Note: Descriptions are shown in the official language in which they were submitted.
. l04as~
The present invention relates to a hydraulic percussive
machine which may be used for destroying various constructions,
forging parts, driving in piles etc. and, when employing a
means for rotating said machine via a drill rod, for making
holes and deep wells in soil in mining. tunnelling, construction
work and the like.
` Known in the art is a hydraulic percussive machine com-
prising: a housing with passages for fluid, a stepped hammer
piston adapted to move axially in said housing and adjoining
with its larger diameter portion the front portion of the
machine. The piston hammer is pressed by a resilient member
against the front portion of the machine and is reciprocated by
the pressure fluid to effect forward and return strokes.
During its forward strokes the hammer piston applies impacts
. to an anvil of a tool installed in the housing at the front -
portion of the machine. The hydraulic machine is provided with
a stepped pressure difference ring valve fitted over the hammer
piston and reciprocating to distribute the fluid between the
return space of the housing and the atmosphere.
The stepped hammer piston of the known hydraulic percus-
' sive machine is made as an integral part with two steps of
~ .
different diameters, a smaller area end face of the hammer
piston step being in the rear portion space of the housing ~
1~ which is in constant communication with the pressure pipeline. -
:~ With the ring valve being in the foremost position (towards
the tool), its passages communicate with the passages in the
housing whereby the return space is connected to the pressure
pipeline. The pres`sure fluid enters the return space and
effects return stroke of the hammer piston compressing-a spring
~ 30 arranged between the head face of the hammer-piston larger
~ diameter step and an annular projection of the housing. At the
,~ end of the return stroke (away from the tool) the hammer piston
'
-~ - . , , . ,, ., .. ,. ,, ".~ . / .. . .. ... ..
104~
touches the inner annular projection of the valve by its outer
annular projection and separates the valve from the anvil that
causes the valve, due to the difference in the end face areas
to move backward under the action of the fluid away from the
tool thus opening the discharge passages~ The valve passages
are overlapped by the side cylindrical walls of the housing and
the return space is disconnected from the pressure pipeline thus
resulting in a hydraulic shock above the hammer piston and in
the pressure pipeline. A combined action of the hydraulic
shock, excess pressure of the fluid against the hammer piston
smaller diameter step end faca, and of the releasing spring
makes the hammer piston accomplish the forward stroke expelling
the fluid from the return space outside. At the end of said
stroke the hammer piston shifts the valve to the foremost
position towards the tool to shut off the discharge passages ~i
and strikes the anvil connected with the tool. The stoppage
. ,~ .
`- of the hammer piston results in the second hydraulic shock in
` the pipeline, said shock plus the fluid excess pressure causing ~
; the hammer piston to effect its return stroke and the cycle ~ -
repeats. ~
~`~ A disadvantage of said hydraulic percussive machine ~ - -
~ resides in that the steps of its hammer piston are interconnected
`t rigidly, being an integral part, that increases energy losses
of the hydraulic shocks in the pressure pipeline and neces- -
sitates a special compensator (cavity) for damping hydraulic
shocks in the hose or string of drilling pipes which deliver -
the pressure fluid to said machinç. The compensator consumes ~
~ a part of the hydraulic shock energy, complicates the design of - ~ -
j the hydraulic machine and reduces the operational stability
thereof.
' The object of the present invention is to provide a ~ ~-
~, hydraùlic percussive machine of a simple design.
- 2 -
. . .
. . .
l04a97l
Another object of the invention is to provide a
hydraulic machine reliable in operation.
` Still another object of the invention is to provide a
hydraulic machine with a reduced weight and minimum number of
parts.
The principal object of the invention is to provide a
hydraulic machine with increased efficiency.
Yet another object of the invention is to provide a
hydraulic machine which might be used as a hydraulic hammer,
and, when employing a rotating means, for drilling holes and
deep wells.
These and other objects of the invention are achieved
by providing a hydraulic percussive machine, comprising: a
-1~ housing with passages for fluid, a stepped hammer piston
j adapted to move axially in said housing, pressed resiliently
with its larger diameter step against the front portion of the
machine and reciprocating under the action of the pressure --
J` fluid to effect forward and return strokes and to apply impacts
-~ during said forward strokes against an anvil linked with a tool
mounted in the housing at the front portion of the machine, and
a stepped pressure difference ring valve fitted over the hammer
piston and adapted to reciprocate for distributing the pressure
~` fluid between the return space and the atmosphere. According -
to the present invention the hammer piston is divided into two
different diameter portions, a larger diameter portion being ~`
.
the hammer piston, while the smaller diameter one, the plunger,
and a resilient member is arranged between said portions.
It is preferable that the separated hammer piston end
face facing the rear portion of the machine have a longitudinal
cylindrical chamber whose section area is smaller than the back
face area, an axial cylindrical chamber is provided at the rear
portion of the machine housing, and a plunger is made hollow and
~, ` .
7~`' -' . . .. .
lO~r~l
has a hollow cylinder at one side thereof arranged to be axially
movable in said cylindrical chamber of the hammer piston' and at
the other end, a hollow cylinder, also adapted to be axially
movable in said space of the housing, whose section area is
smaller than the area of the piston back face, the area of the
hollow cylinder end face located in the housing space exceeding
the area of the end face of the hollow cylinder arranged in the
cylindrical chamber of the hammer piston.
Such a design provides for transmitting the hydraulic
shocks by a direct flow of the fluid to the bottom of the axial
cylindrical chamber of the separated hammer piston,~and via
the plunger, to the resilient member that increases the machine
efficiency and rules out the necessity of a compensator for -- -
, damping hydraulic shocks in the pressure pipeline running to
the machine. Besides, the above design provides for reducing
the overall dimensions of the machine.
It is preferable that the outer side surface of the
separated hammer piston be provided with an annular projection
-
while the inner surface of the housing, with a corresponding
, 20 step, said projection and the step forming an annular chamber,
the housing wall at this step has passages connecting the annular
chamber with the atmosphere when said hammer piston is in the
direction to the tool, during its idle stroke said hammer piston
compressing the air received in the annular chamber through said
passages and delivering it through an annular gap between the
housing and said hammer piston to the space between the separated
j hammer piston and the plunger, wherein said compressed air serves ;~
as a resilient member, thus ensuring automatic supply of the
, compressed air to said chamber of the housing and creating the , ~;
resilient member without the necessity for an additional compen-
;, sator under the hammer piston, that increases the machine effi-
ciency and rules out the spring whose service life is considerably
- 4 - -
J
10~09~1
short by the member with practically unlimited life.
It is also possible to embody the resilient member
arranged between the separated hammer piston and the plunger in
the form of a compression spring which should be used when
employing compressed air is difficult, for instance, while using
the hydraulic percussive machine as a submersible apparatus for
: drilling deep flooded wells.
This invention discloses a reliable hydraulic percus-
sive machine of a simpler design, lesser weight and higher effi-
ciency if compared with the known machines of the similar type.
This hydraulic machine may be advantageously used as a hydraulic
. hammer (quartering hammer) and a hydraulic percussive clevice for
making holes and deep wells in soil. :
The invention is explained hereinbelow by way of : -
examples with reference to the accompanying drawings, wherein:
FIGURE 1 is a longitudinal section of the hydraulic
percussive machine according to the invention,
FIGURE 2 is section II of Figure 1,
~ FIGURE 3 is a hydraulic percussive machine, according
.~ 20 to the invention, whose piston end face
directed towards the machine rear portion
is not pressed against the housing during
~: forward and return strokes of the piston,
FIGURE 4 is a longitudinal section of a hydraulic
percussive machine according to the invention,
made in the form of a hydraulic hammer (quar- -
tering hammer), :~
FIGURE 5 is detail A of Figure 4,
FIGURE 6 is detail B of Figure 4. ::
- 30 A hydraulic percussive machine shown in Figures 1, 2
., and 3 may be used as a hydraulic hammer (quartering hammer) and
a percussive device for making holes and deep wells in soil when
:~J ,~ ~ -
~ ' ' '''~;
~,,,, ,.,. . ,, ., . ,, ,, , , ," , .. . . . . . . . . .
.
employing a tool rotating means and a respective tool.
The hydraulic percussive machine has a stepped housing
1 adjoining the front portion of the machine and housing 2
adjoining the rear portion thereof. ;~
A larger diameter hammer piston 3 adjoining the front
` portion of the machine and a smaller diameter plunger 4 adjoining
the rear portion thereof are arranged in the housings 1 and 2
to be axially movable thereinside.
~ rranged between the hammer piston 3 and plunger 4 is a
cylindrical compression spring 5.
Secured in the housing 1 at the machine front portion
is an anvil 6 fastened to a tool 7 for making holes and deep
wells.
` During operation of the machine, the hammer piston 3
, end face directed to the machine front portion applies impacts
~ to the anvil 6 which transmits it to the structure being destroy-
`` ed via the tool 7. --
The housing 1 is closed with a cover made in the form
of a splined nut 8 accommodating the anvil 6. Discharge passages
9 are made in the splined nut 8 and in the anvil 6. The housing
1 is provided with passages 10, 11 and an annular groove 12.
1 The housing 2 has passages 13, 14, 15, space 16 and
connection 17 which serve (but for the passage 15) together with
the passage 11 and annular groove 12 for supply of the pressure
fluid to the supply and return spaces respectively.
The passage 15 connects the annular compensating space
15a which is not subject to the fluid pressure, with the housing
2. This rules out formatio~ of the water cushion in said space
due to seepage of the pressure fluid from the inside of the
machine through the packing glands, otherwise, said fluid might
brake the movement of the hammer piston 3 during the return
. .
~troXe (in the direction away from the tool). ~ -
-- 6 --
,, .
10~
The machine housing 2 is attached by the connection 17
to the string of drilling pipes (not shown) wherethrough the pres-
sure fluid is fed to the machine. The hydraulic percussive
machine is rotated by a separate rotating mechanism (not sho~m)
arranged at the well mouth via the string of drilling pipes.
If the machine is employed as a hydraulic hammer for
driving in piles, forging, destroying various structures, when
no rotating mechanism is needed, the connection 17 is coupled
with the pressure pipeline by a special reinforced hose (not
10 shown).
Mounted in the housing 1 on the hammer piston 3 is a
pressure difference ring valve 18 with an internal eccentric
annular projection 19 and passages 20 which serve for admitting
the pressure fIuid into the supply return space of the housings
~, 1 and 2 for effecting return stroke (in the direction away from
the tool). ~`
The hammer piston 3 front portion has an annular projec-
tion 21, while the rear portion thereof, an axial cylindrical
`~ chamber 22 whose section area is smaller than that of the piston
20 back face effective area.
An axial cylindrical space 16 is made in the housing
of the machine rear portion. The plunger 4 is made hollow and
i has a hollow cylinder 4a at one side thereof, said cylinder ; `
J being adapted for axial displacement in said cylindrical chamber
~ 22 of the hammer piston 3, and a hollow cylinder 4b at the other
; side, which is also adapted for axial displacement in said space
16 of the housing. The space 16 section area is smaller than
the area of the piston back face, the area of the end face 4c
1 of the hollow cylinder 4b located in the space 16 of the housing -~
`' 30 2, exceeding the area of the end face 4d of the hollow cylinder ~-
4a located in the cylindrical chamber 22 of the hammer piston 3. ` -~
,, Such a design of the machine rules out the necessity ; `
~ _ 7 _
. , .
10~0~71.
for damping the hydraulic shocks by a special damper (cavity)
which is usually arranged at a certain distance from the machine
- on the pipeline whereby the pressure fluid is delivered thereto.
This increases the machine efficiency since the hydraulic shocks
at the forward and return strokes of the hammer piston 3 transmit
their energy via the piston 4 to the spring 5 which relays said
energy to the hammer piston during the forward stroke. `
The inner annular projection 19 of the valve 18 is off-
set from the machine longitudinal axis and its internal diameter
exceeds the diameter of the annular projection 21 of the hammer
piston 3 by the run fit clearance.
This is done to ensure that the valve 18 can be fitted
through the annular projection 21 to the expanded part of the
hammer piston 3 outside the machine but does not slip off from ~ -
said part during operation of the assembled machine by engaging
the projection 21 of the hammer piston with its projection 19.
~ Inasmuch as the valve 18 is made with the eccentric projection,
i~ the hammer piston 3 separates the valve 18 from the anvil 6 at
`~ the end of its return stroke (in the direction away from the
~ 20 tool).
jA The hydraulic percussive machine shown in Figures 4
and S may be used only as a hydraulic hammer (quartering hammer)
for destroying various structures, forging metals, driving in
piles and the like. The impacts are applied by the end face of
the front portion of the hammer piston 3.
3 Constructionally the hydraulic hammer is somewhat
j different from the hydraulic machine shown in Figures 1 through 3.
The additional fluid passages 23 are made in the
2 eccentric annular projection 19 of the hydraulic hammer pressure
' 30 different valve 18. The hammer piston 3 is made with an addi-
`~ tional packing glands 25, 26 and an additional annular projection
24, while the housing 2 has a respective step 27 and suction
~ - 8 -
" .,
s :
",
104(~71
passages 28. Provided between mating rubber packing glands 29
and 30 of the hammer piston 3 outer and inner surfaces which
seal two different media (fluid and compressed air) are annular
grooves 31 and 32 connected to each other and to the atmosphere
by passages 33, 34, 35, 36. This is intended to remove fluid
seeped throu~h packing glands 29a, 29, 30a, 30 to the atmosphere
to prevent ingress thereof into the receiver cavity 37 filled
with compressed air supplied from the atmosphere by the annular
projection 24 of the hammer piston 3 which moves together with
the packing gland 25 in the annular cavity 38 of the additional
step 27 of the housing 2. i;-
The compressed air is delivered during the return
stroke of the hammer piston 3 through the annular gap 38a
(Fig. 5) between the housing 2 and the hammer piston 3 and then
through the packing gland 26 whose edges face the receiver
cavity 37 and operate as a non-return valve. Provided in the
housing 2 near the receiver cavity 37 is a connection 39 which
accommodates a check (release) spring-loaded valve 40, which is
adjusted for a definite pressure of the compressed air in the
cavity 37 by the nut 41 with the passage 42.
The cover 43 is closed with a bolt 44. The bolt has a
`~ through hole 45 for attachment of a cable (not shown) to sus- ~
pend the hydraulic hammer in operation. ~ -
The cover 8 of the housing 1 before the valve 18 is
y provided with an annular projection 46 (Figs. 4, 6) which
;/ embraces the valve 18 projection 47 directed towards the tool
and forms an annular gap 48 for passing the fluid between its
i -'
inner surface and the outer side surface of the front projection
47 of the valve 18. Due to this, the valve operates at the -~
initial stage of its return stroke towards the machine rear `
portion until passages 20 are overlapped at any increased
section area of the discharge passages 9 and maximum pressure
of the compressed air in the receiver cavity 37 that increases
, _ g _
.
104~
the efficiency and reliability of the machine. The value "h" of
the projection 46 protrusion through the plane of the valve 18
adjoining the cover 8 is assumed to equal or exceed the diameter
of the passa~es 20 of the valve 18 by 1.5-2.
The valve 18 section area at the projection 47 exceeds
that of the rear portion of the valve.
The cover 43 (Fig. 4) of the housing 2 has an addition-
al step 49 which receives an additional annular projection of
the hollow plunger 4. The area of the annular projection 50
not compensated by the pressure is in the annular space Sl of
the cover 43 which communicates with the atmosphere via passages
52. The additional step 49, projection 50 and space 51 wi~h
, passages 52 are necessary only if replacing the spring with
compressed air or other gaseous agent whose pressure should always
be below the pressure of the working fluid so that the hammer
piston is shifted back towards the machine rear portion during
? a return stroke thereof, therefore the area of the hollow
plunger 4 end face acted upon by the compressed air or other
~, gaseous agent should exceed the difference of the areas of its
. 20 end faces acted upon by the fluid, otherwise the plunger 4 ~-
cannot be retained in the extreme position shown in Fig. 4
between the hydraulic shocks which is necessary for a trouble-
free operation of the machine.
To describe the machine operation the position shown
, in Fig. 1 is assumed to be the initial one.
; When in this position, the valve 18 is pressed against
the anvil 6, the discharge passages are shut-off, while the ;-
passages 20 of the valve are opposite the annular groove 12 -
thus connecting the return space of the housings 1 and 2 via -~-
the passages 20, annular groove 12, passages 11, 13, 14 with the
supply spaces 16, 22 and the pressure pipeline (string of drill-
,' ing pipes or reinforced hose).
- 1 0 - ~,
..
,.. . . . .
104(~
The pressure fluid from the delivery pipeline (not shown) via
the connection 17 arrives at the supply spaces 16, 22 and via
passages 14, 13, 11, 12, 20 to the return space of the housings
1 and 2, shifts the hammer piston 3 backward (rightward in the
drawing) due to the difference of the areas of the end faces
whereon the pressure fluid acts: the piston back face area is
larger than the piston head face area corresponding to the
section area axial chamber 22. The hammer piston 3 effects its
return stroke compressing the spring 5.
After passing the preset distance the hammer piston
3 engages the inner eccentric annular projection 19 of the valve
18 by its annular projection 21 and separates the valve from the
anvil 6 thus opening the discharge passages 9.
~ Then the valve 18 continues moving backward independ-
.j ently under the pressure of the fluid flowing from the return
space due to the difference of the area of the valve opposite
end faces which corresponds to the area of the valve 18 not
~, subject to the fluid pressure and being in the annular gap 18a
of the housing 1 coupled with the atmosphere via the passages 10.
~ 20 At the beginning of the backward movement of the valve2~ 18, its passages 20 displace.relative to the annular groove 12 `
and get rapidly overlapped by the cylindrical walls of the . ~`
~ housing 1, the hammer piston 3 stops and the hydraulic shock -
`~ above the hammer piston and in the pressure pipeline is trans- . :~
~ , .
mitted to the hammer piston 3 through the larger end face 4e
of the plunger 4 and spring 5, and directly through the bottom
of its axial chamber 22. .
~ The hydraulic shock and the fluid excess pressure
i exerted on the bottom of the chamber 22 as well as the releasing ~-.
spring 5 make the hammer piston rush forward (leftward in the
drawing) discharging the fluid from the return space of the
, housings 1 and 2 outside through the open annular gap between ~ .
"
,",, . ,, . " .. ..
~04(3~
the housing 1 and anvil 6 and then through the discharge passages.
The hammer piston 3 meets the valve 18 approaching by
the pressure of the discharge fluid, carries the valve along,
applied impact against the anvil 6 secured with the tool 7, --
presses the valve 18 to the anvil 6, thus ceasin~ expell of -
the fluid outside from the return space of the housings 1 and 2
and the hydraulic shock occurring again in the pressure pipeline
is then transmitted via the passages 20 of the valve 18 into
the return space of the housings 1 and 2.
The hydraulic shock and excess pressure forces make
the hammer piston 3 effect the return stroke and the cycle
repeats.
The hydraulic percussive machine shown in Figure 3
iS of the same design and is based on the same operating prin-
ciple as the above-disclosed machine shown in Figure 1, the only
difference residing in that the spring 5 (Figure 3) does not
J
press the plunger 4 against the rear portion of the housing 2
during the forward and return strokes of the hammer piston, the ~ ~ '
rearmost position of the hammer piston 3 (in the direction away
from the tool) including, due to w~lich the plunger 4 has an easy
backward stroke effected together with the hammer piston 3 and
spring 5 during the return stroke of the hammer piston. Only
with the hammer piston in the extreme positions, when the
hydraulic shocks are formèd, the plunger 4 with spring 5 serves
to damp the hydraulic shocks. The damped energy of the hydraulic
. ,:: . .
shocks is transmitted via the spring 5 to the hammer piston 3
; which relays it to the anvil 6 simultaneously with the energy
of the hydraulic shocks and excess pressure of the fluid
-~, delivered through the bottom of the chamber 22.
The embodiment of the machine shown in Figure 3 has ~
t' no advantages over the embodiment of Figure 1 as to the efficien- -
cy or other characteristics thereof. This embodiment is
- 12 -
.. ;.; , , ,.,,",, ,. "" ,,:, ,, ,": :" "; .~ . j .. ,~ i .. . .
; ~04~71
preferably used when the machine is to have a small cross
section to drill minimum diameter wells (70-80 mm).
In the latter case the return space of the hammer-
piston 3 exceeds but slightly the supply space thereof and the
pressure of the fluid exerted on the hammer piston 3 during its
return strokes may prove insufficient for overcoming the resist-
ance of the spring arranged according to Figure 1. Therefore,
it is preferable that the plunger 4 is arranged without being
pressed by the spring 5 to the rear portion of the housing 2
and with a free space for ensuring a backward motion cf the
~' plunger 4 to exceed the stroke of the hammer piston 3, i.e. .
, as illustrated in Figure 3.
The operating principle of the hydraulic percussive ..
} machine shown in Figure 4 is the same as that of the machine of
Figures 1 and 3, the only difference consisting in that the -
hammer piston impacts are applied to the object being destroyed - :
directly by the hammer piston back face, while the spring 5
found in the embodiment of Figures 1 and 3 is replaced in the
machine of Figure 4 by the compressed air which is delivered :
automatically by the hammer piston 3 during the return stroke
thereof to the receiver cavity 37 of the housing 2 which does
not contact the fluid.
~, :
.~, .
.. ..
: :: . -`'
. ~ .
`.- .
.~ ~
, .
s .. - 13 -
