CN201747559U - Compressor - Google Patents

Abstract

The utility model discloses a compressor, which comprises a cylinder, an upper bearing and a lower bearing, wherein the upper bearing and the lower bearing are respectively provided with a vent hole, and a lower bearing, the cylinder at least comprises two anechoic chambers, and the vent hole of the upper bearing, more than two anechoic chambers of the cylinder and vent hole of the lower bearing are communicated in series to form a anechoic structure. In the utility model, the mode with one anechoic chamber of the existing cylinder is changed into the mode with more than two anechoic chambers, the total anechoic quantity can be improved, the frequency characteristic of an anechoic device can be improved, the anechoic chambers can be designed into anechoic chambers with different sections or lengths, so that the anechoic frequency range can be further enlarged, and the anechoic effect can be improved.

Description

Compressor

Technical field

The utility model relates to compressor field, particularly a kind of noise-reducing structure of rotary compressor.

Background technique

Existing noise-reducing structure schematic representation as shown in Figure 2.

Existing noise-reducing structure is made up of an anechoic chamber 21 ' of upper bearing (metal) l exhaust hole 11, lower bearing 3 exhaust holes 31 and cylinder 2.The noise reduction principle: it is to utilize the unexpected expansion of pipeline section to cause acoustic impedance sudden change in the passage, makes along the sound wave of some frequency of pipe transmmision and can't pass silencing apparatus and the reflected back sound source is gone.Because sound wave can't pass silencing apparatus, also just pass not come out, thereby reach the purpose of noise elimination.

For example shown in Figure 3, bearing exhaust hole 11,31 cross sections are S ₁, 21 ' cross section, anechoic chamber is S ₂, length is l.

The sound deadening capacity of silencing apparatus can be by weighing at the incidence sound intensity levels of silencing apparatus entry end and in the transmission sound intensity of the silencing apparatus outlet end attenuation between the two.Because square being directly proportional of the sound intensity and acoustic pressure, so the sound deadening capacity formula that obtains silencing apparatus at last is,

$L_{\mathrm{NR}}=10\lg [1+{\left(\frac{s_{21}-s_{12}}{2}\sin \mathrm{kl}\right)}^2]---\left(F1.1\right)$

Wherein

λ is that sound wave is long.As can be seen from the above equation, the sound deadening capacity size is by divergence ratio S ₂₁Decision, frequency of noise elimination characteristic are by the length l decision of expansion, because sin kl is a periodic function, visible sound deadening capacity is also done cyclically-varying with frequency.

Following formula also shows simultaneously: work as sin ²During kl=1, promptly kl is

Odd-multiple the time, the sound deadening capacity of anechoic chamber's silencing apparatus reaches maximum value, at this moment, $L_{\mathrm{NR}\max }=10\lg [1+{\left(\frac{s_{21}-s_{12}}{2}\right)}^2]---\left(F1.2\right)$

The respective frequencies of sound deadening capacity maximum is called the maximum frequency of noise elimination in anechoic chamber: $f_{\max }=(2n-1)\frac{c}{4l}---\left(F1.3\right)$

In the formula, c is a sound propagation velocity, and the following formula deformable is: $l=(2n-1)\frac{c}{4f_{\max }}=(2n-1)\frac{\mathrm{\λ}}{4}---\left(F1.4\right)$

Following formula explanation: when anechoic chamber's length equals the odd-multiple of 1/4 wavelength of sound wave, can on these frequencies, obtain the noise elimination effect of maximum.

The acoustic characteristics of silencing apparatus is periodically variable, and promptly the sound wave of some frequency can pass through silencing apparatus undampedly.

When sin kl=0, promptly kl is

Even-multiple the time, the sound deadening capacity of expansion chamber silencing apparatus reaches minimum value, L _NRmin=0, corresponding sound wave can pass through silencing apparatus undampedly.This is a shortcoming of single-unit expansion chamber silencing apparatus.The corresponding frequencies of this moment can be calculated by following formula by frequency,

$f_{\min }=\frac{\mathrm{nc}}{2l}---\left(F1.5\right)$

Following formula can be deformed into: $l=\frac{\mathrm{nc}}{2f_{\min }}=n\frac{\mathrm{\λ}}{2}---\left(F1.6\right)$

Following formula shows: when anechoic chamber's length l equaled the integral multiple of 1/2 wave length of sound, the sound wave of its corresponding frequencies can pass through undampedly, does not promptly play the noise elimination effect.

Because the general broad of frequency range of noise if silencing apparatus can only be eliminated some frequency content, and allows other frequency contents pass through smoothly, this obviously is disadvantageous.In order to overcome this shortcoming, must improve its acoustic attenuation performance.

Summary of the invention

For solving the frequency range problem of smaller of above-mentioned existing silencing apparatus noise reduction, the purpose of this utility model is to provide a kind of compressor, and its noise-reducing structure can enlarge the scope of noise reduction frequency, thereby improves erasure effect.

The purpose of this utility model is achieved in that a kind of compressor, comprises cylinder and the upper bearing (metal), the lower bearing that are provided with exhaust hole, and it is characterized in that: described cylinder comprises at least two anechoic chambers; At least two anechoic chambers of upper bearing (metal) exhaust hole, cylinder and the series connection of lower bearing exhaust hole are communicated with and constitute noise-reducing structure.

Anechoic chamber on the described cylinder is communicated with by connecting through hole.

The cross section of described anechoic chamber is circular, oval.

The sectional area of described anechoic chamber, equal in length.

The sectional area of described anechoic chamber, be uneven in length.

The sectional area of described anechoic chamber is greater than the sectional area of upper bearing (metal) exhaust hole.

The sectional area of described anechoic chamber is greater than the sectional area of cylinder connecting through hole.

The sectional area of described anechoic chamber is greater than the sectional area of lower bearing exhaust hole.

The anechoic chamber that the utility model will have cylinder now is transformed into more than two, not only can improve total sound deadening capacity, and can improve the frequency characteristic of silencing apparatus, and the anechoic chamber can be designed to different sectional area or length mutually, the noise reduction frequency is further enlarged, thereby improve erasure effect.

Description of drawings

Fig. 1 is the compressor sectional drawing of prior art;

Fig. 2 is a prior art noise-reducing structure schematic representation;

Fig. 3 is the profile analysis figure of prior art noise-reducing structure;

Fig. 4 is the utility model noise-reducing structure schematic representation;

Fig. 5 is the profile analysis figure of the utility model noise-reducing structure.

Embodiment

Below the contrast Figure of description further describes the utility model, but the utility model includes but not limited to method and structure cited in the example.

Embodiment

As shown in Figure 1, the utility model is a kind of compressor, comprises cylinder 2, is provided with upper bearing (metal) 1, the lower bearing 3 of exhaust hole.

As shown in Figure 4, cylinder 2 is provided with two anechoic chambers 21,23, and two anechoic chambers 21,23 of upper bearing (metal) exhaust hole 11, cylinder and 31 series connection of lower bearing exhaust hole are communicated with the formation noise-reducing structure.Two anechoic chambers 21,23 on the cylinder 2 are communicated with by a connecting through hole 22.The sectional area of these two anechoic chambers 21,23, length can be arranged to equate, be more preferably and be arranged to not wait, solve the problem that existing noise-reducing structure is not eliminated the noise to some frequency by two different sectional areas in anechoic chamber, their frequency of passing through is staggered mutually by the anechoic chamber that different length is set.

The cross section of anechoic chamber 21,23 can be circle, ellipse or other slick and sly cambered surface.Preferably, the sectional area of two anechoic chambers 21,23 is greater than the sectional area of upper bearing (metal) exhaust hole 11, the sectional area of two anechoic chambers 21,23 is greater than the sectional area of cylinder connecting through hole 22, and the sectional area of two anechoic chambers 21,23 is greater than the sectional area of lower bearing exhaust hole 31.

As shown in Figure 5, the length of establishing first segment anechoic chamber 23 is l, to certain frequency f ₀Sound deadening capacity is 0, has according to 1.6 of formula F

$l=\frac{\mathrm{nc}}{2f_0}=n\frac{\mathrm{\λ}}{2}---\left(F1.7\right)$

Make the length of the second joint anechoic chamber 23

Substitution following formula F1.7 can get

$l_0=(2n-1)\frac{\mathrm{\λ}}{4}=(2n-1)\frac{c}{4f_0}$

Work as second the joint anechoic chamber 21 length be l ₀The time, just in time equal the odd-multiple of 1/4 wavelength of sound wave, by formula F 1.4 as can be known, in frequency f ₀The last sound deadening capacity that obtains maximum.As long as l and l ₀The odd-multiple that differs 1/4 wavelength can reach similar effect.During practical application, l and l ₀Might not require to differ 1/4 wavelength, can set it according to the required frequency that abates the noise.

As Fig. 4, noise-reducing structure of the present utility model mainly is made up of following five parts:

1. the exhaust hole 31 on the lower bearing 3, the 2. anechoic chamber 23 on the cylinder 2,3. cylinder 2 connecting through holes 22, the 4. anechoic chamber 21 on the cylinder 2, the 5. exhaust hole 11 on the upper bearing (metal) 1.

Wherein:

The sectional area of the sectional area＞exhaust hole 31 of anechoic chamber 21,23,

The sectional area of the sectional area＞connecting through hole 22 of anechoic chamber 21,23,

The sectional area of the sectional area＞exhaust hole 11 of anechoic chamber 21,23.

The cross section of anechoic chamber 21,23 can be circular, oval or other shape.

The sectional area and the length of anechoic chamber 21,23 can equate, also can be unequal, design according to the experiment situation.In the present embodiment, the sectional area of anechoic chamber 21 and length are all greater than anechoic chamber 23.

The noise reduction process:

At first gas enters from exhaust hole 31, and gas expands in anechoic chamber 23 (carrying out the noise reduction first time) then, the connecting through hole 22 of flowing through again, in anechoic chamber 21, reexpand (secondary noise reduction), last gas is discharged from exhaust hole 11.

Claims (8)

1. a compressor comprises cylinder and the upper bearing (metal), the lower bearing that are provided with exhaust hole, and it is characterized in that: described cylinder comprises at least two anechoic chambers; The plural anechoic chamber of upper bearing (metal) exhaust hole, cylinder and the series connection of lower bearing exhaust hole are communicated with the formation noise-reducing structure.

2. compressor according to claim 1 is characterized in that: be communicated with by connecting through hole between the anechoic chamber on the described cylinder.

3. compressor according to claim 1 is characterized in that: the cross section of described anechoic chamber is for circular, oval.

4. compressor according to claim 1 is characterized in that: the sectional area of described plural anechoic chamber, equal in length.

5. compressor according to claim 1 is characterized in that: sectional area, the length of described plural anechoic chamber are different.

6. compressor according to claim 1 is characterized in that: the sectional area of described anechoic chamber is greater than the sectional area of upper bearing (metal) exhaust hole.

7. compressor according to claim 1 is characterized in that: the sectional area of described anechoic chamber is greater than the sectional area of cylinder connecting through hole.

8. compressor according to claim 1 is characterized in that: the sectional area of described anechoic chamber is greater than the sectional area of lower bearing exhaust hole.

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