JPH0625679Y2 - Rotary compressor - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a rotary compressor, and more particularly to a rotary compression capable of reducing noise caused by pressure pulsation of discharge gas discharged from a compression element as much as possible. Regarding the machine.

[Technical Background of the Invention and its Problems] Generally, as shown in FIG. 10, the compression element of a rotary compressor includes a cylinder 1, a main bearing 2, a sub bearing 3, a rotary shaft 4,
The roller 5 and the blade 6 are mainly included, and are driven by rotation of a rotary shaft 4 connected to an electric element 7 provided above the roller 5. The rotating shaft 4 is axially supported by the main bearing 2 and the sub bearing 3, and the main bearing 2
The sub-bearing 3 covers the upper side and the lower side of the annularly formed cylinder 1 to form a compression space 8 therein. In the compression space 8, the roller 5 is fitted to the eccentric shaft portion 4a of the rotary shaft 4 to roll on the inner wall of the cylinder 1. The roller 5 is slidably provided on the cylinder 1 and The inside of the compression space 8 is partitioned into a high pressure side and a low pressure side by the abutting blade 6.

Further, the auxiliary bearing 3 is provided with a discharge port 9 that communicates with the high pressure side of the compression space 8 and a discharge valve 10 that opens and closes the discharge port 9. The discharge valve 10 is covered to form a substantially annular shape. The valve cover 11 is mounted, and a valve cover chamber 12 through which compressed gas is discharged is formed on the lower surface side of the auxiliary bearing 3.

By the way, as shown in FIG. 11, the discharge valve 10 has one end 10a fixed to the auxiliary bearing 3 and the other end free end 10b seated on the discharge port 9 to close it. When the pressure in the compression space 8 becomes equal to or higher than the set pressure value, the free end 10b is separated from the discharge port 9 by the pressure and the compressed gas is discharged into the valve cover chamber 12. Therefore, pressure pulsation of the discharge gas is generated in the valve cover chamber 12, and discharge noise is generated from the compression element 13 due to this pulsation.

For this reason, the conventional compression element 13 is shown in FIGS.
As shown in the drawing, the sub-bearing 3 and the cylinder 1 are provided with a bottomed cylindrical space 14 opened in the valve cover chamber 12 at a position shifted by 180 ° from the position where the discharge port 9 is formed. By reversing the phase of the pressure pulsation generated in the valve cover chamber 12 in the bottomed cylindrical space 14, the pressure pulsation generated in the valve cover chamber 12 is canceled to reduce the discharge noise. .

However, the pressure pulsation when the compressed gas is discharged from the discharge port 9 is a pressure wave region of a half region A on the discharge port 9 side in the annular valve cover chamber 12, which is Its discharge port 9 and 180 °
The other half area B on the opposite side is a pressure wave area. Therefore, the conventional setting position of the bottomed cylindrical space 14 is improper and the pulsation reducing effect has not been sufficiently obtained.

[Object of the Invention] The present invention was created in view of the above circumstances, and an object thereof is to provide a rotary compressor capable of reducing discharge noise caused by pressure pulsation of discharge gas as much as possible. is there.

In order to achieve the above object, the present invention forms a discharge port in a bearing of a compression element, installs a discharge valve to open and close the port, and installs a valve cover to cover the discharge valve. In a rotary compressor having an annular valve cover chamber provided therein, a bottomed cylinder that faces the valve cover chamber, introduces pressure pulsation of discharge gas generated in the valve cover chamber, and reverses and reverses the phase of the pulsation. A body-shaped space is continuously provided, and the bottomed cylindrical body-shaped space is connected to the discharge port by 90 degrees.
And the depth of the bottomed cylindrical space is formed to be about ¼ of the average circumferential length of the valve cover chamber. By arranging a bottomed cylindrical space in series facing the valve cover chamber near the discharge mechanism, the phase of the high pressure component of the pressure pulsation generated in the valve cover chamber can be reversed in the cylindrical space to enable the pressure pulsation. It can be reduced as much as possible.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, the rotary compressor 21 includes a hermetic casing 22 in which a compression element 23 is arranged in a lower portion and an electric element 24 is arranged in an upper portion. The electric element 24 and the compression element 23 are connected by a rotary shaft 25, and the rotary shaft 25 is supported by a main bearing 26 and a sub bearing 27 of the compression element 23.

The compression element 23 includes the main bearing 26, the sub-bearing 27, and the rotary shaft 2.
5 and its eccentric shaft portion 25a, roller 28, cylinder 2
9 and blades 30 and the like. The cylinder 29 is formed in an annular shape and is fixed to the closed case 22, a main bearing 26 and a sub bearing 27 are provided on the upper and lower parts of the cylinder 29, and a compression space 31 is formed inside them. A roller 28 is provided in the compression space 31 so as to be fitted to the eccentric shaft portion 25a of the rotary shaft 25.
8 is adapted to roll on the inner wall surface of the cylinder 29 by the rotation of the rotary shaft 25. The blade 30 is slidably provided in a blade groove 32 formed in a cylinder 29, and is urged by a spring 33 so that its tip portion abuts against the roller 28 so that the compression space 31 is located on the high pressure chamber side. It is divided into the low-pressure chamber side.

The auxiliary bearing 27 is provided with a discharge mechanism 34 for discharging the fluid (refrigerant) compressed in the compression space 31 in the compression element 23 to the outside of the compression element 23 when the pressure exceeds a predetermined pressure. There is. The discharge mechanism 34 includes a discharge port 35 and a discharge valve 36 that opens and closes the discharge port 35, and a valve cover 37 is mounted below the auxiliary bearing 27 so as to cover the discharge mechanism 34 and a valve cover chamber. 38 is formed.

The valve cover 37 is formed in a substantially annular shape as shown in FIGS. 1 and 2, and has two portions which form 90 ° from the discharge port 35 and are symmetrically positioned on the circumference thereof. Is provided with throttle portions 39, 39, and the valve cover chamber 38 is divided into a discharge chamber 38a having a discharge valve 36 and a chamber chamber 38b, and the outside portion of the throttle portions 39, 39 is a flange of the auxiliary bearing 27. It is adapted to be fixed to the portion 27a by a bolt or the like.

As shown in FIGS. 2 and 3, the discharge valve 36 is a reed valve 36a, and the flange portion 2 of the sub bearing 27 is provided.
7a has a groove 40 for accommodating the reed valve 36a.
Is formed, and the discharge port 35 is opened in the groove 40. The reed valve 36a is formed of a flat plate material, one end of which serves as a fixed end 36b, which is cantilevered and fixed to a flat fixed surface 41 formed in the groove 40 by a screw 42 or the like to form a free end 36c. The other end serves as a valve body portion 36d, which is seated on the valve seat portion 35a of the discharge port 35 to open and close it.

By the way, in the valve cover chamber 38, the compression element 23
Since the compressed gas is periodically discharged by opening and closing the discharge valve 36, pressure pulsation occurs in the valve cover chamber 38. As shown in FIG. 4, when the compressed gas is discharged from the discharge port 35, this pressure pulsation becomes a high pressure region of the pressure distribution on the side of the discharge chamber 38a having the discharge valve 36, and on the other chamber chamber 38b side. The pressure distribution becomes a low pressure region of and flows from the fixed end 36b side of the discharge valve 36 to the free end 36c side, and the pressure pulsation of a specific frequency having a wavelength matching the average circumferential length of the valve cover chamber 38. Is amplified and noise is generated.

Therefore, in the present invention, in order to reduce the noise transmitted through the valve cover 37 due to the pressure pulsation, as shown in FIG. , A bottomed cylindrical space 43 that penetrates the flange portion 27a of the auxiliary bearing 27 and reaches the cylinder 29, and inverts the phase of the high-pressure component of the pressure pulsation in the cylindrical space 43, whereby the valve cover chamber 38 The pressure pulsation that occurs inside is canceled out, so that the pressure pulsation is reduced as much as possible.

That is, the cylindrical space 43 has the fixed end 36 b of the discharge valve 36.
On the opposite side of the discharge port 35 from the discharge port 3
The discharge port 3 within the range of 90 ° from 5 to the throttle 39
It is provided in the vicinity of 5 and its axial length is formed to be approximately 1/4 of the average circumferential length ₀ of the valve cover chamber 38.

Next, the operation of the present invention will be described.

As shown in FIG. 4, from the discharge port 35 to the reed valve 36.
The compressed gas flowing out to the discharge chamber 38a side of the valve cover chamber 38 by pushing down the a (discharge valve) flows in the circumferential direction,
As shown in the graph of the figure, a pressure pulsation having a primary frequency f ₁ (wavelength λ = ₀ ) corresponding to an average circumferential length of ₀ of the valve cover chamber 38 is generated in the valve cover chamber 38. At this time, the pressure pulsation component is distributed on the discharge chamber 38a side, and the component is distributed on the chamber chamber 38b side. The pressure pulsation of the component generated on the discharge chamber 38a side is introduced into the cylindrical space 43, and the length of the cylindrical space 43 is formed to be about 1/4 of the average circumferential length ₀ of the valve cover chamber 38. Therefore, the valve cover chamber 3 is reflected by its closed end.
When returning to 8 the phase is inverted. Therefore, the pressure pulsation that has its phase inverted and returned to the inside of the valve cover chamber 38 and the pressure pulsation that flows in the valve cover chamber 38 in the circumferential direction cancel each other out, and as a result, the valve cover chamber 38.
The amplitude of the pressure pulsation generated inside is suppressed and the pulsation is reduced. Therefore, the pressure pulsation is suppressed from being emphasized / amplified, the noise transmitted from the valve cover 37, that is, the discharge noise from the compression element 23 due to this is reduced, and the opening / closing operation of the reed valve 36a is also lightened. As a result, the electric power required for the compressor 21 is reduced, and the compression efficiency is further improved.

[Modified Embodiment] FIG. 6 shows a first modified embodiment.
In the valve cover chamber 38 on the side of the discharge chamber 38a, two cylindrical spaces 43, 43 are connected in series. Its cylindrical space 4
The lengths of both 3, 43 are formed to be approximately 1/4 of the average circumferential length ₀ of the valve cover chamber 38. If a plurality of cylindrical spaces 43, 43 are provided in this manner, pressure pulsation By further suppressing the amplitude, the pressure pulsation can be further reduced.

Further, FIG. 7 shows a second modified example, in which the lengths of the two cylindrical spaces 43a and 43b are different. Similar to the one described above, the length of the one cylindrical space 43a is formed to be approximately 1/4 of the average circumferential length ₀ of the valve cover chamber 38, and the length of the other cylindrical space 43b. b is formed to be about 1/8, and the pulsation frequency f ₁ of the _{first order} is 2 which is determined by the average circumferential length ₀ of the valve cover chamber 38.
The next frequency f ₂ is also reduced. That is,
Secondary frequency is _f 2 = 2 · _{f 1,} because it is _f 1 = C _{/ 1/0} if the sound velocity and _{C, f 2 = C · 2} /0 , and the wavelength of the second-order frequency lambda ₂ It becomes _0/2. Therefore, the length b of the cylindrical space 43b for reducing the pressure pulsation of the secondary frequency may be about 1/8 of the average circumferential length ₀ of the valve cover chamber 38.

Moreover, what is shown in FIG. 8 and FIG. 9 shows a third modified embodiment. In this embodiment, discharge mechanisms 34 and 34 are provided on both the main bearing 26 and the sub bearing 27 of the compression element 23 to cover the discharge mechanisms 34 and 34, and the main bearing 26 and the sub bearing 27 have valve covers respectively. 37, 37 are provided, and the valve cover chambers 38, 38 are individually formed. Then, the valve cover chambers 38, 38 are connected to the discharge chambers 38a, 38a side to form the bottomed cylindrical spaces 43, 43, respectively. In addition, the cylindrical space 4
As shown in the first modification example and the second modification example, reference numerals 3 and 43 denote discharge chambers 38a, 38 of the valve cover chambers 38, 38, respectively.
It is needless to say that a may be provided in plural.

[Effects of the Invention] In summary, according to the present invention, the following excellent effects are exhibited.

(1) The bearing of the compression element having a discharge port is provided with a valve cover that covers the discharge port to form an annular valve cover chamber, and the valve cover chamber is faced to introduce pressure pulsation generated in the valve cover chamber. Then, since the bottomed cylindrical space for reversing the phase thereof is returned, the pressure pulsation generated in the valve cover chamber can be reduced as much as possible.

(2) Since the pressure pulsation generated in the valve cover chamber can be reduced, the noise transmitted from the valve cover due to the pressure pulsation can be reduced.

(3) The tubular space is arranged within a range of 90 degrees with respect to the discharge port in the valve cover chamber, and the depth of the tubular space is about 1/4 of the average circumference length of the valve cover chamber. Since it is formed, the pressure pulsation generated in the valve cover chamber can be further reduced.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a preferred embodiment of a rotary compressor according to the present invention, FIG. 2 is a view taken along the line II--II in FIG. 1, and FIG. 3 is III-- in FIG. A sectional view taken along the line III, FIG. 4 is a diagram showing a flow of pressure pulsation generated in the valve cover chamber, FIG. 5 is a graph showing pressure pulsation generated in the valve cover chamber, and FIG. 6 is a first modified embodiment. FIG. 7 is a sectional view of an essential part showing a second modified embodiment, FIG. 8 is a side sectional view of a rotary compressor showing a third modified embodiment, and FIG.
Fig. 10 is a sectional view taken along the line IX-IX in the drawing, Fig. 10 is a side sectional view of a conventional rotary compressor, and Fig. 11 is a view taken along the line XI-XI in Fig. 10. In the figure, 23 is a compression element, 26 and 27 are bearings, 34 is a discharge mechanism, 37 is a valve cover, 38 is a valve cover chamber, 4
Reference numeral 3 is a bottomed cylindrical space.

Claims (3)

[Scope of utility model registration request] 1. A rotary compressor in which a discharge port is formed in a bearing of a compression element, a discharge valve is provided to open and close the port, and a valve cover is provided to cover the discharge valve to form an annular valve cover chamber. In the above, a bottomed cylindrical space is continuously provided while facing the valve cover chamber and introducing pressure pulsation of the discharge gas generated in the valve cover chamber and inverting and reversing the phase of the pulsation. The body space is arranged within a range of 90 degrees with respect to the discharge port valve, and the bottomed cylindrical body space is formed to have a depth of about ¼ of the average circumferential length of the valve cover chamber. A rotary compressor characterized by the above. 2. The rotary compressor according to claim 1, wherein a plurality of the bottomed cylindrical spaces are provided within a range of 90 degrees with respect to the discharge port valve. 3. The valve cover chamber is formed in each of a main bearing and a sub bearing of the compression element, and the bottomed cylindrical space is within a range of 90 degrees with respect to the discharge port of each valve cover chamber. The rotary compressor according to claim 1, wherein the utility models are registered in series.