Thermal/noise management in a scroll pump

Patent metadata

Field	Value
Publication number	US-9611852-B2
Application number	US-201313853655-A
Country	US
Kind code	B2
Filing date	Mar 29, 2013
Priority date	Mar 29, 2013
Publication date	Apr 4, 2017
Grant date	Apr 4, 2017

Abstract

The main sources of heat in a scroll pump are cooled efficiently by a single cooling fan so that noise and, in particular, fan-generated noise, can be kept low. The scroll pump includes a pump head assembly, a pump motor, a cooling fan that produces a cooling air flow in the pump, a cowling in which the pump head assembly, pump motor and cooling fan are housed and juxtaposed with one another in an axial direction of the pump, and a shroud disposed within the cowling and extending around the pump motor to define a tunnel with the motor and through which the air flow of the cooling fan is directed.

First claim

What is claimed is:

1. A scroll pump comprising:
a pump motor comprising a pump motor housing, the pump motor housing comprising an outer peripheral surface;
a pump head assembly comprising a stationary plate scroll fixed in the scroll pump, an orbiting plate scroll, and a drive shaft coupling the pump motor to the orbiting plate scroll;
a cooling fan that produces a cooling air flow in the scroll pump;
a cowling in which the pump head assembly, the pump motor and the cooling fan are housed as juxtaposed with one another in an axial direction of the scroll pump, the cowling having opposite axial ends in the axial direction, the axial ends defining an air inlet and an air outlet, respectively; and
a shroud disposed within the cowling and comprising an inner peripheral surface, the shroud extending around the pump motor and spaced radially therefrom such that a tunnel extending longitudinally in the axial direction of the scroll pump is defined between the outer peripheral surface and the inner peripheral surface, wherein:
the tunnel is open to and connects the air inlet and the air outlet, and the cooling fan is disposed in the scroll pump such that the cooling air flow produced by the cooling fan flows from the air inlet to the air outlet via the tunnel to cool the pump motor; and
the cooling fan is housed within the cowling at the air inlet of the cowling, the pump motor is disposed within the cowling adjacent the air outlet of the cowling, the pump head assembly is interposed in the axial direction between the cooling fan and the pump motor, and the shroud has a first axial end disposed adjacent the pump head assembly and a second axial end at which the shroud is integral with the cowling.

2. The scroll pump as claimed in claim 1 , wherein the cooling air flow output by the fan has a cross-sectional area, perpendicular to the axial direction, that is substantially the same as that of the tunnel.

3. The scroll pump as claimed in claim 2 , wherein the cooling fan has a hub, fan blades radiating from the hub, and a housing having an inner surface surrounding tips of the fan blades, and the cross-sectional area of the cooling air flow is substantially the same as that of a space delimited by and between the hub and the inner surface of the housing of the fan.

4. The scroll pump as claimed in claim 1 , wherein the cowling defines at least one channel therein that channels the cooling air flow in a direction from the air inlet towards the air outlet thereof, the tunnel comprises a first axial end and a second axial end, the first axial end of the tunnel is open to and contiguous with the channel, the second axial end of the tunnel is disposed closer to the air outlet than the first axial end of the tunnel, and the shroud is a solid annular body and is integrated with the cowling such that the channel leads into the tunnel only via the first axial end of the tunnel.

5. The scroll pump as claimed in claim 1 , wherein the cowling defines at least one channel therein that channels the cooling air flow in a direction from the air inlet towards the air outlet thereof, the shroud is an annular body having perforations extending radially therethrough, and the perforations are open to the channel such that the cooling air flow produced by the fan flows through the perforations and impinges the pump motor before flowing to the air outlet.

6. The scroll pump as claimed in claim 5 , the shroud has axial ends that are sealed with respect to the channel such that the cooling air flow produced by the fan can flow into the tunnel only through the perforations in the shroud.

7. The scroll pump as claimed in claim 1 , further comprising a circuit board having circuitry that controls an operation of the pump, and wherein the circuit board is disposed in the path of the cooling air flow so as to be cooled by the air flow.

8. The scroll pump as claimed in claim 7 , wherein at least part of the circuit board is exposed within the tunnel such that the cooling air flow produced by the fan passes over the circuit board before passing out of the pump through the air outlet.

9. The scroll pump as claimed in claim 8 , wherein the circuit board comprises an inverter circuit that converts one AC frequency to another AC frequency.

10. The scroll pump as claimed in claim 7 , wherein the cowling defines at least one channel therein that channels the cooling air flow in a direction from the air inlet towards the air outlet thereof, and the circuit board is disposed in the channel such that the cooling air flow produced by the fan passes over the circuit board.

11. The scroll pump as claimed in claim 10 , wherein the cowling has an auxiliary opening therethrough spaced from the air outlet and open to the channel in which the circuit board is disposed at a location downstream of the circuit board with respect to the cooling air flow, such that part of the cooling air flow produced by the fan passes over the circuit board and then through the auxiliary outlet.

12. The scroll pump as claimed in claim 1 , wherein the cowling defines at least one channel therein extending from the air inlet and to the tunnel that channels the cooling air flow in a direction from the air inlet towards the air outlet thereof, and the exterior of the pump head assembly is exposed to the channel such that the cooling air flow cools the pump head assembly before passing into the tunnel.

13. The scroll pump as claimed in claim 12 , further comprising a circuit board having circuitry that controls the operation of the pump, and wherein the circuit board is exposed to the tunnel such that the cooling air flow produced by the fan passes over the circuit board before passing out of the pump through the air outlet.

14. The scroll pump as claimed in claim 1 , wherein the cooling fan is disposed in a non-coupled relation to the drive shaft and configured to rotate independently of the drive shaft and the pump motor.

15. The scroll pump as claimed in claim 14 , wherein the cooling fan is disposed upstream of the pump head assembly.

16. The scroll pump as claimed in claim 14 , comprising a multi-speed or variable-speed fan motor coupled to the cooling fan, a sensor configured for monitoring a load on the pump, and a controller configured for regulating a speed of the cooling fan based on a signal received from the sensor indicative of the load on the pump.

17. The scroll pump as claimed in claim 1 , comprising a multi-speed or variable-speed fan motor coupled to the cooling fan, a sensor configured for monitoring a load on the pump, and a controller configured for regulating a speed of the cooling fan based on a signal received from the sensor indicative of the load on the pump.

Assignees

• Agilent Technologies Inc
• Agilent Technologies Inc

Inventors

• Forni Ronald J
• Driscoll Scott
• Galica George

Classifications

• F04D25/08

  the working fluid being air, e.g. for ventilation · CPC title

• F04C18/0215

  where only one member is moving · CPC title

• F04D19/002

  Axial flow fans · CPC title

• F04C29/04 Primary

  Heating; Cooling (of machines or engines in general F01P); Heat insulation (heat insulation in general F16L59/00) · CPC title

• F04C27/004

  Radial sealing elements specially adapted for intermeshing-engagement type pumps, e.g. gear pumps · CPC title