Patent Application
20200291939
The present invention relates to a scroll-type fluid machine.
In a compressor such as a scroll compressor, which is one type of scroll-type fluid machines, customer demand for space saving is high.
As a background art of this technical field, there is JP 2002-371977 A (Patent Document 1). Patent Document 1 discloses a scroll-type fluid machine in which a spiral compression operating chamber with a volume gradually decreasing from an outer circumferential side to an inner circumferential side with a revolution motion while preventing rotation of a turning scroll is partitioned between a fixed scroll and the turning scroll, and the incoming gas is transported, while compressing with the decrease in the volume of the compression operating chamber, in which the scroll-type fluid machine includes a turning bearing provided at one end of a main shaft, a motor side bearing provided at the other end of the main shaft, and a main bearing provided between the turning bearing and the motor side bearing, and at least a part of the turning bearing is located on a side closer to the fixed scroll than the end plate of the turning scroll.
Patent Document 1: JP 2002-371977 A
In Patent Document 1, the motor and a scroll compressor body are set to a direct-drive type, and a bearing position of the scroll compressor body is disposed on a compression chamber side to reduce a size in an axial direction. However, in a motor direct-drive type scroll compressor of such a structure, in some cases, since a radial dimension of the motor is only about a half of a radial dimension of the body, a cooling area of a motor unit decreases, and since no cooling fins are formed, no consideration is given to heat dissipation at all, and it is not possible to use the scroll compressor under a high load such as heat generation of the motor. As the cooling area of each part of a compressor body unit and the motor unit is reduced in this way in order to reduce the size, since the temperature rises and the part is not used as a product, it is necessary to consider each heat radiation.
In this regard, an object of the present invention is to provide a scroll-type fluid machine capable of reducing an axial length and reducing a size, without causing an imbalance between a compressor body unit and a motor unit in terms of dissipation of heat.
In order to solve the above problem, the present invention provides, for example, a scroll-type fluid machine including: a body unit which has a fixed scroll having a lap formed on an end plate thereof, a turning scroll having a lap formed on an end plate thereof to face the lap of the fixed scroll, and a body casing which accommodates the fixed scroll and the turning scroll; and a motor unit which has a drive shaft connected to the body unit to drive the body unit, a rotor rotating integrally with the drive shaft, a stator which imparts a rotational force to the rotor, and a motor casing which accommodates the drive shaft, the rotor and the stator, in which a cooling fin is formed on a surface opposite to a surface on which the laps of the end plates of the fixed scroll and the turning scroll are formed, and when a radial dimension of the end plate of the fixed scroll is defined as α, an axial dimension from a tip of the cooling fin of the fixed scroll to a tip of the cooling fin of the turning scroll is defined as lc, and an axial dimension of the stator is defined as ls, a relation of α/16+lc/4≤ls≤α/4+lc is satisfied.
According to the present invention, it is possible to provide a scroll-type fluid machine capable of reducing an axial length without causing an imbalance between a body unit and a motor unit in terms of dissipation of heat.
Embodiments of the present invention will be described below with reference to the drawings. Incidentally, in the drawings for describing the embodiments, elements having the same functions are denoted by the same names and reference numerals, and the repetitive description thereof will not be provided.
This embodiment will be described with reference to
In
In order to improve the cooling efficiency, the motor casing cooling fin 12 illustrated in
Further, a turning bearing that supports the drive shaft with respect to the turning scroll 6 is disposed on a side closer to the motor unit than the end plate of the turning scroll 6. As a result, compared with a shape in which the turning bearing enters into the end plate in order to reduce the axial dimension, even with the turning scroll 6 and the fixed scroll 7 having the same diameter, a compression amount can be secured without reducing a compression chamber.
In addition, the rotor 4 and the stator 5 are configured to face each other in the axial direction. As a result, the axial dimension can be reduced.
Further, the body unit and the motor unit are attachably and detachably fastened between the body casing 15 and the motor casing 11 by a fastening member.
Further, by making the radial dimension of the motor casing 11 longer than the axial dimension, it is possible to reduce the axial dimension, and at the same time, to secure the cooling area.
Here, in a case where cooling parts of the turning scroll 6, the fixed scroll 7 and the stator 5, which are heating elements, are approximated to a cylinder, when an effective cooling area of a region A indicated by a dotted line and formed by the laps of the fixed scroll 7 and the turning scroll 6 and the cooling fins 13 and 14 is defined as SA and an effective cooling area of a region B indicated by a dotted line and formed only by the stator 5 and a fitting portion of the motor casing 11 with the stator 5 is defined as SB, SA and SB can be approximated by formulas (1) and (2).
S
A=end plate surface area of fixed and turning scrolls+cylinder side area of fixed and turning scrolls=2π×(α/2)2+2πα×lc=πα2/2+2παlc (1)
S
B=motor casing stator unit cylindrical side area=2πDmls (2)
Here, α: a horizontal dimension (a radial dimension of the end plate of the fixed scroll) of the fixed scroll cooling fin 13 with respect to the cooling air,
lc: a distance from the end surface of the turning scroll cooling fin 14 to the end surface of the fixed scroll cooling fin 13,
Dm: a radial dimension of the motor casing (including cooling fin), and
ls: an axial dimension of the stator.
Furthermore, the motor direct-drive type scroll compressor generally has a motor efficiency higher than efficiency of the compressor body. An amount obtained by subtracting the efficiency component from input power is set as a loss, and since respective losses are proportional to respective heat generation amounts, the heat generation amount of the compressor body becomes greater than the heat generation amount of the motor. Here, in the motor direct-drive type scroll compressor of the present embodiment, since heat generation amounts Qc of the fixed scroll and the turning scroll are 10 to 40% with respect to the input of the motor, and a heat generation amount Qs of the stator is about is 10% with respect to the input of the motor, a relational formula between Qs and Qc has a relation of formula (3).
Qc/4≤Qs≤Qc (3)
In order to prevent heat dissipation between the body unit and the motor unit from becoming imbalanced, it is necessary to provide an area corresponding to formula (3), and thus the relation between SA and SB is set to a relation of formula (4).
SA/4≤SB≤SA (4)
Therefore, the following formula (5) is derived from the formulas (1) , (2) and (4).
α2/16αlc/4≤Dmls≤α2/4+αlc (5)
Here, the relation between α and Dm will be described. In the case of α>Dm, since a cooling air passage is complicated or the passage length needs to be lengthened, the pressure loss of the cooling air increases, the air flow rate decreases, and the cooling of the turning scroll and the fixed scroll deteriorates. Also, since Dm is reduced, is increases and an overall axial dimension L increases. On the other hand, in the case of α<Dm, since the cooling air is difficult to flow to the motor casing 11, the motor cooling deteriorates. Further, since the motor casing is large, it is necessary to adopt a structure of a cooling air guiding member to avoid this. As a result, the cooling air guiding member has a complicated shape, the pressure loss increases, and the cooling air volume decreases. For the above reasons, the relation between α and Dm is set to the relation of formula (6).
α=Dm (6)
Since the approximation of formula (6) is established, the tip of the cooling fin of the motor casing is at least outside the outermost circumferential surface of the lap formed on the fixed scroll.
Using formula (6), formula (5) becomes formula (7).
α/4+lc/4≤ls≤α/4+lc (7)
Therefore, in the present embodiment, by setting α, lc, and ls to satisfy the formula (7), it is possible to provide a motor direct-drive type scroll compressor capable of equalizing the heat dissipation of the body unit and the motor unit and reducing the axial length. Therefore, miniaturization and temperature reduction of the motor direct-drive type scroll compressor can be attained at the same time, resulting in a customer merit.
The present invention is not limited to the embodiments described above, but includes various modified examples. For example, although the scroll compressor has been described in the above embodiment, it may be, for example, a blower, a pump or the like other than the compressor, and may be a so-called scroll-type fluid machine. Furthermore, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2016/072718 | 8/3/2016 | WO | 00 |
