Patent Description:
There has been known a device including a rotor as a uniaxial eccentric screw and a stator through which the rotor is inserted, which transports a liquid material or fluid. This sort of device is referred to as a uniaxial eccentric screw pump or also Mohno Pump. The stator of the device has interference for tightening (interference) that elastically deforms due to rotation of the rotor, and transports the liquid material or fluid by taking advantage of the elastic action of the stator.

For example, <CIT> discloses a fluid transport device in which the capacity of a transport space formed by a through-hole of a stator is arranged to decrease toward a flow direction from an inlet port to a discharge port in order to solve a problem of bubble generation that occurs when a fluid that is highly volatile or contains a large amount of dissolved gas is discharged.

Furthermore, <CIT>- <CIT> discloses a uniaxial eccentric screw pump in which interference on a discharge port side is arranged to be smaller than interference on an inlet port side in order to prevent a problem of a stator crack or breakage that occurs when it is used under a situation where capacity efficiency of a fluid transport path is less than one and discharge pressure is high.

<CIT> discloses a renewable moineau-type pumping mechanism.

However, the devices in the above documents have an issue that, when the fluid is discharged from the discharge port, pulsation occurs and uniformly metered discharge cannot be performed.

In a case where the device in the above documents is incorporated into a fluid circulation circuit to be used as a circulation pump, there is an issue that a flow in the circulation circuit pulsates and is not kept constant.

In a case where the device in the above documents is used to discharge a liquid material onto a work surface, there is an issue that pulsation when a line is drawn on the work surface will cause a non-uniform line width.

Therefore, an object of the present invention is to provide a fluid transfer device that can solve an issue of pulsation that occurs when a fluid is pumped out by eccentrically rotating a male-screw-shaped rotor within a stator having a female-screw-shaped insertion hole, an application device including the fluid transfer device, and an application method.

A fluid transfer device according to the present invention is a fluid transfer device including: an outer cylinder; a stator that has an insertion hole as a female-screw-shaped through-hole and is provided on an inner periphery of the outer cylinder; and a male-screw-shaped rotor that is connected to a rotor driving part and eccentrically rotates in contact with an inner periphery of the stator, wherein the fluid transfer device is capable of transferring a fluid in a transport path formed by the stator and the rotor, by eccentrically rotating the rotor inserted through the insertion hole, wherein the stator includes an inlet portion that spans a certain range through a longitudinal direction from an inlet of the transport path, an outlet portion that spans a certain range through the longitudinal direction from an outlet of the transport path, and a central portion located between the inlet portion and the outlet portion, wherein the stator is subject to smaller contact force by the rotor at the inlet portion and the outlet portion than contact force by the rotor at the central portion.

In the fluid transfer device, the stator may have a smaller amount of interference by the rotor at the inlet portion and the outlet portion than an amount of interference by the rotor at the central portion, whereby the stator may be subject to smaller contact force by the rotor at the inlet portion and the outlet portion than contact force by the rotor at the central portion.

In the fluid transfer device, an amount of interference by the rotor may decrease gradually from the central portion toward the outlet or the inlet.

In the fluid transfer device, contact force by the rotor at the central portion may be uniform through the longitudinal direction.

In the fluid transfer device, (A) contact force A1, A2, A3, A4 may satisfy a relationship A4 > A2 > A3 > A1, where A1 denotes contact force between the rotor and the stator at the inlet of the transport path, A2 denotes contact force between the rotor and the stator at a position that is one turn of the rotor from the inlet of the transport path, A3 denotes contact force between the rotor and the stator at a position between the inlet of the transport path and the position that is one turn of the rotor from the inlet of the transport path, and A4 denotes contact force between the rotor and the stator at a longitudinally central portion of the transport path, and (B) contact force B1, B2, B3, B4 may satisfy a relationship B4 > B2 > B3 > B1, where B1 denotes contact force between the rotor and the stator at the outlet of the transport path, B2 denotes contact force between the rotor and the stator at a position that is one turn of the rotor from the outlet of the transport path, B3 denotes contact force between the rotor and the stator at a position between the outlet of the transport path and the position that is one turn of the rotor from the inlet of the transport path, and B4 denotes contact force between the rotor and the stator at the longitudinally central portion of the transport path.

In the fluid transfer device, an amount of interference by the rotor at a longitudinally central portion of the insertion hole may be uniform through the longitudinal direction.

In the fluid transfer device, (A) amounts of interference A1, A2, A3, A4 may satisfy a relationship A4 > A2 > A3 > A1, where A1 denotes an amount of interference between the rotor and the stator at the inlet of the transport path, A2 denotes an amount of interference between the rotor and the stator at a position that is one turn of the rotor from the inlet of the transport path, A3 denotes an amount of interference between the rotor and the stator at a position between the inlet of the transport path and the position that is one turn of the rotor from the inlet of the transport path, and A4 denotes an amount of interference between the rotor and the stator at a longitudinally central portion of the transport path, and (B) amounts of interference B1, B2, B3, B4 may satisfy a relationship B4 > B2 > B3 > B1, where B1 denotes an amount of interference between the rotor and the stator at the outlet of the transport path, B2 denotes an amount of interference between the rotor and the stator at a position that is one turn of the rotor from the outlet of the transport path, B3 denotes an amount of interference between the rotor and the stator at a position between the outlet of the transport path and the position that is one turn of the rotor from the inlet of the transport path, and B4 denotes an amount of interference between the rotor and the stator at the longitudinally central portion of the transport path.

In the fluid transfer device, a longitudinally central portion of the insertion hole may span a range of two turns of the rotor or more.

In the fluid transfer device, the inlet portion may be within a range exceeding one turn of the rotor from the inlet of the transport path, and the outlet portion may be within a range exceeding one turn of the rotor from the outlet of the transport path.

In the fluid transfer device, a longitudinal range of the central portion of the stator may be longer than respective longitudinal ranges of the inlet portion and the outlet portion.

In the fluid transfer device, an interference amount ratio of interference by the rotor at the inlet portion and the outlet portion of the stator to interference by the rotor at the central portion of the stator may be within <NUM>:<NUM> to <NUM>:<NUM>.

In the fluid transfer device, a shape and/or a material property of the inlet portion and the outlet portion of the stator may be specified differently from the central portion of the stator such that contact force with the rotor at the inlet portion and the outlet portion is smaller than contact force with the rotor at the central portion.

In the fluid transfer device, either one element of a material property and a thickness of the stator, along with an amount of interference of the stator, at an inlet portion of the transport path, may be specified differently from a central portion of the insertion hole such that contact force with the rotor at the inlet portion of the stator is smaller than contact force with the rotor at the central portion of the stator, and either one element of a material property and a thickness of the stator, along with an amount of interference of the stator, at an outlet portion of the transport path, may be specified differently from the central portion of the insertion hole such that contact force with the rotor at the outlet portion of the stator is smaller than contact force with the rotor at the central portion of the stator.

In the fluid transfer device, the longitudinally central portion of the stator may be made of material with greater elasticity than material of the inlet portion and/or the outlet portion of the stator.

In the fluid transfer device, an upstream end portion and a downstream end portion of the outer cylinder may have inner peripheries with a larger diameter than a longitudinally central portion of the outer cylinder.

In the fluid transfer device, the longitudinally central portion of the outer cylinder may have an inner periphery with a constant diameter.

In the fluid transfer device, the longitudinally central portion of the outer cylinder may have a female-screw-shaped inner periphery with a same pitch as the stator.

In the fluid transfer device, an outer periphery of the outer cylinder may have an uneven shape at a position corresponding to the female-screw-shaped inner periphery.

In the fluid transfer device, the inner periphery at the upstream end portion of the outer cylinder may be formed by a tapered surface of which diameter increases toward an upstream end of the outer cylinder, and the inner periphery at the downstream end portion of the outer cylinder may be formed by a tapered surface of which diameter increases toward a downstream end of the outer cylinder.

In the fluid transfer device, the outer cylinder may include an upstream end portion inner periphery of which inner periphery diameter is constant, an inlet-side tapered surface connecting the upstream end portion inner periphery with the central portion, a downstream end portion inner periphery of which inner periphery diameter is constant, and an outlet-side tapered surface connecting the downstream end portion inner periphery with the central portion.

In the fluid transfer device, a range of the inner periphery with the larger diameter at the upstream end portion of the outer cylinder may be longer than a range of the inner periphery with the larger diameter at the downstream end portion of the outer cylinder.

In the fluid transfer device, a ratio of a range of the inlet portion of the stator to a range of the central portion of the stator may be within <NUM>:<NUM> to <NUM>:<NUM>, and a ratio of a range of the outlet portion of the stator to the range of the central portion of the stator may be within <NUM>:<NUM> to <NUM>:<NUM>.

In the fluid transfer device, the stator may include a transport action zone having interference by the rotor and a non-transport action zone that is located on an upstream side from the transport action zone and is not in contact (has no interference) with the rotor.

In the fluid transfer device, an inner periphery of the insertion hole constituting the non-transport action zone may be formed by a tapered surface of which diameter increases from a center side of the insertion hole toward an inlet side.

In the fluid transfer device, a capacity of the non-transport action zone may be smaller than a capacity of any of transport spaces within the insertion hole that are located in the transport action zone and are opened and closed by eccentric rotation of the rotor.

In the fluid transfer device, contact force with the rotor at the inlet portion and/or the outlet portion of the stator may be weakest when the rotor is at a highest position and a lowest position.

In the fluid transfer device, the fluid transfer device may be a liquid-material discharge device further including a nozzle member having a discharge port through which the fluid flowing out from the outlet of the transport path is discharged.

An application device according to the present invention is an application device including: the fluid transfer device described above; and a relative movement device that moves the fluid transfer device and an application target relative to each other.

An application method according to the present invention is an application method of drawing a line with a uniform width on a work surface using the application device described above.

According to the present invention, it is possible to solve an issue of pulsation that occurs in a pumped-out fluid when the fluid is pumped out by eccentrically rotating a rotor within a stator.

Embodiments of a fluid transfer device of the present invention will be described below using a liquid-material discharge device as an example. Note that a technical idea of the present invention can be applied not only to the liquid-material discharge device but also to, for example, a circulation pump incorporated into a fluid circulation circuit. In addition, a fluid to be transferred by the fluid transfer device is not limited to a liquid material, and may be a fluid object such as powder and paste.

<FIG> is a partial sectional side view of a liquid-material discharge device <NUM> according to a first embodiment. Hereinafter, for convenience of explanation, a nozzle member <NUM> side may be referred to as a front side (front) and an opposite side to the nozzle member <NUM> may be referred to as a rear side (back).

The liquid-material discharge device <NUM> includes a rotor driving device <NUM> provided on the rear side of a main body <NUM>, and a stator unit <NUM> provide on the front side.

The main body <NUM> is hollow and houses a coupling member <NUM> and a shaft <NUM> inside. A rear-side end portion of the shaft <NUM> is coupled to the rotor driving device <NUM> via a coupling <NUM>, and driving force from the rotor driving device <NUM> is transmitted thereto. Rotation of the shaft <NUM> by the rotor driving device <NUM> causes a rotor <NUM> connected to the shaft via the coupling member <NUM> to eccentrically rotate. The rotor driving device <NUM> may be combined with a versatile external rotating device. In addition, a supply tube <NUM> is connected to a top surface of the main body <NUM>, and a liquid material is supplied from a reservoir not shown to a liquid-material supply port <NUM>. Here, the liquid material within the reservoir may be pressurized by a compressed air, a piston, or the like. A top of the supply tube <NUM> is provided with a bubble releasing hole <NUM>. The bubble releasing hole <NUM> may be plugged during use. A back-end portion of the main body <NUM> is a connector <NUM> to which a power supply cable (not shown) is connected.

The stator unit <NUM> includes a stator <NUM> and an outer cylinder <NUM> that fixes the stator <NUM>. The stator unit <NUM> is detachably fixed to the rotor driving device <NUM> with known means such as a screw clamp or a chuck so that slippage, backlash, and the like will not occur even when the rotor <NUM> rotates within the stator <NUM> by being driven by the rotor driving device <NUM> as described above.

The outer cylinder <NUM> is a cylindrical body made of metal, ceramics, or the like, and has a constant thickness from a front-end portion to a back-end portion in the present embodiment. Since the outer cylinder <NUM> tightly fixes the stator <NUM>, even when the rotor <NUM> to be described later rotates within the stator <NUM> by being driven by the rotor driving device <NUM>, neither slippage of the stator <NUM> within the outer cylinder <NUM> nor gap between the stator and the outer cylinder <NUM> occurs. A front-side end portion of the outer cylinder <NUM> communicates with the nozzle member <NUM> having a liquid-material outlet (discharge port). The liquid-material discharge device <NUM> of the present embodiment is held such that a work as an application target and the nozzle member <NUM> face each other at an arbitrary angle to be used. An outer peripheral shape of the outer cylinder <NUM> is straight with a constant diameter in <FIG>, but is not limited to the illustrated shape, and may include, for example, a step or a curve. Moreover, the outer peripheral shape may have unevenness along unevenness of an inner periphery of the outer cylinder <NUM> so that the inner periphery of the outer cylinder <NUM> will be made visible. Furthermore, an outer periphery of the outer cylinder <NUM> may be provided with a groove, a thread, a flange, or the like. It should be noted that, since the outer cylinder <NUM> and the stator <NUM> are roughly depicted in <FIG>, detailed description thereof will be given with reference to <FIG> and subsequent figures.

<FIG> illustrates explanatory views of the outer cylinder <NUM>, the stator <NUM>, and the rotor <NUM> according to the first embodiment. (a) is a side sectional view when the rotor <NUM> is at its highest position (<NUM>°), (b) is a back view, (c) is a B-B sectional view of (a), (d) is a C-C sectional view of (a), (e) is a side sectional view of the outer cylinder <NUM> only, and (f) is a back view of the outer cylinder <NUM> only. In <FIG>, an insertion hole <NUM> has an outlet in a left end surface and an inlet in a right end surface.

As shown in <FIG>, the stator <NUM> is arranged within the outer cylinder <NUM> in tight contact with the inner periphery of the outer cylinder <NUM>. The stator <NUM> has the insertion hole <NUM> having an inner periphery like a female screw, and forms a transport path in cooperation with the rotor <NUM> that is arranged within the insertion hole <NUM> and has an outer periphery like a male screw. That is, the transport path is a flow path formed by the stator <NUM> and the rotor <NUM>, and appears only in a state where the rotor <NUM> is inserted through the stator <NUM>. In <FIG>, the right end of the outer cylinder <NUM> is a start position of the transport path (inlet of the transport path), and the left end of the outer cylinder <NUM> is an end position of the transport path (outlet of the transport path). A transport action zone is configured where the rotor <NUM> eccentrically rotating within the insertion hole <NUM> slides in tight contact with the fixed stator <NUM> so as to transfer a liquid material within the transport path. In the present embodiment, the insertion hole <NUM> from the right end to the left end constitutes the transport action zone (it should be noted that an insertion hole <NUM> illustrated in <FIG> to be described later also includes a non-transport action zone).

The stator <NUM> is an elastic body made of elastic material such as rubber or resin. The stator <NUM> has interference (interference for tightening) that elastically deforms when pressed by the rotor <NUM> inserted through the insertion hole <NUM>, and transports the liquid material within the insertion hole <NUM> by elastic action caused by rotation of the rotor <NUM>. Here, interference (interference for tightening) is "tightening tolerance" and means an overlap thickness (dimensional difference, amount of interference). In the present embodiment, the inner periphery of the stator <NUM> has a shape of a female screw with two threads and has a constant pitch within a range where it is in contact with the rotor <NUM>.

It should be noted that the female screw shape of the stator <NUM> is not limited to the example shape of the female screw with two threads, and can be a shape of any female screw. The number of threads of the stator <NUM>, if changed, can be n+<NUM>, which is the number n of threads of the rotor <NUM> plus one. Furthermore, the winding direction of the female screw of the stator <NUM> may be counterclockwise (left-hand screw) or clockwise (right-hand screw). In the specification, a clockwise stator with respect to an advancing direction of the liquid material will be described.

The rotor <NUM> has a shape of a male screw with one thread. The rotor <NUM> is arranged within the insertion hole <NUM> of the stator <NUM>, and eccentrically rotates to dynamically form two lines of transport paths within the insertion hole <NUM>. In more detail, cavities (closed spaces) with a phase shift of <NUM>° in a rotation period of the rotor <NUM> are alternately formed in the two lines of transport paths. The cavities filled with the liquid material moves from the inlet side to the outlet side, and the liquid material is thereby transported. A rear-side end portion of the rotor <NUM> is coupled to the shaft <NUM> via the coupling member <NUM>, and the rotor <NUM> eccentrically rotates when driving force from the rotor driving device <NUM> is transmitted to the shaft <NUM>. The rotor <NUM> has a constant diameter and a constant pitch at least within a range where it is in contact with the stator <NUM>.

It should be noted that the male screw shape of the rotor <NUM> is not limited to the shape of the male screw with one thread, and can be a shape of any male screw to match the shape of the inner periphery of the stator <NUM>. In the present embodiment, the male screw shape of the outer periphery of the rotor <NUM> is illustrated as being uniform in its longitudinal direction, but may not be uniform. It is possible to make interference thicker at a central portion of the transport path and thinner at both of end portions by forming the inner periphery of the stator <NUM> into a female screw shape depending on the male screw shape of the outer periphery of the rotor <NUM>.

As illustrated in <FIG>, when the rotor <NUM> is at its highest position, a transport space 21a that has the maximum opening area and forms a first-line cavity is formed below the rotor <NUM> at an inlet portion, to which the liquid material is supplied from the supply tube <NUM>. When the rotor <NUM> rotates from the illustrated position, a transport space 22a (see <FIG> to be described later) that forms a second-line cavity is dynamically formed above the rotor <NUM> at the inlet portion, and the opening area of the transport space 21a shrinks. As illustrated in <FIG>, when the rotor <NUM> is at its highest position, a transport space 21c that forms a first-line cavity is formed below the rotor <NUM> at a B-B line position (see <FIG>). When the rotor <NUM> rotates from the illustrated position, while a sectional area of the transport space 21c below the rotor <NUM> shrinks, a transport space 22c that forms a second-line cavity is created above the rotor <NUM> and a sectional area thereof further expands along with the rotation of the rotor <NUM> (see <FIG> to be described later).

As illustrated in <FIG>, when the rotor <NUM> is at its highest position, transport spaces <NUM>, <NUM> are formed on the right and left sides of the rotor <NUM> at a C-C line position. Here, the transport space <NUM> communicates with transport spaces 21c and 22b to form the first-line cavity, and the transport space <NUM> communicates with transport spaces 21b and 22c to form the second-line cavity (for positions of the transport spaces 21b, 21c, 22b, 22c, see <FIG>). When the rotor <NUM> rotates from the illustrated position, a sectional area of one of the transport spaces <NUM>, <NUM> on the right and left sides of the rotor <NUM> shrinks, and a sectional area of the other expands. For example, when the rotor <NUM> rotates from <NUM>° to <NUM>°, the transport space <NUM> is closed and the sectional area of the transport space <NUM> is maximized.

In this way, the rotation of the rotor <NUM> causes repetition of the motion of forming and closing transport spaces of the two lines at opposite positions across the rotor <NUM> in each section (including the B-B section and the C-C section) perpendicular to a flow-path direction of the stator <NUM>, resulting in movement of the cavities filled with the liquid material toward the outlet side. The liquid material that has been transported through the two lines of transport paths within the insertion hole <NUM> merges and is discharged from the nozzle member <NUM>. In order to prevent pulsation of the liquid material transported through the two lines of transport paths, it is necessary to supply a sufficient amount of liquid material to fully fill each cavity of each transport path, and to ensure smooth confluence of the liquid material transported through the two lines of transport paths. In order to realize these conditions, it is important to adjust contact force between the rotor <NUM> and the stator <NUM> at an inlet portion and an outlet portion of the insertion hole <NUM>.

The present invention solves an issue of pulsation by making tightening force of the stator in an area where the rotor and the stator are in contact with each other smaller at both of end portions than at a central portion thereof. In other words, an issue of pulsation is solved by arranging distribution of contact force between the rotor and the stator over the longitudinal direction such that the contact force is smaller at both of the end portions than at the central portion of the stator. The stator <NUM> can be divided into three regions in terms of the contact force with the rotor <NUM>. That is, the stator <NUM> can be divided into a central portion where the contact force with the rotor <NUM> is constant, an inlet portion (region on the inlet side from the central portion) where the contact force with the rotor <NUM> is smaller than at the central portion, and an outlet portion (region on the outlet side from the central portion) where the contact force with the rotor <NUM> is smaller than at the central portion. In the example of <FIG>, the portion between B<NUM> and B<NUM> is the central portion, the portion between B<NUM> and B<NUM> is the inlet portion, and the portion between B<NUM> and B<NUM> is the outlet portion.

The contact force of the stator can be adjusted by adjusting a shape of the stator (for example, an amount of interference, thickness) and/or a material property of the stator (for example, repulsive force (rebound resilience), hardness). In the first embodiment, the contact force of the stator <NUM> corresponding to the above-described three regions is realized by adjusting the amount of interference. That is, compared to the central portion where the amount of interference is constant over the longitudinal direction of the stator <NUM>, the contact force is adjusted by making the amount of interference smaller at both of the end portions so that the issue of pulsation is solved. A method of adjusting the contact force of the stator <NUM> in the first embodiment will be described in detail below with reference to <FIG>.

The area of the stator <NUM> in contact with the rotor <NUM> is pressed by the rotor <NUM> to constitute interference S<NUM>, S<NUM>. As can be seen from the interference S<NUM>, S<NUM> drawn in black in <FIG>, in the first embodiment, the stator <NUM> arranged in tight contact with the inner periphery of the outer cylinder <NUM> has the interference S<NUM>, S<NUM> that is smaller near both of the end portions than at the longitudinally central portion. Here, the longitudinal direction of the stator <NUM> means the same direction as a direction from an inlet toward an outlet or a direction from the outlet toward the inlet, and is a direction perpendicular to a radial direction. The stator <NUM> includes a central portion 11c where the amount of interference is constant, an inlet portion 11a where the amount of interference decreases gradually (stepwise) from the central portion 11c toward the inlet (upstream), and an outlet portion 11b where the amount of interference similarly decreases gradually (stepwise) from the central portion 11c toward the outlet (downstream). The stator thickness is made thinner at the inlet portion 11a and the outlet portion 11b of the stator <NUM> than at the central portion 11c to achieve the smaller amount of interference. Thus, the contact force between the rotor <NUM> and the stator <NUM> is weaker at the inlet portion and the outlet portion than at the central portion 11c. In the first embodiment, a quantitative interference ratio of both of the end portions to the longitudinally central portion of the stator <NUM> is, for example, end portions : central portion = <NUM>:<NUM> to <NUM>:<NUM>. It should be noted that longitudinal ranges (longitudinal lengths) of the inlet portion 11a and the outlet portion 11b of the stator <NUM> are the same as ranges (longitudinal lengths) of the inlet portion and the outlet portion of the insertion hole <NUM>.

<FIG> is a side sectional view of an outer cylinder <NUM>, a stator <NUM>, and a rotor <NUM> according to a related art, and (b) is a side sectional view of the outer cylinder <NUM>, the stator <NUM>, and the rotor <NUM> according to the first embodiment. As can be seen from interference S<NUM>, S<NUM> drawn in black in <FIG>, in the related art, an inner periphery of the outer cylinder <NUM> has a constant diameter in the longitudinal direction, and an inner periphery (female screw shape) of the stator <NUM> arranged inside thereof is also uniformly formed in the longitudinal direction. Furthermore, a male screw shape of an outer periphery of the rotor <NUM> is uniformly formed in the longitudinal direction. Thus, interference formed by the rotor <NUM> and the stator <NUM> in cooperation is also constant. That is, an amount of the interference S<NUM>, S<NUM> is constant throughout the longitudinal direction of the outer cylinder <NUM>. For this reason, the related art has an issue that pulsation easily occurs when the liquid material that has passed through the two lines of transport paths merges. In addition, the related art also has an issue that pulsation easily occurs due to insufficient supply of the liquid material to an inlet of the stator <NUM>. Specifically, while the rotor <NUM> operates within a range of the interference, there occurs a time period when the liquid material is not supplied to a transport space. For example, in a case of a device where an opening of the inlet of the stator <NUM> is closed by interference when the rotor is at <NUM>° position, the liquid material is not supplied during the rotation from <NUM>° to <NUM>° (and from <NUM>° to <NUM>°). Decrease in a supply amount of the liquid material by an amount during the rotation from <NUM>° to <NUM>° (and from <NUM>° to <NUM>°) leads to decrease in a discharge amount since a decreased amount of liquid material is transported, which causes pulsation.

On the other hand, in the first embodiment, as can be seen from the interference S<NUM>, S<NUM> drawn in black in <FIG>, the range of the interference S<NUM>, S<NUM> is smaller near both of the ends of the outer cylinder <NUM> than at the central portion. In more detail, an inner diameter size of the outer cylinder <NUM> is constant through the longitudinal direction, but a diameter of the inner periphery (female screw shape) of the stator <NUM> arranged inside thereof increases stepwise from the position B<NUM> on the right side of a central portion of the insertion hole <NUM> toward the position B<NUM> of the inlet. Thus, the amount of interference formed by the rotor <NUM> and the stator <NUM> in cooperation decreases toward the inlet (B<NUM> > B<NUM> > B<NUM>). Also in the outlet portion, the diameter of the inner periphery (female screw shape) of the stator <NUM> similarly increases stepwise from the position B<NUM> on the left side of the central portion of the insertion hole <NUM> toward the position B<NUM> of the outlet. Thus, the amount of interference formed in cooperation with the rotor <NUM> decreases toward the outlet (B<NUM> > B<NUM> > B<NUM>). For this reason, in the first embodiment, it is possible to solve the issue that pulsation easily occurs when the liquid material that has passed through the two lines of transport paths merges and the issue that pulsation easily occurs due to insufficient supply of the liquid material to the inlet of the stator. For example, in the present invention, assuming that the rotor's highest position is <NUM>° position, a state where the liquid material is supplied to a transport space at the inlet-side end portion (inlet of the transport path) continues till the rotor reaches <NUM>° (preferably, till it reaches <NUM>°, more preferably, till immediately before it reaches <NUM>°). Similarly, a state where the liquid material is supplied to a transport space of the other line at the inlet-side end portion (inlet of the transport path) continues till the rotor reaches <NUM>° (preferably, till it reaches <NUM>°, more preferably, till immediately before it reaches <NUM>°).

<FIG> is a sectional view at the inlet portion of the insertion hole <NUM> when the rotor <NUM> is at its highest position (<NUM>°), and <FIG> is a sectional view at the longitudinally central portion of the insertion hole <NUM> when the rotor <NUM> is at its highest position (<NUM>°). A movement length necessary for opening the inlet portion of the insertion hole <NUM> (from S<NUM> to an opening position H<NUM>) in <FIG> is shorter than a movement length necessary for opening the longitudinally central portion of the insertion hole <NUM> (from S<NUM> to an opening position H<NUM>) in <FIG>, although respective positions of the upper end of the rotor <NUM> are the same. That is, interference S<NUM> (<FIG>) at the inlet portion of the insertion hole <NUM> is smaller than interference S<NUM> (<FIG>) at the central portion by P<NUM>, and thus the liquid material is more easily supplied to the inlet of the transport path.

From a viewpoint of accepting more liquid material into a cavity without delay, it is important to open the inlet of the transport path promptly (shorten the closed time period).

A liquid-material transport action caused by the rotating motion of the rotor <NUM> will be described with reference to <FIG>.

As illustrated in <FIG>, when the rotor <NUM> is at <NUM>° position (highest position), a transport space 21a that forms a cavity appears below the rotor <NUM> at the most upstream point, and the transport space 21a is filled with the liquid material supplied from the supply tube <NUM>. When the rotor <NUM> is at <NUM>° position, a transport space above the rotor <NUM> is closed.

As illustrated in <FIG>, when the rotor <NUM> rotates to <NUM>° position, a transport space 22a that forms a cavity appears above the rotor <NUM> at the most upstream point. Here, the most upstream transport space 22a is also filled with the liquid material supplied from the supply tube <NUM>. A transport space 22b links with the transport space 21a below the rotor <NUM> on the near side in a depth direction of the paper of the figure (on the left side as viewed from the inlet side) to form the cavity (see the transport space <NUM> in <FIG>). Along with decrease in a sectional region of the transport space 21a below the rotor <NUM>, the liquid material present in the transport space 21a moves toward the transport space 22b. It should be noted that, for the purpose of explanation, the transport space 21a and the transport space 22b that form the single cavity are denoted with respective different numerals. The same applies hereinafter.

As illustrated in <FIG>, when the rotor <NUM> rotates to <NUM>° position (lowest position), the transport space 22a above the rotor <NUM> has the maximum opening as can be seen from the front sectional view. On the other hand, the transport space 21a below the rotor <NUM> is closed, and the liquid material that has been present in the transport space 21a moves toward the transport space 22b. The transport space 22a with the maximum opening is filled with the liquid material supplied from the supply tube <NUM>.

As illustrated in <FIG>, when the rotor <NUM> rotates to <NUM>° position, a sectional region of the transport space 22a that forms the cavity above the rotor <NUM> decreases. The transport space 22a links with a transport space 21b below the rotor <NUM> on the far side in the depth direction of the paper of the figure (on the right side as viewed from the inlet side) to form the cavity (see the transport space <NUM> in <FIG>). Along with decrease in the sectional region of the transport space 22a, the liquid material present in the transport space 22a moves toward the transport space 21b. Furthermore, along with decrease in a sectional region of the transport space 22b, the liquid material present in the transport space 22b moves toward a transport space 21c. When the transport space 21a reappears below the rotor <NUM> at the most upstream point, the transport space 21a is filled with the liquid material supplied from the supply tube <NUM>.

As illustrated in <FIG>, when the rotor <NUM> rotates to <NUM>° position, the transport space 22a that forms the cavity above the rotor <NUM> is closed. In this process, the liquid material that has been present in the transport space 22b moves toward the transport space 21c, and the liquid material that has been present in the transport space 22a moves toward the transport space 21b. When the transport space 21a reappears below the rotor <NUM> at the most upstream point, the transport space 21a is filled with the liquid material supplied from the supply tube <NUM>. Here, the transport spaces 21a, 21b, 21c, ··· that have appeared below the rotor <NUM> form respective cavities divided by tight contact between the rotor <NUM> and the stator <NUM>.

As described above, the liquid material is transported from the inlet side toward the outlet side within the insertion hole <NUM> by repeating the rotating motion of the rotor <NUM> from <NUM>° to <NUM>°. When the liquid material is transported by rotating the rotor <NUM>, it is important to fill the cavities with the sufficient amount of the liquid material in order to prevent pulsation. Especially, it is preferable to arrange the contact force with the stator <NUM> when the rotor <NUM> is at its highest position (<NUM>°) and lowest position (<NUM>°) to be smaller.

Supplementary explanation will be given about a formation situation of a transport space in a configuration with small interference and a configuration with large interference with reference to <FIG>.

<FIG> is a comparison diagram for explaining formation situations of transport spaces from <NUM>° to <NUM>° for the configuration with small interference of the stator <NUM> (left diagram) and the configuration with large interference (right diagram).

As illustrated in <FIG>, when the rotor <NUM> is at its highest position (<NUM>°), no transport space is formed above the rotor <NUM> both in the configuration with small interference (left diagram) and the configuration with large interference (right diagram).

As illustrated in <FIG>, when the rotor <NUM> rotates and is somewhat lowered from its highest position, a transport space <NUM> is formed above the rotor <NUM> in the configuration with small interference (left diagram). Meanwhile, in the configuration with large interference (right diagram), the transport space <NUM> is not formed above the rotor <NUM>.

As illustrated in <FIG>, when the rotor <NUM> further rotates, the transport space <NUM> is formed above the rotor <NUM> also in the configuration with large interference (right diagram). Meanwhile, in the configuration with small interference (left diagram), the transport space <NUM> above the rotor <NUM> forms a larger section than that in the configuration with large interference (right diagram).

As illustrated in <FIG>, when the rotor <NUM> rotates <NUM>°, transport spaces <NUM>, <NUM> of which sections are the same in size are formed above and below the rotor <NUM> both in the configuration with small interference (left diagram) and the configuration with large interference (right diagram).

As can be seen from <FIG>, the small interference of the stator <NUM> results in prompt elimination of tight contact between the rotor <NUM> and the stator <NUM>. Especially, adopting the configuration with small interference at the outlet portion of the stator <NUM> is preferable because the prompt elimination of the tight contact between the rotor <NUM> and the stator <NUM> allows the liquid material within the cavities formed within the transport paths to flow out without delay.

As illustrated in <FIG>, when the rotor <NUM> rotates <NUM>°, the transport spaces <NUM>, <NUM> of which sections are the same in size are formed above and below the rotor <NUM> both in the configuration with small interference (left diagram) and the configuration with large interference (right diagram).

As illustrated in <FIG>, in a state where the rotor <NUM> has rotated slightly from <NUM>°, the sectional region of the transport space <NUM> above the rotor <NUM> has decreased also in the configuration with large interference (right diagram). Meanwhile, in the configuration with small interference (left diagram), the transport space <NUM> of which sectional region is larger than that in the configuration with large interference (right diagram) is maintained above the rotor <NUM>.

As illustrated in <FIG>, when the rotor <NUM> further rotates and gets somewhat closer to its highest position, the sectional region of the transport space <NUM> above the rotor <NUM> decreases but is not closed in the configuration with small interference (left diagram). Meanwhile, in the configuration with large interference (right diagram), the transport space <NUM> above the rotor <NUM> is closed.

As illustrated in <FIG>, when the rotor <NUM> is at its highest position (<NUM>° (<NUM>°)), the transport space above the rotor <NUM> is closed both in the configuration with small interference (left diagram) and the configuration with large interference (right diagram).

As can be seen from <FIG>, the large interference would result in early start of contact with the stator <NUM> by the rotation of the rotor <NUM> (see <FIG>). At the portion where the rotor <NUM> and the stator <NUM> are in contact with each other, the transport space is closed and the liquid material stops filling the stator <NUM> from the inlet. However, as the rotor <NUM> further continues to rotate and expand a capacity of the cavity that is already closed until it reaches the tightest contact position (<FIG>), a cavity insufficiently filled with the liquid material is sometimes formed. When the cavity insufficiently filled with the liquid material is opened to the nozzle member <NUM> at the outlet portion of the stator <NUM>, it may draw the liquid material from the discharge port of the nozzle member <NUM>, which causes pulsation. That is, an advantageous effect to eliminate pulsation can be obtained by decreasing interference and always forming a cavity fully filled with the liquid material.

Supplementary explanation will be given about a range where interference is relatively small in the stator <NUM>. A "range" to be described below is a range of length in the longitudinal direction of the stator <NUM> unless otherwise specified.

In the first embodiment, interference is provided throughout the longitudinal direction of the stator <NUM>, and a longitudinal range of interference at the central portion of the stator <NUM> is longer than respective longitudinal ranges of interference at the inlet portion and the outlet portion of the stator <NUM>. In the example of <FIG>, the portion from B<NUM> to B<NUM> is the longitudinally central portion of the transport path formed in the insertion hole <NUM>, the portion from B<NUM> to B<NUM> is the inlet portion of the transport path formed in the insertion hole <NUM>, and the portion from B<NUM> to B<NUM> is the outlet portion of the transport path formed in the insertion hole <NUM>.

Cavities within the two lines of transport paths advance with a phase shift of <NUM>° in terms of the rotation of the rotor <NUM>. Thus, when seeking to always obtain the advantageous effect by smaller interference in one of the two lines of transport paths, it is only necessary to make interference small in a range of one turn of the rotor <NUM> from each end portion of the transport path within the stator <NUM>. When seeking to always obtain the advantageous effect by smaller interference both in the two lines of transport paths, it is necessary to make interference small in a range of one to two turns of the rotor <NUM> from each end portion of the transport path within the stator <NUM>.

A purpose of the smaller interference at the inlet portion of the stator <NUM> is to ensure that the liquid material is sufficiently supplied to the inlet of the transport path. In order to achieve this purpose, it is sufficient to make interference small in a range of one turn of the rotor <NUM> or more from the inlet-side end portion of the stator <NUM>, preferably, <NUM> turns of the rotor <NUM> or more from the inlet-side end portion, and more preferably, <NUM> turns of the rotor <NUM> or more from the inlet-side end portion.

On the other hand, a purpose of the smaller interference at the outlet portion of the stator <NUM> is to ensure that the liquid material within the cavities can smoothly move to the nozzle member <NUM>. In order to achieve this purpose, it is sufficient to always obtain the advantageous effect by smaller interference in one of the two lines of transport paths, and thus it is sufficient to make interference small in the range of one turn of the rotor <NUM> from the outlet-side end portion of the stator <NUM>. Smaller interference within such a range can prevent pulsation.

The functional advantage by smaller interference works within a range where the rotor <NUM> and the stator <NUM> are in tight contact with each other. For example, when the insertion hole <NUM> includes a range where the rotor <NUM> and the stator <NUM> are not in contact with each other at all times (non-transport action zone) due to chamfered parts or the like, the rest near the center (transport action zone) other than that range is subject to the advantage.

The rotor <NUM> in this device is two turns long at the shortest. Here, in order to surely transport the liquid material in the central portion of the transport path, a range of the longitudinally central portion of the stator <NUM> is preferably two turns of the rotor or more. Furthermore, the whole stator <NUM> and the whole rotor <NUM> are preferably four turns long or more, and more preferably, <NUM> turns long or more in consideration of manufacturing tolerance of an elastic body. From another viewpoint, the range of the longitudinally central portion of the stator <NUM> is preferably longer than any of the ranges of the inlet portion and the outlet portion of the stator <NUM>. Then, in order to obtain the advantageous effect of the present invention, when the length (range) of the central portion of the stator <NUM> is the shortest, the ratio of inlet portion : central portion : outlet portion is <NUM>:<NUM>:<NUM>, and the proportion of the central portion may be two or more. From a viewpoint where the range of the inlet portion is preferably longer than the range of the outlet portion, when the length of the central portion of the stator <NUM> is the shortest, the ratio of inlet portion : central portion : outlet portion = <NUM>:<NUM>:<NUM>, and the proportion of the central portion may be five or more.

From another viewpoint, it is disclosed that a ratio of the longitudinal range of the inlet portion of the stator <NUM> to the longitudinal range of the central portion is within <NUM>:<NUM> to <NUM>:<NUM>, and a ratio of the longitudinal range of the outlet portion to the central portion of the stator <NUM> is within <NUM>:<NUM> to <NUM>:<NUM>. Again, the longitudinal range of the inlet portion of the stator <NUM> is preferably longer than the longitudinal range of the outlet portion of the stator <NUM>.

In addition, in the first embodiment, amounts of interference near both of the end portions of the stator <NUM> decrease stepwise (in other words, gradually) toward the end portions. In the example of <FIG>, assuming that there are three segments along the longitudinal direction in the inlet portion (or outlet portion) of the stator <NUM>, an amount of interference at the inlet position B<NUM> (or outlet position B<NUM>) is the smallest, and an amount of interference at the midpoint position B<NUM> of the inlet portion (or midpoint position B<NUM> of the outlet portion) is the second smallest. When there is such a variation in the amount of interference, the amount of interference can be said to decrease stepwise. However, the concept of decreasing an amount of interference stepwise (in other words, gradually) in the present invention is not limited to the illustrated mode. The present invention also includes a mode where an amount of interference decreases steplessly or unevenly stepwise at the inlet portion and the outlet portion of the stator <NUM>.

As described above, in the first embodiment, the interference S<NUM>, S<NUM> is smaller near both of the end portions of the stator <NUM> than at the central portion so that the contact force can be smaller near both of the end portions of the stator <NUM> than at the central portion. Therefore, the problem of pulsation can be solved. Accordingly, mounting the liquid-material discharge device <NUM> of the present embodiment on an application device including a relative movement device makes it possible to draw a line with a uniform width on a work surface. The relative movement device, which includes, for example, a known XYZ-axis servomotor and ball screw, allows the discharge port of the liquid-material discharge device <NUM> to move toward any position on a work at any speed.

<FIG> illustrates explanatory views of an outer cylinder <NUM>, a stator <NUM>, and a rotor <NUM> according to a second embodiment. (a) is a side sectional view when the rotor <NUM> is at its highest position (<NUM>°), (b) is a back view, (c) is a B-B sectional view of (a), (d) is a C-C sectional view of (a), (e) is a side sectional view of the outer cylinder <NUM> only, and (f) is a back view of the outer cylinder <NUM>. It should be noted that, in the second embodiment, components other than the outer cylinder <NUM> and the stator <NUM> are similar to those of the first embodiment, and thus will not be described.

As illustrated in <FIG>, an inner diameter of the outer cylinder <NUM> of the present embodiment gets gradually larger near both of the end portions than at the central portion. The outer cylinder <NUM> includes an inlet-side inner periphery 210a that has a tapered shape of which diameter increases toward the inlet, an outlet-side inner periphery 210b that has a tapered shape of which diameter increases toward the outlet, and a central portion inner periphery 210c that forms a cylindrical space of which diameter is constant through the longitudinal direction. In this way, the inner periphery of the outer cylinder <NUM> is beveled such that the diameter increases from the central portion toward the inlet and the outlet, and forms truncated-cone-shaped spaces at an upstream end portion and a downstream end portion. That is, the diameter of the outer cylinder <NUM> of the second embodiment increases stepwise (in other words, gradually) at positions corresponding to the inlet portion and the outlet portion of an insertion hole <NUM>. Here, the concept of increasing a diameter stepwise (in other words, gradually) is not limited to the mode where the diameter increases steplessly as illustrated in <FIG>. The present invention also includes a mode where it decreases unevenly stepwise.

As illustrated in <FIG>, when the rotor <NUM> is at its highest position, a transport space 221c is formed below the rotor <NUM> at a B-B line position. When the rotor <NUM> rotates from the illustrated position, while a sectional area of the transport space 221c below the rotor <NUM> shrinks, a transport space 222c (not shown) is created above the rotor <NUM> and a sectional area thereof further expands along with the rotation of the rotor <NUM>. As illustrated in <FIG>, when the rotor <NUM> is at its highest position, a transport space 221a having the maximum opening area is formed below the rotor <NUM> at the most upstream point. When the rotor <NUM> rotates from the illustrated position, a transport space 222a (not shown) that functions as the inlet of the transport path is dynamically formed above the rotor <NUM>, and the opening area of the transport space 221a shrinks.

As illustrated in <FIG>, transport spaces <NUM>, <NUM> are formed on the right and left sides of the rotor <NUM> at a C-C line position. Here, the transport space <NUM> communicates with the transport space 221c to form a cavity, and the transport space <NUM> communicates with the transport space 222c to form another cavity. When the rotor <NUM> rotates from the illustrated position, a sectional area of one of the transport spaces <NUM>, <NUM> on the right and left sides of the rotor <NUM> shrinks, and a sectional area of the other expands. For example, when the rotor <NUM> rotates from <NUM>° to <NUM>°, the transport space <NUM> is closed and the sectional area of the transport space <NUM> is maximized.

In this way, the rotation of the rotor <NUM> causes repetition of the motion of forming and closing transport spaces of the two lines at opposite positions across the rotor <NUM> in each section (including the B-B section and the C-C section) perpendicular to the flow-path direction of the stator <NUM>, resulting in transportation of the liquid material within the insertion hole <NUM>.

The stator <NUM> made of elastic material is arranged in tight contact with the inner peripheries (210a, 210b, 210c) of the outer cylinder <NUM>. The stator <NUM> is fixed to the stator <NUM> to prevent relative position misalignment between the outer cylinder <NUM> and the stator <NUM> due to rotational movement of the stator <NUM> with respect to the outer cylinder <NUM> caused by the rotating motion of the rotor <NUM>. For example, the outer cylinder <NUM> and the stator <NUM> are adhered to each other. As can be seen from interference S<NUM>, S<NUM> drawn in black in <FIG>, an amount of the interference S<NUM>, S<NUM> is constant over a longitudinally central portion 211c of the stator <NUM> whereas the amount of the interference S<NUM>, S<NUM> gradually decreases at an inlet portion 211a and an outlet portion 211b. In addition, the stator <NUM> is thicker at the inlet portion 211a and the outlet portion 211b than at the longitudinally central portion 211c. Thus, contact force between the rotor <NUM> and the stator <NUM> is much weaker at the inlet portion and the outlet portion than at the central portion. That is, the second embodiment yields a larger difference in the contact force between the longitudinally central portion and the inlet and outlet portions of the stator <NUM> than the first embodiment.

In the present embodiment, the stator <NUM> includes the inlet portion 211a and the outlet portion 211b of which thickness in the radial direction increases gradually (stepwise) toward the end portions, and thus the contact force between the rotor <NUM> and the stator <NUM> diminishes gradually (stepwise) toward the end portions. Note that the mode where the outer cylinder <NUM> is thinner in the radial direction at both of the end portions than at the central portion is not limited to the mode of the second embodiment. For example, the thickness of the outer cylinder <NUM> in the radial direction may decrease from the central portion toward the upstream end portion and the downstream end portion so as to draw a parabolic round shape, or may decrease in steps.

In the second embodiment as described above, the interference S<NUM>, S<NUM> is smaller near both of the end portions (at the inlet portion and the outlet portion) of the stator <NUM> than at the central portion, and the contact force between the rotor <NUM> and the stator <NUM> is weaker at the inlet portion and the outlet portion of the insertion hole <NUM> than at the central portion. Therefore, the problem of pulsation can be solved. Accordingly, mounting the liquid-material discharge device <NUM> of the present embodiment on an application device including a relative movement device makes it possible to draw a line with a uniform width on a work surface.

In addition, the inner diameter of the outer cylinder <NUM> at both of the end portions is made larger than that at the central portion so that the diameter of the stator <NUM> at the inlet portion 211a and the outlet portion 211b smoothly increases, which results in gradual (stepwise) increase in the thickness in the radial direction toward the end portions. Therefore, it is possible to smoothly accept the liquid material into the inlet of the stator <NUM> and to smoothly exhaust the liquid material from the outlet.

<FIG> illustrates explanatory views of an outer cylinder <NUM>, a stator <NUM>, and a rotor <NUM> according to a third embodiment. (a) is a side sectional view when the rotor <NUM> is at its highest position (<NUM>°), (b) is a back view, (c) is a B-B sectional view of (a), (d) is a C-C sectional view of (a), (e) is a side sectional view of the outer cylinder <NUM> only, and (f) is a back view of the outer cylinder <NUM>. It should be noted that, in the third embodiment, components other than the outer cylinder <NUM> and the stator <NUM> are similar to those of the first embodiment, and thus will not be described.

As illustrated in <FIG>, the outer cylinder <NUM> of the present embodiment includes an inlet-side inner periphery 310a that has a tapered shape of which diameter increases toward the inlet, an outlet-side inner periphery 310b that has a tapered shape of which diameter increases toward the outlet, and a central portion inner periphery 310c having a female-screw-shaped inner periphery with the same pitch as a female screw shape of an inner periphery of the stator <NUM>. The outer cylinder <NUM> is the same as the second embodiment in that it has truncated-cone-shaped spaces at the upstream end portion and the downstream end portion, but is different in that the central portion inner periphery 310c has a female screw shape.

The inner periphery of the central portion of the stator <NUM> has a female screw shape with the same pitch as the rotor <NUM>, and an outer periphery of the central portion of the stator <NUM> has a male screw shape with the same pitch as the inner periphery. The stator <NUM> made of elastic material is arranged in tight contact with the inner peripheries (310a, 310b, 310c) of the outer cylinder <NUM>.

In the third embodiment, the central portion inner periphery 310c of the outer cylinder has a female screw shape with the same pitch as the female screw shape of the inner periphery of the central portion of the stator <NUM> so that the thickness of the longitudinally central portion of the stator <NUM> can be uniform. Therefore, contact force with the rotor <NUM> can be uniform over the central portion. When the stator <NUM> and the rotor <NUM> form a transport path in cooperation, a trajectory along which the rotor <NUM> operates is affected by repulsive force generated in elastic deformation of the stator <NUM>. However, this repulsive force is constant all around a contact surface with the rotor <NUM> within the range of the central portion inner periphery 310c. Therefore, in the third embodiment, the trajectory along which the rotor <NUM> operates is steady, resulting in stable construction of the transport path. In other words, in the third embodiment, a posture of the rotor <NUM> is stable all around, which results in a constant shape of cavities.

As illustrated in <FIG>, when the rotor <NUM> is at its highest position, a transport space 321a having the maximum opening area is formed below the rotor <NUM> at the most upstream point. When the rotor <NUM> rotates from the illustrated position, a transport space 322a (not shown) is dynamically formed above the rotor <NUM> at the most upstream point, and the opening area of the transport space 321a shrinks.

As illustrated in <FIG>, a transport space 321c is formed below the rotor <NUM> at a B-B line position. When the rotor <NUM> rotates from the illustrated position, while a sectional area of the transport space 321c below the rotor <NUM> shrinks, a transport space 322c (not shown) is created above the rotor <NUM> and a sectional area thereof further expands along with the rotation of the rotor <NUM>.

As illustrated in <FIG>, transport spaces <NUM>, <NUM> are formed on the right and left sides of the rotor <NUM> at a C-C line position. Here, the transport space <NUM> communicates with the transport space 321c to form a cavity, and the transport space <NUM> communicates with the transport space 322c to form another cavity. When the rotor <NUM> rotates from the illustrated position, a sectional area of one of the transport spaces <NUM>, <NUM> on the right and left sides of the rotor <NUM> shrinks, and a sectional area of the other expands. For example, when the rotor <NUM> rotates from <NUM>° to <NUM>°, the transport space <NUM> is closed and the sectional area of the transport space <NUM> is maximized.

As can be seen from an amount of interference S<NUM>, S<NUM> drawn in black in <FIG>, the amount of the interference S<NUM>, S<NUM> is smaller at an inlet portion 311a and an outlet portion 311b than at a central portion 311c of the stator <NUM>. Thus, the adjustment of the amount of interference also causes the contact force with the rotor <NUM> to be smaller at the inlet portion and the outlet portion of the stator <NUM> than at the central portion.

In addition, as illustrated in <FIG>, the thickness in the radial direction at the central portion 311c of the stator <NUM> is thinner than that at the central portion 211c of the stator <NUM> of the second embodiment. Therefore, the third embodiment yields a larger difference in the contact force with the rotor <NUM> between the longitudinally central portion and the inlet and outlet portions of the stator <NUM> than the second embodiment.

Also in the third embodiment as described above, the contact force with the rotor <NUM> is weaker at the inlet portion and the outlet portion of the stator <NUM> than at the longitudinally central portion. Therefore, the problem of pulsation can be solved. Accordingly, mounting the liquid-material discharge device <NUM> of the present embodiment on an application device including a relative movement device makes it possible to draw a line with a uniform width on a work surface. In addition, it is possible to arrange the difference in the contact force between the longitudinally central portion and the inlet and outlet portions of the stator <NUM> to be larger than that of the second embodiment.

<FIG> illustrates explanatory views of an outer cylinder <NUM>, a stator <NUM>, and a rotor <NUM> according to a fourth embodiment. (a) is a side sectional view when the rotor <NUM> is at its highest position (<NUM>°), (b) is a back view, (c) is a B-B sectional view of (a), (d) is a C-C sectional view of (a), (e) is a side sectional view of the outer cylinder <NUM> only, and (f) is a back view of the outer cylinder <NUM>. It should be noted that, in the fourth embodiment, components other than the outer cylinder <NUM> and the stator <NUM> are similar to those of the first embodiment, and thus will not be described.

As illustrated in <FIG>, the outer cylinder <NUM> of the present embodiment includes an inlet-side inner periphery 410a that has a tapered shape of which diameter increases toward the inlet, an outlet-side inner periphery 410b that has a tapered shape of which diameter increases toward the outlet, and a central portion inner periphery 410c having a female-screw-shaped inner periphery with substantially the same pitch as a female screw shape of an inner periphery of the stator <NUM>. The outer cylinder <NUM> includes the central portion inner periphery 410c having a female screw shape with edges and is thus different from the outer cylinder <NUM> of the third embodiment having a smooth female screw shape with no edges.

The inner periphery of the central portion of the stator <NUM> has a female screw shape with the same pitch as the rotor <NUM>, and an outer periphery of the central portion of the stator <NUM> has a male screw shape having edges with substantially the same pitch as the inner periphery. The stator <NUM> made of elastic material is arranged in tight contact with the inner peripheries (410a, 410b, 410c) of the outer cylinder <NUM>. As can be seen from interference S<NUM>, S<NUM> drawn in black in <FIG>, an amount of the interference S<NUM>, S<NUM> is constant over a central portion 411c of the stator <NUM> whereas the amount of the interference S<NUM>, S<NUM> gradually decreases at an inlet portion 411a and an outlet portion 411b. Thus, the adjustment of the amount of interference also causes contact force with the rotor <NUM> to be smaller at the inlet portion and the outlet portion of the stator <NUM> than at the central portion.

As illustrated in <FIG>, when the rotor <NUM> is at its highest position, a transport space 421a having the maximum opening area is formed below the rotor <NUM> at the most upstream point.

In addition, as illustrated in <FIG>, the thickness in the radial direction at the central portion 411c of the stator <NUM> is thinner than that at the central portion 211c of the stator <NUM> of the second embodiment. Therefore, the difference in the contact force with the rotor <NUM> between the longitudinally central portion and the inlet and outlet portions of the stator <NUM> is larger than that of the second embodiment.

Also in the fourth embodiment as described above, the contact force with the rotor <NUM> is weaker at the inlet portion and the outlet portion of the stator <NUM> than at the central portion. Therefore, the problem of pulsation can be solved. Accordingly, mounting the liquid-material discharge device <NUM> of the present embodiment on an application device including a relative movement device makes it possible to draw a line with a uniform width on a work surface. Compared to the outer cylinder <NUM> of the third embodiment, the shape of the outer cylinder <NUM> of the fourth embodiment imposes fewer restrictions on cutting work to form it. Therefore, manufacturing cost can be reduced.

<FIG> illustrates explanatory views of an outer cylinder <NUM>, a stator <NUM>, and a rotor <NUM> according to a fifth embodiment. (a) is a side sectional view when the rotor <NUM> is at its highest position (<NUM>°), (b) is a back view, (c) is a B-B sectional view of (a), (d) is a C-C sectional view of (a), (e) is a side sectional view of the outer cylinder <NUM> only, and (f) is a back view of the outer cylinder <NUM>. It should be noted that, in the fifth embodiment, components other than the outer cylinder <NUM> and the stator <NUM> are similar to those of the first embodiment, and thus will not be described.

As illustrated in <FIG>, the outer cylinder <NUM> of the present embodiment includes an upstream end portion inner periphery 510a that forms a cylindrical space of which diameter is constant through the longitudinal direction, a downstream end portion inner periphery 510b that forms a cylindrical space of which diameter is constant through the longitudinal direction, a central portion inner periphery 510c that forms a cylindrical space of which diameter is constant through the longitudinal direction, an inlet-side tapered surface 510d, and an outlet-side tapered surface 510e. An inner periphery of the stator <NUM> has a female screw shape with the same pitch as the rotor <NUM>, and an outer periphery of the stator <NUM> has the same shape as the inner peripheries of the outer cylinder <NUM>. The stator <NUM> made of elastic material is arranged in tight contact with the inner peripheries (510a to 510e) of the outer cylinder <NUM>.

As illustrated in <FIG>, when the rotor <NUM> is at its highest position, a transport space 521a having the maximum opening area is formed below the rotor <NUM> at the most upstream point.

In the outer cylinder <NUM> of the present embodiment, the upstream end portion inner periphery 510a and the downstream end portion inner periphery 510b have a cylindrical shape that is larger in diameter than the central portion inner periphery 510c so that contact force with the rotor <NUM> can be relatively weak over respective certain ranges from the inlet and the outlet of the stator <NUM>. Here, the upstream end portion inner periphery 510a of the outer cylinder is formed preferably over a length of one to two turns of the rotor <NUM> from the inlet-side end portion of the stator <NUM>, and the downstream end portion inner periphery 510b is formed preferably over a length of one turn of the rotor <NUM> from the outlet-side end portion of the stator <NUM>.

In addition, in the outer cylinder <NUM> of the present embodiment, a longitudinal range (length) of the upstream end portion inner periphery 510a is longer than a longitudinal range (length) of the downstream end portion inner periphery 510b so that the liquid material can be smoothly accepted into a transport path formed within an insertion hole <NUM>. In more detail, the length of the upstream end portion inner periphery 510a of the outer cylinder is preferably one turn of the rotor <NUM> or more from the inlet-side end portion. Furthermore, it is more preferable to allow the contact force to be weak within a range of <NUM> turns of the rotor <NUM> in order to allow the contact force to be sufficiently weak without being affected by manufacturing tolerance or the like. The relatively long inlet portion of the transport path formed within the insertion hole <NUM> is effective for accepting sufficient liquid material and preventing pulsation.

In the outer cylinder <NUM> of the present embodiment, the thickness of the stator <NUM> in the radial direction increases gradually toward both of the end portions due to the inlet-side tapered surface 510d of which diameter increases toward the inlet and the outlet-side tapered surface 510e of which diameter increases toward the outlet, which also causes the contact force between the rotor <NUM> and the stator <NUM> to diminish gradually (stepwise) toward both of the end portions. A range of an inlet portion 511a of the stator <NUM> of the fifth embodiment corresponds to the upstream end portion inner periphery 510a and the inlet-side tapered surface 510d of the outer cylinder. A range of an outlet portion 511b of the stator <NUM> of the fifth embodiment corresponds to the downstream end portion inner periphery 510b and the outlet-side tapered surface 510e of the outer cylinder, and is shorter than that of the inlet portion 511a of the stator <NUM>. Pulsation can also be prevented in the mode according to the fifth embodiment where the contact force by the rotor <NUM> gradually (stepwise) diminishes on a boundary between the central portion and the inlet portion (or the outlet portion) of the stator <NUM>, and the contact force by the rotor <NUM> is constant in a place closer to the inlet (or the outlet) than the boundary. That is, the technical idea of decreasing the contact force by the rotor <NUM> gradually (stepwise) from the longitudinally central portion of the stator <NUM> toward the outlet and the inlet also encompasses the mode according to the fifth embodiment where the tapered surfaces not adjacent to the outlet and the inlet are provided to inner peripheries of the outer cylinder <NUM>.

As can be seen from interference S<NUM>, S<NUM> drawn in black in <FIG>, an amount of the interference S<NUM>, S<NUM> is smaller at the inlet portion 511a and the outlet portion 511b than at a central portion 511c of the stator <NUM> where the amount of the interference S<NUM>, S<NUM> is constant. Thus, the adjustment of the amount of interference also causes the contact force with the rotor <NUM> to be smaller at the inlet portion and the outlet portion of the stator <NUM>.

Also in the fifth embodiment as described above, the contact force with the rotor <NUM> is weaker at the inlet portion and the outlet portion of the stator <NUM> than at the longitudinally central portion. Therefore, the problem of pulsation can be solved. Accordingly, mounting the liquid-material discharge device <NUM> of the present embodiment on an application device including a relative movement device makes it possible to draw a line with a uniform width on a work surface. In addition, a range of the increased inner periphery diameter of the inlet portion of the outer cylinder <NUM> is longer than those of the second to fourth embodiments so that the contact force at the inlet portion of the insertion hole <NUM> can diminish within the longer range and the liquid material can be further smoothly accepted into the transport path formed within the insertion hole <NUM>. Such an arrangement where the range of the inlet portion of the stator <NUM> with the increased inner periphery diameter is longer than that of the outlet portion can also be combined with and applied to the examples in the third and fourth embodiments.

<FIG> illustrates explanatory views of an outer cylinder <NUM>, a stator <NUM>, and a rotor <NUM> according to a sixth embodiment. (a) is a side sectional view when the rotor <NUM> is at its highest position (<NUM>°), (b) is an A-A sectional view of (a), (c) is a B-B sectional view of (a), (d) is a C-C sectional view of (a), and (e) is a back view with the rotor <NUM> omitted. It should be noted that, in the sixth embodiment, components other than the outer cylinder <NUM> and the stator <NUM> are similar to those of the first embodiment, and thus will not be described.

As illustrated in <FIG>, the outer cylinder <NUM> of the present embodiment includes an upstream end portion inner periphery 610a that forms a cylindrical space of which diameter is constant through the longitudinal direction, a downstream end portion inner periphery 610b that forms a cylindrical space of which diameter is constant through the longitudinal direction, a central portion inner periphery 610c that forms a cylindrical space of which diameter is constant through the longitudinal direction, an inlet-side tapered surface 610d, and an outlet-side tapered surface 610e. An inner periphery of the stator <NUM> has a female screw shape with the same pitch as the rotor <NUM>, and an outer periphery of the stator <NUM> has the same shape as the inner peripheries of the outer cylinder <NUM>. The stator <NUM> made of elastic material is arranged in tight contact with the inner peripheries (610a to 610e) of the outer cylinder <NUM>.

In the outer cylinder <NUM> of the present embodiment, the upstream end portion inner periphery 610a and the downstream end portion inner periphery 610b have a cylindrical shape that is larger in diameter than the central portion inner periphery 610c so that contact force with the rotor <NUM> can be relatively weak over respective certain ranges from the inlet and the outlet of the stator <NUM>.

In addition, in the outer cylinder <NUM> of the present embodiment, as in the fifth embodiment, a longitudinal range (length) of the upstream end portion inner periphery 610a of the outer cylinder is longer than a range (length) of the downstream end portion inner periphery 610b so that the liquid material can be smoothly accepted into a transport path formed within an insertion hole <NUM>, and pulsation can thereby be effectively prevented.

In the present embodiment, an acceptance space 621a is provided adjacent to the inlet portion of the stator <NUM>. An inner diameter of the acceptance space 621a is sized such that the stator <NUM> is not in contact with the rotor <NUM> rotating in the acceptance space 621a. In the acceptance space 621a, the inner periphery of the stator <NUM> is not in contact with the rotor <NUM> at all times. Thus, the acceptance space 621a is a non-transport action zone that does not exert an action of transferring the liquid material. That is, the insertion hole <NUM> of the stator <NUM> of the present embodiment is divided into a transport action zone and the non-transport action zone. A boundary between the transport action zone and the non-transport action zone in the insertion hole <NUM> is located at the most upstream position in the range where the rotor <NUM> is in contact with the stator <NUM>, and is denoted with reference symbol 612a in <FIG>. The place indicated by reference symbol 612a is a start position of the transport path, and is an inlet of the transport path. A downstream side from reference symbol 612a is the transport path that exerts the liquid-material transport action. This transport path is a flow path that appears by inserting the rotor <NUM> having a male-screw-shaped outer periphery into the insertion hole <NUM>, and eccentric rotation of the rotor <NUM> within the insertion hole <NUM> leads to movement of cavities sequentially formed within the transport path and transfer of the liquid material filling the cavities. The acceptance space 621a, which is a space adjacent to the inlet of the transport path, increases in diameter toward an upstream side from the inlet of the transport path.

As illustrated in <FIG>, there is a gap between the inner periphery of the stator <NUM> forming the acceptance space 621a and the outer periphery of the rotor <NUM>. From another viewpoint, an inner diameter of the insertion hole <NUM> of the stator <NUM> is the largest at a most-upstream-side end portion. Furthermore, the acceptance space 621a has a smaller capacity than any cavity formed within the insertion hole <NUM> downstream of the acceptance space 621a.

In the present embodiment, the thickness of the stator <NUM> in the radial direction increases gradually toward the end portions due to the inlet-side tapered surface 610d of the outer cylinder of which diameter increases toward the inlet and the outlet-side tapered surface 610e of which diameter increases toward the outlet, which also causes the contact force between the rotor <NUM> and the stator <NUM> to diminish gradually (stepwise) toward the end portions. Furthermore, in the present embodiment, the contact force between the stator <NUM> and the rotor <NUM> is zero on the upstream side from the inlet of the transport path.

A range of an inlet portion 611a of the stator <NUM> of the present embodiment corresponds to the upstream end portion inner periphery 610a and the inlet-side tapered surface 610d of the outer cylinder <NUM> in the transport action zone, and does not include the non-transport action zone.

A range of an outlet portion 611b of the stator <NUM> of the present embodiment corresponds to the downstream end portion inner periphery 610b and the outlet-side tapered surface 610e of the outer cylinder <NUM>, and is shorter than the inlet portion 611a of the stator <NUM>. The stator <NUM> of the present embodiment does not have a non-transport action zone at the outlet portion 611b, but if it includes a non-transport action zone at the outlet portion, the outlet portion does not include this non-transport action zone.

A length of a longitudinally central portion 611c of the stator <NUM> of the present embodiment is at least twice the length of the inlet portion of the stator <NUM>.

In the stator <NUM> of the present embodiment, the amount of interference is constant at the longitudinally central portion, but decreases gradually (stepwise) from a boundary with the central portion toward the boundary 612a with the acceptance space. Furthermore, in the stator <NUM>, the amount of interference decreases gradually (stepwise) from another boundary with the longitudinally central portion toward the outlet. The thickness of the stator <NUM> in the radial direction is thick at the inlet portion 611a and the outlet portion 611b also due to the increased inner diameter of the upstream end portion inner periphery 610a and the downstream end portion inner periphery 610b of the outer cylinder <NUM>. Therefore, the contact force at the inlet portion and the outlet portion of the insertion hole <NUM> gradually (stepwise) diminishes. In addition, the inner periphery of the stator <NUM> is provided with the tapered surface of which diameter increases toward the upstream side to form the acceptance space 621a near the inlet of the insertion hole <NUM> so that a sufficient amount of the liquid material can be supplied to always fill cavities formed within the insertion hole <NUM>.

In the sixth embodiment as described above, the contact force between the rotor <NUM> and the stator <NUM> is weaker at the inlet portion and the outlet portion of the insertion hole <NUM> than at the central portion, and the acceptance space 621a with the increased diameter is further provided near the inlet for smooth inflow of the liquid material. Therefore, the problem of pulsation can be solved. Accordingly, mounting the liquid-material discharge device <NUM> of the present embodiment on an application device including a relative movement device makes it possible to draw a line with a uniform width on a work surface. It should be noted that, in the present embodiment, the non-transport action zone is provided only at the inlet portion of the insertion hole <NUM>, but the non-transport action zone may also be provided at the outlet portion of the insertion hole <NUM>.

The preferred embodiments of the present invention have been described above. However, the technical scope of the present invention is not limited to the description of the above embodiments. Various alterations and modifications can be applied without departing from the technical idea of the present invention, and such altered or modified modes also fall within the technical scope of the present invention.

For example, in each figure of the above embodiments <NUM> to <NUM>, both of the inner periphery diameters of the upstream end portion and the downstream end portion of the outer cylinder are the same. However, the technical scope of the present invention also includes a mode where the inner periphery diameters of the upstream end portion and the downstream end portion of the outer cylinder are different, and a mode where taper angles thereof are different.

In addition, in the above embodiments <NUM> to <NUM>, for example, the capacity of a transport space at the inlet portion and/or the outlet portion of the insertion hole (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) may be larger than the capacity of the transport space at the longitudinally central portion of the insertion hole (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>). Such a configuration allows the liquid material that has moved in the transport space within the insertion hole to be exhausted in a flow with less pulsation.

Furthermore, in the above embodiments <NUM> to <NUM>, for example, the rotor (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) may be thicker at the longitudinally central portion than at the inlet portion and the outlet portion. Such a configuration allows, even when the inner diameter of the insertion hole of the stator is constant from the inlet to the outlet, the contact force between the rotor and the stator at the inlet portion and the outlet portion of the insertion hole to be smaller than the contact force between the rotor and the stator at the longitudinally central portion of the insertion hole.

Furthermore, in the above embodiments <NUM> to <NUM>, for example, the elasticity of the stator per unit volume at the longitudinally central portion may be larger than the elasticity per unit volume at the inlet portion and/or the outlet portion. As a concrete example, it is disclosed that the longitudinally central portion of the stator is constituted of an elastic body (for example, rubber) that is denser than an elastic body constituting the inlet portion and/or the outlet portion.

Furthermore, the liquid-material discharge device of the above embodiments <NUM> to <NUM> can be used not only for the purpose of applying a liquid material but also as a liquid feed pump of a circulation circuit or the like. It can also be used as a suction pump by rotating the rotor inversely with the above embodiments <NUM> to <NUM>.

It is also possible to combine the above embodiments <NUM> to <NUM> to solve the problem to be solved by the invention. That is, it is possible to adopt any one of solutions of the above embodiments <NUM> to <NUM> at the inlet portion of the insertion hole (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>), and any one of solutions of the above embodiments <NUM> to <NUM> that is different from the inlet portion at the outlet portion of the insertion hole (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>). For example, the following combination is also possible.

Claim 1:
A fluid transfer device (<NUM>) comprising:
an outer cylinder (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>);
a stator (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) that has an insertion hole (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) as a female-screw-shaped through-hole and is provided on an inner periphery of the outer cylinder (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>); and
a male-screw-shaped rotor (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) that is connected to a rotor driving part and eccentrically rotates in contact with an inner periphery of the stator (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>),
wherein the fluid transfer device (<NUM>) is capable of transferring a fluid in a transport path formed by the stator (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) and the rotor (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>), by eccentrically rotating the rotor (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) inserted through the insertion hole (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>),
wherein the stator (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) includes an inlet portion that spans a certain range through a longitudinal direction from an inlet of the transport path, an outlet portion that spans a certain range through the longitudinal direction from an outlet of the transport path, and a central portion located between the inlet portion and the outlet portion,
characterized in that
the stator (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) is subject to smaller contact force by the rotor (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) at the inlet portion and the outlet portion than contact force by the rotor (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) at the central portion.