US2727594A

US2727594A - Water brake

Info

Publication number: US2727594A
Application number: US354296A
Authority: US
Inventors: Jr Joseph A Ganster
Original assignee: IND ENGINEERING Co
Current assignee: IND ENGINEERING Co; INDUSTRIAL ENGINEERING Co
Priority date: 1953-05-11
Filing date: 1953-05-11
Publication date: 1955-12-20
Anticipated expiration: 1972-12-20

Description

Dec. 20, 1955 J. A. GANSTER, JR 2,727,594

WATER BRAKE Filed May 11, 1953 4 Sheets-Sheet 1 Fi /gin Dec. 20, 1955 .J A, GANSTER, JR 2,727,594

WATER BRAKE Filed May 11, 1953 4 Sheets-Sheet 2 1955 JJA. GANSTER, JR 2,727,594

WATER BRAKE Filed May 11, 1953 4 Sheets-Sheet 3 Joke 9% A 6am eIjJn 1955 J. A. GANSTER, JR 2,727,594

WATER BRAKE Filed May 11, 1953 4 Shee ts-Sheet 4 1N1 'ENTOR.

Jake 0AA. ansdg lr ATTORNEYS,

United States Patent WATER BRAKE Joseph A. Ganster, Jr., Bryn Mawr, Pa., assignor to Industrial Engineering Company, Philadelphia, Pa., :1 partnership composed of Joseph A. Ganster, Joseph A. Ganster, Jr., Emily Louise Ganst er and Julia A. Ganster Application May 11, 1953, Serial No. 354,296

3 Claims. (Cl. 188-30) The present invention relates to water brakes of the type which are used for load tests on rotating machinery such as engines, motors and the like.

A purpose of the invention isto obtain more reliable and uniform operation of a water brake under relatively low loads.

A further purpose is to reduce vibration and decrease the likelihood of fatigue failure in a water brake.

A further purpose is to provide auxiliary longitudinally communicating slots at the periphery of the stator plates of a water brake.

A further purpose is to permit the alternative use of the auxiliary slots as key slots so that when wear occurs at the key slots the stator plates can be angularly shifted and reused.

A further purpose is to improve the hydraulic flow around the stator key of a water brake.

Further purposes appear in the specification and in the claims.

In the drawings I have chosen to illustrate one only of the numerous embodiments in which my invention may appear selecting the form shown from the standpoints of convenience in illustration, satisfactory operation and clear demonstration of the principles involved.

Figure 1 is a longitudinal section of the water brake of the invention, the section being staggered and taken on the line 1-1 of Figure 2.

Figure 2 is a left end elevation of Figure 1.

Figure 3 is a right end elevation of Figure 1.

Figure 4 is a transverse section of Figure 1 on the line 44.

Figure 5 is a transverse section of Figure 1 on the line 5-5.

Figure 6 is a transverse section of Figure 1 on the line 66 omitting the rotor.

Figure 7 is a fragmentary transverse section of Figure 1 on the line 77.

Describing in illustration but not in limitation and referring to the drawings:

In the prior art brake tests on rotating equipment were commonly made on a belt type or Prony brake having a spring balance to measure the force. In recent years, extensive use has been made of a water brake, which consumes the energy in frictional heating of the water and determines the horsepower by the heat equivalent, since one horsepower is equal to 42.42 B. t. u. per minute.

When reference herein is made to a water brake it is intended to adopt the commercial terminology, and to designate a fluid brake in which water is usually the medium, although the medium may equally well be oil or any other liquid.

Water brakes have generally given good service and are becoming more popular because they are reliable, simple and compact. As water brakes have been subjected to'more extensive use, however, it has been observed that marked tendencies exist to abrade or wear the metallic parts due to the powerful hydraulic forces developed. This tendency has been found to be pro- 2,727,594 Patented Dec. 20, 1955 nounced on the stator plate keys, which have heretofore been of rectangular section extending radially inwardly from the housing. The wear is not only objectionable because of the need of replacing the keys, but particularly because the key slots of the stator plates have also worn, so that after extensive use, there has been appreciable circumferential freedom of the stator plates in the housing. Where the load is intermittent, as in certain engines, this has caused the stator plates to jump, imparting serious vibration which is harmful not only to the brake but to the equipment being tested. Accordingly it has been necessary to replace stator plates for this cause.

I have discovered that this difliculty can be overcome by providing a series of alternate key slots in the stator plates, so that when wear occurs in the key slots the device can be disassembled and the stator plates turned circumferentially and held using dilferent key slots, and employing the same keys or new keys as desired.

I have further discovered that the Wear on the keys and key slots can be reduced by providing a deflecting surface on the key in the direction motion of the water. Thus the tendency to damage the key and the key slots has been markedly reduced.

In water brakes in the prior art there has been a tendency toward abnormal behavior under low loads. Even under very low loads, the water is thrown to the outside, and there is very considerable drag exerted by the water passing around the long circumferential path adjoining the inner wall of the housing. It has been difiicult to get sufiicient flow through the device to prevent generation of steam under these conditions. I find that the slots at the periphery which are capable of serving as alternate key slots aid in avoiding boiling of the water under low load since adequate longitudinal flow can be obtained under these conditions and thus erratic or inaccurate operation is avoided.

I further find that the clearance, of the order of at least 0.015 inch on a side, between the discs and the housing, plus the slots, aids in providing a cushion of water around the discs, thrown out by the centrifugal force, and reducing vibration.

The water brake of the invention comprises a housing 20 consisting of a tubular drum element 21 and

end closures

22 and 23. The drum element 21 has an annular recess at 24 which receives a reduced end portion 25 of the end closure having an annular slot 26 in which a sealing O ring 27 of rubber or the like is placed. The drum element 21 has lugs 28 at spaced circumferential positions which support studs 30 extending longitudinally through stud openings in projections 31 from the endclosures, the end closures being held in place by nuts 32.

. Each of the end closures mounts a bearing 33 or 34,

Bearing 34 isheld by a retainer 41 secured to the end closure by screws 42 and registered by a pin 43.

The bearings journal a main rotor shaft 44, which mounts the rotor of the brake.

The shaft at the left end in Figure 1 is splined at 45 to interconnect with the shaft of the machine under test, and is threaded to receive nut 46 acting against cushion washer 47 to hold inner race 48 of the bearing 34 against shoulder 50 on the shaft. At the other end the shaft is threaded to receive nut 51 acting against cushion washer 52 to hold inner race 53 of bearing 33 against shoulder 54 on the shaft.

Inside the bearings at the two ends of the housing seals and 56 are mounted in recesses in the end cloure, having external grooves for rubber 0 rings 57, 58, 60 and 61 and held by radially extending screws 62. The seals have labyrinth grooves 63, 64, 65 and 66 which are in close proximity to cylindrical shaft portions 67 and 68 respectively.

Intermediate between the labyrinth sealing surfaces are grooves 70 which are connected by passages 71 to pipes 72 through which grease may be injected into the seals.

The rotor comprises rotor plates 73 which have central openings 74 through which the shaft 44 passes and have key slots 75 which cooperate with a key slot 76 to receive a longitudinal key 77 extending through the mid portion of the shaft. The rotor plates are spaced by spacer rings 78 and the stack of spacer rings and rotor plates are locked in position by nut 80 threaded on the shaft and acting against cushion ring 81 to secure the stack of rotor plates and spacer rings against shoulder 82 on the shaft. The rotor plates are perforated, there being preferably a group of perforations 83 located relatively radially inwardly and a set of larger perforations 84 near the outer edge.

In between each pair of rotor plates is placed a stator plate 85 which is provided with an enlarged opening 86 toward the center providing adequate clearance at 87 for the spacer rings 78. The rotor plates 85 also preferably clear at 88 from the housing at the circumference.

The rotor plates are slotted at 90 around the periphery, and certain of the slots, desirably located at quadrant positions, receive the radial inward projection 91 of a longitudinal key 92. The longitudinal key extends in one of the longitudinal slots 93 in the housing (four are shown). The keys 92 are notched at 94 to engage on either side of the stator plate and hold the stator plate desirably equidistant from the adjoining rotor plates.

The stator plates have relatively smaller perforations 95 distributed around the radial inner portion and relatively larger perforations 96 near the outside.

The keys at positions intermediate between the stator plates have inwardly converging longitudinal surfaces 97, desirably extending at an angle of between 30 and 60 degrees to the radius at the middle of the key, and serving to deflect the water inwardly when it encounters the key.

In addition to the slots which receive the keys, there are several auxiliary key slots around the outside of the stator which would be capable of functioning as key slots should the key slots in use become worn and it be necessary to shift the stator plates angular-1y, with or without introduction of new keys.

Intake pipes 98 are provided in the end closure remote from mounting flange 100 by which the housing is supported and outlet connections 101 are provided extending radially from the opposite end of the water brake. An annular recess 102 provides clearance in the end closure adjoining the inlet to equalize feed from the axially extending inlet pipes.

It will be appreciated that the device of the invention can be readily assembled and disassembled, and can very easily be repaired. When constructed in accordance with the invention it is extremely sturdy and not likely to require .much maintenance.

In operation, the device can be mounted either with the axis vertical or horizontal, and a regulated water pressure applied on the inlet. The water flowing through the brake will of course vary with the load, and the amount of flow and the temperature rise can be determined under the particular conditions of test to give the information required.

In view of my invention and disclosure variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benefits of my invention without copying the structure shown, and I therefore claim all such insofar as they fall within the reasonable spirit and scope of my claims.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. In a water brake, a cylindrical housing, bearing support in the housing, a rotor journalled in the bearing support in the housing and including a plurality of perforated axially displaced plates, perforated stator plates interposed between the respective rotor plates and having a plurality of slots at the periphery of the stator plates, walls forming a longitudinal keyway in the interior of the circumferential wall of the housing and a key extending through and engaging in the keyway and extending through and engaging in the peripheral slots in the stator plates, at least some of the peripheral slots in the stator plates being open and permitting longitudinal communication.

2. In a water brake, a cylindrical housing, bearing support in the housing, a rotor journalled in the bearing support in the housing and having perforated axially displaced rotor plates, perforated stator plates interposed between the rotor plates and extending adjacent to but not into complete contact with the housing at the outside, the stator plates being slotted around the periphery, walls forming longitudinal keyways in the interior of the circumferential wall of the housing and keys extending through and engaging in the keyways, engaging in some of the peripheral slots of the stator plates, but leaving certain other slots in the stator plates open.

3. In a water brake, a cylindrical housing, bearing support in the housing, a rotor journalled in the bearing support in the housing and including a plurality of perforated axially displaced rotor plates, perforated stator plates interposed between the rotor plates and slotted at the periphery, walls forming a keyway in the interior of the circumferential wall of the housing and a key extending longitudinally of the housing, engaging the keyway and extending into the slots at the periphery of the stator plates, the key having inwardly converging faces on opposite longitudinal sides.

References Cited in the file of this patent UNITED STATES PATENTS 1,843,987 Ragan Feb. 9, 1932 2,514,137 OConnor July 4, 1950 2,661,915 OConnor Dec. 8, 1953 FOREIGN PATENTS 348,386 France Apr. 11, 1905