US2407753A

US2407753A - Gear-wheel pump

Info

Publication number: US2407753A
Application number: US416777A
Authority: US
Inventors: Wallgren August Gunn Ferdinand
Original assignee: Bolinder Munktell AB
Current assignee: Volvo Construction Equipment AB
Priority date: 1940-08-15
Filing date: 1941-10-27
Publication date: 1946-09-17
Anticipated expiration: 1963-09-17

Description

Sept. 17,1946. 4 A. G. F. WALLGREN' .-2,4o7,753

GEAR WHEEL PUMP I Fiied Oct. 27, 1941 2 She ets-Sheet 2 Patented Sept. 17, 1946 GEAR-WHEEL PUMP August Gunnar Ferdinand Wallgren, Eskilstuna,

Sweden, assignor to Aktieholaget Bolinder- Munktell, Eskilstuna, Sweden, a corporation of the Kingdom of Sweden Application October 27, 1941, Serial No. 416,777 In Sweden August 15, 1940 4 Claims. 1

This invention relates to gear wheel pumps intended primarily for water impurified by mud, sand and the like, such as sea water which is utilized, for instance, for the cooling of marine engines. Pumps of the gear wheel type have, among other things, the advantage over the reciprocating pumps hitherto used that they may be operated at a higher rotary speed, by reason of which they have smaller dimensions. It has hitherto not been possible, however, to utilize this advantage of gear wheel pumps, inasmuch as the particles entrained with th water wear or damage the bearings as well as the teeth of the pump, so that the pump is rendered inserviceable in a short time.

. The main objects of the invention are to obviate this drawback and to provide a gear whee pump for impurified water, being entirely safe in operation and the capacity of which remains unaltered even after the pump has been in operation for a very longtime.

Further objects and advantages of the invention will be apparent from the followingdescription considered in connection with the accompanying drawings which form a part of this specification, and of which: I

Fig. 1 shows a section through a combined gear wheel pump for water and oil constructed in accordance with the invention;

Fig. 2 is an endwise view of the pump in a plane taken on line IIII in Fig. 1;

Fig, 3 is an endwise view of the pump in a plane taken on line III-III in Fig. 1.

In the embodiment as illustrated, the gear wheel pump is intended to be mounted in a motor frame It, which is provided with an opening over which the pump housing I I is placed. The pump housing may be connected with the frame I I by means of bolts I2. The pump is formed with a pair ofgear wheels I3 for the pumping of oil and with a pair of gear wheels I4 for the pumping of water. The oil circulates between the pump and the various lubricating and cooling places in the motor (not shown), and the water i taken in from the outside for direct or indirect cooling of the motor cylinders in a well known manner. A shaft I5 driven from the motor shaft is mounted in two bearings IS, IT. The one gear wheel I3 for the oil pump is arranged between the bearingsIIi and II. The one gear wheel I4 of the water pump is carried by an overhanging portion of the shaft I5 projecting outside the bearing I I. The two other gear wheels of the oil and water pumps are rigidly connected to a shaft I8, which is mounted on both sides of the gear wheel I3 of the oil pump in bearings I 9, 20. The gear wheel of the water pump is in this case also arranged on the overhanging end portion of the shaft outside the bearing 20. The shaft I5 drives the shaft I8 over the gear wheels I3, while the pair of gear wheels I4 has a clearance between the teeth.- This clearance is of sufficient magni-- tude to prevent sand particles and the like en.-

covers bear on the lateral surfaces of the respec tive gear wheels with the desired clearance, they are provided with shoulders 32- adapted to abut against each other when the bolts 21 are-tightened up. The saidclearances which are of material importance for theproper functioning of.

the gear wheel pumps, will thus be independent of the degree of compression of the packings 28 from case to case.

It is of material importance for the proper functionin of the pump that the water contained in the compartment 24 is prevented from entering the bearings I1, 20. Furthermore, leakage of oil from the oil pump into the water pump is not desirable. To this end, two-pacikings 32 are arranged between the gear wheels I4 and the housing II, as appears from 'Fig; 1.- The hubs 33 of the gear wheels I4 are located for this purpose at the one (external) side of the toothed rims;

so that the requisite space is obtained for the packings. The hubs 33 are connected without any play with the shafts I5, I8 with the aid of sleeves 34, the inner surfaces of which are coni cal, as are the end portions of the shafts and 'which are retainedby means of screws 35. Provided between the hubs 33 and shafts are car- 7 rier pins 36. The hubs are connected in a liquidtight manner with the shafts, so that water caninside of the gear wheel I4 by means of a spiral spring 39. The packing rings 38 are placed in a manner such that the pressure of the respective media is added to the pressure of the spiral spring to bring about a suitable sealing pressure in the sliding surface between the rings and the gear wheels I4. Between the packings, there is a space 40 communicating with the atmosphere over passages 4 I. Water, which may thus penetrate from the gear wheel compartment 24 into the space 40, is led off through the said passages 4|, and cannot reach the bearings I1, 29. If, on the other hand, oil would happen to seek its way out through the other packing 32, the oil will also be led off through the passages 4!. The compartments 22 and 24 are entirely separated from each other, as' will be understood from the above.

The teeth of the pair of gear wheels I 4 may be covered with a layer of rubber 44. If sand. particles or the like would happen to be entrained with the water, these particles being of a greater diameter than the play between the teeth, said rubber layer will prevent damaging of the teeth. The rubber permits of being deformed without disadvantage while the sand grains are passing between the teeth. It will be found suitable to form the gear wheels of the water pump with angular teeth. In the embodiment shown, these gear wheels are of a greater width than the gear wheels l3 of the oil pump.

' Otherwise, the pumps are constructed in a Well known manner with inlets and outlets forthe respective media. The water is taken in through a conduit 46 to the suction side 41. of the water pump. From the pressure side 48 of the pump, the water escapes through a passage 48a and a conduit 49 (Figs. 2 and 3) to the motor. Ihe cover 26 is provided with a partition between the suction and pressure sides of the water pump.

The oil is sucked in to the suction side 52 of the oil pump through a conduit 53, and escapes from the pressure side 54 thereof through a con duit 55. Otherwise, the pumps may be constructed in any known manner, and may be provided with passages, for example, beside the tooth engagement of the respective" pair of gear wheels, to lead off the liquid which is present between the teeth when the latter enter into engagement with one another. Such means are irrelevant to the invention, and for this reason they are not described in detail here.

The invention may be modified in many respects, without departing from the basic idea of the invention. Those parts of the pump which come into contact with the water, which may be salt water, are preferably made from non-corroding material, such as stainless steel.

What I claim'i's:

1. In a gear wheel pump for pumping liquid containing entrained solid particles, a housing having end' walls and partition means for dividing thehousinginto two compartments, a pair of parallel shafts, bearingmeans for journal-ling said shafts in said partition and in one of said end walls, a pair of accurately meshing gears mounted on said shafts in the compartment between said partition means and said one of said end walls, a pair of toothed circular gears mounted on said shafts in the other compartment and in overhung relation with respect to the bearingsin said partition means, the last-mentioned gears having: sufficient play between them to accommodate the entrained solid particles, said other compartment being formed with inlet and outlet openings, and packing means between said partition means and said last-mentioned gears for preventing leakage of fluid between said other compartment and the bearing in said partition means.

2. In a gear wheel pump for pumping liquid containing entrained solid'particle's, a housing having end Walls and a partition there'betwe'en for dividing the housing into two compartments, a pair of bosses extending from saidv partition into one of said compartments, a pair) of parallel shafts, bearing means in said bosses and in the end. wall which bounds the other of said. compartments for rotatably mounting said shafts,

each of said shafts having an over-hung end extending into said one compartment, a pair of accurately meshing gears mounted on said shafts in the other compartment, a pair of toothed circular hollow gears secured to the over-hung ends of said shafts in aid one compartment and surrounding said bosses, the last-mentioned gears having sufiicient play between them to accommo date the entrained solid particles, said other compartment being formed. with inlet and outlet openings, said hollow gears being in fluid tight relation to the respective shafts, and packing means disposed between the interiors of said hollow gears and said bosses for preventing leakage between said on compartment and the bearing means in said bosses.

3. In a gear wheel pump for pumpin liquid containing entrained solid particles, a housing having end walls and a partition therebetween for dividing the housing into two compartments, a pair of bosses extending from said partition into one of said compartments, a pair of parallel shafts, bearing means in said bosses and in the end wall which bounds the other of said compartments for rotatably mounting said shafts,

each shaft having an over-hung end in said one compartment, a pair of accurately meshing gears mounted on said shafts in the other compartment, a pair of toothed circular hollow gears secured to the over-hung ends of said shafts in said one compartment and surrounding said bosses, the last-mentioned gears having sufficient play between them to accommodate the entrained solid particles, said other compartment being formed with inlet and outl t openings, said ends of the shafts being conical, conical sleeves disposed be tween said conical ends and the hubs of said hollow gears, bolts having threaded engagement with tapped holes in said conical ends for forcing said sleeves between the shafts and the hubs to effect a liquid-tight seal therebetween, and packing means disposed between the interiors of said hollow gears and said bosses for preventing leakage between said one compartment and the bearing means in said bosses.

4. In a gear wheel pump for pumping liquid containing entrained solid particles,'a housing having end walls and aparti'tion therebetween for dividing. the housing into two compartments, a pair of bosses extending from said partition into one of said compartments, a pair of parallel shafts, bearing means in said bosses and in-the' end wall which bounds the other of said compartmentslfor rotatably mountingsaid' shafts, each shaft having an over-hung end in said one compartment, a pair of accurately meshing gears" mounted on said shafts in the other compartment, a pair of toothed circular hollow gears secured to the over-hungends of said shafts in said one compartment and surrounding said bosses, the last-mentioned. gears having sufiicient play between them to accommodate the entrained solid particles, said other compartment being formed 7 with inlet and outlet openings, and a pair of axially spaced packing means between the interior of each of said hollow gears and the respective boss which. the gear surrounds, and means forming a drainage passageway from the space between each pair of packing means.

AUGUST GUNNAR FERDINAND WALLGREN'.