Method and arrangement for controlling transmission oil temperature

Abstract

A temperature control arrangement includes a heat exchanger which is fluidly connected via a transmission oil circuit to a transmission of the vehicle. A heat accumulator is fluidly connected to the transmission oil circuit and a control device is arranged in the transmission oil circuit. The control device subdivides the transmission oil circuit into an accumulator circuit containing the heat accumulator and a cooling circuit containing the heat exchanger. The heat accumulator alternately accumulates thermal energy from the transmission oil and delivers previously stored thermal energy to the transmission oil. The control device is configured to direct the transmission oil circulating within the transmission oil circuit at least partially to the heat exchanger and/or to the heat accumulator.

What is claimed is: 
     
         1 . A temperature control arrangement for transmission oil of a vehicle, comprising:
 a heat exchanger fluidly connected to a transmission oil circuit of the transmission of the vehicle and configured to conduct thermal energy from the transmission oil to ambient air;   a heat accumulator fluidly connected to the transmission oil circuit and configured to alternately absorb thermal energy from the transmission oil and to deliver previously stored thermal energy to the transmission oil; and   a control device arranged in the transmission oil circuit by which the transmission oil circuit is subdivided into an accumulator circuit containing the heat accumulator and a cooling circuit containing the heat exchanger, the control device configured to alternately direct the transmission oil circulating within the transmission oil circuit to the cooling circuit and to the accumulator circuit.   
     
     
         2 . The temperature control arrangement of  claim 1 , wherein the control device is configured to direct transmission oil through the heat accumulator in response to an oil temperature being less than a threshold and to direct transmission oil through the heat exchanger in response to the oil temperature being greater than the threshold. 
     
     
         3 . The temperature control arrangement of  claim 1 , wherein the control device is arranged upstream of the heat exchanger. 
     
     
         4 . The temperature control arrangement of  claim 3 , wherein the accumulator circuit and cooling circuit are arranged in parallel. 
     
     
         5 . The temperature control arrangement of  claim 1  wherein the heat accumulator is a chemical heat accumulator. 
     
     
         6 . A temperature control arrangement comprising:
 a heat exchanger;   a chemical heat accumulator; and   a control device configured to direct transmission oil through the heat accumulator in response to a temperature of the transmission oil being less than a threshold and to direct the transmission oil through the heat exchanger in response to the temperature exceeding the threshold.   
     
     
         7 . The temperature control arrangement of  claim 6 , wherein the control device is arranged upstream of the heat exchanger. 
     
     
         8 . The temperature control arrangement of  claim 7 , wherein the heat accumulator and the heat exchanger are arranged in parallel. 
     
     
         9 . The temperature control arrangement of  claim 6  wherein the heat exchanger is an oil to air heat exchanger. 
     
     
         10 . A method of controlling a temperature of transmission oil comprising:
 directing the transmission oil through a heat accumulator such that thermal energy from the transmission oil is absorbed in the heat accumulator;   directing the transmission oil through an oil to air heat exchanger such that the oil is cooled; and   directing the transmission oil through the heat accumulator such that the thermal energy previously absorbed in the heat accumulator is delivered to the transmission oil.   
     
     
         11 . The method of  claim 10  wherein, in response to the transmission oil temperature being less than a threshold, the transmission oil is directed through the heat accumulator but not through the heat exchanger. 
     
     
         12 . The method of  claim 11  wherein, in response to the transmission oil temperature being greater than the threshold, directing a portion of transmission oil flow through the heat accumulator and simultaneously directing a remainder of transmission oil flow through the heat exchanger. 
     
     
         13 . The method of  claim 11  wherein, in response to the transmission oil temperature being greater than the threshold, the transmission oil is intermittently directed through the heat accumulator to charge the heat accumulator.