US2759425A

US2759425A - Axial flow pumps and fluid transmissions having axially adjustable blades

Info

Publication number: US2759425A
Application number: US329039A
Authority: US
Inventors: Edward A Stalker
Original assignee: Individual
Current assignee: Individual
Priority date: 1949-11-07
Filing date: 1952-12-31
Publication date: 1956-08-21
Anticipated expiration: 1973-08-21

Description

Aug. 21. 1956 E. A. STALKER AXIAL FLOW PUMPS AND FLUID TRANSMISSIONS HAVING AXIALLY ADJUSTABLE BLADES Original Filed Nov. 7, 1949 s Sheet s-Sheet 1 m m m h f j 4 7 w m .m a E a m v F W 3 W= n I 21 R in u m m mi o w 2 I 3 I .cli H m a A %/l 4 g 4 k. a V .Zv?x 3 Fig.2

Aug. 21. 1956 E. A. STALKER 2,759,425 AXIAL FLOW PUMPS AND FLUID TRANSMISSIONS HAVING AXIALLY. ADJUSTABLE BLADES Original Filed Nov. 7, 1949 5 Sheets-Sheet 2 INVENTOR. 5c;

flaw/n Aug. 21, 1956 E. A. STALKER AXIAL FLOW PUMPS AND FLUID TRANSMISSIONS HAVING AXIALLY ADJUSTABLE BLADES Original Filed Nov. 7, 1949 )Mf "MAR i i 9 4 \42 56 I62) fi l I T72$174 vaz 3 Sheets-Sheet 3 INVENTOR.

United States Patent AXIAL FLOW PUMPS AND FLUID TRANSMIS- ISgOZFSE HAVING AXlALLY ADJUSTABLE L D S Edward A. Stalker, Bay City, Mich.

Original application November 7, 1949, Serial No. 125,858, now Patent No. 2,693,677, dated November 9, 1955. Divided and this application December 31, 1952, Serial No. 329,039

10 Claims. (Cl. l0337) This application is a division of my application Serial No. 125,858 entitled, Power Transmissions Incorporating a Hydrokinetic Torque Converter Having Adjustable Blades, filed November 7, 1949, now Patent No. 2,693,677.

My invention relates to radial diffusion type.

An object of this invention is to provide a novel means of controlling the amount of diffusion of the fluid flow by shifting pump blades axially.

Another object is to provide automatic means of shifting the blades.

Other objects will appear from the description, drawings and claims.

The above objects are accomplished by the means illustrated in the accompanying drawings in which- Fig. 1 is a fragmentary axial section through a hydraulic transmission disclosing the pump of this invention;

Fig. 2 is a fragmentary development of the blading of the pump wheel showing the associated flow vectors;

Fig. 3 is the blading of Fig. 2 with different flow vectors;

Fig. 4 is a fragmentary radial view of the shroud of the pump wheel;

Fig. 5 is a fragmentary axial section of the pump wheel of Fig. 1;

Fig. 5A is a side elevation of the inner hub element shown in Fig. 5;

Fig. 6 shows a fragment of the pump wheel of Fig. 5 with some of the blading moved to the forward position;

Fig. 7 is an enlarged fragmentary view of the mechanism for controlling the blade displacements according to centrifugal force;

Fig. 8 is a front axial view of the mechanism of Fig. 7;

Fig. 9 is a fragmentary radial view of the case about the tips of the blades of the reaction member; Fig. 10 is a fragmentary development of the blading of the pump and turbine wheels and of the reaction memher or wheel with additional space between bladings for displaying the flow vectors;

Fig. 11 is the same blading as shown in Fig. 10 but with different flow vectors; Fig. 12 is a fragmentary top view of an alternate mechanism for controlling the displacement of the blades, namely according to the torque applied to the turbine Wheel; and

Fig. 13 is a fragmentary transverse section of the turbine wheel hub to display the elastic connection "between the turbine shaft and the wheel hub.

In hydrokinetic torque converters, it is difficult to achieve high efficiency over a wide range of ratio of driven shaft speed to driving shaft speed because of the variation in the direction of the flow relative to the blades of the wheels or rotors of the converter.

In this invention novel means are employed to keep pumps particularly of the the flow approaching the blades at a proper angle. One of these means is to adjust the value of the fluid velocity in the vicinity of the blades.

In Fig. l the torque converter housing is 10, the pump wheel is 12 (or F), the turbine Wheel is 14 (or T) and the reaction member is 16 (or R).

The housing defines the annular passage 20 which forms a ciosed circuit with the

passages

22, 24 and 26 through the respective wheels.

The pump wheel induces the flow through the circut when it is rotated by power input shaft 27 turning gears 28-31, the latter being the pump gear fixed to the pump wheel and rotatable on shaft 27. The shaft 32 is rotatably borne on the turbine wheel.

The gear arrangement provides for a high rotative speed of the pump wheel when the turbine wheel is stationary, that is stalled. At nearly equal speeds of the turbine wheel and pump wheel the latter approaches the rate of rotation of the input shaft 27.

The turbine wheel experiences a torque from the flow acting on its blades 31 to turn the driven shaft 34.

The reaction member realigns the flow from the turbine to give it the proper spin with respect to the pump wheel inlet.

The pump wheel is comprised of the hub 40, the blade assembly 42 and the conical shroud or case means 44. The blades are substantially straight chordwise and at their tip ends they project through diagonal slots 46 in the shroud.

Fig. 2 shows a fragmentary development of a pump wheel blading of the type employed in the converter, with the flow vectors at entrance and exit. The absolute inlet vector is Cm, the peripheral vector is u and the relative inlet vector is V1. At exit the relative vector is V2 and the absolute velocity is C2. The spin added to the fluid is A Cu since the fluid was originally moving in the direction Cm. There is also pressure rise in the rotor because of the radially expanding passages 48 between blades. and the rotor flow is parallel to the blades, the rotor provides pumping action.

Fig. 3 shows a fragmentary development of the same blading as Fig. 2 for a much smaller axial velocity Cm. In this case it will be observed that the relative flow vector V1 makes a much flatter angle 0 with the plane of rotation.

The vectors of Fig. 2 may be considered to correspond to the condition of turbine wheel stalled since then there would be a high axial velocity. Fig. 3 would correspond to a high turbine speed since then the axial velocity is low.

In Fig. 3 the angle of attack a of the blade is so large that the flow will be shocked into entering the wheel and the efficiency will be low. The pump wheel of this invention as shown in Figs. 1 and 4-6 discloses a novel means of avoiding this shock loss.

The blades of the pump wheel are in a tapered passage whose inlet area is smaller than the area at the blade trailing edges. Thus the axial flow velocity is higher at the inlet than at points further downstream. Hence if the blades are displaced upstream they are subjected to a higher fluid velocity. Thus in Fig. 3 the axial velocity Cm would be increased to C1 and the inlet vector V1 would become parallel to the blade chord, which is the most efiicient position for the vector.

The pump wheel as shown in Figs. 1 and 46 has a hub means 51 comprising

telescopic hub sections

50 and 52. One group of blades 54 is fixed on the front hub section 50, and the other group of blades 56 is fixed on the rear or inner hub section 52 and the rear section blades are alternated peripherally with the front section blades.

The blades 54 support the shroud on their tips. The

Thus even though the blades are straight 3 adjustable blades move relative to the blades 54, called reference blades and relative to the shroud.

If the inner hub section is displaced forward the blades 56 are displaced forward where the radial depth of the annular passage 22 is about half of the depth at the leading edge L. E. of blades 54as shown in Fig. 6. Thus the fluid velocity at the leading edges of the blades in the forward position is about twice the velocity at the leading edges of the blades in the rear position. Consequently the angle of approach of the flow to the blades is proper.

It is also to be noted that the flow of fluid in the conduit means proceeds relative to the blades across their trailing edges T. E.

The slots 46 in the conical surface converge somewhat forwardly to accommodate the sections of the blades which are closer together at smaller radii.

When the section 52 is pushed forward it also rotates to accommodate the pitch setting of the blades. For this purpose the hub elements 55 and 57 have external and internal threads respectively of the same pitch as the blade.

When the turbine wheel is stalled the movable pump blades should be in the rear position (Fig. and when the turbine wheel is turned at maximum speed the blades should be in the forward position (Fig. 6). This action may be accomplished automatically in response to one of the power factors of the turbine wheel. The power of the turbine wheel is equal to the product of the two power factors, angular velocity and torque.

In Figs. 1, 7 and 8 a fly weight 60 is pivotally supported at 61 on the turbine wheel. As the wheel rotates the weight moves radially outward due to centrifugal force. The centrifugal movement causes the pump blades 56 to be displaced forward by the mechanism operably connecting the weight to the pump wheel.

The turbine wheel housing 61 pivotally supports the bell crank 62 whose short arm 64 is linked by link 66 to the weight and whose long arm 68 is linked by link 70 to the sliding ring 71 in the groove 72 on gear hub 74 which is fixed to the pump wheel.

As shown particularly in Figs. 1 and 9 the reaction member 16 has axially displaceable blades 80. These are pivotally supported in the hub 82 on the stub shafts 84. The blades project through slots 86 in the inner shroud 88 and slots 90 in the outer shroud 92.

The blades preferably have substantially circular arc cross sections and the slots conform to the blade sections so that they may be slid axially and turned about stub shafts 84. Thus the blades as they move axially change their pitch and also move to a portion of passage 26 having different radial depth. The change in depth changes the axial velocity of the flow and varies the angle of attack of the blades. The rotation of the blades also changes their angle of attack. Either means might be used independently of the other. If the blades were not to be rotated the blades and the

slots

86 and 90 could be straight rather than curved. If the blades are to be rotated without a change in passage depth, the shrouds 83 and 92 can be made parallel.

When the turbine wheel is stalled the reaction member blades are to be forward. For high speed they will be displaced rearward. As for the pump this can be made to depend on a power factor of the turbine.

A fly weight 100 similar to 60 is pivoted on the rear face of the turbine wheel and actuates a bell crank 102 whose arm 104 is linked to the sliding ring 105 on hub 106 by link U13. As the speed of the turbine increases the weight flies outward and displaces the hub 106 and blades 80 rearward. The brackets 110 fixed to 112 slide in a suitable slot 114 in the case member 116.

The fly weights are returned radially inward by the springs 118 each connected at one end to the weight and at the other to the turbine wheel.

Thus as shown in Fig. 1 both the pump wheel and the reaction member can be controlled by the turbine wheel, as a function of its rate of rotation.

Since the blades of the pump wheel are subjected to centrifugal stresses it is desirable to have them fixed to their hub. Then it is desirable to change the angle of attack by displacing the blades forward.

The reaction member does not rotate so its blades are not highly stressed. It is therefore practical to have the blades pivoted to their hub.

Figs. 10 and 11 show fragmentary development of the blading of the wheels and reaction member, the former figure being for the condition of turbine wheel stalled, the latter for the turbine wheel at high speed. The rows of blading are spaced apart to provide space for the vector diagrams.

Referring to Pi g. 10 the fluid leaves the reaction member blades in an axial direction as indicated by vector 130. When the flow is returned to the pump inlet by the annular duct 20 the axial vector has been decreased in magnitude due to the expansion in the pump wheel and the axial flow vector becomes 132. Then the relative or approach vector is 134. The peripheral speed of the pump blade is u and the relative peripheral flow vector is The flow is discharged from the pump wheel with the absolute vector 138. This is also the approach vector to the turbine blades since they are not rotating. The flow leaves the turbine as shown by vector 140. Its magnitude is larger than 138 because of the converging passages of the turbine.

The reaction member blades are forward so the vector 142 of the flow is shorter than and also flatter since it is only the axial component which is influenced by the converging passages of the member. The blades 80 receive the flow without shock.

In Fig. 11 the turbine wheel is turning at a peripheral speed approaching the speed of the pump blades.

The reaction blades have been displaced backward and turned. They direct the flow with the vector 150. The flow is lead from the member to the pump inlet and is given by vector 152. Now the pump blades 56 are forward and the axial velocity is increased by the narrow radial depth of the pump wheel passage. The flow however has a very low axial velocity because the turbine wheel turns along with the pump wheel and reduces the flow velocity. The axial velocity at inlet is indicated by 154. The peripheral component 156 is about the same as the peripheral component 158 of the vector 150.

When combined with the peripheral vector u the vector relative to the blades is 160 and is substantially parallel to the blades as desired.

The flow at leaving the pump has the relative vector 162 and the absolute vector 164.

At entrance to the turbine blading the vector 164 is combined with the relative peripheral vector 166 which is less than u giving the entrance vector 170. This vector is enlarged at leaving to vector 172 giving an absolute leaving vector 174.

Since the axial flow in the reaction member will be accelerated by the converging passage of the member, the vector 174 will become 176. This vector has also been rotated due to the elongation of the axial component while the peripheral remains the same. The new axial component is 180. The peripheral component is 182. The blades 80 in their rearward position are in the proper position to receive the flow without shock and to direct the flow properly to enter the pump wheel inlet without shock.

In a variation of the invention shown in Figs. 12 and 13, the change in the position of the blades is made to depend on the other power factor, namely the torque developed on the turbine wheel. For this purpose the turbine wheel is elastically mounted on its shaft, and the rotational displacement relative to its shaft is'used to govern the displacement of the pump and reaction member blades.

The springs 120 provide for displacement of the turbine wheel relative to the turbine shaft 34. As the wheel is displaced by the fluid applied torque, it rotates the bell crank 222 carried on the arm 224 fixed to the turbine shaft. The longer arm 226 of the bell crank is linked to the sliding ring 105 on the reaction member hub 106. A similar mechanism relates the displacement of the turbine to the pump wheel blades.

The bracket 230 fixed to turbine shaft 34 supports the bell crank 222 on the forward side of the turbine wheel. This crank is connected by link 232 to the sliding ring 71. The cranks are counter-balanced by the weights 236.

When the turbine shaft 34 is held and a high torque is applied to the turbine wheel it moves relative to the shaft and turns bell cranks 222. The movement of the crank displaces the blades toward the turbine. That is the pump blades move backward to the deepest portion of the flow passage and the blades of the reaction member move to the deepest portion of its flow passage. When the torque decreases the blades are moved in the opposite manner.

I use the terms reaction member or reaction wheel interchangeably to denote a bladed structure for turning the flow. This structure may be stationary or rotatable.

While I have illustrated specific forms of the invention, it is to be understood that variations may be made therein and that I intend to claim my invention broadly as indicated by the appended claims.

I claim:

1. In combination in a pump, a hub mounted for rotation about an axis, a case means encircling said hub and spaced radially therefrom, said case means having an inner surface inclined to said axis to define a fluid flow passage having cross sectional areas varying in radial depth along the axial direction, said case means having a plurality of peripherally spaced diagonal slots therein, a plurality of peripherally spaced axial flow blades each extending across said passage into a said slot, and means mounting said blades 011 said hub for axial displacement thereof relative to said case means, said blades being movable while in said slots to said cross section of said passage where portions of said inclined surface are at diiferent distances from said hub and at different radial positions along the radial length of said blades.

2. In combination in an axial flow pump, a hub mounted for rotation about an axis, a shroud having an inner conical surface encircling said hub and spaced radially therefrom defining a fluid flow passage having cross sectional areas increasing in radial depth downstream along the axial direction, said shroud having a plurality of peripheraliy spaced slots therein, said slots being axially and peripherally extending, a plurality of peripherally spaced axial flow blades extending across said passage into said slots, and means mounting said blades on said hub for axial displacement thereof relative to said shroud, said blades being movable while in said slots to said cross section of said passage where portions of said conical surface are at different distances from said hub and at different radial positions along the radial length of said blades.

3. In combination in an axial flow pump, a hub means mounted for rotation about an axis, a case means encircling said hub and spaced radially therefrom, said case means having an inner surface inclined to said axis to define a fluid flow passage having cross sectional areas varying in radial depth along the axial direction, and a plurality of reference blades spaced peripherally about said hub means and connected to said case means for support thereof, said case means having a plurality of peripherally spaced diagonal slots therein, a plurality of peripherally spaced adjustable blades extending across said passage each into a said slot, and means mounting said adjustable blades on said hub means for rotation therewith and for axial displacement relative to said c'ase means and said reference blades, said blades being movable while in said slots to said cross section of said passage where portions of said inclined surface are at diiferent distances from said hub and at different radial positions along the radial length of said blades.

4. In combination in a pump, a hub means mounted for rotation about an axis, a case means encircling said hub and spaced radially therefrom, said case means having an inner surface inclined to said axis to define a fluid flow passage having cross sectional areas varying in radial depth along the axial direction, said case means having a plurality of peripherally spaced diagonal slots therein, a plurality of peripherally spaced adjustable blades extending across said passage each into a said slot, means mounting said blades on said hub means for axial displacement relative to said case, said blades being movable while in said slots to said cross section of said passage where portions of said inclined surface are at different distances from said hub and at different radial positions along the radial length of said blades, and a plurality of reference blades supported on said hub each at a locality peripherally adjacent to a said adjustable blade in at least one axial position thereof, said case means being fixed to said reference blades at the tips thereof for support thereby, said reference and adjustable blades being rotatable with said hub.

5. In combination in a pump, a hub means mounted for rotation about an axis, a case means encircling said hub and spaced radially therefrom, said case means having an inner surface inclined to said axis to define a fluid flow passage having cross sectional areas varying in radial depth along the axial direction, said case means having a plurality of peripherally spaced diagonal slots therein, a plurality of peripherally spaced adjustable blades extending across said passage each into a said slot, means mounting said blades on said hub means for axial displacement relative to said case, said blades being movable while in said slots to said cross section of said passage where portions of said inclined surface are at different distances from said hub and at different radial positions along the radial length of said blades, and means supporting said case means on said hub means, said blades and said case means being rotatable with said hub means.

6. In combination in an axial flow pump, a conduit means having flow cross sections of diflerent radial depths axially therealong for the flow of fluid therethrough, a pump wheel means comprising a first wheel and a second Wheel, each said wheel having a plurality of peripherally spaced axial flow blades with fluid flow passages between them, each said blade having leading and trailing edges extending radially, each said wheel being mounted in said conduit means for rotation about an axis to impel a flow of fluid axially through each said Wheel in the same axial direction, and means to displace one of said wheels axially relative to the other to another said cross section of said conduit means of substantially different radial depth as a function of the rate of rotation of said other wheel.

7. In combination in an axial fiow pump, a conduit means having flow cross sections of different radial depths axially therealong for the flow of fluid therethrough, a pump wheel means comprising a first wheel and a second wheel, each said wheel having a plurality of peripherally spaced axial flow blades with fluid flow passages between them, each said blade having leading and trailing edges extending radially, each said wheel being mounted in said conduit means for rotation about an axis to impel a flow of fluid axially through each said wheel in the same axial direction, and means to displace one of said wheels axially relative to the other to another said cross section of said conduit means of substantially different radial depth as a function of the rate of rotation of said other wheel, and with said blades of said first wheel disposed across substantially the whole radial extent of said conduit means at said cross sections thereof.

8. In combination in an axial flow pump, a conduit means having flow cross sections of different radial depths axially therealong for the flow of fluid therethrough, a pump wheel means comprising a first wheel and a second wheel, each said wheel having a plurality of peripherally spaced axial flow blades with fluid flow passages between them, each said blade having leading and trailing edges extending radially, said wheels being mounted closely adjacent in said conduit means for rotation about an axis to impel a flow of fluid axially through each said wheel in the same axial direction, and means to displace one of said wheels axially relative to the other to another said cross section of said conduit means of substantially different radial depth as a function of the rate of rotation of said other wheel, and with said blades of said first wheel disposed across substantially the Whole radial extent of said conduit means at said cross sections thereof.

9. In combination in an axial flow pump, a conduit means having inner surfaces thereof defining flow cross sections of different radial depths axially therealong for the flow of pumped fluid therethrough, a pump wheel means comprising a first wheel and a second wheel, each said wheel having a plurality of peripherally spaced axial flow blades with fluid flow passages between them, each said blade having leading and trailing edges extending radially, each said wheel being mounted in said conduit means for rotation about an axis to impel a flow of fluid axially through between the blades of each said wheel in the same direction at all radial points therebetween, and means to displace one of said wheels axially relative to the other from a said cross section to another said cross section of said conduit means of substantially different radial depth as a function of the rate of rotation of one of said wheels while maintaining said blades of said displaced wheel in substantially as close proximity to a said surface at one said cross section as at the other said cross section.

10. In combination in an axial flow pump, a conduit means having inner surfaces thereof defining flow cross sections of different radial depths axially therealong for the flow of pumped fluid therethrough, a pump wheel means comprising a first wheel and a second wheel, each said wheel having a plurality of peripherally spaced axial flow blades with fluid flow passages between them, each said blade having leading and trailing edges extending radially, each said wheel being mounted in said conduit means for rotation about an axis to impel a flow of fluid axially through between the blades of each said wheel in the same direction at all radial points therebetween, and means to displace one of said wheels axially relative to the other from one said cross section to another said cross section of said conduit means of substantially different radial depth while maintaining said blades of said displaced wheel in substantially as close proximity to a said surface at one said section as at the other said cross section.

References Cited in the file of this patent UNITED STATES PATENTS 2,061,997 Dunn Nov. 24, 1936 2,428,134 Zeidler Sept. 30, 1947 2,440,445 Jandasek Apr. 27, 1948