Clutched hydraulic system for a refuse vehicle

1. A hydraulic system for a vehicle, comprising:

a variable displacement pump configured to pressurize a fluid based on a pump stroke, wherein the variable displacement pump includes an output, a swash plate, and a feedback valve positioned to control an orientation of the swash plate, and wherein the pump stroke varies based on the orientation of the swash plate;

a clutch positioned to selectively couple the variable displacement pump with an engine when engaged and selectively decouple the variable displacement pump from the engine when disengaged;

an actuator coupled to the output of the variable displacement pump with a pressure line;

a main valve disposed along the pressure line;

a load sensing line coupling the main valve to the feedback valve of the variable displacement pump;

a load valve disposed along the load sensing line, wherein the load valve includes a movable element configured to limit flow from the main valve to the feedback valve when disengaged; and

a controller coupled to the variable displacement pump and the clutch, wherein the controller is configured to generate a first command signal to disengage the load valve and thereby decrease the pump stroke and thereafter generate a second command signal to disengage the clutch.

2. A hydraulic system for a vehicle, comprising:

a variable displacement pump configured to pressurize a fluid based on a pump stroke, wherein the variable displacement pump includes an output, a swash plate, and a feedback valve positioned to control an orientation of the swash plate, and wherein the pump stroke varies based on the orientation of the swash plate;

a clutch positioned to selectively couple the variable displacement pump with an engine when engaged and selectively decouple the variable displacement pump from the engine when disengaged;

an actuator coupled to the output of the variable displacement pump with a pressure line;

a load sensing line coupling the main valve to the feedback valve of the variable displacement pump;

a main valve disposed along the pressure line, wherein the main valve includes a movable element configured to limit flow from the variable displacement pump to the actuator and the load sensing line when disengaged; and

a controller coupled to the variable displacement pump and the clutch, wherein the controller is configured to generate a first command signal to disengage the main valve and thereby decrease the pump stroke and thereafter generate a second command signal to disengage the clutch.

3. The hydraulic system of claim 2 , further comprising a speed sensor positioned to monitor a speed of the engine.

4. The hydraulic system of claim 3 , wherein the controller is configured to generate the first command signal when the speed of the engine exceeds a first threshold.

5. The hydraulic system of claim 4 , wherein the controller is configured to generate the second command signal when the speed of the engine exceeds a second threshold.

6. The hydraulic system of claim 5 , wherein the controller is configured to generate a third command signal to engage the clutch when the speed of the engine falls below a third threshold.

7. A hydraulic system for a vehicle, comprising:

a variable displacement pump configured to pressurize a fluid based on a pump stroke, wherein the variable displacement pump includes an output, a swash plate, and a feedback valve positioned to control an orientation of the swash plate, and wherein the pump stroke varies based on the orientation of the swash plate;

a clutch positioned to selectively couple the variable displacement pump with an engine when engaged and selectively decouple the variable displacement pump from the engine when disengaged;

an actuator coupled to the output of the variable displacement pump with a pressure line;

a load sensing line coupling the main valve to the feedback valve of the variable displacement pump;

a main valve disposed along the pressure line, wherein the main valve includes a movable element configured to limit flow from the variable displacement pump to the actuator and the load sensing line when disengaged;

a load valve disposed along the load sensing line, wherein the load valve includes a movable element configured limit flow from the main valve to the feedback valve when disengaged; and

a controller coupled to the variable displacement pump and the clutch, wherein the controller is configured to generate a first command signal to disengage the main valve and the load valve and thereby decrease the pump stroke and thereafter generate a second command signal to disengage the clutch.

8. The hydraulic system of claim 1 , further comprising a speed sensor positioned to monitor a speed of the engine.

9. The hydraulic system of claim 8 , wherein the controller is configured to generate the first command signal when the speed of the engine exceeds a first threshold.

10. The hydraulic system of claim 9 , wherein the controller is configured to generate the second command signal when the speed of the engine exceeds a second threshold.

11. The hydraulic system of claim 10 , wherein the controller is configured to generate a third command signal to engage the clutch when the speed of the engine falls below a third threshold.

12. The hydraulic system of claim 3 , further comprising a speed sensor positioned to monitor a speed of the engine.

13. The hydraulic system of claim 12 , wherein the controller is configured to generate the first command signal when the speed of the engine exceeds a first threshold.

14. The hydraulic system of claim 13 , wherein the controller is configured to generate the second command signal when the speed of the engine exceeds a second threshold.

15. The hydraulic system of claim 14 , wherein the controller is configured to generate a third command signal to engage the clutch when the speed of the engine falls below a third threshold.