TWM535123U - Fluid static pressure cylinder - Google Patents

Description

Hydrostatic cylinder

The present invention relates to a counterweight of a machine tool, in particular to a hydrostatic cylinder.

The vertical axis of the machine tool generally uses a weight mechanism to reduce the load on the motor. The simplest weight mechanism uses a weight. For example, the Republic of China Certificate No. M363350 patent is a linkage at the top of a machine head. The component is connected to a weight by bypassing the top of a column. This weight design is poor in dynamic characteristics due to the doubled head quality.

Another commonly used weighting mechanism is the use of a hydraulic cylinder, such as the Republic of China Certificate No. M317895, which is provided with a counterweight cylinder between the working head and the top of a column, the piston and piston of the counterweight cylinder. The rods need to be provided with sealing parts. Since the sealing parts must be closely matched with the cylinder block and the piston rod, the piston and the piston rod will generate considerable friction when moving. This frictional force will affect the micro-increment in addition to the dynamic characteristics. Therefore, the purpose of precision micro-feeding cannot be achieved.

Therefore, the object of the present invention is to provide a hydrostatic cylinder which can reduce friction, has good dynamic characteristics and can achieve precise micro-feeding.

Thus, the novel hydrostatic cylinder comprises a cylinder, a piston unit and a piston rod. The cylinder extends along an axis and includes a cylinder wall surrounding the axis and forming a piston chamber and at least one feed flow passage communicating with the piston chamber, the piston unit being slidably disposed on the piston along the axis a cavity, and the piston cavity is partitioned into a first region and a second region, the piston unit includes a first end surface adjacent to the first region, a first axis along the axis opposite to the first end surface and adjacent to a second end surface of the second region, an outer ring surface connected between the first end surface and the second end surface and opposite to the cylinder wall, and an oil guiding body extending from the first end surface toward the second end surface a plurality of holes, a plurality of flow passages communicating from the oil guiding holes toward the outer annular surface, and a plurality of pressure grooves recessed from the outer annular surface and respectively communicating with the divided flow passages, the piston rod extending along the axis, including a corresponding to The second end surface is connected to the inner end of the piston unit and an outer end opposite to the inner end and extending outside the cylinder.

The utility model has the following advantages: the piston unit is provided with the flow guiding hole, the partial flow channels and the pressure grooves, and when the pressure fluid is introduced into the first region of the piston cavity, the piston unit corresponding to the pressure groove and the piston unit A hydrostatic bearing is formed between the cylinders, and the piston unit is free from friction when moving relative to the cylinder, and the dynamic characteristics are good and the ultra-precision micro-feeding can be achieved.

Referring to FIG. 1 , FIG. 2 and FIG. 3 , a first embodiment of the present hydrostatic cylinder comprises a cylinder 10 , a piston unit 20 , a supporting unit 30 , a bearing seat 40 , a ball bearing 50 , and A piston rod 60.

The cylinder block 10 extends along an axis L and has a hollow cylindrical shape, and includes a cylinder wall 12 surrounding the axis L and forming a piston chamber 11, and a lower cover 13 disposed at one end of the cylinder wall 12, An upper cover 14 opposite to the lower cover 13 and sealed at the other end of the cylinder wall 12, a feed flow path 15 corresponding to the lower cover 13 and an extraction flow corresponding to the upper cover 14 Road 16. In addition, the upper cover 14 and the outlet flow path 16 may be omitted and the top of the second area 112 may be directly connected to a return groove (not shown).

The piston unit 20 is slidably disposed in the piston chamber 11 along the axis L, and the piston chamber 11 is partitioned into a first region 111 communicating with the feed channel 15 and communicating with the outlet channel a second region 112 of the piston unit 20, the piston unit 20 includes a piston 21 and a plurality of throttle portions 22, the piston 21 having a first end surface 211 adjacent to the first region 111, and a direction L along the axis L opposite to the first portion An end surface 211 and a second end surface 212 adjacent to the second region 112, and an outer annular surface 213 connected between the first end surface 211 and the second end surface 212 and opposite to the cylinder wall 12 An oil collecting groove 214 recessed in the outer ring surface 213, a flow guiding hole 215 disposed along the axis L and extending from the first end surface 211 toward the second end surface 212, and most of the guiding hole 215 facing the outer annular surface a branching passage 216 communicating with and extending in a radial direction perpendicular to the axis L, a plurality of pressure grooves 217 recessed from the outer annular surface 213 and respectively communicating with the divided passages 216, and a plurality of recesses 217 recessed from the outer annular surface 213 And extending parallel to the axis L and communicating with the bus passages 218 of the oil collecting grooves 214, one end of each of the collecting channels 218 is connected to the first The two end faces 212 are connectable to the second region 212. The piston 21 also has a connecting post 219 projecting from the second end face 212 and extending along the axis L.

The sub-flow passages 216 are in the shape of a class of holes, and have a middle portion 201 connected to the flow guiding hole 215, an outer side portion 202 disposed between the middle portion 201 and the outer annular surface 213, and a side opposite to the outer side portion. And a closed portion 203 disposed between the middle portion 201 and the outer ring surface 213 and a threaded portion 205 disposed at the middle portion 201 and the outer portion 202. The pressure grooves 217 are respectively connected to the outer side portions. 202.

The throttling portions 22 of the present embodiment are formed as separate parts and are respectively mounted to the sub-flow passages 216 and are screw-locked to the threaded portions 205, respectively. In addition, the throttling portions may be directly formed into a reduced diameter hole shape and disposed between the divided flow passages and the pressure grooves (not shown), and may also achieve the purpose of throttling.

The support unit 30 is coupled between the piston unit 20 and the piston rod 60, and includes a lower support ring 31 radially disposed on the second end surface 212, and a lower support ring 31 disposed along the axis L. a side upper support ring 32, a plurality of balls 33 disposed between the lower support ring 31 and the upper support ring 32, and a lock member 34 for locking the upper support ring 32 to the piston 21, the upper support The ring 32 has the ability to be radially offset relative to the lower support ring 31. The lower support ring 31 has a sleeve hole 311 disposed in the connecting post 219, and there is no clearance between the lower sleeve hole 311 and the connecting post 219, and the lower support ring 31 is radially opposite to the piston 21 The upper support ring 32 has a set of upper sleeve holes 321 formed in the column 219, and a gap is formed between the upper sleeve hole 321 and the connecting post 219, and the clearance is utilized. The upper support ring 32 is radially displaceable relative to the connecting post 219. The locking member 34 has a spacer 341 disposed on the large diameter section of the upper sleeve hole 321 and a locking screw 342 disposed on the spacer 341 and locked to the connecting post 219.

The bearing block 40 is coupled to the piston 21 through the support unit 30. The bearing block 40 of the embodiment is fixed on the top of the upper support ring 32 and has a concave spherical surface 42 defining a spherical cavity 41. The spherical chamber 41 is disposed along the axis L.

The spherical bearing 50 is mounted in the spherical chamber 41 and is rotatable relative to the bearing housing 40, and has a convex spherical surface 51 attached to the concave spherical surface 42 and a pair of central holes 52 disposed on the axis L.

The piston rod 60 extends along the axis L, and includes an inner end 61 corresponding to the second end surface 212 and connected to the central hole 52 of the spherical bearing 50, and a side opposite to the inner end 61 along the axis L. An outer end 62 is provided outside the cylinder 10.

As shown in FIG. 1 to FIG. 3, when the piston unit 20 is raised, pressure fluid is introduced into the first region 111 of the piston chamber 11 by the feed flow passage 15, and the piston unit 20 can be pushed toward the piston unit 20. The direction of the flow path 16 is taken out, and at the same time, the pressure fluid (which may be pressurized oil in the embodiment) flows through the flow guiding hole 215, and the pressure fluid passes through the throttling portions 22 by the arrangement of the equal dividing passages 216. The outer section 202 flows to the pressure grooves 217, and a hydrostatic bearing is formed between the piston unit 20 corresponding to the pressure groove 217 and the cylinder 10. At the same time, there is still a relatively slidable gap between the outer ring surface 213 of the piston 21 and the cylinder wall 12. A pressure fluid infiltrates into the gap between the outer ring surface 213 and the cylinder wall 12 and forms a The oil film, by the action of the hydrostatic bearing and the oil film, can make the piston 21 and the cylinder 10 move without friction, and the dynamic characteristics are better, and the arrangement of the hydrostatic cylinder can be balanced. The purpose of the utility model is to reduce the load of a driving motor for driving a ball screw (not shown). The pressure fluids of the pressure tanks 217 are collected again into the oil collection grooves 214, and finally the second flow paths 218 are drained to the second region 112 (the fluid in the second region 112 is at normal pressure), and finally It is discharged from the take-out flow path 16 to facilitate recycling.

When the piston unit 20 is lowered and moved toward the direction in which the feed flow path 15 is provided, and the pressure fluid in the first region 111 is pressed by the piston 21, the pressure fluid is again introduced by the flow guiding hole 215. Also, a hydrostatic bearing is formed between the piston unit 20 corresponding to the pressure groove 217 and the cylinder block 10. Therefore, when the piston unit 20 is moved bidirectionally with respect to the cylinder block 10, it is preferable to produce a hydrostatic bearing. Dynamic characteristics.

The outer end 62 of the piston rod 60 of the hydrostatic cylinder of the present invention can be coupled to a machine tooling head (not shown) and coupled to the ball bearing 50 by the inner end 61 of the piston rod 60. The bearing 50 is nested with the bearing housing 40. The bearing housing 40 is fixed to the upper support ring 32. The upper support ring 32 is locked to the connecting post 219 of the piston 21 through the locking member 34. The movable rod 60 can be The weight of the machine tool head is supported by the piston unit 20.

The steel ball 33 between the upper support ring 32 and the lower support ring 31 can absorb the radial deviation of the axial direction of the piston rod 60 with respect to the axis L. By the cooperation of the concave spherical surface 42 of the bearing housing 40 and the convex spherical surface 51 of the spherical bearing 50, the axial deviation of the axis L of the hydrostatic cylinder from the axial direction of the piston rod 60 can be absorbed, so that the hydrostatic cylinder can be improved. The assembly is improved and the smoothness of the movement of the piston 21 is improved.

As shown in FIG. 4, the second embodiment of the present novel hydrostatic cylinder differs from the first embodiment in that the second end surface 212' of the piston unit 20' has a plurality of pressure grooves 23' and a plurality of The pressure guiding groove 23' is formed in a unitary manner between the pressure dividing groove 23' and the branching passage 216', and has a bottom end surface 31' opposite to the second end surface 212', and along the axis L. A top end surface 32' opposite to the bottom end surface 31' and a sleeve hole 33' extending from the bottom end surface 31' toward the top end surface 32' and disposed along the axis L. The inner diameter of the sleeve hole 33' is larger than the outer diameter of the connecting post 219', and the supporting unit 30' has a radial displacement capability relative to the piston unit 20', so that the supporting unit 30' can absorb the The radial deviation of the axial direction of the piston rod 60 relative to the axis L. The pressure fluid can be drained to the pressure groove 23' to create a hydrostatic bearing between the bottom end surface 31' and the second end surface 212', and the support unit 30' and the piston unit 20' can be The function of the hydrostatic bearing is formed and the smoothness of the movement of the piston 21' is improved.

As shown in FIG. 5, the third embodiment of the present hydrostatic cylinder differs from the second embodiment in that the bearing housing 40" further has a pressure groove 43 that can be recessed from the concave spherical surface 42". And a drain passage 44" that is connectable to the pressure groove 43' and the branch passage 216" through the support unit 30", and functions to generate a hydrostatic bearing between the concave spherical surface 42" and the convex spherical surface 51" The hydrostatic bearing is formed between the bearing housing 40" and the spherical bearing 50", and the smoothness of the movement of the piston 21" is improved.

It is worth mentioning that the above-mentioned embodiment of the present invention is described by a counterweight cylinder of a machine tool. In fact, the technical features of the present invention can also be applied to a piston and a cylinder of a compressor or an engine (not shown), and Keep the compressor or engine running smoothly.

In summary, the novel hydrostatic cylinder has a simple overall structure and is easy to manufacture, and a hydrostatic bearing can be formed between the cylinder and the outer annular surface, so that the piston unit can be opposite to the cylinder. No friction is generated during exercise, the dynamic characteristics are good, and the ultra-precision micro-feeding can be achieved, and the purpose of the present invention can be achieved.

However, the above is only the embodiment of the present invention, and when it is not possible to limit the scope of the present invention, all the simple equivalent changes and modifications according to the scope of the patent application and the contents of the patent specification are still This new patent covers the scope.

10‧‧‧Cylinder
L‧‧‧ axis
11‧‧‧ piston cavity
111‧‧‧First area
112‧‧‧Second area
12‧‧‧Cylinder wall
13‧‧‧Under the cover
14‧‧‧Upper cover
15‧‧‧feed runner
16‧‧‧Extracting the runner
20‧‧‧piston unit
21‧‧‧Piston
211‧‧‧ first end face
212‧‧‧second end face
213‧‧‧ outer annulus
214‧‧ ‧ oil groove
215‧‧‧Inlet
216‧‧ ‧ runner
201‧‧‧ middle section
202‧‧‧Outer section
203‧‧‧Expanded section
205‧‧ Thread Department
217‧‧‧pressure tank
218‧‧ ‧ Confluence channel
219‧‧‧Connecting column
22‧‧‧ Throttling Department
30‧‧‧Support unit
31‧‧‧ lower support ring
311‧‧‧Lower hole
32‧‧‧Upper support ring
321‧‧‧Set of holes
33‧‧‧ balls
34‧‧‧Locks
341‧‧‧shims
342‧‧‧Locking screws
40‧‧‧ bearing housing
41‧‧‧ spherical room
42‧‧‧ concave spherical surface
50‧‧‧Spherical bearings
51‧‧‧ convex spherical surface
52‧‧‧ center hole
60‧‧‧ piston rod
61‧‧‧Inside
62‧‧‧Outside
20'‧‧‧piston unit
21'‧‧‧Piston
212'‧‧‧second end face
216'‧‧‧Sewer
219'‧‧‧ Connecting column
23'‧‧‧ Pressure tank
24'‧‧‧drain
30'‧‧‧Support unit
31'‧‧‧ bottom end
32'‧‧‧ top surface
33'‧‧‧ Set of holes
21"‧‧‧Piston
216" ‧ ‧ split runner
30”‧‧‧Support unit
40"‧‧‧ bearing housing
42"‧‧‧ concave spherical surface
43”‧‧‧pressure tank
44”‧‧‧Drainage channel
50"‧‧"spherical bearings
51"‧‧‧ convex spherical surface

BRIEF DESCRIPTION OF THE DRAWINGS Other features and advantages of the present invention will be apparent from the following description of the drawings, wherein: Figure 1 is a cross-sectional view of a first embodiment of a hydrostatic cylinder of the present invention; Figure 3 is a cross-sectional view taken along line III-III of Figure 1; Figure 4 is a partially enlarged schematic view of a second embodiment of the hydrostatic cylinder of the present invention; and Figure 5 is a fluid of the present invention A partially enlarged schematic view of a third embodiment of a hydrostatic cylinder.

10‧‧‧Cylinder

L‧‧‧ axis

11‧‧‧ piston cavity

111‧‧‧First area

112‧‧‧Second area

12‧‧‧Cylinder wall

13‧‧‧Under the cover

14‧‧‧Upper cover

15‧‧‧feed runner

16‧‧‧Extracting the runner

22‧‧‧ Throttling Department

30‧‧‧Support unit

31‧‧‧ lower support ring

32‧‧‧Upper support ring

33‧‧‧ balls

40‧‧‧ bearing housing

50‧‧‧Spherical bearings

60‧‧‧ piston rod

61‧‧‧Inside

62‧‧‧Outside

20‧‧‧piston unit

21‧‧‧Piston

216‧‧ ‧ runner

215‧‧‧Inlet

Claims (8)

A hydrostatic cylinder comprising: a cylinder extending along an axis and including a cylinder wall surrounding the axis and forming a piston chamber and at least one feed passage communicating with the piston chamber; a piston unit, The piston chamber is slidably disposed along the axis, and the piston chamber is partitioned into a first region and a second region, the piston unit includes a first end surface adjacent to the first region, and an axis along the axis a second end surface opposite to the first end surface and adjacent to the second area, an outer annular surface connected between the first end surface and the second end surface and opposite to the cylinder wall, and the first end a flow guiding hole extending toward the second end surface, a plurality of flow dividing passages communicating from the flow guiding hole toward the outer annular surface, and a plurality of pressure grooves recessed from the outer annular surface and respectively communicating with the divided flow passages; and The piston rod extends along the axis and includes an inner end corresponding to the second end surface and connected to the piston unit and an outer end extending along the axis opposite to the inner end and extending outside the cylinder. The hydrostatic cylinder according to claim 1, wherein the split runners of the piston unit are in the shape of a class of holes, and each has a middle portion connected to the flow guiding hole, and a middle portion and the outer annular surface. An outer side section, a closed section opposite to the outer side section and disposed between the middle section and the outer annular surface, and a throttle portion disposed between the middle section and the outer side section. The hydrostatic cylinder according to claim 1, further comprising a supporting unit coupled between the piston unit and the piston rod, the supporting unit comprising a lower supporting ring radially positioned on the second end surface, An upper support ring disposed along one side of the lower support ring and a plurality of balls disposed between the lower support ring and the upper support ring, the upper support ring having a radial offset relative to the lower support ring ability. The hydrostatic cylinder of claim 3, further comprising a bearing housing that is positionable relative to the upper support ring and a ball bearing coupled to the piston rod and rotatable relative to the bearing housing, the bearing The seat has a concave spherical surface defining a spherical cavity, the spherical bearing being mounted in the spherical cavity and having a convex spherical surface attached to the concave spherical surface. The hydrostatic cylinder according to claim 4, wherein the piston unit further has a connecting post protruding from the second end surface and extending along the axis, the lower supporting ring being sleeved on the connecting post and along the diameter Positioning is created relative to the piston unit, the upper support ring being radially displaceable relative to the connecting post. The hydrostatic cylinder according to claim 4, wherein the bearing housing further has at least one pressure groove recessed from the concave spherical surface and at least one drainage through the support unit to communicate with the pressure groove and the flow dividing channel A hydrostatic bearing can be produced between the concave spherical surface corresponding to the pressure groove and the convex spherical surface. The hydrostatic cylinder of claim 1, further comprising a support unit coupled between the piston unit and the piston rod, the support unit being unitary and having a bottom end surface opposite to the second end surface, a top end surface opposite the bottom end surface along the axis and a sleeve hole extending from the bottom end surface toward the top end surface and disposed along the axis L, the piston unit further having a protrusion from the second end surface and along the An axially extending connecting post having an inner diameter greater than an outer diameter of the connecting post and having the support unit radially offset relative to the piston unit. The hydrostatic cylinder according to claim 3 or claim 7, wherein the second end surface of the piston unit has at least one pressure groove and at least one drainage channel respectively communicating between the pressure groove and the branch flow path.