Hydraulic device with a separate filler insert for volume reduction of a hydraulic circuit

Abstract

A hydraulic device for a work vehicle includes a device body, a plug, and a filler insert. The device body includes a wall structure between surfaces defining an internal passage, the internal passage including an access channel having a first diameter, the access channel extending from an access port in the device body to a hydraulic fluid channel, the hydraulic fluid channel extending from an inlet in the first surface through the wall structure to an outlet in the second surface to convey hydraulic fluid through the wall structure. A plug is mounted to the device body to close the access port. A filler insert is adjacent to the plug and has a handle including a circular cross-section having a second diameter smaller than the first diameter so as to be separated from the inner wall surface of the access channel. An annular space around the handle in the access channel allows the hydraulic fluid to surround at least a portion of the handle of the filler insert.

Description

Technical Field

[0001] The present disclosure relates to hydraulic components of work vehicles and / or work vehicle implements, and in particular to improved hydraulic response of the hydraulic components. Background Art

[0002] Work vehicles, such as those used in the construction, forestry, agriculture, and mining industries, often include hydraulic components for providing power to various systems onboard or connected to the work vehicle, including various drives and work tools. In certain applications, hydraulic components may be required to provide very fast and accurate power delivery. The hydraulic circuits of conventional hydraulic components may have internal passages created through machining operations such as drilling and punching, which leave behind legacy ports and passages that are not needed to accommodate and transmit the pressurized hydraulic fluid within the hydraulic circuit. The presence of such redundant passages can affect the performance of the hydraulic circuit, the hydraulic device, and the work vehicle. Summary of the Invention

[0003] A hydraulic device for a work vehicle includes one or more features for reducing the internal volume of a pressurized hydraulic fluid containing circuit of the device.

[0004] In one aspect, the present disclosure provides a hydraulic device comprising a device body, a plug, and a filling insert. The device body has a first surface, a second surface, and a wall structure between the first and second surfaces. The wall structure defines a plurality of internal passages, including access channels and hydraulic fluid channels, the access channels at least partially having a cylindrical inner wall surface having a first diameter. The access channels extend from an access port in the device body through the wall structure to the hydraulic fluid channels, and the hydraulic fluid channels extend from an inlet in the first surface of the device body through the wall structure to an outlet in the second surface of the device body, thereby conveying hydraulic fluid from the inlet through the wall structure to the outlet. The plug is fixedly or removably mounted to the device body to seal the access port. The filling insert is disposed within the access channel adjacent to or connected to the plug within the access channel, and has a cylindrical shank at least partially comprising a circular cross-section having a second diameter that is smaller than the first diameter of the inner wall surface of the access channel so as to be separated from the inner wall surface of the access channel. An annular space between the shank of the fill insert and the inner wall surface of the access channel allows the hydraulic fluid to surround at least a portion of the shank of the fill insert.

[0005] In other aspects, the present disclosure provides a hydraulic transmission for a work vehicle and a work vehicle having the hydraulic transmission. The hydraulic transmission includes: a plurality of gears providing a plurality of gear ratios; a clutch for shifting the plurality of gears between the plurality of gear ratios; a transmission body; one or more control valves; a plug and a filler insert. The clutch is powered at least in part by hydraulic pressure. The transmission body mounts the plurality of gears and the clutch within an internal cavity. The transmission body has a first surface, a second surface, and a wall structure between the first and second surfaces. The wall structure defines a plurality of internal passages including access channels and hydraulic fluid passages. The access channels at least partially have a cylindrical inner wall surface having a first diameter. The access channels extend from an access port in the transmission body through the wall structure to the hydraulic fluid passages. The hydraulic fluid passages extend from an inlet in the first surface of the transmission body through the wall structure to an outlet in the second surface of the transmission body to deliver hydraulic fluid from the inlet through the wall structure to the outlet. The one or more control valves are mounted to the outlet of the transmission body and are in fluid communication with the hydraulic fluid passage, the one or more control valves being configured to actuate the clutch. The plug is fixedly or removably mounted to the transmission body to seal the access port. The filler insert is disposed within the access passage proximate to the plug or connected to the plug within the access passage. The filler insert has a cylindrical shank, the shank at least partially comprising a circular cross-section having a second diameter, the second diameter being smaller than the first diameter of the inner wall surface of the access passage so as to be separated from the inner wall surface of the access passage. An annular space between the shank of the filler insert and the inner wall surface of the access passage allows the hydraulic fluid to flow around at least a portion of the shank of the filler insert.

[0006] The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features and advantages will be apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] At least one embodiment of the present disclosure is described below with reference to the accompanying drawings, in which:

[0008] Figure 1 is a perspective view of an exemplary work vehicle in the form of a wheel loader including a transmission having a hydraulic circuit with a separate filler insert according to the present disclosure;

[0009] Figure 2 yes Figure 1an isometric view of an exemplary transmission of an exemplary wheel loader;

[0010] Figure 3 It is along Figure 2 a partial cross-sectional view taken along line 3-3;

[0011] Figure 4 yes Figure 3 A partial cross-sectional view of region 4-4 with a first exemplary filler insert; and

[0012] Figure 5 is a similar partial cross-sectional view, but with a second exemplary filler insert.

[0013] In the various drawings, like reference numerals represent like elements. For simplicity and clarity of illustration, descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the exemplary and non-limiting embodiments of the present invention described in the subsequent detailed description. It should also be understood that unless otherwise indicated, features or elements shown in the drawings are not necessarily drawn to scale. DETAILED DESCRIPTION

[0014] Embodiments of the present disclosure are illustrated in the figures of the accompanying drawings briefly described above. Various modifications to the exemplary embodiments may be devised by those skilled in the art without departing from the scope of the invention as set forth in the appended claims.

[0015] Overview

[0016] Work vehicles often include hydraulic systems that scale up the power delivered by the prime mover to various components of the work vehicle, such as wheels and implements. In certain applications, the hydraulic system may need to provide very fast and accurate power delivery. The hydraulic circuits of conventional hydraulic components may have internal passages created through machining operations such as drilling and punching, which leave behind legacy ports and passages that are not required for the hydraulic circuit. These redundant passages unnecessarily expand the internal volume of the hydraulic circuit and increase hydraulic flow requirements. This can introduce lag or inconsistency in the control of the pressurized hydraulic fluid within the hydraulic circuit due to the increased flow and the creation of areas within the hydraulic circuit for air to enter. Air is a gas and is therefore compressible. Due to fluctuations in pressure within the hydraulic circuit, the air can change in volume, thereby changing the characteristic response of the hydraulic circuit. Inconsistent or unresponsive operation of the hydraulic circuit can reduce its performance to below that required for certain applications.

[0017] A hydraulic device for a work vehicle may include a hydraulic circuit having one or more internal hydraulic fluid channels for delivering pressurized hydraulic fluid to hydraulic components and one or more access channels formed to provide internal access ports within the device body for fabricating the hydraulic fluid channels. As used herein, an "access channel" is an external or internal channel that is not used to deliver hydraulic fluid to hydraulic components, but rather allows the internal access ports within the device body to form a fluid-carrying channel for the hydraulic circuit. Thus, the access channel is in fluid communication with the hydraulic fluid channels and contains hydraulic fluid; however, the access channel is not part of the main flow path of the hydraulic circuit that provides power to the hydraulic components or returns to the tank, and in this sense, can be considered a non-operating channel of the hydraulic circuit. Therefore, if the access channel is not used when fabricating the hydraulic fluid channels, it can and likely will be omitted.

[0018] The present disclosure relates to a hydraulic device for a work vehicle in which one or more filler inserts (which may also be considered "volume" inserts) are mounted within an access channel primarily to occupy the internal volume of the access channel. The volume occupied in the access channel reduces the volume of hydraulic fluid within the access channel and thereby reduces the volume of hydraulic fluid within the hydraulic circuit. This reduces the hydraulic fluid volume and throughput flow requirements of the hydraulic circuit and can reduce the presence of air in the hydraulic circuit by reducing or eliminating "dead zones" within the hydraulic circuit where air may accumulate, particularly during idle periods when the hydraulic circuit is not pressurized (e.g., during a cold start of a work vehicle engine). Reducing air within the hydraulic circuit improves the consistency and responsiveness of the hydraulic circuit by reducing or avoiding attendant pressure and flow fluctuations that may be caused by the compression of the air.

[0019] The filler insert can be installed within the access channel with a loose fit, distinguished, for example, from a press fit, a slip fit, or a transition fit, wherein a portion or all of the filler insert is spaced from the access channel's inner wall surface, such as by an annular space defined between the access channel's inner diameter and the filler insert's outer diameter. This loose fit allows a certain volume of hydraulic fluid to reside in this annular space between the filler insert and the inner wall surface. During use, the filler insert, while completely or partially physically separated from the main body of the hydraulic device, remains stationary, held in place by fluid pressure, and does not contact the access channel's inner wall surface (e.g., rattle). The filler insert does not affect any damping within the hydraulic circuit, and the hydraulic circuit can generally be undamped. In some cases, the filler insert can occupy a majority of the access channel's internal volume, and in certain embodiments and applications, the filler insert can occupy approximately 85% to approximately 99% of the access channel's internal volume, leaving only a thin layer of fluid surrounding some or all of the filler insert. The filling insert may occupy the aforementioned volume values ​​in terms of the total volume of the access channel, the volume based on the cross-sectional area of ​​the access channel, or both.

[0020] The filler insert may include or be accompanied by a plug that seals the external access port of the access channel in which the filler insert is disposed. The plug reduces or prevents the outflow of hydraulic fluid from the hydraulic circuit and prevents the ingress of contaminants into the hydraulic circuit. The plug securely engages the access port of the access channel, for example, by a threaded or press-fit fit, and may include, be connected to, or seal the access port. In some examples, the filler insert is a separate component that is completely physically disconnected from the main body of the hydraulic device and the plug connected to the main body. In this case, the entire filler insert is spaced apart from the inner wall surface of the access channel and is completely surrounded by hydraulic fluid, including along its circumference and ends. In other examples, the filler insert and the plug are integral or shared components (formed simultaneously from the same material using the same process), wherein the filler insert forms a free-ended shank having a circumferential surface and a free end that is physically disconnected from the main body of the device. In either case, the filler insert is considered "separate" from the inner wall surface of the access channel. Whether or not the fill insert is physically connected to the plug, the plug may be used to house the fill insert and maintain the fill insert in position within the access passage by directly abutting contact with the fill insert or the hydraulic fluid encapsulating the fill insert.

[0021] One exemplary application in which the hydraulic device for a work vehicle disclosed herein can be advantageously implemented is in a hydraulically controlled transmission. A work vehicle transmission may have one or more clutches for shifting gears, which are applied or released under hydraulic pressure metered by one or more control valves. Smooth operation of a work vehicle under extreme loads (e.g., gross vehicle weights of approximately 30 to 50 tons or more) may require highly accurate and rapid clutch operation. Under such heavy loads, unexpected slippage or delay in clutch operation can result in abrupt shift changes, which can interrupt the smooth motion of the work vehicle, potentially causing operator discomfort, interfere with the payload, and stress the transmission. Therefore, the control valves for the clutches must precisely apply the required hydraulic fluid pressure. A work vehicle transmission having such desirable characteristics is provided herein and is at least partially achieved by incorporating a hydraulic circuit having an internal passageway with one or more volumetric inserts, including a filler insert disposed within the access passageway. As described above, the filler insert serves to reduce the volume of hydraulic fluid in the hydraulic circuit and mitigate the harmful effects of air within the hydraulic circuit that can impede control valve accuracy. Due to the filler insert, the hydraulic circuit is able to operate the control valves and clutches more consistently and accurately, and thus the transmission is able to shift more smoothly during operation of the work vehicle. The disclosed volume insert arrangement can improve transmission performance, including response time and shift feel, particularly during cold starts when air or aerated oil may have otherwise been introduced into the access passage. Furthermore, the disclosed volume insert can extend the life of clutch (or other) hydraulic components.

[0022] Exemplary embodiment of a hydraulic device with a separate filler insert for volume reduction of a hydraulic circuit

[0023] refer to Figure 1In some embodiments, the disclosed work vehicle 10 can be a wheel loader, although the hydraulic circuits and volume inserts described herein can be applied to a wide variety of work vehicle platforms, such as other construction vehicles (e.g., motor graders), agricultural vehicles including tractors, and forestry vehicles (e.g., forwarders). As shown, the work vehicle 10 can be considered to include a chassis consisting of a chassis 12 that supports a work tool 16. The work tool 16 is selectively positioned by various combinations of structural elements (e.g., arms, crossbars, pivot joints, etc.) and controllably moved using any number of actuators (such as hydraulic cylinders). The work vehicle 10 can also be considered to include a powertrain 22, an operator compartment 24, a control system 26, and a hydraulic system 28. The work vehicle 10 can be supported off the ground by ground-engaging wheels or tracks. In the example shown, the work vehicle 10 includes driven rear wheels 30 mounted on a rear axle (not shown) (one or more on the left / right side of the work vehicle 10) and steerable front wheels 32 mounted on a front axle (not shown) (one on the left / right side of the work vehicle 10).

[0024] Control system 26 can control various aspects of work vehicle 20, particularly the characteristics of powertrain 22. Control system 26 can include a work vehicle electronic control unit (ECU) or a dedicated controller. In some embodiments, control system 26 can be configured to receive input commands and interact with an operator via a human-machine interface or operator interface (not shown) and various sensors, units, and systems onboard or remote to work vehicle 20; and in response, control system 26 generates one or more types of commands for implementation by powertrain 22 and / or various systems of work vehicle 20 (e.g., hydraulic system 28).

[0025] Generally, the powertrain 22 includes a propulsion source, such as an engine 34, which supplies power to the work vehicle 10, either directly as mechanical power or after conversion to electrical power (e.g., via a battery) or hydraulic power. In one example, the engine 34 is an internal combustion engine, such as a diesel engine, which is controlled by an engine control module (not shown) of the control system 26. It should be noted that the use of an internal combustion engine is merely an example, and a fuel cell, an electric motor, a hybrid gas-electric motor, or other power generation device may be used as a propulsion source. The engine 34 selectively drives the wheels or tracks of the work vehicle 10, such as the rear wheels 30, or both the rear wheels 30 and the front wheels 32. In addition, the powertrain 22 has a wheel steering component 36, which includes various devices (e.g., a power steering pump and lines, a steering mechanism, and the like) that connect a manual steering input (e.g., an operator steering control or wheel) and / or an automatic steering input (via the control system 26) to one or more of the plurality of wheel sets (e.g., the front wheels 32).

[0026] The powertrain 22 of the work vehicle 10 also includes a hydraulic transmission 38. For example, the transmission 38 can be mounted on the rear frame 12 of the work vehicle 10 at a location behind the operator's cab 24. During operation, the transmission 38 transmits power (e.g., via rotational motion from the engine 34 and / or electric motor) to driven components of the work vehicle 10 (e.g., the work implement 16, the rear wheels 30, the wheel steering assembly 36, and / or other components) having a gear arrangement that provides the desired mechanical reduction between the engine output and the driven components. To provide the desired gear arrangement to the driven component(s), the transmission 38 of the work vehicle 10 houses a hydraulic circuit 40, which is part of the hydraulic system 28 and functions to direct pressurized hydraulic fluid through the transmission 38 and distribute it to one or more clutches, torque converters, and the like, using various channels, valves, pumps, filters, and the like. The one or more clutches shift between multiple forward gear ratios and a reverse gear arrangement for transmission to the rear wheels 30. According to an embodiment of the present disclosure, the hydraulic circuit 40 includes one or more electro-hydraulic control valves, such as the control valve 42, which may be, for example, an electrically controlled modulating valve (ECMV), which controls one or more clutches (such as the clutch 44) of the transmission 38, as described below in conjunction with Figures 2 to 5 Generally, the control valve 42 senses the oil pressure in the hydraulic circuit 40 and meters the flow of hydraulic fluid to provide a desired pressure downstream to the hydraulic components using feedback control via the control system 26. Various other types of control valves (e.g., proportional valves, modulating valves, proportional modulating valves, and the like) and / or other types of hydraulic components may be suitable for use with the hydraulic circuits of the present disclosure.

[0027] The control system 26 generates commands for controlling the flow of pressurized hydraulic fluid through the hydraulic circuit 40 by sending command signals to various valves and pumps within the transmission 38. In the disclosed example, the control system 26 sends commands to an exemplary electro-hydraulic control valve 42 to engage or disengage the clutch 44 and to maintain a target pressure for actuating the clutch 44. The hydraulic control valve 42 is configured to provide a desired hydraulic fluid pressure, such as in the range of approximately 100 to 400 pounds per square inch (PSI), to the clutch 44. In one example, the desired pressure can be approximately 300 PSI. The hydraulic control valve 42 monitors the pressure in the hydraulic circuit and / or the pressure at the clutch 44 and can provide adjustments up to approximately 400 times per second to maintain optimal clutch performance.

[0028] Typically, control system 26 can be configured as a computing device with an associated processor device and memory architecture, configured as a hydraulic controller, an electrical controller, an electro-hydraulic controller, or other controller. Thus, control system 26 can be configured to perform various computational and control functions related to powertrain 22 (and other machinery). Control system 26 can communicate electronically, hydraulically, or otherwise with various other systems or devices of work vehicle 20. For example, control system 26 can communicate electronically or hydraulically with various actuators, sensors, and other devices within (or outside) work vehicle 20 (including various devices associated with powertrain 22). Typically, control system 26 generates command signals based on operator input, operating conditions, and routines and / or schedules stored in memory. In some examples, control system 26 can additionally or alternatively operate autonomously without input from a human operator. Control system 26 can communicate with other systems or devices (including other controllers) in various known ways, including via a CAN bus, wireless communication devices, hydraulic communication devices, or other means.

[0029] Also refer to Figure 2The transmission 38 includes a device body, shown as a transmission body 50, which is defined by a first housing body 52 (shown as a front housing body) and a second housing body 54 (shown as a rear housing body). The terms "front" and "rear" as used herein are defined relative to the fore-aft travel of the work vehicle 10 in which the transmission body 50 is incorporated. Generally, the transmission body 50 houses various mechanical components, including gears, shafts, bearings, and other such components arranged to provide a gear reduction from input to output. During assembly, the various mechanical components housed within the transmission body 50 may be initially installed within the first housing body 52. ​​The second housing body 54 may then be placed together with the first housing body 52. ​​Finally, the first housing body 52 and the second housing body 54 may be joined together using, for example, bolts or other fasteners. When assembled, first and second housing bodies 52, 54 form an internal cavity 55 that defines a sump to hold a reservoir of oil used to lubricate and / or cool the various mechanical components of transmission 38 and to supply oil to at least a portion of hydraulic system 28. As shown, a hydraulic pump assembly 56 draws oil from the reservoir of internal cavity 55 through supply line 58 to recirculate a supply of pressurized hydraulic fluid to transmission 38.

[0030] The transmission 38 includes an output shaft assembly 60, which includes one or more output shafts 62 mounted in corresponding output gear mounts 64. The output shafts 62 also extend through the first housing body 52. ​​Various additional shafts and gears (not shown) are rotatably supported in the gear mounts, including an input gear mount 66 for mounting an input shaft that receives rotational input from the engine 34. The various additional gears are mechanically linked between an input gear (not shown) in the input gear mount 66 and the output shaft assembly 60. The gears of the transmission 38 can be arranged in multiple stages with different effective gear ratios. In other embodiments, various other gear train configurations are possible. The output shaft assembly 60 provides a selective mechanical connection (e.g., via a splined shaft) to a corresponding rotatable component of the work vehicle 10, such as a portion of the powertrain 22 operatively connected to the rear wheels 30 or a rotatable component operatively connected to the work tool 16.

[0031] Also refer to Figure 3, a portion of the hydraulic circuit 40 is formed in a device body, here shown as a second housing body 54. The second housing body 54 defines a plurality of surfaces, including a first surface 70 on a lateral side of the transmission 38, a second surface 72 facing the rear of the transmission 38, a third surface 74 opposite the first surface, and a fourth surface 76 opposite the second surface and facing the interior of the transmission 38. A wall structure 80 extends between the first surface 70 and the second surface 72. The wall structure 80 defines a plurality of internal passages 82, 84, 86, 88, 90 that are in fluid communication to define a portion of the hydraulic circuit 40. In use, the plurality of internal passages 82, 84, 86, 88, 90 contain pressurized hydraulic fluid (e.g., oil).

[0032] The second housing body 54 also mounts hydraulic components that are operatively connected to the hydraulic circuit 40. One or more hydraulic fluid passages 82 carry hydraulic fluid from a hydraulic system 28 of the work vehicle 10 (e.g., Figure 2 , a hydraulic supply tank 41 from the hydraulic pump assembly 56 (shown in FIG. 1 ) is connected to the control valve 42 or another hydraulic component. As shown, the hydraulic fluid passage 82 includes a component passage 84, which houses the control valve 42. The hydraulic fluid passage 82 includes one or more crossover passages 86 extending to other areas of the second housing body 54 and an additional component passage 88, which similarly houses an additional control valve 92. The hydraulic fluid passage 82, component passage 84, crossover passage 86, and additional component passage 88 all deliver pressurized hydraulic fluid from the hydraulic system 28 at an inlet 94 to a hydraulic component, such as the control valve 42 or the additional control valve 92, at an outlet 96. An access passage 90, one of the plurality of internal passages 82, 84, 86, 88, 90, extends from the hydraulic fluid passage 82 to an access port 98 and, therefore, to the exterior of the second housing body 54. While the access passage 90 is in fluid communication with the other passages 82, 84, 86, 88, 90, it does not serve as part of the hydraulic flow path between the hydraulic supply tank 41 and any hydraulic component of the transmission 38 of the work vehicle 10.

[0033] Also refer to the first example Figure 4, a filler insert 100 is mounted in the access passage 90 together with a plug 102, which is mounted at the access port 98 and extends into the access passage 90. The plug 102 closes the access port 98 to prevent the hydraulic fluid from leaving the second housing body 54 and to prevent contaminants and debris from entering the hydraulic circuit. The plug 102 may include a gasket 106 or be connected to a gasket 106 to improve the seal. To this end, the plug 102 includes an annular wall 108 that fits tightly in the access port 98, for example, by a threaded fit or a press fit. In this example, the plug 102 and the filler insert 100 are separate parts, and the access passage 90 at least partially provides a shoulder 110, which is defined by a radially inwardly extending wall to accommodate the inner end of the filler insert 100. Thus, during use, pressurized hydraulic fluid in the access passage 90 completely surrounds the filler insert 100 on all sides (i.e., around its annular circumference and the circular axial ends) including between the filler insert 100 and the plug 102. The shoulder 110 may be formed by an additional countersinking operation after the hydraulic circuit 40 is drilled out of the second housing body 54.

[0034] The filler insert 100 defines a shank 112 having a shape complementary to an inner wall surface 114 of the access passage 90. For example, the shank 112 and the access passage 90 may both be generally cylindrical (or the shank 112 may be cylindrical) and at least partially have a circular cross-section. The inner wall surface 114 defines a first diameter 116, and the shank 112 defines a second diameter 118 that is smaller than the first diameter 116, thereby creating an annular space 120 between the shank 112 and the inner wall surface 114. The annular space 120 allows hydraulic fluid to surround and encapsulate the shank 112 of the filler insert 100, and creates a gap 122 between the shank 112 and the inner wall surface 114, the plug 102, and the shoulder 110. The shoulder 110 causes the first diameter 116 of the access passage to be larger than the third diameter 124 of the hydraulic fluid passage 82, and the second diameter 118 of the shank 112 is also larger than the third diameter 124, so as to bookend and accommodate the filler insert 100 within the access passage 90. In some cases, such as in the illustrated example, the filler insert 100 (here, the shank 112) can occupy approximately 85% to approximately 99% of the volume of the access passage 90, which can be determined based on the total volume of the access passage 90 or based on the cross-sectional area (i.e., the radial dimension of the first diameter 116 can be approximately 85% to approximately 99% of the second diameter 118). In either case, at the upper end of this range, the hydraulic fluid surrounding the shank 112 is effectively a thin coating of hydraulic fluid around the shank 112. The filler insert 100 can be formed from a rigid material such as steel or other metal. The filler insert 100 thus occupies a majority of the volume within the access passage 90, in fact, substantially all of the volume within the access passage 90, with only a small amount of hydraulic fluid (in some cases a thin coating of hydraulic fluid) enveloping the filler insert 100. This results in a low-cost, easily manufactured / assembled mechanism for reducing air within a hydraulic circuit and mitigating the associated adverse effects on the consistency and responsiveness of the hydraulic circuit and hydraulic device (e.g., transmission 38).

[0035] Now refer to Figure 5 , the second example of a filler insert 100' and a plug 102' provides a Figure 4 In this example, the filler insert 100' includes a plug 102' that is integrally formed as a single, unitary part (eg, formed simultaneously from the same material and by the same process). Similar to Figure 4In the example of FIG. 1 , pressurized hydraulic fluid in the access passage 90′ completely surrounds the filler insert 100′, except that the proximal longitudinal end 130′ of the filler insert 100′ is not surrounded because the proximal longitudinal end 130′ is integrally formed with the plug 102′. Specifically, the plug 102′ seals the access port 98 to prevent hydraulic fluid from exiting the second housing body 54 and may include a gasket 106 to improve sealing. To this end, the plug 102′ includes an annular wall 108′ that fits tightly within the access port 98, such as by a threaded fit or a press fit.

[0036] The filler insert 100' defines a shank portion 112' having a shape complementary to the inner wall surface 114' of the access passage 90', for example, both the shank portion 112' and the access passage 90' ​​can be generally cylindrical and at least partially have a circular cross-section. The inner wall surface 114' defines a first diameter 116', and the shank portion 112' has a second diameter 118' that is smaller than the first diameter 116', thereby creating an annular space 120' between the shank portion 112' and the inner wall surface 114, the annular space 120' allowing hydraulic fluid to circulate around the shank portion 112' of the filler insert 100' and creating a gap 122' between the shank portion 112' and the inner wall surface 114'. In this example, the shank portion 112' is omitted. Figure 4 The shoulder 110 of the hydraulic fluid passage 82 is formed such that the first diameter 116' of the access passage is substantially equal to the third diameter 124 of the hydraulic fluid passage 82, and the second diameter 118' of the shank portion 112' is less than the third diameter 124. The plug 102' retains the filler insert 100' within the access passage 90'. The shank portion 112' can occupy approximately 85% to approximately 99% of the volume of the access passage 90', which can be determined based on the total volume of the access passage 90' ​​or based on the cross-sectional area (i.e., the radial dimension of the first diameter 116' can be approximately 85% to approximately 99% of the second diameter 118'). In either case, at the upper end of this range, the hydraulic fluid surrounding the shank portion 112' can be a thin coating of hydraulic fluid around the shank portion 112'. As with the previous examples, the filler insert 100' can be formed from a rigid material such as steel or another metal. The filler insert 100' thus occupies most or substantially all of the volume within the access passage 90, with only a small amount of hydraulic fluid (in some cases a thin coating of hydraulic fluid) encapsulating the filler insert 100'. This results in a low-cost, easily manufactured / assembled mechanism for reducing air within a hydraulic circuit and mitigating the associated adverse effects on the consistency and responsiveness of the hydraulic circuit and hydraulic device (e.g., transmission 38).

[0037] Within the transmission 38, the hydraulic circuit 40 delivers pressurized hydraulic fluid from a portion of the hydraulic system 28 to the control valve 42 via internal passages 82, 84, 86, 88. Due to the filler inserts 100, 100', the access passages 90, 90' contain a relatively small volume of hydraulic fluid in the annular spaces 120, 120' that does not substantially contribute to the flow to the control valve 42. The filler inserts 100, 100' do not completely block the access passages 90, 90' to prevent potential hydraulic fluid flow, but rather minimize the available volume in the access passages 90, 90'. At the same time, the plugs 102, 102' ensure that the hydraulic circuit 40 remains closed.

[0038] Embodiments of hydraulic circuits having filler inserts may include additional manifestations of the disclosed features or rearrangements thereof. While the disclosed filler inserts and internal passages are substantially cylindrical, various other shapes are contemplated, including those having tapered and / or non-circular cross-sections. Thus, the disclosed volume inserts may be of any shape designed to loosely fit within the intended internal passage(s). The volume inserts may be suitable for a variety of applications, particularly in various hydraulic circuits where it may be desirable to reduce excess fluid volume in unused or degraded passages in the same manner as the access passages disclosed herein.

[0039] Enumerated example of a hydraulic device with a separate filling insert for volume reduction of a hydraulic circuit

[0040] In addition, the following examples are provided and are numbered for ease of reference.

[0041] 1. A hydraulic device for a work vehicle, the hydraulic device comprising: a device body, the device body having a first surface, a second surface, and a wall structure between the first surface and the second surface, the wall structure defining a plurality of internal passages, the plurality of internal passages including an access passage and a hydraulic fluid passage, the access passage at least partially having a cylindrical inner wall surface having a first diameter, the access passage extending from an access port in the device body through the wall structure to the hydraulic fluid passage, the hydraulic fluid passage extending from an inlet in the first surface of the device body through the wall structure to an outlet in the second surface of the device body to transfer hydraulic fluid from the inlet through the wall structure. structure for delivering to the outlet; a plug, which is fixedly or removably mounted to the device body to close the access port; and a filling insert, which is arranged in the access channel near the plug or connected to the plug in the access channel, the filling insert having a cylindrical shank, the shank at least partially including a circular cross-section having a second diameter, the second diameter being smaller than the first diameter of the inner wall surface of the access channel so as to be separated from the inner wall surface of the access channel; wherein the annular space between the shank of the filling insert and the inner wall surface of the access channel allows the hydraulic fluid to surround at least a portion of the shank of the filling insert.

[0042] 2. The hydraulic device of example 1, wherein the plug and the filling insert are separate parts.

[0043] 3. The hydraulic device of example 2, wherein the hydraulic fluid completely surrounds the filler insert.

[0044] 4. The hydraulic device of example 1, wherein the plug and the filling insert are formed as a one-piece part.

[0045] 5. A hydraulic device according to Example 1, wherein the access channel defines a shoulder, the shoulder being adjacent to the end of the filling insert opposite the plug, the shoulder having a radially extending wall located between the access channel and the hydraulic fluid channel to retain the filling insert within the access channel.

[0046] 6. The hydraulic device of example 1, wherein the plug and the filling insert occupy about 85% to about 99% of the volume of the access channel.

[0047] 7. The hydraulic device of example 1, wherein the access passage extends from the hydraulic fluid passage to an exterior of the device body without being connected to another component of the work vehicle; and wherein the hydraulic fluid passage delivers hydraulic fluid from a hydraulic supply source of the work vehicle to the hydraulic device.

[0048] 8. A hydraulic transmission device for a work vehicle, the hydraulic transmission device comprising: a plurality of gears, the plurality of gears providing a plurality of transmission ratios; a clutch, the clutch being used to shift the plurality of gears between the plurality of transmission ratios, the clutch being powered at least in part by hydraulic pressure; a transmission body, the transmission body mounting the plurality of gears and the clutch within an inner cavity, the transmission body having a first surface, a second surface, and a wall structure between the first surface and the second surface, the wall structure defining a plurality of internal passages, the plurality of internal passages comprising an access passage and a hydraulic fluid passage, the access passage at least partially having a cylindrical inner wall surface having a first diameter, the access passage extending from an access port in the transmission body through the wall structure to the hydraulic fluid passage, the hydraulic fluid passage extending from an inlet in the first surface of the transmission body through the wall structure to the transmission body the access passage and the clutch; a first portion of the second hydraulic fluid passage being connected to the first hydraulic fluid passage and a second portion of the second hydraulic fluid passage being connected to the first hydraulic fluid passage; a second hydraulic fluid passage being connected to the first hydraulic fluid passage and the clutch ... hydraulic fluid passage being connected to the first hydraulic fluid passage and the clutch; a hydraulic fluid passage being connected to the first hydraulic fluid passage and the clutch; a hydraulic fluid passage being connected to the first hydraulic fluid passage and the clutch; a hydraulic fluid passage being connected to the first hydraulic fluid passage and the clutch; a hydraulic fluid passage being connected to the first hydraulic fluid passage and the clutch; a hydraulic fluid passage being connected to the first hydraulic fluid passage and the clutch; a hydraulic fluid passage being connected to the first hydraulic fluid passage and the clutch; a hydraulic fluid passage being connected to the first hydraulic fluid passage and the clutch; a hydraulic fluid passage being connected to the first hydraulic fluid passage and the clutch; a hydraulic fluid passage being connected to the first hydraulic fluid passage and the clutch; a hydraulic fluid passage being connected to the first hydraulic fluid passage and the clutch; a hydraulic fluid passage being connected to the first hydraulic fluid passage and the clutch; a hydraulic fluid passage being connected to the first hydraulic fluid passage and the clutch; a hydraulic fluid passage being

[0049] 9. A hydraulic transmission device according to Example 8, wherein the transmission body is defined by a first body part and a second body part: the first body part has the plurality of internal channels; and the second body part is mountable to the first body part, the first body part and the second body part together defining the inner cavity.

[0050] 10. A hydraulic transmission device according to Example 8, wherein the access channel extends from the hydraulic fluid channel to the outside of the transmission body in a manner that is not connected to a component of the hydraulic transmission device; and wherein the hydraulic fluid channel at least partially transmits hydraulic fluid from the hydraulic supply source of the work vehicle to the one or more control valves.

[0051] 11. The hydraulic transmission of example 8, wherein the plug and the filler insert are separate parts.

[0052] 12. The hydraulic transmission of example 11, wherein the hydraulic fluid completely surrounds the filler insert.

[0053] 13. The hydraulic transmission of example 8, wherein the plug and the filling insert are formed as a one-piece part.

[0054] 14. A hydraulic transmission device according to Example 13, wherein the access channel defines a shoulder, the shoulder being adjacent the end of the filler insert opposite the plug, the shoulder having a radially extending wall located between the access channel and the hydraulic fluid channel to retain the filler insert within the access channel.

[0055] 15. The hydraulic transmission of example 8, wherein the plug and the filler insert occupy about 85% to about 99% of the volume of the access passage.

[0056] in conclusion

[0057] Thus, embodiments of a hydraulic device, such as a transmission, for a work vehicle have been described that includes a hydraulic circuit having a filler insert feature that is housed within and separated from a redundant internal passage (e.g., an internal passage that makes access to the passage). The filler insert reduces unneeded internal volume of the hydraulic circuit, thereby reducing volumetric and flow requirements for the hydraulic fluid. By reducing the internal volume and hydraulic fluid volume within the hydraulic circuit, the filler insert also serves to reduce or eliminate air that is entrained within the hydraulic fluid or otherwise trapped within dead zones of the hydraulic circuit. In certain applications requiring high speed and high precision, such a volume reduction and the accompanying air reduction can improve the consistency and performance of the hydraulic circuit and thereby enhance the operation of the hydraulic device by improving the response time and accuracy of the hydraulic device.

[0058] As used herein, unless the context clearly indicates otherwise, the singular forms "a," "an," and "said" are intended to include the plural forms as well. It will be further understood that the terms "include" and / or "comprise," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0059] The description of the present disclosure is presented for the purpose of illustration and description, but is not intended to be exhaustive or limited to the disclosure in the disclosed form. Without departing from the scope and spirit of the present disclosure, many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments explicitly cited herein have been selected and described to best explain the principles of the present disclosure and its practical application, and to enable other persons of ordinary skill in the art to understand the present disclosure and recognize the various substitutions, modifications and variations of the described (one or more) examples. Therefore, a variety of different embodiments and embodiments other than those explicitly described are also within the scope of the appended claims.

Claims

1. A hydraulic device for a work vehicle, the hydraulic device comprising: A device body having a first surface (70), a second surface (72), and a wall structure (80) between the first surface (70) and the second surface (72), wherein the wall structure (80) defines a plurality of internal passages (82, 84, 86, 88, 90), wherein the plurality of internal passages (82, 84, 86, 88, 90) include an access passage (90) and a hydraulic fluid passage (82), wherein the access passage (90) at least partially has a cylindrical inner wall surface (114) The device body has a first surface having a first diameter (116), the access channel (90) extending from an access port (98) in the device body through the wall structure (80) to the hydraulic fluid channel (82), and the hydraulic fluid channel (82) extending from an inlet (94) in the first surface (70) of the device body through the wall structure (80) to an outlet (96) in the second surface (72) of the device body to deliver hydraulic fluid from the inlet (94) through the wall structure (80) to the outlet (96); a plug (102) fixedly or removably mounted to the device body to close the access port (98); and a filling insert (100) disposed within the access channel (90) adjacent to the plug (102) or connected to the plug (102) within the access channel (90), the filling insert (100) having a cylindrical shank (112) at least partially comprising a circular cross-section having a second diameter (118) that is smaller than the first diameter (116) of the inner wall surface (114) of the access channel (90) so as to be separated from the inner wall surface (114) of the access channel (90); wherein an annular space (120) between the shank (112) of the filler insert (100) and the inner wall surface (114) of the access channel (90) allows the hydraulic fluid to surround at least a portion of the shank (112) of the filler insert (100).

2. The hydraulic device according to claim 1, wherein: The stopper (102) and the filling insert (100) are separate parts.

3. The hydraulic device according to claim 2, wherein: The hydraulic fluid completely surrounds the filler insert (100).

4. The hydraulic device according to claim 1, wherein: The stopper (102) and the filling insert (100) are formed as a one-piece part.

5. The hydraulic device according to claim 1, wherein: The access passage (90) defines a shoulder (110) proximate an end of the filler insert (100) opposite the plug (102), the shoulder (110) having a radially extending wall between the access passage (90) and the hydraulic fluid passage (82) to retain the filler insert (100) within the access passage (90).

6. The hydraulic device according to claim 1, wherein: The plug (102) and the filling insert (100) occupy about 85% to about 99% of the volume of the access channel (90).

7. The hydraulic device according to claim 1, wherein: The access passage (90) extends from the hydraulic fluid passage (82) to the exterior of the device body without being connected to another component of the work vehicle; and The hydraulic fluid passage (82) transmits hydraulic fluid from a hydraulic supply source (41) of the work vehicle to the hydraulic device.

8. A hydraulic transmission device for a work vehicle, the hydraulic transmission device comprising: a plurality of gears providing a plurality of gear ratios; a clutch (44) for shifting the plurality of gears between the plurality of gear ratios, the clutch (44) being powered at least in part by hydraulic pressure; A transmission body, the transmission body mounting the plurality of gears and the clutch (44) within an inner cavity (55), the transmission body having a first surface (70), a second surface (72), and a wall structure (80) between the first surface (70) and the second surface (72), the wall structure (80) defining a plurality of internal passages (82, 84, 86, 88, 90), the plurality of internal passages (82, 84, 86, 88, 90) including an access passage (90) and a hydraulic fluid passage (82), the access passage (90) at least partially having a cylindrical shape an inner wall surface (114), the cylindrical inner wall surface having a first diameter (116), the access passage (90) extending from an access port (98) in the transmission body through the wall structure (80) to the hydraulic fluid passage (82), the hydraulic fluid passage (82) extending from an inlet (94) in the first surface (70) of the transmission body through the wall structure (80) to an outlet (96) in the second surface (72) of the transmission body to deliver hydraulic fluid from the inlet (94) through the wall structure (80) to the outlet (96); one or more control valves (42, 92) in fluid communication with the hydraulic fluid passage (82) and configured to actuate the clutch (44); a plug (102) fixedly or removably mounted to the transmission body to close the access port (98); and a filling insert (100) disposed within the access channel (90) adjacent to the plug (102) or connected to the plug (102) within the access channel (90), the filling insert (100) having a cylindrical shank (112), the shank (112) at least partially comprising a circular cross-section having a second diameter (118) that is smaller than the first diameter (116) of the inner wall surface (114) of the access channel (90) so as to be separated from the inner wall surface (114) of the access channel (90); wherein an annular space (120) between the shank (112) of the filler insert (100) and the inner wall surface (114) of the access channel (90) allows the hydraulic fluid to surround at least a portion of the shank (112) of the filler insert (100).

9. The hydraulic transmission device according to claim 8, wherein: The gearbox body is defined by a first body portion (52) and a second body portion (54): The first body portion (52) has the plurality of internal passages (82, 84, 86, 88, 90); and The second body portion (54) is mountable to the first body portion (52), the first body portion (52) and the second body portion (54) together defining the interior cavity (55).

10. The hydraulic transmission device according to claim 8, wherein: The access passage (90) extends from the hydraulic fluid passage (82) to the exterior of the transmission body without being connected to any component of the hydraulic transmission; and The hydraulic fluid passage (82) at least partially conveys hydraulic fluid from a hydraulic supply source (41) of the work vehicle to the one or more control valves (42, 92).

11. The hydraulic transmission device according to claim 8, wherein: The stopper (102) and the filling insert (100) are separate parts.

12. The hydraulic transmission device according to claim 11, wherein: The hydraulic fluid completely surrounds the filler insert (100).

13. The hydraulic transmission device according to claim 8, wherein: The stopper (102) and the filling insert (100) are formed as a one-piece part.

14. The hydraulic transmission device according to claim 13, wherein: The access passage (90) defines a shoulder proximate an end of the filler insert (100) opposite the plug (102), the shoulder having a radially extending wall between the access passage (90) and the hydraulic fluid passage (82) to retain the filler insert (100) within the access passage (90).

15. The hydraulic transmission device according to claim 8, wherein: The plug (102) and the filling insert (100) occupy about 85% to about 99% of the volume of the access channel (90).

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