Smart two-pump apparatus, control and method

A method of controlling a first fluid cooling circuit and a second fluid cooling circuit, the method comprising:

• providing a first pump and a second pump;
• providing a circuit-changing valve defining a first inlet connected to the first pump and a second inlet connected to the second pump, and having a first outlet connected to the first fluid cooling circuit and a second outlet connected to the second fluid cooling circuit;
• the valve having a spool shiftable relative to the first inlet and the second inlet and the first outlet and the second outlet;
• when the first pump generates a pressure in the first inlet greater than a pressure generated by the second pump in the second inlet, thereby shifting the spool to cause the first pump and the second pump to be connected in a serial arrangement where the first inlet is connected to the second outlet and the second inlet is connected to the first outlet, thus causing fluid from the first pump and the second pump to flow in series through both the first fluid cooling circuit and the second fluid cooling circuit;
• and
• when the second pump generates pressure in the second inlet greater than the pressure generated by the first pump in the first inlet, thereby shifting the spool to cause the first pump and the second pump to be connected in a parallel arrangement where the first inlet is connected to the first outlet and the second inlet is connected to the second outlet, thus causing fluid from the first pump to flow only through the first fluid cooling circuit and fluid from the second pump to flow only through the second fluid cooling circuit.

A method of controlling first and second fluid cooling circuits, comprising:

• providing a first positive displacement pump and a second positive displacement pump
• providing a circuit-changing valve defining a first inlet connected to the first pump and a second inlet connected to the second pump, and having a first outlet connected to the first cooling circuit and a second outlet connected to the second cooling circuit;
• the valve having a spool shiftable relative to the first inlet and the second inlet and the first outlet and the second outlet;
• when a flow direction of the first pump is reversed, generating a negative pressure in the first inlet less than the pressure in the second inlet that shifts the spool to a first position;
• and
• when a flow direction of the second pump is reversed, generating a negative pressure in the second inlet less than the pressure in the first inlet that shifts the spool to a second position.

A vehicle apparatus, comprising:

• a wheeled vehicle including a power plant and an energy source connected to the power plant, with both the power plant and the energy source generating heat;
• a first fluid cooling circuit connected to the power plant and a separate second fluid cooling circuit connected to the energy source;
• a first pump;
• a second pump;
• a valve housing defining a first inlet connected to the first pump and a second inlet connected to the second pump, and a first outlet connected to the first cooling circuit and a second outlet connected to the second cooling circuit;
• a single spool shiftable relative to the first inlet and the second inlet and the first outlet and the second outlet;
• a spool-shifting device operably connected to one or more of the first inlet, the second inlet, the first outlet, and the second outlet;
• the valve housing, the single spool, and the spool-shifting device being configured and operably interconnected so that a difference in fluid pressure created by the first pump causes the single spool to shift to a first position and causes the first pump and the second pump to be connected in a serial arrangement where the first inlet is connected to the second outlet and the second inlet is connected to the first outlet, thus causing fluid from the first pump and the second pump to flow in series through both the first circuit and the second circuit;
• and
• the valve housing and the single spool being configured so that a difference in fluid pressure created by the second pump causes the single spool to shift to a second position and causes the first pump and the second pump to be connected in a parallel arrangement where the first inlet is connected to the first outlet and the second inlet is connected to the second outlet, thus causing fluid from the first pump to flow only through the first fluid cooling circuit and fluid from the second pump to flow only through the second fluid cooling circuit.