Hybrid fire fighting vehicle

1. A fire fighting vehicle comprising:

a chassis;

a front axle coupled to the chassis;

a rear axle coupled to the chassis;

an engine coupled to the chassis;

an energy storage device coupled to the chassis;

an electromechanical transmission coupled to the chassis and configured to drive at least one of the front axle or the rear axle;

a fluid tank coupled to the chassis and configured to store a fluid;

a pump configured to provide the fluid from the fluid tank to a fluid outlet; and

a power divider positioned between the engine, the pump, and the electromechanical transmission, the power divider including a first interface coupled to the engine, a second interface coupled to the pump, and a third interface coupled to the electromechanical transmission;

wherein the electromechanical transmission is (i) selectively mechanically coupled to the engine by the power divider and (ii) electrically coupled to the energy storage device to facilitate driving the at least one of the front axle or the rear axle; and

wherein the pump is selectively mechanically coupled to the engine by the power divider to facilitate pumping the fluid to the fluid outlet.

2. The fire fighting vehicle of claim 1 , wherein the electromechanical transmission:

selectively receives a mechanical input from the engine through the power divider and generates electricity based on the mechanical input;

selectively provides the electricity to the energy storage device for storage as stored energy; and

selectively uses at least one of (i) the electricity generated from the mechanical input or (ii) the stored energy to drive the at least one of the front axle or the rear axle.

3. The fire fighting vehicle of claim 1 , further comprising a transfer case having a front axle interface coupled to the front axle and a rear axle interface coupled to the rear axle, wherein the electromechanical transmission is configured to provide an input to the transfer case to facilitate driving the front axle and the rear axle.

4. The fire fighting vehicle of claim 1 , wherein the electromechanical transmission includes a front axle interface coupled to the front axle and a rear axle interface coupled to the rear axle, and wherein the electromechanical transmission is configured to drive both the front axle and the rear axle.

5. The fire fighting vehicle of claim 1 , wherein the power divider includes (i) a first clutch positioned between the first interface and the second interface and (ii) a second clutch positioned between the first interface and the third interface, further comprising at least one of:

(i) an accessory drive coupled to the third interface of the power divider (a) between the power divider and the electromechanical transmission and (b) in a through-shaft arrangement, wherein the accessory drive can be driven by the engine through the power divider when the second clutch is engaged, and wherein the accessory drive can be back-driven by the electromechanical transmission when the second clutch is disengaged; or

(ii) a third clutch positioned between the third interface and the electromechanical transmission.

6. The fire fighting vehicle of claim 5 , wherein the fire fighting vehicle includes the accessory drive, and wherein the accessory drive includes:

a base coupled to a housing of the power divider;

a plurality of accessory pulleys coupled to the base, each of the plurality of accessory pulleys coupled to a respective vehicle accessory;

a drive pulley coupled to the third interface; and

a belt coupling the drive pulley to the plurality of accessory pulleys.

7. The fire fighting vehicle of claim 1 , wherein the electromechanical transmission is configured to accelerate the fire fighting vehicle from 0 to 50 miles-per-hour in 30 seconds or less while the fluid tank is at a maximum fluid capacity.

8. The fire fighting vehicle of claim 7 , wherein the fire fighting vehicle is an airport rescue fire fighting (ARFF) vehicle, and wherein the maximum fluid capacity is at least 1,000 gallons.

9. The fire fighting vehicle of claim 8 , wherein the engine has a power output of less than 750 horsepower.

10. The fire fighting vehicle of claim 9 , wherein the maximum fluid capacity is at least 2,500 gallons.

11. The fire fighting vehicle of claim 10 , wherein the electromechanical transmission is configured to accelerate the fire fighting vehicle from 0 to 50 miles-per-hour in 28 seconds or less while the fluid tank is at the maximum fluid capacity.

12. The fire fighting vehicle of claim 11 , wherein at least one of (i) the rear axle is a tandem rear axle or (ii) the front axle is a tandem front axle.

13. The fire fighting vehicle of claim 12 , wherein the maximum fluid capacity is at least 3,000 gallons.

14. The fire fighting vehicle of claim 13 , wherein the electromechanical transmission is configured to accelerate the fire fighting vehicle from 0 to 50 miles-per-hour in 25 seconds or less while the fluid tank is at the maximum fluid capacity.

15. The fire fighting vehicle of claim 14 , wherein the power output of the engine is less than 650 horsepower.

16. The fire fighting vehicle of claim 15 , wherein the fluid tank is a water tank, further comprising an agent tank coupled to the chassis, the agent tank having a maximum agent capacity of at least 150 gallons.

17. The fire fighting vehicle of claim 16 , wherein the power output of the engine is less than 600 horsepower and the energy storage device has a battery capacity of less than 60 kilowatt hours.

18. The fire fighting vehicle of claim 1 , wherein the fire fighting vehicle is a municipal fire fighting vehicle, and wherein the fluid tank has at least a 200 gallon capacity.

19. A fire fighting vehicle comprising:

a chassis;

a front axle coupled to the chassis;

a rear axle coupled to the chassis;

a single engine coupled to the chassis, the single engine having a power output of less than 750 horsepower;

a battery pack coupled to the chassis, the battery pack having a battery capacity of less than 60 kilowatt hours;

an electromechanical transmission coupled to the chassis, electrically coupled to the battery pack, and configured to drive the front axle and the rear axle;

a water tank coupled to the chassis and configured to store water, the water tank having a maximum water capacity of at least 1,000 gallons;

an agent tank coupled to the chassis and configured to store an agent, the agent tank having a maximum agent capacity of at least 150 gallons;

a pump system configured to pump the water and the agent from the water tank and the agent tank, respectively, to a fluid outlet; and

a power divider positioned between the single engine, the pump system, and the electromechanical transmission, the power divider including:

a first interface coupled to the single engine;

a second interface coupled to the pump system;

a third interface coupled to the electromechanical transmission;

a first clutch positioned between the first interface and the second interface to selectively couple the single engine to the pump system; and

a second clutch positioned between the first interface and the third interface to selectively couple the single engine to the electromechanical transmission;

wherein the electromechanical transmission is configured to accelerate the fire fighting vehicle from 0 to 50 miles-per-hour in 30 seconds or less while the water tank is at the maximum water capacity and the agent tank is at the maximum agent capacity.

20. A fire fighting vehicle comprising:

a chassis;

a front axle coupled to the chassis;

a rear axle coupled to the chassis;

a driver coupled to the chassis;

a battery pack coupled to the chassis;

an electromechanical transmission coupled to the chassis, electrically coupled to the battery pack, and configured to drive at least one of the front axle or the rear axle;

a pump system configured to pump a fluid from a fluid source to a fluid outlet;

a power divider including:

a first interface coupled to the driver;

a second interface coupled to the pump system;

a third interface coupled to the electromechanical transmission;

a first clutch positioned between the first interface and the second interface to selectively couple the driver to the pump system; and

a second clutch positioned between the first interface and the third interface to selectively couple the driver to the electromechanical transmission; and

an accessory drive coupled to the third interface of the power divider (i) between the power divider and the electromechanical transmission and (ii) in a through-shaft arrangement, the accessory drive including:

a base coupled to the power divider;

a plurality of accessory pulleys coupled to the base, each of the plurality of accessory pulleys coupled to a respective vehicle accessory;

a drive pulley coupled to the third interface, wherein the drive pulley can be driven by the driver through the power divider when the second clutch is engaged, and wherein the drive pulley can be back-driven by the electromechanical transmission when the second clutch is disengaged; and

a belt coupling the drive pulley to the plurality of accessory pulleys.