Heating systems – Heat and power plants – Vehicle
Reexamination Certificate
2000-05-19
2001-10-30
Joyce, Harold (Department: 3744)
Heating systems
Heat and power plants
Vehicle
C122S026000, C126S247000
Reexamination Certificate
active
06308896
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a heat generator comprising a working chamber defined in a housing, a viscous fluid accommodated in the working chamber, and a rotor rotationally driven by an external power source. More in particular, the invention relates to a heat generator in which the working chamber includes a heat generating area for accommodating the rotor in such a manner as to secure a fluid-tight gap between the partitioning wall thereof and the rotor for generating the heat by shearing the viscous fluid, existing in the fluid-tight gap, with the rotor, a storage area for accommodating viscous fluid beyond the volume of the fluid-tight gap, and at least one opening in the boundary between the heat generating area and the storage area for communicating between the two areas.
2. Description of the Related Art
A heat generator comprising a viscous fluid (hereinafter referred to as the oil) such as silicone oil sealed in a fluid-tight heat generating chamber defined in a housing in which heat is generated by fluid friction as the oil is sheared by a rotor is known as an auxiliary heat source of an automotive heating system (see, for example, Japanese Unexamined Patent Publication No. 2-246823). In this type of heat generator, the oil constantly subjected to shearing degenerates quickly and the heat generating performance cannot be maintained for a long time. For this reason, a heat generator mechanically designed to prevent or delay oil degeneration as much as possible has been proposed.
An example is a viscous heater (heat generator), disclosed in Japanese Unexamined Patent Publication No. 10-95224, comprising a heat generating chamber and a storage chamber in the housing. The partitioning wall between the heat generating chamber and the storage chamber is formed with at least a recovery hole (recovery path) and at least a supply hole (supply path), through which the viscous fluid is replaced and circulated between the heat generating chamber and the storage chamber. The replacement/circulation avoids the case in which specific oil molecules are subjected to protracted continuous shearing, and allows the viscous oil to rest in the storage chamber to recover its original viscoelasticity. Thus, oil degeneration is delayed. Further, the heat generator described in the same patent publication comprises at least a recovery groove and at least a supply groove extending substantially along the diameter in the inner wall surface of the heat generating chamber in an opposed relation to the shearing surface of the rotor. The recovery groove is for leading the oil from the outer peripheral area of the rotor to the recovery hole, and the supply hole is for leading the oil from the supply hole to the outer peripheral area of the rotor. The recovery groove and the supply groove promote the oil outflow from the heat generating chamber and the oil inflow from the storage chamber to the heat generating chamber to thereby improve the efficiency of the replacement/circulation.
As described above, some patent publications already disclose an idea of an oil shearing type of heat generator comprising a recovery groove (and a recovery path) and a supply groove (and a supply path) formed in the partitioning wall between a heat generating chamber and a storage chamber to promote the replacement/circulation of the oil. Nevertheless, the conditions for arranging the grooves and paths for securing the required heat generating ability while replacing and circulating the oil have yet to be theoretically analyzed or studied in depth. It has thus far been very difficult, therefore, to reflect the idea in the actual machine and commercialize it. Even if the desirable conditions of arrangement have been discovered in the stage of developing a working model of the product, it has been the incidental result of trial and error.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a heat generator and a design method for the heat generator in which the factors for determining the desirable conditions for the arrangement of the grooves and paths formed in the partitioning wall between a heat generating area and a storage area are clarified thereby to secure the replacement/circulation of the viscous fluid between the heat generating area and the storage area and the heat generating performance of the viscous fluid at the same time.
According to the present invention, there is provided a heat generator comprising a working chamber defined in a housing, a viscous fluid accommodated in the working chamber, and a rotor rotationally driven by an external power,
wherein the working chamber includes a heat generating area for accommodating the rotor in such a manner as to secure a fluid-tight gap between the partitioning wall and the rotor and generates heat by shearing the viscous fluid existing in the fluid-tight gap by rotation of the rotor, a storage area for accommodating the viscous fluid exceeding the volume of the fluid-tight gap, and at least one opening formed in the boundary between the heat generating area and the storage area for communicating the two areas,
wherein the working chamber includes supply means for transferring the viscous fluid in the storage area to the heat generating area at the time of rotation of the rotor and recovery means for transferring the viscous fluid in the heat generating area to the storage area at the time of rotation of the rotor,
wherein the recovery means includes at least a recovery groove formed in the partitioning wall of the working chamber in opposed relation to the shearing surface of the rotor for trapping the viscous fluid existing in the fluid-tight gap and forcibly transferring the viscous fluid toward the opening at the time of rotation of the rotor, and
wherein the supply means and the recovery means are so constructed that the outflow ratio (&agr;), i.e. the ratio of the amount of the viscous fluid flowing out of the heat generating area due to the forcible transfer function of the recovery groove to the total amount of the viscous fluid flowing into the heat generating area from the storage area due to the transfer function of the supply means is not more than 0.92.
In this heat generator, the replacement/circulation of the viscous fluid occurs between the storage area and the heat generating area, through the opening, at the time of rotation of the rotor by the cooperation between the supply means and the recovery means arranged in the working chamber. The heat generating performance can be maintained for a long time as the result of the continued replacement/circulation with the flow rate of the viscous fluid into the heat generating area and the flow rate of the viscous fluid out of the heat generating area in equilibrium. The mere equilibrium between the flow rate of the viscous fluid into and out of the heat generating area, however, cannot necessarily exhibit the maximum heat generating performance of the heat generator. The outflow ratio (&agr;) defined here provides a new index of characteristic evaluation (or a design measure) permitting the heat generating performance in the heat generating area to be set at the desired level while making possible both the proper replacement/circulation of the viscous fluid and a suitable equilibrium between the inflow and outflow of the viscous fluid in the heat generating area. It has been substantiated by experiments conducted on working models that this outflow ratio &agr; has a predetermined relationship with the heat generation amount and provides an influential index for controlling the filling ratio (or occupancy) of the viscous fluid in the fluid-tight gap of the heat generating area while holding the balance between inflow and outflow of the viscous fluid in the heat generating area (refer to the DESCRIPTION OF THE PREFERRED EMBODIMENTS and FIG.
9
).
The concept of the outflow ratio &agr; has been created from the theoretical analysis of the transfer balance and the transfer driving force of the viscous fluid between the stor
Hoshino Tatsuyuki
Moroi Takahiro
Niwa Masami
Suzuki Shigeru
Boles Derek S.
Joyce Harold
Kabushiki Kaisha Toyoda Jidoshokki Seisakusho
Woodcock Washburn Kurtz Mackiewicz & Norris LLP
LandOfFree
Heat generator and design method thereof does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Heat generator and design method thereof, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Heat generator and design method thereof will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2575954