Direction control apparatus for condenser fan

Abstract

 The condenser fan assembly contains a plurality of independently operated condenser fans, each of which includes a motor (2) that is connected to a fan blade (1) by means of a shaft (3). A housing (7) surrounds the shaft (3) of each motor (2) and in anchored in the end bell (5) of the motor (2). A one-way clutch (6) is mounted in the housing (7) and is connected to the shaft (3) to permit rotation of the motor (2) in one direction and prevent rotation of the motor (2) in the opposite direction.

Description

[0001] A fan assembly is a conventional component of the condenser section of air conditioning units. Condenser sections are advantageously equipped with a plurality of fans, not all of which are always in operation simultaneously.

[0002] Problems arise when a condenser section includes more than a single fan. One such problem is the so-called "windmill" effect. Air currents generated by the fan or fans in operation may cause blades of a fan or fans of the condenser section not in operation, and consequently their corresponding idle motors, to rotate. This is the so-called "windmill" effect.

[0003] Frequent windmilling rotation will occur in a direction opposite that of the fan or fans in operation. When idle fans so windmilling are actuated, high forces will have to be applied to their motors, shafts, and fan propellers to correct their direction, which may damage their motor's shaft, fan propellers, their response, waste energy, and otherwise impair their performance.

[0004] Prior attempts to control "windmilling" of idle fans include the presence of "egg-crate-like" baffle partitions dividing and separating each fan one from another, thereby isolating the air path of each. Fig. 1 shows a typical prior art fan-assembly unit having baffle partitions. The use of these partitions has not been entirely successful and, under certain conditions, can adversely effect the flow of air through the unit.

[0005] It is an object of this invention to provide a new and efficient means and method controlling or eliminating the windmilling of idle condenser fans.

[0006] This object is achieved in an apparatus according to the preambles of the claims and by the features of the characterizing parts thereof.

[0007] In accordance with the present invention, there is provided with each fan assembly that may cycle on and off of a condenser section a motor direction control means e.g., a clutch or ratcheting mechanism) such that any motion in the opposite direction of desired rotation will automatically activate the direction control means which will prevent reverse rotation.

[0008] Fig. 1 is a perspective view showing a prior art roof top fan assembly unit containing two condenser fan units with the fan blades removed for clarity.

[0009] Fig. 2 is a side elevation with sections broken away showing a condenser fan according to the present invention with a clutch unit attached thereto.

[0010] Fig. 3 is an enlarged view showing a clutch unit according to the present invention mounted upon the end bell of a fan housing.

[0011] Turning initially to Fig. 1 there is shown a typical roof top air cooled condenser unit generally referenced (10) containing a number of condenser sections mounted in a side by side relationship wherein the activity of one section can produce a windmilling effect upon an adjacent section when the fan 1 of an adjacent section is idle. The condenser sections are mounted in a frame 11 of the type normally found on rooftops of buildings.

[0012] The present invention will now be described with reference to the preferred embodiment. Figs. 2 and 3 show the relationship among the essential components of a clutch motor fan assembly according to the present invention.

[0013] Each fan of an air conditioning condenser section (10) Fig. 1 is equipped with a fan blade (1) which is connected to fan motor (2) by a fan shaft (3). A clutch assembly (4) to control motor rotation, surrounds the lower portion of fan shaft (3) and is protected from rain, snow and other adverse climatic elements by rain shield (5). A fan guard (4) is disposed parallel to, and in a plane above the upper surface of fan blade (1) to isolate the fan blade from accidental contact with a solid object.

[0014] The clutch assembly (4), which houses clutch (6), is attached to fan motor (2) by means of teeth (8) which project from clutch housing (7). The clutch assembly (4) is enclosed in motor bell (5) of fan motor (2) so as to surround fan motor shaft (3), as shown in Fig. 3.

[0015] The clutch assembly (4), which houses clutch (6), is press fitted into clutch housing (7). The clutch assembly is attached to fan motor (2) by means of teeth (8) which are embedded in and anchored to motor bell (5) of fan motor (2) so as to surround fan motor (3) as shown in Fig. 3. A suitable clutch is manufactured by Torrington Co. of Torrington, CT. The clutch can be activated automatically or manually to lock motor shaft (3) when it begins to turn in one direction and to release motor shaft (3) when it begins to tum in the opposite direction.

[0016] While the preferred embodiment employs a clutch as the means to control the direction of fan motor rotation, it will be appreciated that other motor direction control means lie within the scope of the present invention. For example, a ratcheting mechanism can be substituted for a clutch. In one such embodiment, the teeth of the ratcheting mechanism are attached to the fan motor shaft and the pawl or catch of the ratcheting mechanism is disposed in the surrounding housing. Similarly, without departing from the spirit of the present invention, the housing to enclose and protect the motion control means can be attached to the motor bell by means other than teeth such as, for example, by spiral threads disposed around the bottom of the housing which engages a collar or socket in the motor bell or by means of a bayonet mount, or by rivets.

Claims

1. Air conditioning apparatus which includes a condenser fan having fan blades and a shaft which is operatively connected to said fan blades and to means for rotating said fan blades in one direction, rotation means characterized by means to restrict motor rotation of the fan blades in the opposite direction.

2. In air conditioning apparatus which includes a plurality of independently operated fan blades, each of which is operatively connected to a means for rotating said fan blades in one direction, the improvement in combination therewith being characterized by a means to restrict a motor rotation direction of each rotation means in an opposite direction.

3. Air conditioning apparatus as claimed in claim 1 wherein the means to restrict motor rotation means is a clutch.

4. Air conditioning apparatus as claimed in claim 1 wherein the means to restrict motor rotation means is a ratcheting mechanism.

5. The apparatus of claim 1 wherein the means for rotating said fan blades is a motor for rotating the shaft in one direction and an end bell through which the shaft passes, a housing surrounding said shaft that is anchored to said end bell and a one-way clutch mounted in said housing for engaging said shaft to permit the shaft to rotate in said one direction and prevent the shaft from rotating in an opposite direction.

Drawing