Patent Description:
Motorised valves are used in aircraft hydraulic systems to control the flow of fluid. Some such motorised valves include a rotary valve shaft. It is known to determine the operating condition of the motorised valve by determining the position of the rotatable valve shaft.

To determine the operating condition of the valve, a position sensor on a housing of a valve assembly is used to detect a feature on the valve shaft to determine the position of the shaft. The position sensor communicates and is provided power through wires connected to other modules in or on the housing. Such position sensors include micro-switches. One problem with a sensor monitoring a feature of the shaft is that the number of positions of the shaft that may be determined is limited. <CIT> describes a valve with a smart handle including a memory to log relevant data. A valve assembly according to the preamble of claim <NUM> is known from <CIT>.

According to an aspect, there is provided a valve assembly according to claim <NUM>.

The valve assembly may be a hydraulic valve assembly.

The indicator may extend annularly about the shaft.

The indicator may comprise an annularly extending surface spaced from the shaft, wherein the surface defines the feature configured to be detected by the position sensor. The feature may be an indent in the surface. The feature may be a protrusion on the surface. The feature may be one of a plurality of features. The features may be disposed annularly around the annularly extending surface. At least one feature may differ from at least one other feature. The at least one feature may differ in annular length from the at least one other feature.

The indicator may comprise a cam. The annularly extending surface may be a cam surface. The annularly extending surface may be an inwardly facing surface.

The position sensor may comprise a contact sensor.

The contact sensor may comprise a microswitch.

The position sensor may comprise at least one of an ultrasonic sensor, a hall sensor, and an IR proximity reflective sensor.

The indicator may comprise at least a first surface section and a second surface section. The position sensor on the valve shaft may be configured to remotely detect the difference between the first surface section and a second surface section to determine the position of the valve shaft.

The position sensor may be in the valve shaft.

The valve shaft may comprise a first portion and a second portion. The position sensor may be between the first and second portions.

The first and second portions may be spaced by a spacer.

The indicator may be removable from the housing.

The indicator may be a ring. The indicator may be a cam ring.

The valve assembly may comprise a key configured to orientate the indicator in the housing.

The key may comprise a protrusion on one of the indicator and the housing and a recess on the other of the indicator and the housing.

The position sensor may be a first position sensor. The sensor assembly may comprise a second position sensor.

The indicator may comprise a first indicator part and a second indicator part, wherein the first position sensor may be configured to detect the first indicator part and the second position sensor may be configured to detect the second indicator part.

The valve assembly may comprise a transfer arrangement configured to transfer at least one of power and a communication signal. The transfer arrangement may comprise a first transfer module rotatable with the valve shaft, and a second transfer module on the housing wherein the first and second transfer modules communicate to transfer the at least one of power and a communication signal.

The first transfer module may comprise a wireless power receiving module, and the second transfer module may comprise a wireless power transmitting module.

At least one of the wireless power receiving module and the wireless power transmitting module may comprise an induction coil.

The first transfer module may comprise a wireless data receiving module, and the second transfer module may comprise a wireless data transmitting module.

The housing may define a sealed chamber and the position sensor may be in the sealed chamber. The sealed chamber may be a hermetically sealed chamber.

The first transfer module may be in the sealed chamber and the second transfer module may be external to the sealed chamber.

According to an aspect (not claimed) there is provided a sensor assembly for indicating the position of a valve shaft of a valve assembly, the sensor assembly comprising: a position sensor mountable on a valve shaft; and an indicator mountable on a housing to extend annularly about the valve shaft; wherein the position sensor is configured to rotate with the valve shaft and detect a feature of the indicator to determine the position of the valve shaft.

The position sensor may comprise a contact sensor. The indicator may comprise a cam.

According to an aspect (not claimed), there is provided a valve assembly comprising:
a housing; a valve shaft rotatable in the housing; and a transfer arrangement configured to transfer at least one of power and a communication signal, comprising a first transfer module rotatable with the valve shaft, and a second transfer module on the housing wherein the first and second transfer modules communicate to transfer the at least one of power and a communication signal.

According to claim <NUM> there is provided a method of determining an angular position of a rotatable valve shaft of a valve assembly.

With combined reference to the Figures, a hydraulic valve assembly <NUM> is described below. The hydraulic valve assembly <NUM> is shown in <FIG> including a valve arrangement <NUM>, a drive arrangement <NUM> and a monitoring arrangement <NUM>. The hydraulic valve assembly has a housing <NUM> as shown in <FIG> and <FIG>. The valve arrangement <NUM> has a valve shaft <NUM>. The valve shaft <NUM> extends from the housing <NUM>. The valve arrangement <NUM> has a valve head <NUM> with a flow path <NUM> formed through the valve head <NUM>. The valve head <NUM> is ball shaped in the shown embodiment but the shape of the valve head <NUM> can differ. The housing <NUM> forms part of a housing assembly including a head housing portion (not shown) for the valve head <NUM>. The head housing portion may be formed with or separable from the housing <NUM>. The valve head <NUM> is received in a chamber (not shown) and is rotatable with respect to a fluid inlet and a fluid outlet (not shown) to move the valve assembly <NUM> between different operating flow conditions, for example an open flow condition and a closed flow condition. Operation of such a valve is known and features of the valve arrangement are omitted from the Figures. Although the valve assembly described herein is a hydraulic valve assembly, other valve assemblies are envisaged.

As shown in <FIG> & <FIG>, the drive arrangement <NUM> includes a motor <NUM>, acting as a valve drive means, and the rotatable valve shaft <NUM>. The shaft <NUM> communicates between the motor <NUM> and the valve head <NUM>. The shaft <NUM> is fixed with the valve head <NUM> such that rotation of the shaft <NUM> about its longitudinal axis actuates the valve head <NUM>. The shaft <NUM> and valve head <NUM> are integrally formed in the present embodiment.

The shaft <NUM> extends in an axial direction in the housing <NUM>. The motor <NUM> is at a first end of the shaft <NUM>. The valve head <NUM> is at a second end of the shaft <NUM>. The motor <NUM> is in the housing <NUM>. The shaft <NUM> extends through the housing <NUM> at one end.

The monitoring arrangement <NUM> has a sensor assembly <NUM> and a transfer arrangement <NUM>. The transfer arrangement <NUM> is configured to provide power to the sensor assembly <NUM>. The transfer arrangement <NUM> is configured to communicate signals from the sensor assembly <NUM> to a controller <NUM>. In embodiments, the transfer arrangement <NUM> may provide at least one of providing power to the sensor assembly <NUM> and communicating signals from the sensor assembly <NUM>.

As shown in <FIG>, the housing <NUM> defines a first chamber <NUM> and a second chamber <NUM>. The housing <NUM> comprises an outer shell <NUM>. The sensor assembly <NUM> is in the first chamber <NUM>. The motor <NUM> is in the second chamber <NUM>. A barrier <NUM> separates the first and second chambers <NUM>, <NUM>. The shaft <NUM> extends through the barrier <NUM>. The barrier <NUM> forms a wall. A shaft bore <NUM> extends through the barrier <NUM>. An inner seal <NUM> fluidly seals the barrier <NUM> with the shaft <NUM>. The inner seal <NUM> comprises first and second seal elements 25a, 25b. An outer seal <NUM> fluidly seals the barrier <NUM> with the outer shell <NUM>. As such, the first and second chambers <NUM>, <NUM> are isolated from each other. The first chamber <NUM> is sealed from external to the housing <NUM>. A fluid seal is formed. In embodiments, the forming of a fluid seal by the o-rings is aided by an adhesive, for example epoxy or glue. In embodiments the fluid seal is a hermetic seal. In an embodiment, the first and second chambers <NUM>, <NUM> are fluidly isolated. In embodiments, the barrier <NUM> is omitted.

The housing <NUM> comprises first and second housing portions 29a, 29b. The housing portions 29a, 29b form the outer shell <NUM>. Each housing portion 29a, 29b has a cup arrangement which form the outer shell <NUM> when brought together at their open ends. The housing configuration may differ. A fastener arrangement (not shown) releasably mounts the housing portions 29a, 29b with each other. In embodiments, the housing portions 29a, 29b can be threadingly engaged. In the shown embodiment, the housing is cylindrical, although the shape of the housing may differ.

The housing <NUM> has an inner surface <NUM>. The inner surface <NUM> forms the peripheral wall of the first chamber <NUM>. The inner surface <NUM> is a circumferentially extending surface in the present arrangement. The inner surface <NUM> is formed by an annular wall <NUM>. The housing <NUM> has end walls <NUM>, <NUM>. The shaft <NUM> extends through an opening in one of the end walls <NUM>.

The motor <NUM> of the hydraulic valve assembly <NUM> is engaged with the rotatable valve shaft <NUM>. A coupling <NUM> couples the shaft <NUM> with the motor <NUM>. The motor <NUM> is configured to drive rotation of the rotatable valve shaft <NUM>. The motor <NUM> is an electric motor, however it can be appreciated that any motor <NUM> capable of rotating the shaft <NUM> could be used. In the shown embodiment the motor <NUM> is disposed within the housing <NUM> however, the motor <NUM> could be disposed external to the housing <NUM>. In such an embodiment, the housing <NUM> may have a single chamber.

The sensor assembly <NUM> is disposed in the housing <NUM>. The transfer arrangement <NUM> is disposed in the housing <NUM>. A first transfer module <NUM> of the transfer arrangement <NUM> is on the shaft <NUM>. A second transfer module <NUM> of the transfer arrangement <NUM> is fixed with the housing <NUM>. In the present embodiment, the first module <NUM> is in the first chamber <NUM> and the second module <NUM> is in the second chamber <NUM>.

The sensor assembly <NUM> will now be described in detail with reference to <FIG>. The sensor assembly <NUM> comprises a first sensor configuration <NUM> and a second sensor configuration <NUM>. The number of sensor configurations may vary, and in one configuration is a single sensor configuration. Each sensor configuration <NUM>, <NUM> is configured to detect an angular position of the shaft <NUM> in the housing <NUM>.

The first sensor configuration <NUM> comprises a first position sensor <NUM> and a first indicator <NUM>. The second sensor configuration <NUM> comprises a second position sensor 60a and a second indicator 70a. The first and second sensor configurations <NUM>, <NUM> are axially arranged. An exploded view is shown in <FIG>, which includes the sensor assembly <NUM> shown in <FIG>, along with part of the shaft as well as other features omitted in Figure <NUM>. A cross sectional view of <FIG> is shown in <FIG>.

The first position sensor <NUM> is configured to detect its orientation with respect to the first indicator <NUM>. The first position sensor <NUM> is a contact sensor. That is, the first position sensor <NUM> contacts against another feature to determine its position. In embodiments, the first position sensor <NUM> is a non-contact sensor, such as an optical sensor as will be described below. In the present embodiment the first position sensor <NUM> is a microswitch. The first position sensor <NUM> is located on the rotatable valve shaft <NUM>. The first position sensor <NUM> rotates with the rotatable valve shaft <NUM>. The first indicator <NUM> is fixedly mounted with the housing <NUM>.

The first position sensor <NUM> comprises a body <NUM> and a contact element <NUM>. The contact element <NUM> is a movable sensor arm. The sensor arm protrudes from the body <NUM>. The contact element <NUM> extends substantially radially with a free end <NUM> contactable with the first indicator <NUM>. The contact element <NUM> is biased radially outwardly. That is the contact element is biased against the first indicator <NUM>. The movable sensor arm is pivotable. Movement of the contact element actuates a switch (not shown). The first position sensor <NUM> rotates with the shaft. In the present arrangement, the first position sensor <NUM> is in the valve shaft <NUM> (as shown in <FIG>). Disposing the first position sensor <NUM> in the shaft <NUM> helps to provide a compact valve assembly. In embodiments, the first position sensor <NUM> protrudes, at least partially, from an outer side <NUM> of the valve shaft <NUM> and may be on the outer side <NUM> of the valve shaft <NUM>. The contact element <NUM> is movable between an extended position (as shown in <FIG>) and a retracted position (as shown in <FIG>). In the extended position the free end <NUM> is disposed at a greater radial distance from the rotational axis of the shaft <NUM> than in the retracted position. In embodiments, the contact element <NUM> is operable in a plurality of positions and the first position sensor <NUM> is configured to detect the plurality of different positions.

Referring in particular to <FIG>, the first indicator <NUM> of the first sensor configuration <NUM> comprises a first cam <NUM>. The first cam <NUM> interacts with the first position sensor <NUM>. The first cam <NUM> guides the contact element <NUM>. The first cam <NUM> has a cam surface. The cam surface is formed by an inner surface <NUM> of the first indicator <NUM>, although alternative surfaces may form the cam surface. The first cam <NUM> forms a cam ring. The first indicator <NUM> extends annularly around the shaft <NUM>. The first indicator <NUM> is arranged in the housing <NUM> to extend annularly around the first position sensor <NUM>.

The first indicator <NUM> is mounted in the housing <NUM>. The first indicator <NUM> is fixedly mounted in the housing <NUM>. The first indicator <NUM>, in embodiments, is integrally formed with the housing <NUM>. In the present embodiment, the first indicator <NUM> is removable from the housing <NUM> as is shown in <FIG>. As such, the first indicator <NUM> is interchangeable and may be replaced by a different first indicator <NUM>, for example one with a different cam shape. By changing indicators, it is possible to adjust or change the positions of the valve shaft <NUM> that can be detected by a sensor configuration. The capacity to replace an indicator with a new indicator with a different shape allows the functionality of the valve assembly to change without the need to replace the whole system.

The first indicator <NUM> is axially aligned with the first position sensor <NUM>. As such, the position sensor <NUM> is configured to detect its angular orientation with respect to the first cam <NUM>. The first cam <NUM> is spaced from the shaft <NUM>. The shaft <NUM> rotates in the first cam <NUM>. The inner surface <NUM> is spaced from the shaft by an annular gap. The first position sensor <NUM> contacts the inner surface <NUM>. When the shaft <NUM> rotates, the contact element <NUM> slides along the cam surface. The radial distance of the cam surface varies along its circumferential length. That is, the radial distance from the rotational axis of the shaft <NUM> to the cam surface varies in an annular direction.

The inner surface <NUM> has a first surface section <NUM>. The first surface section <NUM> is spaced from the rotational axis of the valve shaft <NUM> by a first radial distance R1 (as shown in <FIG>). The inner surface <NUM> has a recess <NUM>. The recess <NUM> is in the first surface section <NUM>. The recess <NUM> defines a second surface section <NUM>. The second surface section <NUM> is spaced from the valve shaft <NUM> by a second radial distance R2 (as shown in <FIG>). The second radial distance R2 is greater than the first radial distance R1. In embodiments, the second surface section <NUM> is a protrusion. In such an arrangement, second radial distance R2 is less than the first radial distance R1.

A transition portion <NUM> is provided at each juncture <NUM> of the first surface section <NUM> and the second surface section <NUM>. The transition portion <NUM> has a connecting surface <NUM> which provides a transition between the first and second surface sections. The connecting surface <NUM> is angled with respect to each of the first and second surface sections <NUM>, <NUM>. The connecting surface <NUM> has an arcuate profile, but may be linear, or partially linear. The connecting surface <NUM> at each juncture <NUM> provides a smooth transition for the contact element <NUM> moving between the first and second surface sections <NUM>, <NUM>. In other embodiments, the cam can have a different number of surface sections. In an embodiment with more than two surface sections, each surface section may differ in radial distance from the central axis, or two surface sections may be separated by an intermediate surface section having a different radial distance.

With reference in particular to <FIG>, <FIG>, the second position sensor 60a is configured to detect its orientation with respect to the second indicator 70a. The second position sensor 60a is a contact sensor 61a. That is, the second position sensor 60a contacts against another feature to determine its position. In embodiments, the second position sensor 60a is a non-contact sensor, such as an optical sensor as will be described below. In the present embodiment the second position sensor <NUM> is a microswitch. The second position sensor 60a is substantially the same as the first position sensor <NUM>, as described above, in the present embodiment, and so a detailed description will be omitted. The second position sensor 60a is located on the rotatable valve shaft <NUM>. The second position sensor 60a rotates with the rotatable valve shaft <NUM>. The first and second position sensors <NUM>, 60a are provided in a stacked configuration.

Referring to <FIG>, the second indicator 70a of the second sensor configuration <NUM> comprises a second cam 71a. The second cam 71a interacts with the second position sensor 60a. The second cam 71a guides the contact element 61a of the second position sensor 60a. The second cam 71a has a cam surface. The cam surface is formed by an inner surface 72a of the second indicator 70a, although alternative surfaces may form the cam surface. The second cam 71a forms a cam ring. The second indicator 70a extends annularly around the shaft <NUM>. The second indicator 70a is arranged in the housing <NUM> to extend annularly around the second position sensor 60a.

The second indicator 70a is mounted in the housing <NUM>. The second indicator 70a is fixedly mounted in the housing <NUM>. The second indicator 70a, in embodiments, is integrally formed with the housing <NUM>. In the present embodiment, the second indicator 70a is removable from the housing <NUM>. As such, the second indicator 70a is interchangeable and may be replaced by a different second indicator 70a, for example one with a different cam shape.

The second indicator 70a is axially aligned with the second position sensor 60a. As such, the second position sensor 60a is configured to detect its angular orientation with respect to the second cam 71a. The second cam 71a is spaced from the shaft <NUM>. The shaft <NUM> rotates in the second cam 71a. The inner surface 72a is spaced from the shaft by an annular gap. The second position sensor 60a contacts the inner surface 72a. When the shaft <NUM> rotates, the contact element 61a slides along the cam surface. The radial distance of the cam surface varies along its circumferential length. That is, the radial distance from the rotational axis of the shaft <NUM> to the cam surface varies in an annular direction.

The inner surface 72a has a first surface section 73a. The first surface section 73a is spaced from the rotational axis of the valve shaft <NUM> by a first radial distance. The inner surface 72a has a recess. The recess is in the first surface section 73a. The recess defines a second surface section 75a. The second surface section 75a is spaced from the valve shaft <NUM> by a second radial distance. The second radial distance is greater than the first radial distance. In embodiments, the second surface section 75a is a protrusion. In such an arrangement, second radial distance is less than the first radial distance. It can be appreciated that the radial distances can be equal to the radial distances R1 and R2 respectively, or different from R1 and R2, with another feature distinguishing the first and second surface sections.

A transition portion 76a is provided at each juncture of the first surface section 73a and the second surface section 75a. The transition portion 76a has a connecting surface which provides a transition between the first and second surface sections. The connecting surface is angled with respect to each of the first and second surface sections 73a, 75a. The connecting surface has an arcuate profile, but may be linear, or partially linear. The connecting surface at each juncture provides a smooth transition for the contact element 61a moving between the first and second surface sections 73a, 75a. In other embodiments, the cam can have a different number of surface sections. In an embodiment with more than two surface sections, each surface section may differ in radial distance from the central axis, or two surface sections may be separated by an intermediate surface section having a different radial distance.

The second sensor configuration <NUM> is configured to detect a different position of the valve shaft <NUM> to the first sensor configuration <NUM>. The second cam 71a of the second sensor configuration <NUM> is offset with respect to the first cam <NUM> of the first sensor configuration <NUM>. The second indictor 70a is disposed in the housing <NUM> at an angular offset of <NUM> degrees. That is, the second cam 71a of the second indicator 70a is rotated about the central axis by <NUM> degrees to the first cam <NUM> of the first indicator <NUM>. The second surface sections <NUM>, 75a of the first and second indicators <NUM>, 70a are therefore offset from each other. The first and second position sensors <NUM>, 60a contact the respective second surface sections <NUM>, 75a of the first and second indicators <NUM>, 70a at different rotational positions of the shaft <NUM>. The first and second position sensors <NUM>, 60a are able to determine different angular positions of the shaft <NUM>, for example the position of the shaft <NUM> when the valve is in an open flow condition and the position of the shaft when the valve is in a closed flow condition. With such an arrangement it is possible to positively determine the position of the shaft <NUM>, and therefore the valve <NUM> in both open and closed flow conditions. It will be understood that although the angular offset is shown to be <NUM> degrees that other offsets are possible.

In embodiments the first and second indicators <NUM>, 70a are aligned with each other, or a single indicator is used with a common cam surface, and the position sensors <NUM>, 60a are angularly offset from each other, for example at <NUM> degrees. In another embodiment, the first and second indicators <NUM>, 70a are aligned on the housing and the first and second position sensors <NUM>, 60a are aligned on the shaft <NUM>, and the multiple position sensors are used for redundancy.

The first and second indicators <NUM>, 70a are provided in a stacked configuration. The first indicator <NUM> is stacked on the second indicator 70a.

With reference in particular to <FIG>, the shaft <NUM> comprises a first valve shaft portion <NUM> and a second valve shaft portion <NUM>. The first and second position sensors <NUM>, 60a are disposed between the first valve shaft portion <NUM> and the second valve shaft portion <NUM>. The first and second shaft portions <NUM>, <NUM> are axially aligned. The position sensors <NUM>, 60a are in the rotatable valve shaft <NUM>. The first valve shaft portion <NUM>, second valve shaft portion <NUM>, and the position sensors <NUM>, 60a are connected and configured to rotate together. It can be appreciated that any number of valve shaft portions can be used. For example, an intermediate shaft portion may be disposed between the two position sensors <NUM>, 60a.

Referring to <FIG> and <FIG>, the first and second valve shaft portions <NUM>, <NUM> are spaced by a spacer arrangement <NUM>. Two spacers 45a are shown in the figures, although the number of spacers may differ. The spacers 45a are a plurality of rods connecting the valve shaft portions <NUM>, <NUM>. The first and second position sensors <NUM>, 60a are received between the spacers 45a. In embodiments, the spacer arrangement <NUM> is integrally formed with one or both shaft portions <NUM>, <NUM>. A connecting flange <NUM> is provided at a sensor end <NUM> of the first shaft portion <NUM>. A connecting plate <NUM> is provided at an opposing sensor end <NUM> of the second shaft portion <NUM>. The connecting plate <NUM> is mounted at the opposing sensor end <NUM> by a mount 49a. The connecting plate <NUM> may be integrally formed. The spacers 45a extend between the connecting flange <NUM> and connecting plate <NUM>. This arrangement helps provide spacing in the shaft for the sensors.

With reference to <FIG>, <FIG>, a key arrangement <NUM> mounts the first and second indicators <NUM>, 70a in the housing. The key arrangement <NUM> comprises keys <NUM> and corresponding keyways <NUM>. Each of the first and second indicators <NUM>, 70a has a pair of keys <NUM>. The number of keys <NUM> may differ and may be a single key. The corresponding keyways <NUM> are formed in the housing <NUM> to receive the keys <NUM>. Each keyway <NUM> is an axially extending channel <NUM> formed in the wall of the housing <NUM>. The first and second indicators <NUM>, 70a are configured to slide fit in the housing <NUM>. The first and second indicators <NUM>, 70a are configured to slide from an open end of the housing <NUM> when the housing <NUM> is disassembled. The keys <NUM> are configured to travel axially along the channel <NUM> so that the first indicator <NUM> can be located in the housing <NUM>. A shoulder <NUM> is located to limit movement of the first and second indicators <NUM>, 70a. The shoulder <NUM> is configured to axially locate the first and second indicators <NUM>, 70a. The shoulder <NUM> is positioned at one end of the keyway <NUM>. The first indicator <NUM> abuts against the shoulder <NUM>. The second indicator 70a abuts against the first indicator <NUM>. In embodiments, a spacer may be used to space the first and second indicators <NUM>, <NUM>. The key arrangement <NUM> locates the first and second indicators <NUM>, 70a and prevents rotation in the housing.

The transfer arrangement <NUM> will now be described in detail with reference to <FIG>. The first transfer module <NUM> is in the first chamber of the housing <NUM>. The first transfer <NUM> module is on the valve shaft <NUM>. The first transfer module <NUM> rotates with the valve shaft <NUM>. The first transfer module <NUM> is a disc. The first transfer module <NUM> is disposed on the valve shaft <NUM>. The valve shaft <NUM> extends through the first transfer module <NUM>. The second transfer module <NUM> is in the second chamber <NUM> of the housing <NUM>. The second transfer module <NUM> is stationary with respect to valve shaft <NUM>. The second transfer module <NUM> is fixed on the housing <NUM>. The second transfer module <NUM> is a disc. The first transfer module <NUM> and the second transfer module <NUM> are separated by the barrier <NUM>. The transfer modules <NUM>, <NUM> may be spaced axially. In other embodiments, the first transfer module <NUM> and the second transfer module <NUM> can be any shape.

The first transfer module <NUM> comprises a printed circuit board (PCB). The first transfer module <NUM> comprises a power receiving module. The first transfer module <NUM> is configured to transfer electrical power to the sensor assembly <NUM>. A connector <NUM> communicates the first transfer module <NUM> with the first and second position sensors <NUM>, 60a. The first transfer module <NUM> has a receiver <NUM> for receiving wireless electrical power. The receiver <NUM> is an induction coil. The first transfer module <NUM> has a converter <NUM> for converting wireless electrical power into a useful form for the sensor assembly <NUM>. For example, the first transfer module <NUM> has a converter, inverter, rectifier or the like for converting the wirelessly transmitted electrical power into a form that can be used by the position sensors <NUM>, 60a. The second transfer module <NUM> is a power transmitting module. The second transfer module has a receiver 83a for receiving electrical power from a power source <NUM>. The second transfer module <NUM> has a converter 84a. The converter 84a is configured to convert the electrical power into a form that can be wirelessly transmitted. The second transfer module <NUM> has a transmitter <NUM>. The transmitter <NUM> is configured to transmit electrical power. The transmitter <NUM> is an induction coil. The electrical power is transmitted by electromagnetic induction. The receiver <NUM> of the first transfer module <NUM> is configured to receive electrical power from the transmitter <NUM> of the second transfer module <NUM>. In other embodiments, the wireless power transfer means can be a different power transfer means.

In embodiments, the first and second transfer modules are printed circuit boards (PCB). The components of the first and second transfer modules are produced from a copper layer of a PCB. For example, the induction coil is shaped from a copper layer of a PCB. In other embodiments the first and second transfer modules are formed by different means. In other embodiments the components of the first and second transfer modules are produced by different means, for example, a transmitter may be a short range antenna.

The first transfer module <NUM> comprises a wireless data transmitting module. The first transfer module <NUM> is configured to receive data/signals from the position sensors <NUM>, 60a. The first transfer module <NUM> has a signal receiver <NUM>. The signal receiver <NUM> is configured to receive signals from the sensor assembly <NUM>. The first transfer module <NUM> has a signal transmitter <NUM>. The signal transmitter <NUM> is configured to transmit the signals received by the signal receiver <NUM>. The second transfer module <NUM> comprises a wireless data receiving module. The second transfer module <NUM> comprises a signal receiver 86a. The signal receiver 86a of the second transfer module <NUM> is configured to receive signals from the signal transmitter <NUM> of the first transfer module <NUM>. In some embodiments, at least one of the first transfer module <NUM> and/or the second module <NUM> comprises an induction coil. In some embodiments the second transfer module includes a signal transmitter 87a. The signal transmitter 87a of the second transfer module <NUM> is configured to transmit the signals received by the signal receiver 86a of the second transfer module <NUM>. The signal transmitter 87a of the second transfer module <NUM> may be configured to communicate with a controller <NUM> in some embodiments.

A controller <NUM> is operable to control the first transfer module <NUM> and the second transfer module <NUM>. The controller <NUM> may be on one or both of the first transfer module <NUM> and the second transfer module <NUM>, or may be separate. The controller <NUM> comprises a processor 89a and a memory 89b. The controller <NUM> is configured to determine the position of the valve shaft <NUM> in dependence on signals received from the first and second position sensors <NUM>, 60a.

In embodiments, the first transfer module <NUM> and the second transfer module <NUM> may comprise any component that may be configured for wireless power transmission and/or wireless data transmission between the first transfer module <NUM> and the second module <NUM>.

With combined reference to <FIG> operation of the sensor assembly <NUM> will now be described in detail.

The valve shaft <NUM> is located in the housing <NUM>. The valve shaft <NUM> rotates about the rotational axis. The rotation of the valve shaft <NUM> is driven by the motor <NUM>. Rotation of the valve shaft <NUM> rotates the valve head <NUM>. Rotating the valve head <NUM> changes the operating condition of the valve assembly <NUM>. The motor <NUM> is operated to rotate the valve shaft <NUM> in the housing <NUM>. Initially the first and second contact elements <NUM>, 61a lie in contact with the respective first and second cam <NUM>, 71a surfaces in a first position. In this first position the first contact element <NUM> is in contact with the second surface section <NUM> of the first indicator <NUM>. That is the first contact element <NUM> is in the recess <NUM>. The first contact element <NUM> is biased into the extended position as determined by the second radial distance R2. The first contact element <NUM> is therefore actuated and a signal is transmitted to the controller <NUM>. The first contact element <NUM> therefore positively detects that the shaft <NUM>, and therefore the valve head <NUM>, is in a first operating condition, for example a closed flow condition. The second contact element 61a is in contact with the first surface section 73a of the second indicator 70a. The second contact element 61a is biased into the retracted position as determined by the first radial distance R1. The second contact element 61a is therefore not actuated.

As the valve shaft <NUM> is rotated, the first and second position sensors <NUM>, 60a rotate with the valve shaft <NUM>. The first contact element <NUM> slides along the internal surface <NUM> of the cam <NUM> as the valve shaft <NUM> rotates, and so slides arcuately along the second surface section <NUM>. The second contact element 61a slides along the internal surface 72a of the second cam 71a, and so slides arcuately along the first surface section 73a of the second indicator 70a. As further rotation of the valve shaft <NUM> occurs, the first position sensor <NUM> is rotated such that the contact element <NUM> moves into contact with the transition portion <NUM> and then into contact with the first surface section <NUM>. The first contact element <NUM> is biased into the retracted position as determined by the first radial distance R1. The first contact element <NUM> is therefore not actuated. The second position sensor 60a is rotated such that the contact element 61a moves into contact with the transition portion 76a and then into contact with the second surface section 75a. The second contact element 61a is biased into the extended position as determined by the second radial distance R2.

The second contact element 61a is therefore actuated and a signal is transmitted to the controller <NUM>. The second contact element 61a therefore positively detects that the shaft <NUM>, and therefore the valve head <NUM>, is in a second operating condition, for example an open flow condition. By providing a position sensor on the shaft, it is possible to maximize the circumferential length of the indicator. The number of positions that can be detected can be increased. That is to say the number of surface sections of the indicator can be increased. The length of the surface sections are not limited, and can be increased or decreased as required. Increasing the cam length helps to provide a reliable sensor assembly. It is also possible to easily replace the indicators. In some embodiments, the contact element <NUM> is spaced from the first indicator <NUM> at various positions of the valve shaft <NUM>. In such an embodiment the contact element <NUM> is not of adequate length to extend the annular gap between the valve shaft <NUM> and the second surface section <NUM> of the first indicator <NUM>.

Interaction between the contact element <NUM> of the first position sensor <NUM> and the second surface section <NUM> of the first indicator <NUM> indicates a first position of the valve shaft <NUM>. Interaction between the contact element <NUM> of the first position sensor <NUM> and the first surface section <NUM> of the first indicator <NUM> indicates a second position of the valve shaft <NUM>.

Interaction between the contact element <NUM> of the first position sensor <NUM> and the transition portion <NUM> of the first indicator <NUM> occurs when the valve shaft <NUM> rotates from the first position to the second position. The contact element <NUM> transitions from the first position of the contact element <NUM> to the second position of the contact element <NUM>. Disposing the indicator <NUM> on the housing <NUM> helps reduce the stress on the contact element <NUM> when the valve shaft <NUM> is rotating to a different position. The length of the transition portion <NUM> of the cam can be increased, and less steep/sharp. This helps reduce the wear on the contact element and may help decrease the need for maintenance. The operational life of the contact element <NUM> would be improved.

In other embodiments, the process of position detection of the second position sensor 60a can be different from the first position sensor <NUM>. In the present embodiment, the first position sensor <NUM> and the second position sensor 60a are each microswitches acting as contact sensors. In various embodiments, the first position sensor <NUM> and/or the second position sensor 60a may be a proximity ultrasonic sensor, hall sensor, IR proximity reflective sensor or any other sensor capable of detecting the indicator <NUM>.

An embodiment of the sensor configuration will now be described in detail with reference to <FIG>, <FIG>. In this embodiment, the hydraulic valve assembly including the valve arrangement, the drive arrangement and the monitoring arrangement is substantially the same as described above. However, in this embodiment the sensor assembly <NUM> differs.

In this embodiment, the position sensor is a non-contact sensor. The non-contact sensor in the present embodiment is an optical sensor <NUM>. The optical sensor <NUM> is arranged with the shaft as described above, however the position sensor acts in a non-contact configuration with a corresponding indicator <NUM>. The optical sensor <NUM> has an optical detection device <NUM>. The optical detection device <NUM> has an optical transmitter <NUM> and an optical receiver <NUM>.

The transmitter <NUM> is configured to emit electromagnetic radiation. The transmitter <NUM> is aligned to emit in the radial direction. The transmitter <NUM> is configured to transmit pulses of electromagnetic radiation. In some embodiments, the transmitter <NUM> continuously transmits electromagnetic radiation. In various embodiments the direction that radiation is emitted by the transmitter, the waveform of emitted radiation and the wavelength of emitted radiation are different and are not limited to the described embodiment. The receiver <NUM> is configured to detect electromagnetic radiation from the environment. The receiver <NUM> is configured to convert the detected electromagnetic radiation into an electrical signal. The electrical signal is indicative of the detected electromagnetic radiation. In embodiments the receiver <NUM> is configured to detect intensity of the electromagnetic radiation. In embodiments, the transmitter <NUM> and the receiver <NUM> are combined as a transceiver.

In embodiments wherein the position sensor <NUM> is an optical sensor, the indicator <NUM> associated with the position sensor <NUM> may have substantially the same arrangement as described above. However, the indicator <NUM> in the present arrangement has an inner surface having a constant radius around the circumference of the indicator <NUM>. The indicator <NUM> in this embodiment comprises a first surface section <NUM> of the inner surface has reflective properties. The first surface section <NUM> is configured to reflect electromagnetic radiation impinging on the first surface section <NUM>. In embodiments the first surface section <NUM> is configured to reflect a greater proportion of electromagnetic radiation of a particular wavelength range than the second surface section <NUM>. The second surface section <NUM> of the indicator <NUM> has non-reflective or reduced reflective properties. The second surface section <NUM> is configured to absorb electromagnetic radiation impinging on the second surface section <NUM>. In embodiments the second surface section <NUM> is configured to absorb a greater proportion of electromagnetic radiation of a particular wavelength range than the first surface section <NUM>.

The reflective and non-reflective properties of the first and second surface section <NUM>, <NUM> are configured to reflect and absorb electromagnetic radiation in the same wavelength range. In embodiments, the first and second surface sections <NUM>, <NUM> are configured to have high reflectance and absorption respectively for electromagnetic waves of approximately the same wavelength that the optical detection device <NUM> is configured to detect. In embodiments, the first and second surface sections <NUM>, <NUM> have reflecting and absorbing coatings respectively that provide the first and second surface sections <NUM>, <NUM> with reflecting and absorbing properties. It can be appreciated that the reflection and absorption properties of the first and second surface sections <NUM>, <NUM> can be a result of any attribute of the indicator <NUM>, for example the materials or the surface structure. In the shown embodiment, the inner surface of the indicator <NUM> is a ring. However the inner surface of the indicator <NUM> can be any shape.

In an embodiment wherein the radius of the inner surface of the indicator varies, similar to the cam described in previous embodiments, the optical sensor may instead or also detect the proximity of the indicator.

In one an embodiment, the first position sensor comprises an IR proximity reflective sensor. In this embodiment, the reflective coating is configured to reflect infra-red light. In the present embodiment, the position sensor is configured to detect the proximity of the indicator <NUM> to the valve shaft <NUM>. The operation of such a non-contact position sensor would be similar to that of the contact sensor already described. The surface sections of the indicator are disposed at different radial distances from the valve shaft. The position sensor is configured to identify the surface section being detected. The position sensor is configured to compare the detected proximity of the surface section of the indicator with known distances of the different surface sections of the first indicator.

In other embodiments, the or each position sensor is a proximity ultrasonic sensor, hall sensor, or any other type of sensor configured to detect a position of the valve shaft. Each position sensor may be the same type of position sensor, or the type of position sensor may differ.

The circumferential length of the surface sections of the indicators can be adjusted to adjust the accuracy of position detection. The accuracy of position detection of a position of the valve shaft can be adjusted by increasing or decreasing the circumferential length of the corresponding surface section of the indicator. The accuracy of the sensor assembly can be adjusted by replacing the original indicators with new indicators. The sensor assembly <NUM> is therefore flexible and can be configured for different operating requirements without the need to redesign or replace the entire sensor assembly. Increasing the length of a surface section of the indicator decreases the accuracy of detecting the corresponding position of the valve shaft (vice versa if the length is decreased). This has the potential benefit of reducing the impact of systematic errors in position detection (e.g. calibration errors).

Claim 1:
A valve assembly (<NUM>) comprising:
a housing (<NUM>);
a valve shaft (<NUM>) rotatable in the housing; and
a sensor assembly,
characterised in that the sensor assembly (<NUM>) is in the housing for detecting the angular position of the valve shaft;
wherein the sensor assembly in the housing comprises:
an indicator (<NUM>) on the housing; and
a position sensor (<NUM>) on the valve shaft in the housing configured to detect a feature of the indicator to determine the angular position of the valve shaft.