CN205137688U - Air -conditioning indoor unit - Google Patents

Abstract

The utility model provides an air conditioner indoor unit. The indoor unit of the air conditioner includes a shell, which has a first air inlet, a second air inlet and an air outlet; a centrifugal fan, which is arranged in the shell; and a heat exchanger, at least part of which has a flat heat exchange section and is located between the centrifugal fan and Between the first air inlets; the drainage and air guide device is arranged at the air outlet in the casing, and is configured to introduce the airflow from the centrifugal fan and the airflow from the second air inlet into it for mixing, and make the mixed airflow with Blow out from the air outlet in a manner that has a velocity component in a direction parallel to the axis of rotation of the centrifugal fan; and a plurality of air guide vanes configured to adjust the airflow entering the air guiding device in a direction perpendicular to the axis of rotation of the centrifugal fan flow direction. The air conditioner indoor unit can not only improve the fluidity and temperature adjustment of the space air when the indoor unit of the wall-mounted air conditioner is used, but also can adjust the flow direction of the airflow entering the air guiding device.

Description

air conditioner indoor unit

technical field

The utility model belongs to the technical field of air conditioning, in particular to an air conditioning indoor unit.

Background technique

The indoor units of the existing wall-mounted air conditioners are all strip-shaped, and use a cross-flow fan and a bent evaporator for air supply. The indoor unit of the wall-mounted air conditioner is not only prone to appearance visual aesthetic fatigue, but also the wind after heat exchange of the bending evaporator is directly blown out from the air outlet under the action of the internal cross-flow fan, and all the blown air is heat exchange air. One disadvantage of this kind of air supply is that the air sent out is all heat exchange air, the air volume is small, and the indoor air circulation speed is slow; another disadvantage is that the air sent out is not soft enough, especially in the cooling mode, the cool air blown out The wind blows directly on the user, and the user feels uncomfortable.

In addition, because the indoor units of the existing wall-mounted air conditioners are elongated, they are not only bulky and occupy a large installation space, but also not beautiful enough to meet the diverse needs of the market.

Utility model content

The purpose of this utility model is to overcome at least one defect of the existing wall-mounted air conditioner indoor unit, and to provide a novel air conditioner indoor unit, which can not only send out a large amount of air, but also blow out soft mixed air with a suitable temperature, so as to improve the use of air conditioners. The fluidity and temperature regulation of space air when the wall-mounted air conditioner is indoor unit.

A further object of the present invention is to direct the direction of the airflow in the left-right direction (the direction perpendicular to the rotation axis of the centrifugal fan).

Another further object of the utility model is to provide an air conditioner indoor unit with a small volume and a beautiful appearance.

In order to achieve at least one of the above objectives, the utility model provides an air conditioner indoor unit, which includes:

a housing having a first air inlet, a second air inlet and an air outlet;

The centrifugal fan is arranged in the housing, and its rotation axis or the extension line of the rotation axis passes through the first air inlet, and is configured to promote the flow of air from the first air inlet to the air outlet;

A heat exchanger, at least part of the heat exchange section is flat, at least part of the heat exchange section is perpendicular to the rotation axis of the centrifugal fan, and is located between the centrifugal fan and the first air inlet;

The air guiding device is arranged at the air outlet in the casing, configured to introduce the airflow from the centrifugal fan and the airflow from the second air inlet into it for mixing, and make the mixed airflow parallel to the rotation of the centrifugal fan Blow out from the air outlet in a manner that has a velocity component in the direction of the axis; and

A plurality of air guide vanes are arranged in parallel and spaced between the impeller of the centrifugal fan and the air guide device along the direction perpendicular to the rotation axis of the centrifugal fan, and are configured to adjust the inlet air guide in the direction perpendicular to the rotation axis of the centrifugal fan. The flow direction of the airflow of the wind device.

Optionally, each air guide vane is rotatably installed around an axis parallel to the rotation axis of the centrifugal fan between the impeller and the air guiding device.

Optionally, the air guiding device includes at least three wind guiding rings; at least three wind guiding rings are sequentially arranged between the second air inlet and the air outlet, and the central ring holes of the at least three wind guiding rings communicate with each other, so as to A through-air passage is formed, and the through-air passage connects the second air inlet and the air outlet;

A heat exchange air channel connecting the centrifugal fan and the through-air channel is formed between every two adjacent air guide rings, so as to guide the airflow from the centrifugal fan to the through-airway to mix with the airflow from the second air inlet.

Optionally, each air guide slice spans all heat exchange air ducts of the air guiding device.

Optionally, each air guide vane in some or all of the air guide vanes is provided with at least one relief notch, so that at least one wind guide ring located in the middle is respectively inserted into one relief notch.

Optionally, the air-conditioning indoor unit further includes: a linkage rod, which is rotatably mounted to a plurality of air guide vanes in sequence at different positions along its length direction; and a driving device configured to drive a plurality of air guide vanes to rotate.

Optionally, the first air inlet is arranged at the front upper part or the rear upper part of the casing; the second air inlet is arranged at the rear lower part of the casing; and the air outlet is arranged at the front lower part of the casing.

Optionally, the housing includes: a rear shell, a rear wall with a second air inlet opening at the lower part, and an accommodating cavity wall extending forward from the inner surface of the rear wall to define an accommodating space for the centrifugal fan and the air guiding device The centrifugal fan is installed on the upper part of the accommodation space, and the air-drainage guide device is installed on the lower part of the accommodation space; and the front panel is installed on the forward opening of the rear shell, and the upper part is provided with a first air inlet, and the lower part is provided with an air outlet.

Optionally, the air guiding device also includes an air channel wall, which is fixedly connected or integrally formed with the volute of the centrifugal fan, and defines the air guiding channel alone or together with the casing, so that all the airflow from the centrifugal fan flows from The heat exchange air duct enters the through air duct.

Optionally, the volute includes a front volute, which is arranged at the forward opening of the accommodation space, and an air inlet of the centrifugal fan is opened on it; the air channel wall includes a front side air channel wall, which is arranged at the forward opening of the accommodation space and each air guide vane is rotatably installed on the front side air channel wall or the front side volute.

Because the air conditioner indoor unit of the utility model has the first air inlet and the second air inlet, and adopts the centrifugal fan and the air guiding device, it not only has the advantages of large air supply volume, fast indoor air circulation speed, and high heat exchange efficiency, but also can The non-heat-exchange air is mixed with the heat-exchange air after heat exchange, which increases the overall air intake of the indoor unit of the air conditioner, accelerates the flow of indoor air, and further improves the overall uniformity of the indoor air. Such mixed air is relatively soft, and the user will feel more comfortable when it is blown on the body, and the user's comfort experience effect is improved. In addition, the volume of the indoor unit of the air conditioner can also be made smaller, which is not only convenient for installation and movement, but also can be manufactured into various indoor units with beautiful appearance.

Further, since the air-conditioning indoor unit of the present invention has a plurality of air guide vanes between the impeller and the air guide device, the flow direction of the airflow entering the air guide device can be adjusted in a direction perpendicular to the rotation axis of the centrifugal fan. , so that the air outlet angle of the volute air duct can be increased, which is convenient for dispersing the airflow or controlling the direction of the airflow according to needs, so as to speed up the flow of indoor air. Moreover, the direction of the airflow flowing out of the air outlet can also be adjusted to a certain extent in the left and right directions by adjusting the direction of the airflow entering the airflow guiding device through a plurality of airguide vanes.

According to the following detailed description of specific embodiments of the utility model in conjunction with the accompanying drawings, those skilled in the art will be more aware of the above and other objectives, advantages and features of the utility model.

Description of drawings

Hereinafter, some specific embodiments of the present utility model will be described in detail in an exemplary rather than restrictive manner with reference to the accompanying drawings. The same reference numerals in the drawings designate the same or similar parts or parts. Those skilled in the art will appreciate that the drawings are not necessarily drawn to scale. In the attached picture:

Fig. 1 is a schematic structural diagram of an air conditioner indoor unit according to an embodiment of the present invention;

Fig. 2 is a schematic sectional view of the air conditioner indoor unit shown in Fig. 1;

Fig. 3 is a schematic exploded view of the air conditioner indoor unit shown in Fig. 1;

Fig. 4 is a schematic partial structural diagram of the air conditioner indoor unit shown in Fig. 1;

Fig. 5 is a schematic exploded view of a partial structure of the air conditioner indoor unit shown in Fig. 1;

Fig. 6 is a schematic structure diagram of another viewing angle of the air conditioner indoor unit shown in Fig. 1 .

detailed description

Fig. 1 is a schematic structural diagram of an air-conditioning indoor unit according to an embodiment of the present invention, and Fig. 2 is a schematic cross-sectional view of the air-conditioning indoor unit shown in Fig. 1 . As shown in Fig. 1 and Fig. 2, the embodiment of the utility model provides an air conditioner indoor unit. The air conditioner indoor unit may include a housing 20 , a centrifugal fan 30 , a heat exchanger 40 and an air guiding device 50 . The housing 20 may have a first air inlet, a second air inlet and an air outlet. Centrifugal blower 30 can have impeller 31 and volute 32, is arranged in casing 20, and its axis of rotation or the extension line of this axis of rotation passes through the first air inlet, so that its air inlet faces the first air inlet, and configured to promote air flow from the first air inlet to the air outlet.

At least part of the heat exchange section of the heat exchanger 40 is flat, at least part of the heat exchange section is perpendicular to the rotation axis of the centrifugal fan 30 and is located between the centrifugal fan 30 and the first air inlet. Specifically, the heat exchanger 40 is a plate heat exchanger; Set up in sequence, and multiple plate heat exchangers are connected in parallel.

The air guiding device 50 can be arranged at the air outlet in the casing 20, and is configured to combine the airflow from the centrifugal fan 30 (that is, the airflow from the first air inlet and after heat exchange through the heat exchanger 40) with the airflow from the second airflow. The airflow of the air inlet is introduced therein to be mixed, and the mixed airflow is blown out from the air outlet in such a manner that it has a velocity component in a direction parallel to the rotation axis of the centrifugal fan 30 .

The centrifugal fan 30 and the plate-shaped heat exchanger 40 not only significantly increase the air supply volume of the air-conditioning indoor unit, accelerate the indoor air circulation speed, but also improve the heat exchange efficiency between the heat exchanger 40 and the air; it can also make the air-conditioning indoor The volume of the air conditioner is smaller, which is convenient for the installation and movement of the air conditioner indoor unit; and it can also be conveniently processed into various air conditioner indoor units with beautiful appearance. The projection in the plane of the air conditioner is circular or oval, which makes the appearance of the entire air conditioner indoor unit unique and beautiful, which is completely different from the existing strip-shaped wall-mounted air conditioner indoor unit, and meets the individual aesthetic needs of users. It should be noted here that the projection of some shells 20 on a plane perpendicular to the axis is approximately circular, and should also belong to a special form of a circle, that is, it belongs to a kind of concept of the present invention. The air guiding device 50 can make the wind blown by the air conditioner indoor unit softer.

In particular, in the embodiment of the present utility model, the indoor unit of the air conditioner may also include a plurality of air guide vanes 60 to adjust the flow direction of the airflow entering the air guide device 50, that is, to adjust the air intake direction of the air guide device 50, and also to That is, the flow direction of the airflow flowing out of the centrifugal fan 30 is adjusted. Specifically, a plurality of air guide vanes 60 are arranged in parallel and spaced between the impeller 31 and the air guide device 50 along the direction perpendicular to the rotation axis of the centrifugal fan 30 , and are arranged in a direction perpendicular to the rotation axis of the centrifugal fan 30 The flow direction of the airflow entering the air guiding device 50 is adjusted. Here, being arranged between the impeller 31 and the air guiding device 50 can also include being arranged at the inlet of the air guiding device 50 or being arranged in the inlet of the air guiding device 50, and is also used to adjust the air flow entering the air guiding device 50. The direction of air flow.

For example, the first air inlet is disposed on the upper front side or the upper rear side of the casing 20 . The second air inlet is disposed at the lower rear side of the casing 20 . The air outlet is disposed at the lower front side of the casing 20 . As shown in Figures 3 and 4, each wind guide vane 60 is rotatably installed between the impeller 31 and the air guide device 50 around an axis parallel to the rotation axis of the centrifugal fan 30, that is to say, each guide vane The wind vane 60 is rotatably mounted between the impeller 31 and the air guide device 50 around a horizontal longitudinal axis, so as to adjust the flow direction of the airflow entering the air guide device 50 in the left-right direction (transverse direction). The indoor unit of the air conditioner can increase the air outlet angle of the volute air duct, so as to facilitate the dispersion of the air flow or control the direction of the air flow as required, so as to accelerate the flow of indoor air. Moreover, the direction of the airflow flowing out of the air outlet can also be adjusted to a certain extent in the left and right directions by adjusting the direction of the airflow entering the airflow guiding device 50 by the plurality of airguiding fins 60 .

In some further embodiments of the present invention, as shown in FIG. 5 , the air conditioner indoor unit further includes a linkage rod 71 and a driving device 72 . The linkage rod 71 is sequentially and rotatably installed on the plurality of wind guide vanes 60 at different positions along its length direction. The driving device 72 is configured to drive the plurality of wind guide vanes 60 to rotate. For example, the driving device 72 can be a stepping motor, which directly drives one air guide vane 60 to rotate, so that the air guide vane 60 drives other air guide vanes 60 to rotate. For another example, the driving device 72 may include a stepping motor and a connecting rod, and the two ends of the connecting rod are respectively installed on the output shaft of the stepping motor and one end of the linkage rod 71 .

In some embodiments of the present invention, as shown in FIG. 2 and FIG. 3 , the flow guiding device 50 includes at least three wind guiding rings. The at least three air guide rings are sequentially arranged between the second air inlet and the air outlet, and the central ring holes of the at least three air guide rings communicate with each other to form a through-air passage, which communicates with the second air inlet and the air outlet. air outlet. A heat exchange air channel connecting the centrifugal fan 30 and the through-air channel is formed between every two adjacent air guide rings, so as to guide the airflow from the centrifugal fan 30 to the through-airway to mix with the airflow from the second air inlet. Further, the width of the heat exchange air channel can be gradually reduced along the direction of air flow. When the centrifugal fan 30 is working, the negative pressure that can be formed in the through-air passage introduces the airflow that does not exchange heat with the heat exchanger 40 from the second air inlet, so that after heat exchange from the first air inlet and through the heat exchanger 40 The airflow from the second air inlet is mixed with the airflow from the second air inlet to the through air passage, so as to blow out a softer mixed airflow. The air guiding device 50 is particularly suitable for use in conjunction with the centrifugal fan 30 , so that the wind flowing out from the air outlet of the centrifugal fan 30 enters the air guiding device 50 more smoothly.

In this embodiment, each air guiding fin 60 spans all the heat exchanging air channels of the air guiding device 50 to effectively guide the airflow entering each heat exchanging air channel. Preferably, each air guide vane 60 in some or all of the air guide vanes 60 is provided with at least one relief notch 61, so that at least one air guide ring located in the middle is respectively inserted into a concession notch 61, so that the indoor unit of the air conditioner Compact structure.

In some embodiments of the present invention, the casing 20 includes a rear case 21 and a front panel 22 detachably installed at the front opening of the rear case 21 . The upper part of the front panel 22 is provided with a first air inlet, and the lower part is provided with an air outlet. The air outlet faces obliquely downward, and its inclination angle is 4° to 40°, preferably 10°. The arrangement of the air outlet in this way, combined with the structural design of the air guiding device 50, enables the wind sent from the air outlet to flow forward and downward. Further, a baffle plate 24 may also be provided at the first air inlet to guide the airflow and/or open and close the first air inlet. The shielding plate 24 is rotatably mounted to the housing 20 at its lower end edge.

The rear shell 21 may have a rear wall 211 , a peripheral wall and an accommodating cavity wall 212 . A second air inlet is opened at the lower part of the rear wall 211 . The accommodating cavity wall 212 extends forward from the inner surface of the rear wall 211 to define an accommodating space for accommodating the centrifugal fan 30 and the air guiding device 50 . Further, as shown in FIG. 6 , a wall hanging plate 80 may be provided on the upper part of the rear surface of the rear wall 211 , and the air conditioner indoor unit may be fixed on the wall through the wall hanging plate 80 . The lower part of the rear surface of the rear wall 211 can be recessed inwardly, and the second air inlet is formed on the lower part of the rear surface of the rear wall 211, so that air enters the second air inlet from the gap between the lower part of the rear surface of the rear wall 211 and the wall.

The centrifugal fan 30 can be a one-way centrifugal fan, and is installed on the upper part of the accommodating space. The air guiding device 50 is installed at the lower part of the accommodating space. The heat exchanger 40 is a plurality of plate heat exchangers, and the plurality of plate heat exchangers are arranged in sequence along the vertical direction. For example, the number of plate heat exchangers can be two, which are the first plate heat exchanger 41 with a larger area and longer length at the bottom and the second plate heat exchanger with a smaller area and shorter length at the top. The heat exchanger 42 is used to make full use of the shape of the shell 20 to expand the heat exchange area of the heat exchanger 40 and improve the heat exchange efficiency. A heat exchanger fixing frame 43 may also be provided to install the first plate heat exchanger 41 and the second plate heat exchanger 42 in the casing 20 .

In the embodiment of the present utility model, the air guiding device 50 can also include an air channel wall 54, which is fixedly connected or integrally formed with the volute 32 of the centrifugal fan 30, and defines the air guiding channel separately or together with the housing 20 , so that all the airflow from the centrifugal fan 30 enters the through-air passage from the heat exchange air passage. For example, the air channel wall 54 and the rear wall 211 of the casing 20 can jointly define the air guide channel. Specifically, the volute 32 of the centrifugal fan 30 may include a front volute disposed at the forward opening of the accommodation space and a peripheral volute extending backward from the front volute, and a centrifugal fan is provided on the front volute. 30 air inlet. The volute 32 of the centrifugal fan 30 and the inner surface of the rear wall 211 define a volute air duct. The air channel wall 54 may include a front air channel wall disposed at the forward opening of the accommodation space and a peripheral air channel wall extending backward from the front air channel wall. The front air channel wall is preferably integrally formed with the front volute, and the peripheral air channel wall is preferably integrally formed with the peripheral volute, so as to make the air flow more smoothly. The projection of the lower part of the peripheral air channel wall on the front air channel wall is preferably semicircular, so that all the airflow from the centrifugal fan 30 enters the through air channel from the heat exchange air channel. In some alternative embodiments of the present utility model, the volute 32 of the centrifugal fan 30 only includes the front volute, and the air duct wall 54 only includes the front air duct wall. The volute 32 and the air channel wall 54 cover the front opening of the accommodating space, together with the accommodating cavity wall 212 and the rear wall 211 , define the volute air channel and the guide air channel.

In the embodiment of the present invention, as shown in FIG. 5 , each wind guide vane 60 is rotatably mounted on the front air duct wall 54 or the front volute 32 . Specifically, the front side air channel wall or the front side volute protrudes to the inside with a plurality of rotating shafts arranged at intervals along the horizontal and transverse direction, and the front side air channel wall or the front side volute is aligned along the arrangement direction of the plurality of rotating shafts. One outer side is provided with a turning hole. A rotating shaft of the driving device 72 is inserted into a rotating hole of the wind guide vane 60 through the rotating hole. The rotating holes of the other air guide vanes 60 are respectively installed on a rotating shaft.

Further, the at least three wind guiding rings of the air guiding device 50 are the rear wind guiding ring 51, the front wind guiding ring 53, and one or more intermediate wind guiding rings located between the rear wind guiding ring 51 and the front wind guiding ring 53. Circle 52. The rear air guide ring 51 extends forward from the edge of the second air inlet to be integrally formed with the rear wall 211 . A through hole is opened on the front side air channel wall 54 , and the front air guiding ring 53 extends forward from the edge of the through hole to form an integral body with the air channel wall 54 . Such setting not only significantly improves the convenience of processing, but also facilitates the flow of airflow, improves the smoothness of airflow flow, and reduces noise. Further, in this embodiment, there are three wind guiding rings, which are the front wind guiding ring 53 , the middle wind guiding ring 52 and the rear wind guiding ring 51 . The middle air guide ring 52 can be installed on the rear air guide ring 51 through a plurality of connecting pieces. The plurality of connecting pieces also have the function of guiding the airflow.

In the embodiment of the present utility model, the indoor unit of the air conditioner may further include a water receiving pan 90 fixed to the housing 20 and/or the front air guiding ring 53 and located between the heat exchanger 40 and the front air guiding ring 53 . The water receiving tray 90 can extend horizontally and horizontally, and the bottom of the tank is slightly inclined so that one end of the tank bottom is lower than the other end of the tank bottom, and the lower end of the tank bottom of the water receiving tray 90 can be opened for connecting condensed water The outlet hole of the drain pipe.

So far, those skilled in the art should recognize that although a number of exemplary embodiments of the present invention have been shown and described in detail herein, they can still be used according to the present invention without departing from the spirit and scope of the present invention. Many other variations or modifications that conform to the principles of the utility model are directly determined or derived from the disclosed content of the new model. Therefore, the scope of the present invention should be understood and deemed to cover all such other variations or modifications.

Claims (10)

1. An air-conditioning indoor unit, characterized in that, comprising: a housing having a first air inlet, a second air inlet and an air outlet; A centrifugal fan is arranged in the housing, and its rotation axis or the extension line of the rotation axis passes through the first air inlet, and is configured to promote air flow from the first air inlet to the air outlet; A heat exchanger, at least part of the heat exchange section is flat, the at least part of the heat exchange section is perpendicular to the rotation axis of the centrifugal fan, and is located between the centrifugal fan and the first air inlet; The air guiding device is arranged at the air outlet in the housing, configured to introduce the airflow from the centrifugal fan and the airflow from the second air inlet into it for mixing, and make the mixed airflow blown out from the air outlet in a manner having a velocity component in a direction parallel to the rotational axis of the centrifugal fan; and A plurality of air guide vanes are arranged in parallel and spaced between the impeller of the centrifugal fan and the air guiding device along a direction perpendicular to the rotation axis of the centrifugal fan, and are configured to rotate perpendicular to the rotation of the centrifugal fan. The direction of the airflow entering the air guiding device is adjusted in the direction of the axis. 2. The air conditioner indoor unit according to claim 1, characterized in that: Each of the air guide blades is rotatably installed around an axis parallel to the rotation axis of the centrifugal fan between the impeller and the air guiding device. 3. The air conditioner indoor unit according to claim 2, characterized in that: The air guiding device includes at least three wind guiding rings; The at least three wind guiding rings are sequentially arranged between the second air inlet and the air outlet, and the central ring holes of the at least three wind guiding rings communicate with each other to form a through air channel, and the through The air duct communicates with the second air inlet and the air outlet; A heat exchange air channel connecting the centrifugal fan and the through-air channel is formed between every two adjacent air guide rings, so as to guide the airflow from the centrifugal fan to the through-air channel and from the through-air channel. The airflow in the second air inlet is mixed. 4. The air conditioner indoor unit according to claim 3, characterized in that: Each of the air guide vanes spans all the heat exchange air passages of the air guiding device. 5. The air conditioner indoor unit according to claim 4, characterized in that: Each of the part or all of the air guide vanes is provided with at least one relief notch, so that at least one wind guide ring located in the middle is respectively inserted into one of the relief notches. 6. The air conditioner indoor unit according to claim 3, further comprising: a linkage rod, which is sequentially rotatably mounted to the plurality of air guide vanes at different positions along its length; and The driving device is configured to drive the plurality of wind guide vanes to rotate. 7. The air conditioner indoor unit according to claim 3, characterized in that: The first air inlet is arranged on the front upper part or the rear upper part of the housing; The second air inlet is arranged at the rear lower part of the housing; The air outlet is arranged at the lower front side of the housing. 8. The air conditioner indoor unit according to claim 7, wherein the housing comprises: The rear shell has a rear wall with the second air inlet opening at the lower part, and an accommodating cavity wall extending forward from the inner surface of the rear wall to define an accommodating space for the centrifugal fan and the air guiding device The centrifugal fan is installed on the upper part of the accommodation space, and the air guiding device is installed on the lower part of the accommodation space; and The front panel is installed at the forward opening of the rear shell, the first air inlet is opened on the upper part, and the air outlet is opened on the lower part. 9. The air conditioner indoor unit according to claim 8, characterized in that: The air guiding device also includes an air channel wall, which is fixedly connected or integrally formed with the volute of the centrifugal fan, and defines the air guiding channel alone or together with the casing, so that the air from the centrifugal fan All the airflow enters the through air passage from the heat exchange air passage. 10. The air conditioner indoor unit according to claim 9, characterized in that: The volute includes a front volute, which is arranged at the forward opening of the accommodating space, and an air inlet of the centrifugal fan is opened on it; The air channel wall includes a front side air channel wall, which is arranged at the forward opening of the accommodating space; and Each of the air guide vanes is rotatably mounted on the front side air duct wall or the front side volute.