Sanitary design gear pump

• US 20020159906A1
• Filed: 10/19/2001
• Published: 10/31/2002
• Est. Priority Date: 10/20/2000
• Status: Active Grant

• Current Assignee: HY-PRO Corporation (Donaldson Company Incorporated), Oden Machinery, Inc.
• Original Assignee: Niagara Pump Corporation
• Inventors: Jezuit, Richard J. Jr., Tufte, Gregory N., Messing, David C., Amyotte, Frank L., Phallen, Iver J., Maki, Bruce A.
• Granted Patent: US 6,808,374 B2
• Time in Patent Office: Days
• US Class Current: 418/132
• CPC Class Codes: F04C 13/001 Pumps for particular liquids
• CPC Class Codes: F04C 13/005 Removing contaminants, deposits or scale from the pump; Cleaning
• CPC Class Codes: F04C 2/086 Carter
• CPC Class Codes: F04C 2/18 with similar tooth forms F04C2/16 takes precedence
• CPC Class Codes: F05C 2225/04 PTFE [PolyTetraFluorEthylene]

Abstract

A sanitary design gear pump in which two gear shaft bearing blocks constitute hand removable structural end bodies of the pump. The gear shaft bearing journals extend completely through the blocks for easy cleaning and are sealed by O-rings retained by simple clamp plates. Gear cavity bore extends only the length of the largest gears, among interchangeable gear sizes. Bearing block to gear cavity seals are located at the ends of the gear bore to eliminate entrapment zones, minimal intrusion of the bearing blocks into the gear cavity allowing a large pump operating temperature range. Shaft seals of many different types can be contained in a simple hand removable cartridge. Complete pump disassembly is by one manually operated tee-handled clamp fastener. The drive and driven gear shafts are of different diameters to aid and assure correct assembly. The assembled pump slides into a pump mount with integral tie rods sealing the pump and securing it to the mount. The mount foot is reverse of the body, allowing the pump ports orientation to be selected at 90° intervals by a pin and groove engagement of the pump body and mount. The pump mount allows repeated pump removal without loss of pump-drive alignment. The drive gear shaft is splined to allow free pump removal from its mount and drive to pump disassembly without need to remove a shaft coupling. Pump displacement can be altered, requiring only interchange of gears and the drive end bearing block. The pump design meets the requirements of the 3-A Sanitary Standard 02-09 as promulgated by the 3-A Sanitary Standards Symbol Administrative Council.

Claims

1. A sanitary design gear pump comprising:

a pump housing having a gear cavity bore extending from one end to the other end of the housing;

drive and idler gear assemblies disposed within the gear cavity bore, the drive and idler gear assemblies including meshing drive and idler gears mounted between the ends of gear shafts;

two gear shaft bearing blocks mounted within the gear cavity bore, which blocks constitute hand removable structural end bodies of the gear pump, the bearing blocks including gear shaft support bearings which are through holes completely piercing the bearing blocks; and

structure to hold the bearing blocks within the pump housing during operation.

2. The sanitary design gear pump as set forth in claim 1 further characterized by structure for sealing the through holes, said structure including seal rings and a seal plate applied against the outer face of the bearing block.

3. The sanitary design gear pump as set forth in claim 1 wherein the gear shaft bearing blocks have outer faces, the outer faces being provided with gear shaft seal ring glands which are sized to grip the seal rings during the pump assembly process thereby easing and simplifying pump assembly.

4. The sanitary design gear pump as set forth in claim 1 wherein the diameter of the through holes in the bearing blocks is less than the width of the bearing blocks thereby permitting the bearing length to be much longer than the gear shaft diameter without impairment of cleanability of the device.

5. The sanitary design gear pump as set forth in claim 1 wherein the gear cavity bore which extends from one end to the other end of the housing has a central generally oval shaped gear cavity which receives the gears, and a cylindrical portion which receives the gear shaft bearing blocks, each bearing block being provided with a pilot portion which extends into the gear cavity a small amount, and wherein a seal is mounted on the face of the bearing block adjacent the pilot portion, the parts being so arranged and constructed that the bearing block to body seal arrangement allows seal disengagement immediately upon start of withdrawal of the bearing block from the pump, thus greatly easing hand disassembly be reducing the vacuum formed by such bearing block withdrawal.

6. The sanitary design gear pump as set forth in claim 5 in which the pilot portions of the bearing blocks enter into the gear cavity for a distance no greater than 12.5% of the end to end length of the bearing block.

7. The sanitary design gear pump as set forth in claim 1 wherein the gear cavity bore which extends from one end to the other end of the housing has a central oval shaped portion which receives the gears, which gears may be of a varying lengths, whereby by using differing drive and idler gear assemblies the volumetric flow range of the sanitary design gear pump is variable over a range of 6:

1 with a single gear housing.

8. The sanitary design gear pump as set forth in claim 1 further comprising the provision of a drive gear dynamic shaft seal comprised of a single cartridge assembly provided with a flange, and which is removed from and installed onto its shaft by manually gripping or grasping the flange.

9. The sanitary design gear pump as set forth in claim 8 in which the driven gear dynamic seal cartridge is retained in and sealed to the bearing block by static seal rings and a simple shaft seal clamp plate applied against a flange on the seal cartridge and the outer face of the bearing block, the clamp plate being held in place by the pump assembly means.