Patent Description:
Configurations of a heat pump (refrigerator) employing a Stirling engine type have been conventionally widely known. While a so-called reciprocating heat pump and a rotary heat pump are proposed as the heat pump of this type, it is said that the rotary heat pump is more suited than the reciprocating heat pump since being easier to achieve noise reduction and miniaturization. As recent rotary heat pumps, a rotary heat pump configured as disclosed in <CIT> is proposed.

<CIT> refers to a heat pump device in a compact structure by utilizing the basic constitution of a rotary piston engine and separating a compression section from an expansion section. <CIT> discloses a unitary rotor side-seal member arranged to be coupled to a flank of a rotor of a rotary engine. <CIT> refers to a rotary engine, comprising a stator that includes a bladed heat transfer stator segment comprising an outer surface comprising a plurality of blades creating a flowpath on the outer surface. <CIT> discloses a heat engine which operates generally on the basis of the Carnot cycle and includes a rotor mounted within a chamber and sealed relative to the chamber by means of a plurality of radiating vanes.

As illustrated in <FIG>, a rotary heat pump RHP disclosed in <CIT> employs configurations with two rotary members, i.e., a displacer-side rotary member DR and a power-side rotary member PR. It is desired that a heat pump as well as an air conditioner and an automobile each equipped with a heat pump is further miniaturized and reduced in weight from current dimensions. With the configurations of the rotary heat pump RHP disclosed in <CIT>, however, a problem remains that it is impossible to meet a requirement to further miniaturization and weight reduction of the heat pump as well as the air conditioner and the automobile each equipped with this heat pump.

Furthermore, rapid electrification has been recently underway at the level of laws and regulations in the automobile industry. However, energy densities of current batteries insufficiently meet demanded power of vehicle-mounted systems typified by, for example, a power controller, a drive system, a preventive safety device, and an in-vehicle air-conditioning system mounted in automobiles. Owing to this, efficiency improvement is adamantly demanded for all of these vehicle-mounted systems. The air conditioner that serves as the in-vehicle air conditioning system, in particular, has high power consumption and it may be said that the improvement in the efficiency of the air conditioner is a challenge to be solved as soon as possible in the electrification of automobiles.

Therefore, an object of the present invention is to provide a rotary heat pump capable of realizing further miniaturization, weight reduction and efficiency improvement, compared with a current status, an air conditioner equipped with this rotary heat pump, and an automobile capable of accelerating electrification.

The dependent claims describe optional embodiments of the invention.

A rotary heat pump, includes: a rotary drive section including: a rotary shaft; a stationary gear into which the rotary shaft is inserted; a rotor that has a rotor gear formed to have larger diameter dimensions than outside diameter dimensions of the stationary gear and engaged with the stationary gear, and that makes an eccentric rotation as the rotary shaft rotates; a rotary housing formed to be capable of demarcating a radially outward region of the rotor along a peritrochoid curve defined by the eccentric rotation of the rotor; a first side housing that has an insertion hole for inserting the rotary shaft, that covers one end side of the rotary housing, and that fixes the stationary gear; and a second side housing that covers an other end side of the rotary housing; a heat exchange fin provided on an outer surface of the rotary housing in each of a compression region where a region demarcated by an outer circumferential surface of the rotor and an inner circumferential surface of the rotary housing has a smallest planar area and an expansion region where the region has the largest planar area; and a bypass path that communicates a plurality of the expansion regions with one another.

With this invention, heat dissipation and heat absorption can be performed in one rotary structure, so that it is possible to greatly reduce a size, reduce a weight, and improve efficiency of the rotary heat pump, compared with a conventional rotary heat pump.

Furthermore, it is preferable that the bypass path is coupled with a bypass hole formed in at least one of the first side housing and the second side housing in the expansion region.

It is thereby possible to prevent an increase in outer dimensions due to the bypass path.

It is further preferable that the rotor and the rotary housing are a Wankel rotor and a Wankel rotary housing.

It is thereby possible to employ a widely-known rotary structure, so that reliability of the rotary structure can be enhanced.

Furthermore, there is an invention as an air conditioner equipped with the rotary heat pump according to any one of the above and also an invention of an automobile to which this air conditioner is mounted.

These inventions can contribute to miniaturization, weight reduction, and high efficiency of the air conditioner. Furthermore, these inventions can contribute to miniaturization and weight reduction of the automobile equipped with such an air conditioner. In addition, energy saving of the vehicle-mounted systems allows for acceleration of electrification of the automobile.

With configurations of the rotary heat pump according to the present invention, rotary structure sections can be integrated into one part, so that it is possible greatly reduce the size, reduce the weight, and improve efficiency, compared with the rotary heat pump according to the conventional technique. In addition, it is possible to reduce the size, reduce the weight, and improve the efficiency of the air conditioner equipped with this rotary heat pump. Furthermore, by being equipped with this air conditioner, it is possible to reduce the size and the weight of the automobile and to accelerate the electrification of the automobile.

A rotary heat pump <NUM> according to the present invention will be described hereinafter with reference to the drawings.

<FIG> is a plan view illustrating an internal structure of the rotary heat pump <NUM> according to an example with a perspective view of a second side housing <NUM>. The rotary heat pump <NUM> includes a rotary drive section <NUM> and heat exchange fins <NUM> provided on an outer wall surface of the rotary drive section <NUM>. The rotary drive section <NUM> in the present embodiment has a rotary shaft <NUM>, a stationary gear <NUM>, a rotor <NUM>, a rotary housing <NUM>, a first side housing <NUM>, and the second side housing <NUM>. A structure of this rotary drive section <NUM> is such that parts formed from a metal material and heat insulation portions <NUM> that are parts formed from a heat insulating material are alternately disposed in a circumferential direction. As is obvious from <FIG>, in the present embodiment, a form that employs a Wankel rotary drive section <NUM> in the rotary heat pump <NUM> will be described.

A first end portion of the rotary shaft <NUM> is rotatably supported in an internal space of the rotary drive section <NUM>, while a second end portion thereof projects outside of the rotary drive section <NUM> from an insertion hole (not illustrated) of the first side housing <NUM>. The second end portion of the rotary shaft <NUM> is coupled with an output shaft of a prime mover provided outside of the rotary drive section <NUM> (note that neither the prime mover nor the output shaft is illustrated) by a well-known scheme. Furthermore, the stationary gear <NUM> which is inserted from an outer surface side of the first side housing <NUM> and through which the rotary shaft <NUM> is inserted is fixedly screwed into the insertion hole of the first side housing <NUM>. As such a rotary shaft <NUM>, an eccentric shaft is suitably used as in the case of a rotary engine.

At least a required thickness range of an outer surface of the rotor <NUM> in the present example is formed into an outer shape of a so-called Reuleaux triangle (Wankel rotor) by a heat insulating material, and a fitting hole <NUM> of the rotor <NUM> is fitted into a rotary journal <NUM> formed in the rotary shaft <NUM> so that the rotor <NUM> is fixed in a state of being rotatable together with the rotary shaft <NUM>. In a plan view of the rotor <NUM>, a rotor gear <NUM> that has larger diameter dimensions than outside diameter dimensions of the stationary gear <NUM> and the fitting hole <NUM>, that is formed on the same axis as the fitting hole <NUM>, and that is engaged with the stationary gear <NUM> is formed in a central portion of the rotor <NUM>. The stationary gear <NUM> and the rotor gear <NUM> fixed to the first side housing <NUM> are engaged with each other only in a required range in the circumferential direction. Therefore, when the rotary shaft <NUM> rotates, the rotor <NUM> makes a motion of an eccentric rotation around the rotary shaft <NUM> (stationary gear <NUM>).

The rotary housing <NUM> is formed into a cocoon-shaped cylindrical body (Wankel rotary housing) that can planarly demarcate a radially outward region of the rotor <NUM> along a peritrochoid curve defined by the eccentric rotation of the rotor <NUM>. One opening surface of the rotary housing <NUM> is covered with the first side housing <NUM> in which the insertion hole (not illustrated) for inserting the stationary gear <NUM> into an interior of the rotary housing <NUM> (rotary drive section <NUM>) is formed. The rotary shaft <NUM> is inserted into the stationary gear <NUM>, and the rotary shaft <NUM>, the stationary gear <NUM>, and the first side housing <NUM> are sealed by a well-known scheme.

Moreover, the second side housing <NUM> is mounted to the other opening surface of the rotary housing <NUM> in a state of being sealed with the rotary housing <NUM>. Basic configurations of such a rotary drive section <NUM> can be designed similar to configurations of a so-called rotary engine from which intake/exhaust sections and an ignition sections are excluded. In the present embodiment, it is preferable that spaces surrounded by the rotor <NUM>, the rotary housing <NUM>, the first side housing <NUM>, and the second side housing <NUM> are sealed with seal members (not illustrated) provided appropriately. Each of the spaces is filled with helium that is an example of a refrigerant.

Furthermore, the heat exchange fins <NUM> are provided in a plurality of circumferential locations each over a required range on an outer surface of the rotary housing <NUM>. In the circumferential direction of the rotary housing <NUM>, a shape and a planar area of a region demarcated by an inner circumferential surface of the rotary housing <NUM> and an outer circumferential surface of the rotor <NUM> vary with the eccentric rotation of the rotor <NUM>. In the present embodiment, when the rotary shaft <NUM> is set as a rotation center, two compression regions <NUM> where a demarcated region has a smallest planar area and two expansion regions <NUM> where the demarcated region has a largest planar area are formed, and the compression areas <NUM> and the expansion region <NUM> are alternately disposed at intervals of <NUM> degrees in the circumferential direction of the rotary housing <NUM> with a planar central portion of the rotary housing <NUM> assumed as a rotation center.

Out of the heat exchange fins <NUM>, the fins provided upright on the outer wall surface of the rotary drive section <NUM> at positions corresponding to the compression regions <NUM> that are high-temperature regions are heat dissipation fins <NUM> and the fins provided upright on the outer wall surface of the rotary drive section <NUM> at positions corresponding to the expansion regions <NUM> that are low-temperature regions are heat absorption fins <NUM>.

When the rotary drive section <NUM> in the present example is driven to rotate by the prime mover, helium that is the refrigerant and that is filled in the internal space of the rotary drive section <NUM> is sequentially fed to the compression regions <NUM> and the expansion regions <NUM> that appear alternately in the circumferential direction of the rotary housing <NUM> to switch over between a high-temperature state and a low-temperature state. Furthermore, in the present example, required range portions including at least boundaries between the compression regions <NUM> and the expansion regions <NUM> in the circumferential direction of the rotary housing <NUM>, the first side housing <NUM>, and the second side housing <NUM> are formed from the heat insulating material, and the heat insulating material portions serve as the heat insulation portions <NUM>. Disposing such heat insulation portions <NUM> in boundary portions between the compression regions <NUM> and the expansion regions <NUM> enables even the single-rotor type rotary drive section <NUM> to exchange heat with outside air to be subjected to heat exchange in the heat dissipation fins <NUM> and the heat absorption fins <NUM>. It is noted that the first side housing <NUM> and the second side housing <NUM> according to the present embodiment are entirely formed from the heat insulating material.

By employing the form of the rotary heat pump <NUM> according to the present embodiment, a fully gas phase Carnot cycle heat pump structure can be provided. While the rotor <NUM> according to the present embodiment rotates once in an internal space of the rotary housing <NUM>, each of heat dissipation and heat absorption can be performed twice. These operations can ensure efficient heat exchange while ensuring small-sized, lightweight configurations and low noise. In addition, by accelerating the rotation of the output shaft of the prime mover to increase a revolving speed of the rotor <NUM>, rapid heating and rapid cooling can be conveniently ensured.

<FIG> is a perspective plan view of the second side housing <NUM> of the rotary heat pump <NUM> according to an embodiment, and illustrates a state in which the internal structure of the rotary heat pump <NUM> is depicted. In the present embodiment, same configurations as those in the first embodiment are denoted by the same reference signs used in the example and detailed descriptions of the configurations are omitted herein.

The rotary heat pump <NUM> according to the present embodiment is characterized by further having a bypass path <NUM> that communicates the two expansion regions <NUM> with each other, compared with the configurations described in the first embodiment. Furthermore, the rotary heat pump <NUM> differs from the rotary heat pump <NUM> according to the first embodiment in that each of a series of heat dissipation fins <NUM> and a series of heat absorption fin <NUM> are provided upright in one location and that the heat insulation portions <NUM> are provided only in two locations.

The bypass path <NUM> according to the present embodiment is coupled to bypass holes 34A penetrating the rotary housing <NUM> in the expansion regions <NUM>, respectively. By communicating the two expansion regions <NUM> with each other in this way, it is possible to greatly increase a volume of each expansion region <NUM> continuous with the compression region <NUM> and promote a fall in temperature due to expansion of helium. While the two expansion regions <NUM> are brought into communication in the present embodiment, the heat absorption fins <NUM> are provided upright only on the outer wall surface of the rotary housing <NUM> corresponding to the expansion region <NUM> provided right after the compression region <NUM>. Furthermore, the expansion region <NUM> (expansion region <NUM> located right before the compression region <NUM> that is the high-temperature region) communicated with the above expansion region <NUM> by the bypass path <NUM> may be entirely formed in the heat insulation portion <NUM>. Moreover, as illustrated in <FIG>, a bypass path heat sink <NUM> can be provided on the bypass path <NUM>.

Moreover, helium is not substantially compressed in the compression region <NUM> at a position put between the expansion regions <NUM> that are brought into communication by the bypass path <NUM> in the rotary heat pump <NUM> according to the present embodiment, so that this part is not provided with the heat dissipation fins <NUM> or the heat insulation portion <NUM>. As described above, in the rotary heat pump <NUM> according to the present embodiment, the number of the heat dissipation fins <NUM>, the heat absorption fins <NUM>, and the heat insulation portions <NUM> to be provided can be reduced, so that it is conveniently possible to contribute to further miniaturization, weight reduction, and manufacturing cost reduction of the rotary heat pump <NUM>.

As described above, the rotary heat pump <NUM> according to the present invention has been described on the basis of the embodiments; however, the present invention is not limited to the above embodiments. For example, the form in which the rotary heat pump <NUM> according to the embodiments described above employs the Wankel rotary drive section <NUM> has been described; however, the present invention is not limited to this structure and a structure of a well-known rotary drive section <NUM> can be applied as appropriate. When many expansion regions <NUM> are present in the structure of the rotary drive section <NUM>, a plurality of, i.e., three or more expansion regions <NUM> may be communicated with one another by the bypass path <NUM>. It is thereby possible to provide expansion areas formed from the plurality of expansion regions <NUM> in a plurality of locations in the circumferential direction of the rotary drive section <NUM>.

Furthermore, as illustrated in <FIG>, in the rotary heat pump <NUM> according to the second embodiment, the bypass holes 34A are provided in the rotary housing <NUM> in the expansion regions <NUM> and the bypass path <NUM> is coupled with the bypass holes 34A; however, the present invention is not limited to this form. As illustrated in <FIG>, the rotary heat pump <NUM> can have a form in which the bypass holes 34A passing through the first side housing <NUM> in a thickness direction are provided as an alternative to the bypass holes 34A provided in the rotary housing <NUM>, and in which the bypass holes 34A in a plurality of expansion regions <NUM> are coupled together by the bypass path <NUM>. These bypass holes 34A can also be provided in the second side housing <NUM> instead of the first side housing <NUM>, or can be provided in both the first side housing <NUM> and the second side housing <NUM>. By providing the bypass path <NUM> within a planar region of the rotary drive section <NUM> in this way, it is conveniently possible to reduce an area of the bypass path <NUM> that occupies the plane, compared with the rotary heat pump <NUM> according to the second embodiment.

Similarly, while the form in which the bypass path heat sink <NUM> is provided on the bypass path <NUM> and in which heat exchange (heat absorption) can be also performed in the bypass path <NUM> is described in the second embodiment, the present invention is not limited to this form. The bypass path <NUM> can be formed from a heat insulating material or a form in which the bypass path heat sink <NUM> is not provided can be employed.

Moreover, the form in which helium with high heat conductivity is filled into the rotary drive section <NUM> as the refrigerant is described in the present embodiments; however, the refrigerant with such properties is not limited to helium and a well-known refrigerant such as hydrogen or carbon dioxide can be used as appropriate.

Furthermore, as illustrated in <FIG>, there is also an invention as an air conditioner <NUM> equipped with the rotary heat pump <NUM> described above. Moreover, as illustrated in <FIG>, there is also an invention of an automobile <NUM> to which the air conditioner <NUM> equipped with the rotary heat pump <NUM> described in the present embodiments is attached. Since specific configurations of the air conditioner <NUM> and the automobile <NUM> are well known, detailed descriptions thereof are omitted herein. The air conditioner <NUM> according to the present invention can realize miniaturization, weight reduction, and high efficiency. In addition, the automobile <NUM> according to the present invention can not only realize the miniaturization and the weight reduction but also accelerate electrification of the automobile <NUM> by greatly saving energy.

Furthermore, a form in which the rotary heat pumps <NUM> described above are disposed in series in an axial direction of the rotary shaft <NUM> can be employed. This results in an increase in an occupied volume of the rotary heat pumps <NUM>; however, if a long and thin space can be allocated, it is possible to provide the rotary heat pump <NUM> with a higher performance and the air conditioner <NUM> and the automobile <NUM> each equipped with this rotary heat pump <NUM>.

Claim 1:
A rotary heat pump (<NUM>), comprising:
a rotary drive section (<NUM>) including: a rotary shaft (<NUM>); a stationary gear (<NUM>) into which the rotary shaft (<NUM>) is inserted; a rotor (<NUM>) that has a rotor gear (<NUM>) formed to have larger diameter dimensions than outside diameter dimensions of the stationary gear (<NUM>) and engaged with the stationary gear (<NUM>), and that makes an eccentric rotation as the rotary shaft (<NUM>) rotates; a rotary housing (<NUM>) formed to be capable of demarcating a radially outward region of the rotor (<NUM>) along a peritrochoid curve defined by the eccentric rotation of the rotor (<NUM>); a first side housing (<NUM>) that has an insertion hole for inserting the rotary shaft (<NUM>), that covers one end side of the rotary housing (<NUM>), and that fixes the stationary gear (<NUM>); and a second side housing (<NUM>) that covers an other end side of the rotary housing (<NUM>);
characterized by heat exchange fins (<NUM>) provided on an outer surface of the rotary housing (<NUM>) in a compression region (<NUM>) where a region demarcated by an outer circumferential surface of the rotor (<NUM>) and an inner circumferential surface of the rotary housing (<NUM>) has a smallest planar area and an expansion region (<NUM>) where the region has the largest planar area; and
a bypass path (<NUM>) that communicates a plurality of the expansion regions (<NUM>) with one another, wherein
the heat exchange fins (<NUM>) include heat absorption fins (<NUM>) provided to the expansion region (<NUM>) on an upstream side among two of the expansion regions (<NUM>) communicated one another by the bypass path (<NUM>), and heat dissipation fins (<NUM>) provided to the compression region (<NUM>) located right after the expansion region (<NUM>) on a downstream side among the expansion regions (<NUM>) communicated one another by the bypass path (<NUM>), and
a bypass path heat sink (<NUM>) is provided on the bypass path (<NUM>).