Vacuum pump

1 . A vacuum pump that is connectable to an external system and configured to evacuate material from the external system, the vacuum pump comprising:

a motor operable at a first speed and a second speed that is slower than the first speed;

a pump assembly driven by the motor, the pump assembly being lubricated and cooled by a lubricant;

a temperature sensor outputting a temperature signal corresponding to a temperature of the lubricant; and

an electronic control unit configured to:

receive the temperature signal from the temperature sensor,

rotate the motor to operate the pump assembly at the second speed when the temperature signal is below a temperature threshold.

2 . The vacuum pump of claim 1 , further comprising a main housing including a motor housing that houses the motor, a pump housing that houses the pump assembly, a partition wall that separates the motor housing and the pump housing, and a battery that is coupled to the motor housing and configured to supply electrical current to the motor, wherein the pump housing is sealed relative to the motor housing to form a compression chamber that holds the lubricant.

3 . The vacuum pump of claim 2 , wherein the temperature sensor is disposed within the pump housing and directly detects a temperature of the lubricant.

4 . The vacuum pump of claim 1 , wherein the electronic control unit is further configured to determine an electrical current value being drawn by the motor, maintain operation of the motor at the second speed while the electrical current value is above a current threshold, and operate the motor at the first speed only after the electrical current value remains below the current threshold for a preset time period.

5 . The vacuum pump of claim 1 , wherein the temperature sensor is a thermistor.

6 . The vacuum pump of claim 1 , wherein the motor is a brushless direct- current electric motor, wherein the vacuum pump further comprises a plurality of power transistors that supply electrical current to the motor, and wherein the temperature sensor is coupled to at least one of the power transistors to detect a temperature of the power transistor, such that the controller receives the temperature signal from the temperature sensor and indirectly detects a temperature of the lubricant based on the temperature of the power transistor.

7 . The vacuum pump of claim 1 , wherein the temperature threshold is 15 degrees Celsius, and wherein the current threshold is 35 amperes.

8 . The vacuum pump of claim 1 , wherein the motor is rotated at 2,500 revolutions per minute when being rotated at the first speeding speed and wherein the motor is rotated at 1,000 revolutions per minute when being rotated at the second speed.

9 . A vacuum pump that is connectable to an external system and configured to evacuate material from the external system, the vacuum pump comprising:

a motor operable at a first speed and a second speed that is slower than the first speed;

a pump assembly driven by the motor, the pump assembly being lubricated and cooled by a lubricant;

a temperature sensor outputting a temperature signal corresponding to a temperature of the lubricant; and

an electronic controller configured to:

receive the temperature signal from the temperature sensor,

rotate the motor to operate the pump assembly at the second speed when the temperature signal is below a temperature threshold, and

rotate the motor to operate the pump assembly at the first speed after the temperature signal is above the temperature threshold.

10 . The vacuum pump of claim 9 , further comprising a main housing including a motor housing that houses the motor, a pump housing that houses the pump assembly, a partition wall that separates the motor housing and the pump housing, and a battery that is coupled to the motor housing and configured to supply electrical current to the motor, wherein the pump housing is sealed relative to the motor housing to form a compression chamber that holds the lubricant.

11 . The vacuum pump of claim 10 , wherein the temperature sensor is disposed within the pump housing and directly detects a temperature of the lubricant.

12 . The vacuum pump of claim 9 , wherein the temperature sensor is a thermistor.

13 . The vacuum pump of claim 9 , wherein the motor is a brushless direct-current electric motor, wherein the vacuum pump further comprises a plurality of power transistors that supply electrical current to the motor, and wherein the temperature sensor is coupled to at least one of the power transistors to detect a temperature of the power transistor, such that the controller receives the temperature signal from the temperature sensor and indirectly detects a temperature of the lubricant based on the temperature of the power transistor.

14 . The vacuum pump of claim 9 , wherein the temperature threshold is 15 degrees Celsius.

15 . The vacuum pump of claim 9 , wherein the controller is further configured to determine an electrical current value being drawn from the motor.

16 . The vacuum pump of claim 15 , wherein the controller maintains operation of the motor at the second speed while the electrical current value is above a current threshold.

17 . The vacuum pump of claim 16 , wherein the controller operates the motor at the first speed after the electrical current value remains below the current threshold for a preset time period, wherein the current threshold is 35 amperes.