Patent Application
20190092126
The present disclosure relates to a rotary shaft assembly with a nested shaft for use with a ventilation system.
Heating, ventilation, and air conditioning (HVAC) systems are widely used. In certain applications, such as automotive, it may be desirable to reduce the size of the HVAC system while improving the functionality of the HVAC system.
According to an aspect of the present disclosure, a rotary shaft assembly includes an outer shaft and a nested shaft disposed within the outer shaft. An outer opening is formed on a circumferential wall of the outer shaft, and a nested opening is formed on a circumferential wall of the nested shaft. The nested shaft is rotatably supported within the outer shaft.
A first embodiment of the present disclosure will be described with reference to
The housing 100 is preferably made of a rigid metal or polymer material, and houses the other components of the HVAC system 1. The housing 100 includes air vents 102, 104, 106. Each air vent 102, 104, 106 is preferably integrally formed in the wall of housing 100, and allows air to exit the HVAC system 1. For example, when the HVAC system 1 is equipped within a vehicle, the air vents 102, 104, 106 may direct air toward the windshield, the upper body of a passenger, or the lower body of a passenger.
The blower 110 is configured to blow intake air in an airflow direction as shown by the arrows in
The evaporator 120 is disposed downstream of the blower 110 in the airflow direction, and is part of a refrigeration cycle (not shown) which includes typical refrigeration cycle components such as an expansion valve, a compressor, and so on. The evaporator 120 is configured to exchange heat between air blown by the blower 110 and an internal coolant which has been cool by the refrigeration cycle. As a result, the evaporator 120 cools the air blown by the blower 110.
The heater 130 is disposed downstream of the evaporator 120, and is configured to heat the air flowing past the heater 130. In the present embodiment, the heater 130 is part of same the refrigeration cycle as the evaporator 120, and therefore is configured to exchange heat between air and an internal coolant (not shown) which has been heated by the refrigeration cycle. However, the heater 130 may alternatively be implemented as an electric heater or other type of heater which may operate independently of a refrigeration cycle.
The slide doors 140, 150 are disposed along the airflow direction within the housing 100, and are configured to direct the path of the air flowing within the housing 100. In other words, the slide doors 140, 150 function as so-called air-mix doors. In particular, the slide doors 140, 150 are disposed downstream of the evaporator 120, and are configured to slide along a slot to either direct air toward the heater 130 or direct air to bypass the heater 130. As illustrated, each slide door 140, 150 is coupled to a respective rotary shaft assembly 200 as a rack and pinion system, such that rotation in the rotary shaft assembly 200 is converted to linear motion in the slide doors 140, 150.
The rotary doors 160, 170, 180 are disposed adjacent to the entrances of respective vents. Specifically, the rotary door 160 is disposed adjacent to the vent 106, the rotary door 170 is disposed adjacent to the vent 102, and the rotary door 180 is disposed adjacent to the vent 104. The rotary doors 160, 170180 are configured to rotate, thereby selectively permitting or prohibiting air from entering their respective vents. As illustrated, the rotary door 160 is also coupled to a rotary shaft assembly 200. In particular, the rotary door 160 is directly attached to its respective rotary shaft assembly 200.
In the present embodiment, each rotary shaft assembly 200 shown in
In
The outer shaft 210 is hollow to define a first passage 212 within the outer shaft 210. An outer opening 214 is formed on the circumferential wall of the outer shaft 210. The outer opening 214 opens into the first passage 212. In addition, an outer engagement portion 219 is formed on one end of the outer shaft 210. The outer engagement portion 219 is configured to be engaged with, e.g., an actuator as will be described later.
The nested shaft 250 is configured to be disposed within the outer shaft 210. In particular, the nested shaft 250 is configured to be rotatably supported within the first passage 212 of the outer shaft 210. The outer shaft 210 and the nested shaft 250 are preferably coaxial so as to share a common axis, but this is not limiting and other arrangements are contemplated. For example, the nested shaft 250 may be loosely fitted within the outer shaft 210, or be supported by a bearing member (not illustrated) disposed within the outer shaft 210. The nested shaft 250 is also hollow to define a second passage 252 within the nested shaft 250. A nested opening 254 is formed on the circumferential wall of the nested shaft 250. The nested opening 254 opens into the second passage 252. In addition, a nested engagement portion 259 is formed on one end of the nested shaft 250. The nested engagement portion 259 is configured to be engaged with, e.g., an actuator as will be described later.
Here, the nested shaft 250 includes a first open end 256 and a second open end 258, both of which open into the second passage 252. In other words, the nested opening 254, first open end 256, and the second open end 258 are all in fluid communication with each other through the second passage 252. It should be noted that the outer shaft 210 is also open-ended. However, since the nested shaft 250 is disposed within the outer shaft 210, the open ends of the outer shaft 210 are effectively the same as the open ends of the nested shaft 250, and therefore are omitted from description herein.
In the present embodiment, the rotary shaft assembly 200 is coupled to an actuator 300. As shown in
In contrast,
It should be noted that the angles A1, A2 depicted in
In the present disclosure, the terms “overlap” and “offset” are intended to denote states of fully overlapping and fully offset. For instance, if the angles A1, A2 of the outer opening 214 and the nested opening 254 are equal, then the outer opening 214 and the nested opening 254 are considered to be overlapping when they are in total alignment (typical measurement errors, control errors, etc. permitting).
If the angles A1, A2 of the outer opening 214 and the nested opening 254 are not equal, then the outer opening 214 and the nested opening 254 are considered to be overlapping when the smaller one of the two openings is entirely enveloped by the larger of the two openings. Similarly, the outer opening 214 and the nested opening 254 are considered to be offset from each other when no overlapping occurs. Any state other than overlapping and offset as defined above may be referred to as “partially overlapping” or “partially offset”.
The nested shaft 250 is configured to be rotatable between at least the state shown in
Returning to
In particular, the actuator 300 is configured to independently control the rotation of the outer shaft 210 to open or close a door, such as the slide doors 140, 150 or the rotary door 160, thereby adjusting the flow of air through the HVAC system 1. For example, an external ECU may control the actuator 300 to rotate the outer shaft 210 in accordance with air conditioning needs. In other words, the outer shaft 210 may be controlled to operate doors in a conventional manner, i.e., without considering the relative rotation angle between the outer shaft 210 and the nested shaft 250.
Then, after the outer shaft 210 is rotated to a desired rotation position (e.g., after opening or closing an air-mix door), the actuator 300 then independently controls the rotation of the nested shaft 250 to set the relative rotation angle between the outer shaft 210 and the nested shaft 250 to open or close the rotary shaft assembly 200 as needed. For example, if the first open end 256 of the nested shaft 250 is fluidly connected to a glove box, the actuator 300 rotates the nested shaft 250 such that the rotary shaft assembly 200 is open when an external ECU determines that the glove box should be cooled.
It should be noted that while the outer shaft 210 and the nested shaft 250 are controlled independently, the outer shaft 210 and the nested shaft 250 may nevertheless be controlled contemporaneously. For example, when the relative rotation angle between the outer shaft 210 and the nested shaft 250 is to be maintained at a constant value, the nested shaft 250 may be controlled to rotate together with the outer shaft 210, thereby maintaining a constant relative rotation angle between the outer shaft 210 and the nested shaft 250.
In the present embodiment, the rotary shaft assembly 200 includes the outer shaft 210 which defines the first passage 212, the outer opening 214 being formed on a circumferential wall of the outer shaft 210, and the nested shaft 250 which defines a second passage 252 and which is rotatably supported within the first passage 212 of the outer shaft 210, the nested opening 254 being formed on a circumferential wall of the nested shaft 250. The nested shaft 250 and the outer shaft 210 are configure to be rotatable with respect to each other about a common axis such that a relative rotation angle between the outer shaft 210 and the nested shaft 250 varies between a first angle at which the outer opening 214 overlaps with the nested opening 254, and a second angle at which the outer opening 214 is offset from the nested opening 254.
As a result of this configuration, the air within the HVAC system 1 may flow directly into each rotary shaft assembly 200, as shown by the arrows in
In a comparative example, if the rotary shaft assemblies 200 are not provided, then additional vents or ports may need to be formed in the housing 100 to supply conditioned air to auxiliary devices or compartments. The number of such vents or ports may be limited due to space constraints. Further, such vents or ports may require additional mounting space both inside and outside of the housing 100, therefore increasing the overall space requirements for mounting the HVAC system 1. In this regard, when compared to the comparative example, the HVAC system 1 of the present embodiment, which is provided with the rotary shaft assemblies 200, may supply heated, cooled, or conditioned air to a greater number of auxiliary devices or compartments, and may be manufactured to be more space efficient.
A second embodiment of the present disclosure will be described with reference to
The nested shaft 450 is configured to be disposed within the outer shaft 210. In particular, the nested shaft 450 is configured to be rotatably supported within the first passage 212 of the outer shaft 210. For example, the nested shaft 450 may be loosely fitted within the outer shaft 210, or be supported by a bearing member (not illustrated) disposed within the outer shaft 210.
The nested shaft 450 is hollow. A partition wall 457 is disposed in the center portion of the nested shaft 450 to divide the inside of the nested shaft 450 into a first nested passage 452 and a second nested passage 453. A first nested opening 454 that opens into the first nested passage 452 is formed on the circumferential wall of the nested shaft 450. A second nested opening 455 that opens into the second nested passage 453 is formed on the circumferential wall of the nested shaft 450. The nested shaft 450 also includes a first open end 456 which opens into the first nested passage 454 and a second open end 458 which opens into the second nested passage 455. In addition, a nested engagement portion 459 is formed on one end of the nested shaft 450. As shown in
The rotary shaft assembly 400 is configured to be coupled to the actuator 300 in a similar manner as in the first embodiment. As such, explanations of this will be omitted for brevity.
In addition, as mentioned previously, the first nested opening 454 and the second nested opening 455 are partially offset from each other in the circumferential direction. This is illustrated in
When the relative rotation angle between the outer shaft 210 and the nested shaft 450 is at the first angle, the first open end 456 is in fluid communication with the outer opening 214 and the second open end 458 is fluidly blocked from the outer opening 214. When the relative rotation angle between the outer shaft 210 and the nested shaft 450 is at the second angle, the first open end 456 is in fluid communication with the outer opening 214 and the second open end 458 is in fluid communication with the outer opening 214. When the relative rotation angle between the outer shaft 210 and the nested shaft 450 is at the third angle, the first open end 456 is fluidly blocked from the outer opening 214 and the second open end 458 is in fluid communication with the outer opening 214.
As a result of this configuration, the air within the HVAC system 1 may flow directly into each rotary shaft assembly 200, and in addition, this air may be directed to flow out of only the first open end 456, only the second open end 458, or both the first open end 456 and the second open end 458. This allows the rotary shaft assembly 200 to be more flexible in directing conditioned air toward auxiliary devices or compartments. For example, the rotary shaft assembly 200 may be controlled (e.g., by an external ECU) such that when receiving cooled air, only the first open end 456 is open, and when receiving heated air, only the second open end 458 is open. In this regard, the HVAC system 1 of the present embodiment may supply heated, cooled, or conditioned air to a greater number of auxiliary devices or compartments, and may be manufactured to be more space efficient.
The present disclosure is described with reference to the above embodiments, but these embodiments are not intended to be limiting. A variety of modifications which do not depart from the gist of the present disclosure are contemplated.
In the above described embodiments, the rotary shaft assembly is described as being open when the outer opening overlaps with the nested opening or nested openings. However, this is not intended to be limiting, and the rotary shaft assembly may be considered to be open as long as the outer opening partially overlaps with a nested opening, such that airflow into the rotary shaft assembly is permitted.
In the above described embodiments, the outer shaft and the nested shaft are illustrated as including a specific number of openings. For instance, in
In the above described embodiments, the nested shaft is described as including the first open end and the second open end, thereby allowing conditioned air to exit out of both ends of the rotary shaft assembly. However, in alternative embodiments, the nested shaft may include only of the first open end, or only the second open end, such that conditioned air only exits out of one end of the rotary shaft assembly.
In the above described embodiments, the outer shaft and the nested shaft are described as being engaged to the actuator through the engagement portions. However, a variety of alternative engagement types are contemplated, as long as the actuator is able to engage the outer shaft and the nested shaft. For example, instead of the engagement portions, gear teeth may be provided on the outer surfaces of the outer shaft and the nested shaft, and the actuator may engage these gear teeth instead. As another example, the outer shaft and the nested shaft may be controlled by a mechanical linkage, e.g., a pin and groove linkage system.
In the above described embodiments, the rotary shaft assembly is described as being coupled to the actuator which independently rotates the outer shaft and the nested shaft. In alternative embodiments, the rotary shaft assembly may instead be connected to separate actuators which independently control respective ones of the outer shaft and the nested shaft. In such a case, one of the actuators may be a conventional type which controls the outer shaft based on conventional door control needs, while another one of the actuators may be a specialized actuator which controls the nested shaft to open or close the rotary shaft assembly.
In the above description, the second embodiment is described as including a partition wall. However, the partition wall may also be applied to the first embodiment as well. For instance, in the first embodiment, the outer opening of the outer shaft may be divided along the axial direction of the outer shaft into two outer openings, and a partition wall may be disposed between the two outer openings such that each outer opening is only fluidly connected to one end of the outer shaft.
In the second embodiment, the outer shaft is provided with a single outer opening, while the nested shaft is provided with the first nested opening and the second nested opening. However, this arrangement may be reversed, such that the outer shaft is provided with two partially offset openings while the nested shaft is provided with a single opening.
In the second embodiment, the first nested opening and the second nested opening are partially offset from each other in the circumferential direction. In an alternative embodiment, the first nested opening and the second nested opening may be completely offset from each other in the circumferential direction.
The outer opening(s) and nested opening(s) described herein are illustrated as having a square outline. In alternative embodiments, these openings may have any type of outlines, such as circular, elliptical, or irregular, as long as fluid may be selected allowed to enter the rotary shaft assembly.
The use of terms such as “first”, “second”, “third”, or “fourth” is solely for the purpose of identification, and is not intended to limit the order or relationships of applicable elements.
