detail later in this document, the valve stem 208, the guide 274, the snap ring 272, the compression spring 276, and the spool 206 can form an inner subassembly 297 (see Figure 8 ) for assembling the valve assembly 200.

[0041] In Figure 7 and Figure 13In certain embodiments, the guide 274 can define a distal spring pocket 280 including a distal shoulder surface 282, while the valve stem 208 can define a proximal spring pocket 284 arranged at its open axial end 258, the proximal spring pocket 284 also including a proximal shoulder surface 286. In such embodiments, the compression spring 276 is housed in these pockets 280, 284 and contacts the distal shoulder surface 282 and the proximal shoulder surface 286.

[0042] Looking Figure 7 and Figure 10 The housing 202 can also define a circumferentially extending peripheral groove 288 that is in communication with the first transverse bore 226, while the first transverse bore 226 can extend completely radially through the housing 202. In other embodiments of the present disclosure, these features can be configured differently.

[0043] Focusing on Figure 7 The first central bore 212 can include a large diameter portion 290 that extends through the second longitudinal end 222 and a small diameter portion 292 that extends through the first longitudinal end 220. When assembled, a plug can be arranged in the small diameter portion 292 to block any flow.

[0044] Additionally, the proximal end 232 of the sleeve 204 can include a stepped pilot pocket 292 that is in communication with the through bore 230 of the sleeve 204 (see also Figure 9 ), while the second longitudinal end 222 of the housing 202 can include a stepped pilot ring 294 that fits into the stepped pilot pocket 292 of the sleeve 204 (see also Figure 10 ). Thus, these components can be mated or fit together as mentioned earlier herein. Other mating can be provided in other embodiments of the present disclosure. For example, these features can be swapped with each other, etc.

[0045] Still looking at Figure 7 The through bore 230 can define a middle diameter portion 295 that extends axially from the stepped pilot pocket 293 toward the distal end 234, and a reduced diameter portion 296 can extend axially from the middle diameter portion 295 toward the edge 237 arranged at the distal end 234. The hydraulic actuation spine 250 can be arranged in the middle diameter portion 295, while the spool annular wall 246 can be arranged in the reduced diameter portion 296 of the through bore 230 of the sleeve 206. The first central bore 212, the third transverse bore 236, and the fourth transverse bore 238 of the housing 202 are in fluid communication with the middle diameter portion 295 on either axial side of the hydraulic actuation spine 250. The third transverse bore 236 can serve as a vent, while the fourth transverse bore 238 can allow a hydraulic signal to reach the hydraulic actuation surface 251 in case of insufficient lubrication.

[0046] External subassembly 298 may be supplied as a kit for field assembly of valve assembly 200. This external subassembly 298 may include housing 202 and sleeve 204, as previously described herein (see [link to previous document]). Figure 8 Flange 224 and edge 237 may be omitted, or may be supplied as separate parts subsequently attached to the housing and sleeve, respectively.

[0047] In such Figure 7 In some embodiments shown, flange 224 may be integral with the body of housing 202 and may be positioned at the first longitudinal end 220. A peripheral recess 288 communicates with a first transverse bore 226, which extends radially through housing 202. A test hole 292 extends from the first transverse bore 226 through flange 224, allowing pressure testing of valve assembly 200 prior to installation into hammer assembly.

[0048] As mentioned earlier herein, when formed as separate components, the housing and sleeve can be attached to each other (this is not necessarily the case in other embodiments of this disclosure). For Figure 7 and Figure 9 In the embodiment shown, the proximal end 232 of sleeve 204 includes a stepped pilot sleeve 292 communicating with a through-hole in sleeve 230. As... Figure 7 and Figure 10 As depicted, the second longitudinal end 222 of the housing 202 includes a stepped pilot ring 294 fitted into a stepped pilot seat 292 of the sleeve 230. A threaded interface may be provided between these features for attaching the housing and the spool valve together, or for allowing components to adhere to each other, etc. When using threads, a wrench facet 239 may be provided on the sleeve (see...). Figure 9 ), and a vise plane is provided on the flange 224 of the housing (see Figure 10 ), used to tighten and loosen these parts.

[0049] Through hole 230 defines an intermediate diameter portion 295 extending axially from stepped pilot sleeve 293 toward distal end 234, and a reduced diameter portion 296 extending axially from intermediate diameter portion 296 toward distal end 234. Third transverse hole 236 and fourth transverse hole 238 are in fluid communication with intermediate diameter portion 295.

[0050] The sleeve may also include a radially inwardly extending edge 237 that partially axially blocks the through-hole 230, and the housing 202 further defines a radially inwardly extending circumferentially extending slot 299 that is axially aligned with and in fluid communication with the second transverse bore 228. In the first transverse bore 226 and the first central bore 212 (see...) Figure 7 and Figure 16The intersection of the tapered tip 256 of the valve stem 208 and the tapered tip 248 of the spool 206 can provide a concave stop surface 300 that can be complementarily shaped to engage the tapered tip 256 of the valve stem 208 to stop axial movement of the valve stem 208.

[0051] When the rim 237 is integral with the sleeve 204, the inner subassembly 297 can be inserted (at least partially) into the sleeve 204 prior to assembly of the outer subassembly 298 to complete the valve assembly 200, as mentioned herein before.

[0052] The inner subassembly 297 can also be provided as a kit to field retrofit or repair the valve assembly 200.

[0053] Taken together Figure 7 and Figure 8 , the inner assembly 297 can include the spool 206, the valve stem 208, the snap ring 272, the guide 274, and the compression spring 276, as mentioned herein before.

[0054] In Figure 7 , the spool 206 further defines a snap ring groove 278 disposed proximate the second axial end 242 and in communication with the second central bore 242. The snap ring 272 is disposed in the snap ring groove 278, and the guide 274 abuts the snap ring 272. The compression spring 276 contacts the guide 274 and the valve stem 208.

[0055] The guide 274 defines a distal spring pocket 280 including a distal shoulder surface 282, and the valve stem 208 defines a proximal spring pocket 284 disposed at the open axial end 258 of the valve stem 208. The proximal spring pocket 284 further includes a proximal shoulder surface 286, and the compression spring 276 contacts the distal shoulder surface 282 and the proximal shoulder surface 286.

[0056] Once assembled, the valve stem tapered tip 256 contacts the spool tapered tip 248, and the valve stem annular wall 262 covers the first bypass hole 252 that is axially aligned with the second transverse bore 228 of the housing 202.

[0057] As Figure 7 , Figure 8 , Figure 11 and Figure 12 , the spool 206 defines a radially outer circumferential surface 302 defining a plurality of circumferentially extending slits 304 and a radially outer circumferential slot 306 that is axially aligned with and in fluid communication with the first bypass hole 252. The valve stem 208 includes a radially inner circumferential surface 308 defining a plurality of circumferentially extending grooves 310 at the interface between the spool annular wall 246 and the valve stem annular wall 262.

[0058] The components of the valve assembly can be manufactured from any suitable material, including but not limited to steel, aluminum, thermoplastics, and the like, so long as the material is sufficiently durable to withstand pressure and is chemically compatible with the fluid being used.

[0059] Any dimensions, configurations, and the like discussed herein can vary as desired or as appropriate from any values or features specifically mentioned herein or shown in the drawings for any embodiment.

[0060] Industrial applicability

[0061] Indeed, the valve assemblies, inner subassemblies, outer subassemblies, and / or hydraulic hammer assemblies constructed in accordance with any embodiment disclosed herein can be sold, purchased, manufactured, or otherwise obtained in an OEM (original equipment manufacturer) or aftermarket environment. In some cases, the various components of the valve assemblies, inner subassemblies, and outer subassemblies can be provided as a kit for repairing or retrofitting a hydraulic hammer assembly or other equipment (e.g., a hydraulic pump or motor, etc.) in the field.

[0062] The valve assembly 200 can be used in a hydraulic hammer assembly 110 as shown in Figure 4 and Figures 14 to 16 .

[0063] Initially, hydraulic fluid enters the first cross bore 226 of the valve assembly from the supply bore 138 (see Figure 4 ). If the lubricant is sufficient and the pressure in the hammer mechanism is lower than the pressure at the supply bore 138, the valve assembly 200 will assume the configuration shown in Figure 14 . Note that the valve stem is shown in the far left position because the spring force has been overcome (the spring is not shown in Figure 14 and Figure 15 ).

[0064] In Figure 14 , the spool 206 shifts to the far left position where it contacts the rim 237 of the sleeve 204. Also, the valve stem 208 shifts to the far left position where it contacts the snap ring 272. As a result, the first bypass bore 252 of the spool 206 and the first flow bore 264 of the valve stem 208 are axially aligned with each other, the spool annular wall 246 covers the second cross bore 228 of the housing 202, and the valve stem tapered tip 256 is axially spaced apart from the spool tapered tip 248, thereby forming a flow path 314 between the valve stem annular wall 262 and the spool annular wall 246. The hydraulic actuation ridge 250 is axially disposed near the fourth cross bore 238 of the sleeve 204 because no hydraulic signal is sent through this bore 238, indicating that the lubricant is insufficient.

[0065] Thus, the valve assembly 200 is in a full flow configuration because no flow is redirected through the bypass. This flow is represented by the arrow 316.

[0066] Over time, the lubricant can begin to become depleted in the hammer assembly. In this case, the hydraulic signal can be sent through the signal hole 140 (see Figure 4 ) to the fourth cross bore 238 to shift the spool 206 to its far right position as shown in Figure 15 . The third cross bore 236 can act as a vent to facilitate this movement.

[0067] In Figure 15 , the second cross bore 228 of the housing 202 is in axial alignment with the first bypass bore 252 of the spool 206 and the first flow bore 264 of the valve stem 208 because the hydraulic actuation spine 250 is axially disposed next to the third cross bore 236 of the sleeve 204. As before, the valve stem conical tip 256 is still axially spaced from the spool conical tip 248.

[0068] Thus, the flow of incoming fluid is split between the bypass and the outlet 320 (see arrow 318), reducing the hammer's work to reduce the likelihood of hammer mechanism wear and / or damage.

[0069] Finally, the hammer mechanism can stop functioning normally, creating a pressure build-up at the outlet 320. In this case, the valve assembly 200 can prevent backflow through it as the increased outlet pressure pushes against the backside of the valve stem 208 or compresses the spring 276 against the incoming hydraulic pressure until it reaches its far right position as shown in Figure 16 .

[0070] In this case, the valve stem conical tip 256 contacts the spool conical tip 248, the valve stem annular wall 262 covers the first bypass bore 252, the first bypass bore 252 is in axial alignment with the second cross bore 228 of the housing 202, and the hydraulic actuation spine 250 is axially disposed next to the third cross bore 236 of the sleeve 204.

[0071] It can be seen that the valve assembly uses a concentric design to supply three different working states or functions, saving space.

[0072] It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments of devices and assembly methods discussed herein without departing from the scope or spirit of the application. Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of various embodiments disclosed herein. For example, some devices can be constructed and operated differently than has been described herein, and certain steps of any method can be omitted, performed in a different order than specifically mentioned, or in some cases performed simultaneously or in sub-steps. In addition, changes or modifications can be made to certain aspects or features of various embodiments to yield further embodiments, and features and aspects of various embodiments can be added to or substituted for other features or aspects of other embodiments in order to provide further embodiments.

[0073] Accordingly, the specification and examples are to be considered exemplary and illustrative only, with the true scope and spirit of the application indicated by the following claims and their equivalents.

Claims

1. A valve assembly (200), comprising: An external subcomponent (298) comprising: A housing (202) comprising at least partially annular body and annular wall (210) defining a first central hole (212) defining a longitudinal axis (214), a circumferential direction (216), a radial direction (218), a first longitudinal end (220) arranged along the longitudinal axis (214), and a second longitudinal end (222) arranged along the longitudinal axis (214). The housing (202) further comprises a flange (224) disposed at the first longitudinal end (220). The first central hole (212) extends through the second longitudinal end (222), and the annular wall (210) further defines a first transverse hole (226) and a second transverse hole (228). The first transverse hole (226) extends radially through the annular wall (210) near the flange (224) to the first central hole (212), and the second transverse hole (228) extends radially through the annular wall (210) to the first central hole (212). The second transverse hole (228) is axially arranged between the second longitudinal end (222) and the first transverse hole (226). A sleeve (204) defining a through hole (230) forming a sleeve annular wall (229), and further defining a proximal end (232) and a distal end (234), the proximal end (232) being configured to mate with a second longitudinal end (222) of the housing (202), the sleeve annular wall (229) further defining a third transverse hole (236) and a fourth transverse hole (238), the third transverse hole (236) extending radially through the sleeve annular wall (229), communicating with the through hole (230) and arranged adjacent to the proximal end (232), the fourth transverse hole (238) extending radially through the sleeve annular wall (229), communicating with the through hole (230) and axially arranged between the third transverse hole (236) and the distal end (234); and An internal subcomponent (297) comprising: A slide valve (206) defining a central bore (244) extending axially through the slide valve (206) to form an annular wall (246); and A valve stem (208) is disposed in the central bore (244). The valve stem (208) defines a closed axial end (254) including a valve stem tapered tip (256), an open axial end (258), and another central bore (260) forming a valve stem annular wall (262), and a first flow hole (264) extending radially through the valve stem annular wall (262) axially disposed between the closed axial end (254) and the open axial end (258). The valve stem (208) includes a stepped body such that the valve stem annular wall (262) bulges radially outward at a position (266) axially disposed between the first flow hole (264) and the open axial end (258).

2. The valve assembly (200) according to claim 1, wherein the housing (202) further defines a peripheral recess (288) communicating with the first transverse bore (226), and the first transverse bore (226) extends radially through the housing (202) and further defines a test hole (292a) extending from the first transverse bore (226) through the flange (224).

3. The valve assembly (200) according to claim 1, wherein the proximal end (232) of the sleeve (204) includes a stepped pilot seat (293) communicating with the through hole (230) of the sleeve (204), and the second longitudinal end (222) of the housing (202) includes a stepped pilot ring (294) fitted into the stepped pilot seat (293) of the sleeve (204).

4. The valve assembly (200) according to claim 3, wherein the through hole (230) defines an intermediate diameter portion (295) extending axially from the stepped pilot sleeve (293) toward the distal end (234), and a reduced diameter portion (296) extending axially from the intermediate diameter portion (295) toward the distal end (234), and the third transverse hole (236) and the fourth transverse hole (238) are in fluid communication with the intermediate diameter portion (295).

5. The valve assembly (200) of claim 1, wherein the housing (202) and the sleeve (204) are separate components, the sleeve (204) further comprising a radially inwardly extending edge (237) that partially axially blocks the through hole (230), and the housing (202) further defining a radially inwardly extending circumferentially extending slot (299) axially aligned with and in fluid communication with the second transverse hole (228).

6. An internal subassembly (297) for assembling a valve assembly (200), the internal subassembly (297) comprising: A spool valve (206) defining a central bore (244) and a hydraulically actuated ridge, the central bore (244) extending axially through the spool valve (206) to form a spool valve annular wall (246), and the spool valve (206) including a spool valve tapered tip (248), the hydraulically actuated ridge extending radially outward from the spool valve annular wall (246), and the spool valve (206) further defining a first bypass orifice extending through the spool valve annular wall (246) to the central bore (244); and A valve stem (208) is disposed in the central bore (244). The valve stem (208) defines a closed axial end (254) including a valve stem tapered tip (256), an open axial end (258), and another central bore (260) forming a valve stem annular wall (262), and a first flow hole (264) extending radially through the valve stem annular wall (262) axially disposed between the closed axial end (254) and the open axial end (258). The valve stem (208) includes a stepped body such that the valve stem annular wall (262) bulges radially outward at a position (266) axially disposed between the first flow hole (264) and the open axial end (258).

7. The internal subassembly (297) of claim 6 further includes a retaining ring (272), a guide (274), and a compression spring (276), wherein the slide valve (206) further defines a retaining ring groove (278) communicating with the central hole (244) of the slide valve (206), the retaining ring (272) being disposed in the retaining ring groove (278), the guide (274) being adjacent to the retaining ring (272), and the compression spring (276) contacting the guide (274) and the valve stem (208).

8. The internal subassembly (297) of claim 7, wherein the guide (274) defines a distal spring seat (280) including a distal shoulder surface (282), and the valve stem (208) defines a proximal spring seat (284) disposed at the open axial end (258), the proximal spring seat (284) further including a proximal shoulder surface (286), and the compression spring (276) contacts the distal shoulder surface (282) and the proximal shoulder surface (286).

9. The internal subassembly (297) according to claim 8, wherein the valve stem tapered tip (256) contacts the spool valve tapered tip (248), and the valve stem annular wall (262) covers the first bypass hole (252).

10. The internal subassembly (297) of claim 6, wherein the slide valve (206) defines a radially outer circumferential surface (302) and a radially outer circumferential slot (306), the radially outer circumferential surface (302) defining a plurality of externally circumferentially extending slits (304), the radially outer circumferential slot (306) being axially aligned with and in fluid communication with the first bypass hole (252), and the valve stem (208) including a radially inner circumferential surface (308) defining a plurality of circumferentially extending grooves (310) at the interface between the slide valve annular wall (246) and the valve stem annular wall (262).

Images