Patent Description:
A vane motor is a mechanical actuator that converts hydraulic pressure into rotation power. <FIG> shows one example of a vane motor according to the related art.

Referring to <FIG>, a rotor is rotatably installed in a casing <NUM>. The casing <NUM> is provided with a fluid inlet <NUM> through which a fluid for generating pressure flows in, and a fluid outlet through which the fluid flows out. If the pressurized fluid flows in through the fluid inlet, the pressurized fluid acts on vanes <NUM> each of which spreads toward the outside of the rotor, and has a variable length. Accordingly, the vanes <NUM> are moving to the pressurized direction, the rotor turns within the casing <NUM>. If the pressurized fluid for applying the pressure to the vanes <NUM> arrives at the fluid outlet <NUM> of the casing, the fluid is discharged through the fluid outlet <NUM> which is a low pressure side.

Specifically, if the pressurized fluid flowing in through the fluid inlet arrives at the fluid outlet which is the low pressure side, the fluid is discharged through the fluid outlet, and thus the pressurized fluid applies the pressure to the vanes in the path to turn the rotor.

The vanes <NUM> are engaged to a rotor body <NUM>, and the length of the respective vanes protruding from the rotor body <NUM> is variable. For the variable feature, the vanes <NUM> are inserted in grooves 231a formed on an outer peripheral surface of the rotor body <NUM>, and are able to move in a longitudinal direction of the groove. Since a gap between the inner wall surface of the casing <NUM> and a rotational shaft <NUM> of the rotor body <NUM> is varied according to a position of the inner wall surface of the casing, the vane <NUM> moves out from the groove 231a of the rotor body <NUM> at the wide gap to increase a protruding length of the vane <NUM>, while the vane <NUM> moves in the groove of the rotor body at the narrow gap to decrease the protruding length of vane.

A resilient member, such as a spring, may be provided between a bottom portion of the rotor groove <NUM> and the vane <NUM> so that the vane can smoothly move in or out from the groove of the rotor body <NUM>. Otherwise, since the vane can slide out from the groove by a centrifugal force of the rotor, a separate spring may not be provided.

At the narrow gap in which the gap between the rotor body <NUM> and the inner wall surface of the casing becomes narrow, when the rotor body <NUM> turns, a distal end of the vane <NUM> is pressurized so that the vane moves in the groove 231a while contacting against the inner wall surface.

However, the vane motor of the related art has problems in that if the gap between the distal end of the vane <NUM> and the inner wall surface of the casing <NUM> is too wide, the fluid leaks through the gap to lead to a loss of pressure, and in that if the gap is too narrow, friction between the vane and the inner wall surface of the casing is increased, so that a lot of energy generated by the pressurized fluid is significantly lost, and thus maintenance costs are increased due to abrasion of the vanes and the inner wall surface. These problems are in a trade-off relation and cannot be completely solved in the vane motor of the prior art. Therefore, for vane motors of various materials and sizes, a proper size of the gap should be acquired on an experimental basis to increase the efficiency and the durability of each vane motor.

In order to increase the rotational force of the rotor by use of the pressurized fluid, the total amount of the force of the fluid acting on the vane should be increased. Since the total amount of the force is equal to the result obtained by multiplying the pressure, which is a force acting on a unit area, by an area of the inner wall surface, to which the pressure is applied, it is necessary to increase the area of the inner wall surface, with which the fluid and the vanes come into contact.

However, if the vane moves out too far from the groove, the vane may be completely released from the groove, or the vane may be vibrated or be in an unstable state while producing the friction between the vane and the inner wall surface of the casing. Therefore, the vane motor should be designed to increase the contact area with the fluid within a limit to keep the connection between the vanes and the rotor in stable.

Therefore, in further prior art, improvements have been made in view of the above problems included in a vane motor of the related art-.

The imaginary rotational axis of the inner liner and the rotational shaft of the rotor can be maintained at constant positions. The vane motor includes a rolling member which, when the inner liner is rotated in the casing, is interposed between an outer surface of the inner liner and the inner wall surface of the casing to reduce friction therebetween.

Similar configurations are known in relation with vane pumps, see <CIT> and <CIT>.

It is an object of the invention to provide a vane motor having configuration capable of improving efficiency.

This object is achieved by the features of claim <NUM>.

In the present invention, the casing is configured in such a way that both ends of an outer liner of a cylindrical shape larger than the inner liner are closed by disc-shaped finish plates.

According to the invention, there is a fine gap between the finish plates and other components like the inner liner, the vanes in axial (longitudinal) direction, so that the components are able to slide with the finish plates, but the pressurized fluid is hardly leaked through the gap.

At least one of the finish plates is provided with a fluid inlet and a fluid outlet. The fluid inlet and the fluid outlet are formed in such a way that at least a portion of the fluid inlet and at least a portion of the fluid outlet is overlapped with a gap or space between the inner liner and the rotor body, when seen in an axial direction, and the fluid inlet and the fluid outlet are extended in an arc shape in a circumferential direction.

In the present invention, the inlet port and the outlet port is located in the gap or space between an inner liner of a cylindrical shape and the rotor body, when seen from a cross-sectional view of the rotational shaft, and preferably, in both edges of the opening of the groove formed on the rotor body to receive the vane, enlarged portion through which a rear surface of the vane is more exposed is formed at the rear side edge portion.

The enlarged portion may be provided on both ends thereof in the longitudinal direction. The enlarged portion formed at the portion in which the start portion of the arc-shaped fluid inlet is overlapped.

At least one of the finish plates might be configured in such a way that the rotational shaft pass through and is exposed out of the finish plate to transmit the rotational force, and a bearing is mounted between the rotational shaft and the finish plate.

According to the present invention, the invention changes the structure of the vane motor of the prior art in which when the rotor turns, the distal ends of the vanes contact against the inner wall surface of the casing, so that the inner wall surface of the casing and the vanes are worn out, to increase a frequency of replacement and repair. Since the energy consumed by the abrasion is decreased and is used to generate the rotational force, the energy converting efficiency of the vane motor is improved.

Repeated use of reference characters throughout the present invention and appended drawings is intended to represent the same or analogous features or elements of the invention.

Hereinafter, preferred embodiments of the invention will be explained in detail in conjunction with the accompanying drawings.

Referring to a vane motor according to the embodiment illustrated in <FIG>,
the vane motor <NUM> of this embodiment includes a casing forming an exterior, an inner liner <NUM> of a cylindrical shape, and a rotor positioned in the inner liner <NUM>.

The casing includes a casing body <NUM> formed of a substantially cylindrical shape, and finish plates <NUM> and <NUM> for finishing both ends of the casing body <NUM> in a longitudinal direction. The finish plates <NUM> and <NUM> are respectively provided with rotational shaft mounting holes <NUM> and <NUM>, through which a rotational shaft <NUM> connected to the rotor passes, arc-shaped fluid inlets <NUM> and <NUM>, through which a pressurized fluid comes in from the outside, and arc-shaped fluid outlets <NUM> and <NUM>, through which the pressurized fluid comes out. A bearing <NUM> is installed in the rotational shaft mounting holes <NUM> and <NUM>, so that the rotational shaft <NUM> does not come into direct contact with the finish plates <NUM> and <NUM>, thereby reducing friction between the rotational shaft <NUM> and the finish plates <NUM> and <NUM>.

The inner liner <NUM> is installed in the casing. The length of the inner liner <NUM> is substantially identical to that of the casing body <NUM>, and both ends of the inner liner <NUM> contact against the inner surfaces of the finish plates <NUM> and <NUM> of the casing in a longitudinal direction, with a fine gap between both ends and the inner surfaces. When the inner liner <NUM> turns in the casing, the inner liner produces sliding friction between the inner surfaces of the finish plates <NUM> and <NUM> and the inner liner. The inner liner <NUM> is laid on a plurality of rolling members <NUM> which are disposed on a concave portion <NUM> formed on the inner wall of the casing wall <NUM>, when the inner liner <NUM> is installed in the casing. The rolling member has a roller 19a and a rolling shaft 19b, and the rolling shaft 19b is formed in the shape of a cylinder or a rotational shaft, and is rotatably installed in parallel with the rotational shaft <NUM>. If the inner liner <NUM> turns in the casing body <NUM>, the rolling shaft coming into contact with the outer surface of the inner liner rotates, and thus there is no sliding friction between the turning inner liner <NUM> and the inner surface of the casing body <NUM>.

The rotor is installed in the inner liner <NUM>, and includes a cylindrical rotor body <NUM> having the rotational shaft <NUM>, and a plurality of vanes <NUM> engaged with each groove 31a of the rotor body <NUM>. The length of the cylinder forming the rotor body <NUM> is substantially identical to that of the casing body <NUM>, and when the rotor turns, both ends of the cylinder come into contact with the inner surfaces of the finish plates <NUM> and <NUM> in the state in which a fine gap is therebetween, thereby producing sliding friction between the inner surfaces of the finish plates <NUM> and <NUM> and both ends thereof.

The connecting manner between the rotor body <NUM> and the vane <NUM> may be substantially identical to that of the vane motor of the prior art. Since the operation of the vane <NUM> in the groove 31a is widely known in the art, the detailed description will be omitted herein.

This embodiment is substantially identical to the first embodiment, except that the rotor is not installed to come into directly contact with the inner surface of the casing body <NUM>, but is installed to come into directly contact with the inner surface of the inner liner <NUM>.

The rotational shaft <NUM> of the rotor is parallel with an imaginary rotational axis of the inner liner <NUM>, but is spaced apart from the rotational axis of the inner liner at a distance. The finish plates <NUM> and <NUM> of the casing are respectively provided with a hole through which the rotational shaft <NUM> penetrates. The position of the hole is spaced apart from the rotational axis of the cylinder forming the casing at a distance.

With the above configuration, the rotor disposed in the casing body <NUM> pushes the inner liner <NUM> of the cylindrical shape against the rolling member <NUM> of the casing body <NUM>, so that an imaginary rotational axis of the cylinder forming the casing body is spaced apart from the imaginary rotational axis of the inner liner <NUM> of the cylindrical shape at an interval. The distance between the rotor body <NUM> and the inner wall surface of the inner liner <NUM> is minimized at the position where the rotor pushes the inner liner <NUM>, and thus the vane <NUM> is completely inserted in the groove 31a so that the rotor body <NUM> contacts against the inner liner <NUM>, or a protruding length of the vane <NUM> from the rotor body <NUM> is decreased. At the opposite side (an opposite side on the basis of the rotational shaft), the distance between the rotor body <NUM> and the inner surface of the inner liner <NUM> is maximized, thereby increasing the protruding length of the vane <NUM> from the rotor body <NUM>.

The groove 31a may be formed in various shapes, if necessary, and the vane <NUM> slidably moving in or out along the groove 31a may be provided in a direction perpendicular to a vertical plane of the cylindrical rotor body <NUM>, but protrudes at a desired angle with respect to the vertical plane. In this embodiment, the groove is formed on an outer peripheral surface of the rotor body <NUM> along the entire length thereof in the longitudinal direction, and is slightly sloped at a desired angle with respect to a radial direction pointing along a radius from the rotational shaft <NUM> toward the rotational direction of the rotor. Therefore, the vane protrudes at a desired angle toward the rotational direction with respect to the vertical plane of the rotor body.

The operation of components of the vane motor with the above configuration will now be described. A supplier for supplying the pressurized fluid to the fluid inlets <NUM> and <NUM> of the vane motor from the outside and a collector for receiving the pressurized fluid from the fluid outlets <NUM> and <NUM> may be connected to the vane motor of this embodiment, similar to the first embodiment, but the rotor body <NUM> and the vanes <NUM> of the rotor are not operated in the casing body <NUM>, but is operated in the inner liner <NUM>.

Specifically, explaining the operation of components in the vane motor with the above configuration, the fluid inlet of the vane motor is connected with the supplier (not illustrated) for supplying the pressurized fluid from the outside. Since both of the finish plates <NUM> and <NUM> installed to both sides of the vane motor are provided with the fluid inlets <NUM> and <NUM> and the fluid outlets <NUM> and <NUM>, the supplier is branched at any point to supply the pressurized fluid to both fluid inlets of the finish plates <NUM> and <NUM>. Similarly, the collector is branched at any point to receive the pressurized fluid from both fluid outlets of the finish plates <NUM> and <NUM>, of which the pressure of the fluid used in the vane motor is decreased.

Specifically, if the arc-shaped fluid inlets <NUM> and <NUM> are supplied with the pressurized fluid, the pressurized fluid passing through the arc-shaped fluid inlets of the finish plate flows in the space between the rotor body and the inner wall surface of the inner liner at that position. The pressurized fluid applies the pressure to the vane forming a portion of an interface of the space. If the pressure applied to the rear surface of the vane is higher than that applied to the front surface, the vane moves forward. Since the rotor provided with the vanes is rotatably fixed by the rotational shaft, the rotor does not move in parallel, but is just rotated. The space between the rotor and the inner wall surface of the inner liner <NUM> is gradually increased from the positions of the fluid inlets <NUM> and <NUM>, and the vane <NUM> protrudes at the most from the groove 31a, so that the pressure applied to the vane is gradually increased. Since the arc-shaped fluid outlets <NUM> and <NUM> start to appear next to the position of the maximum gap, the pressurized fluid comes out through the fluid outlets, so that the pressure of the fluid is decreased.

The rotor of this embodiment is rotated by the pressure difference, similar to the rotor of the vane motor according to the prior art, but the inner liner <NUM> of the cylindrical shape forms the space in which the pressurized fluid operates, instead of the casing. Since the inner liner is not stationary, the rotational force is transferred to the inner liner <NUM> of the cylindrical shape which comes into contact with the distal end of the vane <NUM>, due to the friction, when the rotor turns. The inner liner <NUM> is rotated at the nearly equal linear velocity at the position of the distal end of the respective vanes which forms the outermost circumference of the rotor.

The inner liner is rotated in the casing, and the rolling members <NUM>, such as a rolling shaft, are interposed between the inner liner and the casing to reduce the sliding friction between the inner liner and the casing body <NUM>.

As a result, the abrasion caused by the sliding between the vane and the inner wall surface of the inner liner and the energy consumed by the frictional heat are decreased, and thus the efficiency of producing the rotational force by the pressurized fluid is increased.

Of course, since the finish plates <NUM> and <NUM> of the casing are stationary, and the rotor and the inner liner <NUM> of the cylindrical shape which come into contact with the finish plates are rotated, both ends of the inner liner, the rotor body <NUM> and the vanes come into slidable contact with the finish plates to produce the frictional heat and consume the energy. As compared to the prior art, the energy consumed by the friction is decreased. In order to further improve the efficiency, the size and surface of the finish plates, the rotor body and the vane should be maintained, similar to the prior art, and the bearing <NUM> is interposed between the finish plates of the casing and the rotational shafts to reduce the friction.

While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims.

Claim 1:
A vane motor comprising:
a casing including a fluid inlet (<NUM>) and a fluid outlet (<NUM>), through which a pressurized fluid comes in or out;
a rotor being installed in the casing, turning around a rotational shaft (<NUM>) by the pressurized fluid and including a rotor body (<NUM>) which has a substantially cylindrical shape and an axis coinciding with an axis of the rotational shaft (<NUM>) and a plurality of vanes (<NUM>) which is installed in grooves (31a) formed on an outer circumferential surface of the rotor body (<NUM>) and has a portion protruding from the groove and (the portion) having a length varied in accordance with a rotational phase, and
an inner liner (<NUM>) of a cylindrical shape which is installed in the casing and receives the rotor therein, in which a distal end of the vane (<NUM>) comes into contact with an inner wall surface of the inner liner(<NUM>) while the pressurized fluid is retained therein until the pressurized fluid flowing through the fluid inlet (<NUM>, <NUM>) of the casing is discharged from the fluid outlet (<NUM>, <NUM>) of the casing, and an imaginary rotational axis of the inner liner (<NUM>) is spaced apart from a rotational axis of the rotational shaft (<NUM>) in a parallel state, but is able to rotate together with the rotor when the rotor turns,
characterized in that
the casing is configured in such a way that both ends of an outer liner (<NUM>) of a cylindrical shape larger than the inner liner (<NUM>) are closed by disc-shaped finish plates (<NUM>, <NUM>),
there is a fine gap in axial (longitudinal) direction between the finish plates (<NUM>, <NUM>) and the inner liner (<NUM>) and the vanes (<NUM>), so that the inner liner (<NUM>) and the vanes (<NUM>) are able to slide with the finish plates (<NUM>, <NUM>), but the pressurized fluid is hardly leaked through the gap,
at least one of the finish plates (<NUM>, <NUM>) is provided with a fluid inlet (<NUM>, <NUM>) and a fluid outlet (<NUM>, <NUM>),
an enlarged portion (31b) through which a rear (in respect of rotation direction) surface of the vane (<NUM>) is more exposed is formed on at least one (axial) end of a rear (in respect of rotation direction) side edge portion forming the opening of the groove (31a), and wherein
the fluid inlet (<NUM>, <NUM>) is arc-shaped and, at least at a start portion of the arc-shape, is overlapped with the enlarged portion (31b).