Radial venting axial fan for a power machine

Abstract

A heat exchange system for a power machine that has an engine compartment and a heat exchanger compartment is discussed. The heat exchange system includes a fan housing located between the heat exchanger compartment and the engine compartment. A fan assembly that includes an axial fan and a radial fan coupled to a center shaft having a longitudinal axis extending through the center shaft is positioned within the fan housing. The fan assembly is operably coupled to a fan drive mechanism that is configured to cause the fan assembly to rotate about the longitudinal axis in a first direction and a second direction. First and second control signals from a controller cause the drive mechanism to rotate in the first and second directions, respectively.

1 . A heat exchange system for a power machine having an engine compartment and a heat exchanger compartment, comprising:
 a fan housing located between the heat exchanger compartment and the engine compartment;   a fan assembly positioned within the fan housing, the fan assembly including a center shaft with an axial fan and a radial fan coupled thereto and wherein the fan assembly has a longitudinal axis that extends lengthwise through the center shaft;   a fan drive mechanism operably coupled to the fan assembly and configured to cause the fan assembly to rotate about the longitudinal axis in a first direction and a second direction; and   a controller operably coupled to the fan drive mechanism and configured to provide a first control signal to the fan drive mechanism to cause the fan drive mechanism to rotate in the first direction and a second control signal to the fan drive mechanism to cause the fan drive mechanism to rotate in the second direction.   
     
     
         2 . The heat exchange system of  claim 1 , wherein the controller is configured to receive at least one input signal and wherein the controller provides one of the first and second control signals to the fan drive mechanism based on the at least one input signal. 
     
     
         3 . The heat exchange system of  claim 2 , wherein the at least one signal is indicative of temperature. 
     
     
         4 . The heat exchange system of  claim 2 , wherein the at least one input signal is indicative of the status of a fan override device. 
     
     
         5 . The heat exchange system of  claim 1 , wherein the fan drive mechanism includes:
 a bi-directional motor having an output shaft coupled to the fan assembly; and   a directional control device coupled to the bi-directional motor and configured to cause the output shaft of the bi-directional motor to rotate in the first direction in response to the first control signal and to rotate in the second direction in response to the second control signal.   
     
     
         6 . The heat exchange system of  claim 5 , wherein the bi-directional motor is a hydraulic motor and wherein the directional control device supplies hydraulic oil to the bi-directional motor in response to the first and second control signals. 
     
     
         7 . A power machine having a engine located in an engine compartment and a heat exchanger located in a heat exchanger compartment, the power machine comprising:
 a fan housing having a fan assembly located therein positioned between the engine compartment and the heat exchanger compartment, the fan assembly configured to be rotated in a first direction and a second direction;   a sensor configured to provide a sensor signal indicative of an operational condition;   a fan override device capable of being manipulated by the operator and configured to provide an override signal indicative of the status of the fan override device; and   a controller operably coupled to the fan assembly and configured to receive the sensor signal and the fan override signal wherein the controller is further configured to control rotation of the fan assembly based on the sensor signal and the operator signal.   
     
     
         8 . The power machine of  claim 7 , wherein the controller is configured to control the rate of speed of the rotation of the fan assembly. 
     
     
         9 . The power machine of  claim 7 , wherein the controller is configured to cause the fan assembly to rotate in the first direction based on the sensor signal. 
     
     
         10 . The power machine of  claim 7 , wherein the controller is configured to cause the fan assembly to rotate in the second direction based on the sensor signal. 
     
     
         11 . The power machine of  claim 10 , wherein the controller is configured to cause the fan assembly to change the direction of rotation from the second direction to the first direction after a pre-determined amount of time has elapsed. 
     
     
         12 . The power machine of  claim 7 , wherein the controller is configured to cause the fan assembly to rotate in one of the first direction and the second direction based on the fan override signal. 
     
     
         13 . The power machine of  claim 7 , wherein the controller is configured to cause the fan assembly to rotate in one of the first direction and the second direction based on the fan override signal, and wherein the fan override signal overrides the sensor signal. 
     
     
         14 . A method of exchanging heat in a power machine, comprising:
 providing a fan housing between an engine compartment and a heat exchanger compartment having a fan assembly with an axial fan operably coupled to a radial fan capable of being rotated in two different directions located therein;   receiving a first signal indicative of a status of a fan override input;   receiving a second signal indicative of a status of an operating condition of the power machine; and   controlling the direction of rotation of the fan assembly in response to the first and second signals.   
     
     
         15 . The method of  claim 14 , wherein the step of controlling the direction of rotation of the fan assembly comprises:
 causing the fan assembly to draw air into the fan housing from the heat exchanger and the engine compartment.   
     
     
         16 . The method of  claim 14 , wherein the step of controlling the direction of rotation of the fan assembly comprises:
 causing the fan assembly to force air from the fan housing into the heat exchanger and the engine compartment.   
     
     
         17 . The method of  claim 16 , wherein the step of causing the fan assembly to force air from the fan housing into the heat exchanger and the engine compartment is performed in response to the second signal. 
     
     
         18 . The method of  claim 16 , wherein the step of causing the fan assembly to force air from the fan housing into the heat exchanger and the engine compartment is performed in response to the first signal. 
     
     
         19 . The method of  claim 14 , wherein the step of controlling the direction of rotation of the fan assembly comprises:
 causing the fan assembly to force air from the fan housing into the heat exchanger and the engine compartment; and   after a predetermined amount of time, causing the fan assembly to draw air into the fan housing from the heat exchanger and the engine compartment.   
     
     
         20 . The method of  claim 14 , and further comprising: controlling the rate of speed of rotation of the fan assembly.