Patent Grant
11187214
The present disclosure generally relates to pumps, and more particularly relates to pumps with a unitary pump housing casting.
Many domestic and commercial water usage applications may require relatively high pressures, which may be beyond the capacity of residential and/or municipal water distribution and supply systems. For example, heavy duty cleaning applications may benefit from increased spraying pressure that is greater than the pressure available for common residential and/or municipal water distribution and supply systems. In some situations, various nozzles may be utilized to constrict the flow of the water to provide an increase in the pressure of the resultant water stream. However, many tasks may benefit from even greater pressures than can be achieved with common pressure nozzles that may be attached to a hose. In such circumstances pressure washers may be utilized, in which a power driven pump may be employed to increase the pressure significantly above pressures that are readily achievable using hose attachments. Such elevated pressures may greatly increase the efficiency and/or effectiveness of some cleaning and spraying tasks.
According to an embodiment, a pump may include a pump housing formed as a singular body. The pump housing may include a mounting feature adjacent a first end of the pump housing, the mounting feature configured for mounting the pump relative to a prime mover. The pump housing may also include a drive system cavity formed in the first end of the pump housing, the drive system cavity being sized to receive at least a portion of an axial drive system. The pump housing may further include a pump cylinder extending inwardly into the pump housing from the drive system cavity. The pump may also include a piston guide plate configured to be affixed within the drive system cavity. The piston guide plate may include a piston guide associated with the pump cylinder. The piston guide may be configured to at least partially receive a pump piston therethrough for facilitating alignment and axial movement of a pump piston within the pump cylinder.
One or more of the following features may be included. The axial drive system may at least partially seal the drive system cavity of the pump housing opposite the piston guide plate to provide an integrated oil reservoir between the axial drive system and the piston guide plate. The axial drive system may include a cam plate configured for axially driving the pump piston when the cam plate is rotational driven. The cam plate may be at least partially disposed in the integrated oil reservoir. The piston guide plate may be configured to be affixed to the pump housing by one or more bolts. A head of each of the one or more bolts may be at least partially disposed within the integrated oil reservoir.
The piston guide may include a bore extending through the piston guide plate, and having a seal associated with the bore to mitigate fluid intrusion between the pump piston and the piston guide plate. A seal may be disposed between at least a portion of the piston guide plate and the pump housing. The seal may include an O-ring disposed in a groove around a periphery of the piston guide plate.
The pump may further include one or more fluid passages formed between the pump housing and the piston guide plate. The one or more fluid passages may provide a fluid pathway between the piston guide and a fluid intake of the pump cylinder. The fluid passage may include a channel formed on a surface of the piston guide plate. The channel may be configured to be substantially enclosed by the pump housing when the piston guide plate is assembled with the pump housing.
The pump housing includes an at least partially integrally formed low pressure intake manifold associated with the pump cylinder. The pump housing include an at least partially integrally formed high pressure outlet manifold associated with the pump cylinder.
According to another implementation, a pump may include a pump housing formed as a singular body. The pump housing may include a mounting feature adjacent a first end of the pump housing, the mounting feature configured for mounting the pump relative to a prime mover. The pump housing may also include a drive system cavity formed in the first end of the pump housing. The drive system cavity may be sized to receive at least a portion of an axial drive system. The pump housing may also include a plurality of pump cylinders extending inwardly into the pump housing from the drive system cavity. The pump may also include a plurality of pump pistons. A respective one of the plurality of pump pistons may be reciprocatingly received in a respective one of the plurality of pump cylinders. The pump may further include a piston guide plate configured to be affixed within the drive system cavity. The piston guide plate may include a respective piston guide associated with each of the plurality of pump cylinders. Each piston guide may be configured to at least partially receive a respective pump piston therethrough for facilitating alignment and axial movement of the respective pump piston within the respective pump cylinder.
One or more of the following features may be included. The axial drive system may at least partially seal the drive system cavity of the pump housing opposite the piston guide plate to provide an integrated oil reservoir between the axial drive system and the piston guide plate. The piston guide plate may be configured to be affixed to the pump housing by one or more bolts. A head of each of the one or more bolts may be at least partially disposed within the integrated oil reservoir. A seal may be disposed between the pump housing and the piston guide plate at least partially surrounding each of the one or more bolts.
The piston guide plate may include one or more channels formed on a surface of the piston guide plate. The one or more fluid passages may at least partially surround each respective piston guide, and provide a fluid pathway between each respective piston guide and one or more of a fluid intake of the pump and a drain. The one or more channels may be at least partially enclosed by the pump housing when the piston guide plate is assembled with the pump housing.
The pump housing may include an at least partially integrally formed low pressure intake manifold associated with the plurality of pump cylinders. The pump housing may include an at least partially integrally formed high pressure outlet manifold associated with the plurality of pump cylinders.
According to yet another implementation, a pump may include a pump housing formed as a singular body. The pump housing may include a mounting feature adjacent a first end of the pump housing, the mounting feature configured for mounting the pump relative to a prime mover. The pump housing may also include a drive system cavity formed in the first end of the pump housing. A plurality of pump cylinders may extend inwardly into the pump housing from the drive system cavity. The pump housing may include an at least partially integrally formed low pressure intake manifold associated with the plurality of pump cylinders. The pump housing may further include an at least partially integrally formed high pressure outlet manifold associated with the plurality of pump cylinders. The pump may also include a plurality of pump pistons. A respective one of the plurality of pump pistons may be reciprocatingly received in a respective one of the plurality of pump cylinders. The pump may also include a piston guide plate configured to be affixed within the drive system cavity and sealingly engaged with the pump housing. The piston guide plate may include a respective piston guide associated with each of the plurality of pump cylinders. Each piston guide may be configured to at least partially receive a respective pump piston therethrough for facilitating alignment and axial movement of the respective pump piston within the respective pump cylinder. The pump may further include an axial drive system at least partially disposed within the drive system cavity. The axial drive system may, at least in part, provide an integral oil reservoir within the drive system cavity between the axial drive system and the piston guide plate.
According to an embodiment, the present disclosure may generally relate to a positive displacement pump including a singular, or unitary, housing casting. In some embodiments, the positive displacement pump may be utilized in a pressure washer system. Generally, the pressure washer system may receive an input flow of water, for example, from a domestic or municipal water supply or the like, and may utilize a pump to provide an output flow of the water having a greater pressure than the input flow. It will be appreciated that while the present disclosure may generally be described in the context of pumping water for use with a pressure washer system, a pump consistent with the present disclosure may suitable be used an a variety of applications for pumping a wide variety of fluids and in a wide variety of applications.
In general, the positive displacement pump 10 may include one or more axial piston pumps arranged in the common singular housing casting. The one or more axial piston pumps may be driven by a rotating cam plate, e.g., which may be rotatably driven by a prime mover such as a gas engine or electric motor. In various embodiments, the rotating cam plate may include a fixed angle cam plate (e.g., which may provide a fixed piston pump travel and fixed pump output per rotation of the cam plate) or a variable angle cam plate/swashplate (e.g., which may be capable of providing varying piston pump travel and varying pump output per rotation). Each of the individual piston pumps may be spring driven, e.g., to an intake position (e.g., defining an intake volume within the pump cylinder), and may be driven by the cam plate to the pumped position (e.g., by which fluid drawn into the cylinder may be expelled), e.g., as generally shown in the cross-sectional view of
Consistent with the foregoing, in an illustrative example embodiment, a pump may include a pump housing formed as a singular body. The pump housing may include a mounting feature adjacent a first end of the pump housing, the mounting feature configured for mounting the pump relative to a prime mover. The pump housing may also include a drive system cavity formed in the first end of the pump housing, the drive system cavity being sized to receive at least a portion of an axial drive system. The pump housing may further include a pump cylinder extending inwardly into the pump housing from the drive system cavity.
With further reference to
Further, the singular casting may define an axial drive system cavity 28 (e.g., as shown in
In an implementation, the integral oil reservoir may, at least in part, provide lubrication for the reciprocating movement of the axial pistons and/or for the driving interaction between the cam plate and the axial pistons. As such, wear associated with the axial pistons and/or the cam plate may be reduced as a result of the provided lubrication. As shown in
With particular reference to
It will be appreciated that various O-rings and/or other sealing arrangements may be included between the pump pistons and the piston guides, e.g., to prevent and/or reduce the occurrence or amount of oil from the integral oil reservoir passing into the pump cylinders. Similarly, the various O-rings and/or other sealing arrangements may prevent and/or reduce the occurrence or amount of water from the pump cylinders passing through the piston guide plate into the integral oil reservoir. It will be appreciated that various sealing arrangements may include multiple seals in combination with one another. In embodiments utilizing multiple seals in combination with one another, the multiple seals may be of the same type and/or may include different types of seals and/or sealing arrangements. In some implementations, oil drain holes (e.g., oil drain holes 50, 52, 54) may be provided in the piston guides. The oil drain holes may, for example, allow oil, which may intrude between the piston guide bores and the pump pistons, to drain back to the integral oil reservoir. For example, the reciprocating movement of the pump pistons may draw oil from the integral oil reservoir between the pump pistons and the bores of the piston guides. The migration of the oil through the piston guide plate may be prevented and/or reduced by the O-rings or other sealing arrangements at the top of the piston guide plate. The oil drain holes may be disposed below the seal, for example at the bottom of a cavity or counterbore in the piston guide that at least partially receives the O-ring or other sealing feature. As such, oil may be scraped from the pump piston by the O-ring or other sealing feature and returned to the integral oil reservoir via the oil drain holes. As shown in the illustrated example embodiment, in some implementations a lower portion of the oil drain holes may manifest as a groove in the exterior of the piston guides. However, other configurations may be utilized.
In some embodiments, the piston guide plate may also include one or more water control passages (e.g., water control passages 56, 58, 60) may be formed in the piston guide plate. The water control passages may include molded in features of the piston guide plate or may include machined channels in the piston guide plate. In some embodiments, when the piston guide plate is assembled with the pump housing, the water control passages may form enclosed channels. As shown the water control passages may generally extend between, and in some embodiments surround, the bore of each piston guide. In some such situations, any water that may leak around the pump piston during pumping may flow into the water control passages. According to various embodiments, water flowing into the water control passages may be directed back into a low pressure water inlet, directed to a drain, or otherwise controlled. For example, in some embodiments, the pump housing may include one or more channels or passages that fluidly couple the water control passages with the low pressure water inlet. In some embodiments, as shown in the depicted example, the water control passages may extend to the outer perimeter of the piston guide plate.
In embodiments in which the piston guide plate may prevent and/or reduce the passage of oil from the integral oil reservoir and/or provide water control passages to prevent or control the escape of water leaking past the pump pistons, the piston guide plate may be at least partially sealed relative to the pump housing. For example, an O-ring or other seal may be provided between the piston guide plate and the housing. As shown in the illustrated example embodiment, the piston guide plate may include a groove or channel (e.g., groove 62) that may be configured to include an O-ring or other seal, which may engage the wall of the axial drive system cavity to provide a generally fluid tight seal between the piston guide plate and the housing. While the illustrated embodiment generally depicts an O-ring disposed within a groove in the side of the piston guide plate, it will be appreciated that other sealing arrangements may be implemented, including sealing arrangements that make use of multiple seals (e.g., which may be of the same type of seal/sealing arrangement, and/or may include different types of seals/sealing arrangements). For example, in some embodiments a seal, such as an O-ring or gasket, may be disposed between the top of the piston guide plate and an inner surface of the housing (e.g., a surface within the cavity 28).
In some implementations, the singular pump casting may include an integrated low pressure water inlet manifold and/or an integrated high pressure outlet, as generally shown in
With reference also to
Referring to
Consistent with the present disclosure, a pump may be provided having a singular housing casting that may include integral mounts for attaching the pump relative to a prime mover or chassis, integral pump cylinders, and integral inlet and outlet manifolds. Consistent with such an embodiment, as the pump housing may include only a singular casting, the need to align and attach separate housing components may be avoided. As such, a relatively simpler assembly may be provided that may avoid manufacturing an alignment problems that may result from the use of multiple individual housing components. Additionally, the singular casting may avoid, or reduce, the number of external fasteners, which would otherwise be susceptible to environmental attack and corrosion. Further, the inclusion of at least partially molded in oil and water drains in the singular casting may simplify manufacturing, for example with respect to cross drilling operations or the like. Various additional/alternative features may also be realized through the use of a pump housing including a singular casting.
Various features and implementations of pumps consistent with the present disclosure have been illustrated and described. Various additional and/or alternative features may similarly be implemented in connection with a pump consistent with the present disclosure. For example, a pump consistent with the present disclosure may be implemented to utilize unloader systems of varying configurations and operating principles. For example, as is generally known, an unloader valve may redirect water flow from the high pressure outlet side of the pump when the spray gun valve is closed and/or the outlet is otherwise obstructed. For example, in connection with pumps utilizing a prime mover that may not automatically shut off when the demand for high pressure water is not required, the continuing operation of the positive displacement piston pump against the closed outlet (e.g., resulting from the closed spray gun valve) may place thermal and mechanical stress on the pump system and/or on the prime mover. In such a situation, the unloader system may divert the high pressure fluid from the outlet of the pump back to the inlet side of the pump and/or may otherwise direct the high pressure fluid from the outlet of the pump such that undue stress of operating the positive displacement pump against a closed outlet may be avoided and/or reduced.
Generally two varieties of unloader systems of commonly used: a trapped pressure unloader and a flow activated unloader. A trapped pressure unloader may generally include a check valve (e.g., which may be referred to as a non-return valve) that may seal “trapped” pressure between the check valve and the spray gun valve. This trapped pressure may act on a small piston in the unloader, which may cause a fluid passage to open and allow fluid to flow internally through the pump (e.g., from the high pressure outlet side to the low pressure inlet side). A flow activated unloader may generally utilize a sliding valve that may be acted on by a differential of pressure. For example, a shuttle of the sliding valve may move from one position permitting fluid to flow through the high pressure system (e.g., the pressure washer gun). When the valve of the pressure washer gun is closed (and/or the flow path is otherwise obstructed) the shuttle of the sliding valve may move to a second position redirecting the high pressure fluid through one or more internal passages in the pump (and/or otherwise direct the high pressure fluid), for example, to the low pressure inlet side of the pump. In either unloader system, when the pressure washer gun valve is closed (and/or the flow path is otherwise obstructed), the high pressure fluid may be cause to circulate from the high pressure outlet side of the pump to the low pressure inlet side of the pump (and/or otherwise be released), to reduce and/or eliminate the stress on the pump system resulting from pumping against a closed outlet.
It will be appreciated that the various types of unloader systems (and even different unloader systems of the same type) may have different physical configurations and/or may utilize different fluid pathways to achieve the desired result. Accordingly, the internal components and the features cast within, or machined into, the pump housing to accommodate the unloader systems may vary to suit different applications. Accordingly, the present disclosure should be construed as providing for such different arrangements necessary to suit a variety of unloader system configurations.
In some implementations, a pump system consistent with the present disclosure may be configured to be used in connection with an integrated chemical injection system. In general, a chemical injection system may be implemented to allow an additional agent to be mixed with the high pressure fluid and dispensed along with the high pressure fluid. Examples of some additional agents may include, but are not limited to, detergents, degreasers, cleaning solutions, etc. Often, chemical injection systems may be configured to introduce the additional agents near the high pressure outlet of the pump. For example, in some embodiments, additional agents may be introduced into the stream of high pressure fluid from the pump using a venturi (e.g., which may also be referred to as a mixing tube), which may cause the flow of the high pressure fluid to change velocity and pressure through a series of different sized orifii. Generally, in the absence of atmospheric pressure, a differential of pressures may cause the stream of high pressure fluid form the pump to cavitate as the high pressure fluid passes through the different sized chambers. A fitting may be located in fluid communication with the venturi arrangement. The fitting may include a small check valve that may open when greater fluid flow at relatively lower pressures pass through the venturi causing a vacuum that may display the check valve allowing atmospheric pressure to enter the high pressure fluid stream. The fitting may often include a barbed external feature that may secure a flexible hose to deliver the additional agents from a container into the high pressure fluid stream (e.g., during the relatively lower pressure mode created by the venturi). The additional agents introduced into the high pressure fluid stream may be, for example, delivered through a pressure washer gun to a working surface. As such, a pressure washer including a chemical injection system may allow the pressure washer to utilize cleaning agents, or other additional agents. In some embodiments, the fitting may be removed, or bypassed, to allow the high pressure fluid to be utilized without the introduction of additional agents. As noted above, in some implementations, the fitting may often be attached to the high pressure outlet of the pump, e.g., via a threaded fitting or the like. As such, the fitting may be easily removed from the, in some embodiments.
As generally discussed above, the prime mover (e.g., gasoline engine, electric motor, or the like) may be coupled to the pump to drive the rotating cam plate. In some implementations, the output shaft of the prime mover and the input of the rotating cam plate may be keyed together, e.g., to prevent and/or reduce the likelihood of the prime mover shaft rotationally slipping relative to the cam plate. In some implementations, the output shaft of the prime mover may include an axial groove, or channel, which may provide a keyseat, or pocket, to receive a key. A corresponding groove, or slot, may be provided in the cam plate to provide a keyway. The corresponding keyseat and keyway may allow a key to extend between, and to rotatably couple, the output shaft and the cam plate. In some implementations, the key may be provided as a separate component from the output shaft and from the cam plate. As such, the key may be assembled to one of the output shaft and the cam plate prior to mating the output shaft and the cam plate. In some implementations, assembling the key with the output shaft may require a process to impose a slight amount of deformation to the output shaft, e.g., to create an interference fit or friction fit between the key and the keyseat as a means to secure the key within the key seat. Such a process may, in some situations reduce the likelihood that the key may move out of position during assembly. In this regard, the efficiency and speed of assembly the prime mover to the pump may be improved. It will be appreciated that other arrangements may be provided for rotationally coupling the prime mover and the pump (e.g., including the rotating cam plate).
A variety of features of the pump have been described. However, it will be appreciated that various additional features and structures may be implemented in connection with a pump according to the present disclosure. As such, the features and attributes described herein should be construed as a limitation on the present disclosure.
This application claims the benefit of U.S. provisional patent application Ser. No. 62/486,146, filed on Apr. 17, 2017, entitled “Pump,” the entire disclosure of which is incorporated herein by reference.
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