CN201908899U - Oil cylinder for static pressure vibration exciter - Google Patents

Abstract

The utility model discloses a static pressure vibration exciter oil cylinder, the two ends of the piston are fixedly connected with a piston rod, and each piston rod protrudes from the inner chamber of the cylinder barrel; the cross section of the static pressure bearing is circular, and the outer wall of the static pressure bearing is along the There are annular outer oil grooves at intervals in the axial direction, and the inner wall of the static pressure bearing is provided with annular inner oil grooves in the axial direction. Each annular outer oil groove communicates with an annular inner oil groove through the first through hole; holes; the piston rods respectively pass through a hydrostatic bearing, and the hydrostatic bearings are respectively fixedly connected with an end cover. The bolts are fixedly connected; each end cover housing is provided with an oil inlet hole and a corresponding oil outlet hole, one of the two adjacent annular outer oil grooves is connected to the corresponding oil inlet hole, and the other annular outer oil groove communicate with the corresponding oil outlet hole. The utility model can resist relatively large lateral force and reduce the friction between the piston and the static pressure bearing.

Description

Hydrostatic Vibrator Cylinder

technical field

The utility model relates to a static pressure vibration exciter oil cylinder, which can be widely used in the field of single-degree-of-freedom and multi-degree-of-freedom hydraulic vibration tables, and also has related applications in some aerospace products and metallurgical industries.

Background technique

Ordinary servo exciter cylinders are widely used in hydraulic vibration tables. For ultra-high-frequency high-thrust hydraulic vibration tables, the piston and piston rod of the exciter cylinder perform high-speed reciprocating motion together, and at the same time, they must bear large lateral forces. The force makes the friction between the piston, piston rod and the cylinder wall and seal intensifies, and the external leakage of the hydraulic system increases, so the repeatability of the test is poor. Chinese patent CN11877140A discloses a hydrostatic support-guided hydraulic cylinder, which has four rectangular oil chambers on the inner wall of the hydrostatic bearing and four oil return grooves along the axial direction, so that after the oil enters the oil chamber, it will The oil returns along the axial oil sealing surface and the radial oil sealing surface at the same time, forming an oil film with a certain rigidity. This design can reduce friction to a certain extent, but due to the radial oil return in this design, the piston rod reciprocates at high frequency. At the same time, there is a phenomenon of oil leakage between the oil chambers, and the phenomenon of turbulent flow occurs in the fluid movement, so the lateral force resistance of the piston rod is greatly reduced, and the phenomenon of "shaft holding" may occur, thereby damaging the oil cylinder, which cannot meet the high frequency requirements. Thrust multi-degree-of-freedom hydraulic vibration table requirements. With the development of high-frequency, high-thrust and multi-degree-of-freedom hydraulic vibration tables, the control precision of the vibration system is getting higher and higher, and the requirements for the lateral force resistance of the servo vibration exciter cylinder are getting higher and higher. The utility model can meet the requirements of the cylinder extreme Requirements for low friction and greater resistance to lateral forces. So far, there is no static pressure exciter oil cylinder adopting the static pressure bearing structure in China.

Utility model content

The technical problem to be solved by the utility model is to provide a static pressure exciter oil cylinder which can resist relatively large lateral force and greatly reduce the friction force between the static pressure bearing and the piston.

The technical solution adopted by the utility model to solve the technical problem is: the static pressure vibration exciter oil cylinder includes a cylinder barrel and a piston placed in the inner cavity of the cylinder barrel, and a piston rod is fixedly connected to each of the two ends of the piston, so Each of the piston rods protrudes from the inner cavity of the cylinder. In addition, it also includes locking bolts, a pair of static pressure bearings and a pair of end covers. The cross section of the static pressure bearings is circular, and the static pressure The outer side of the bearing wall is provided with two or more annular outer oil grooves at intervals along the axial direction, and the inner side of the wall of the hydrostatic bearing is axially and correspondingly provided with more than two annular inner oil grooves, and each annular outer oil groove corresponds to the An annular inner oil groove communicates through a first through hole provided on the wall of the hydrostatic bearing; the end cover is provided with a second through hole along the axial direction, and the cross section of the second through hole along the axial direction is stepped The piston rods respectively pass through one of the hydrostatic bearings and form a clearance fit with each other, and the hydrostatic bearings are respectively fixedly connected with one of the end covers, and the hydrostatic bearings are respectively placed on the second end cover of the corresponding end cover. The two ends of the cylinder barrel are respectively placed in the large hole of the second through hole of the corresponding end cover and form a sealing support with each other, and the piston rod and the corresponding end cover A cavity is formed between the middle holes of the second through hole so that the piston can move from the inner cavity of the cylinder into the cavity and form a clearance fit with the cavity; the two end caps are passed through The locking bolts are fixedly connected; the housing of each end cover is provided with an oil inlet hole and a corresponding oil outlet hole, and one of the two adjacent annular outer oil grooves is connected to the corresponding oil inlet hole. communicated, and the other annular outer oil groove communicates with the corresponding oil outlet hole.

Further, there are two first through holes for connecting each annular outer oil groove and corresponding annular inner oil groove in the utility model, and the two first through holes form a 90° angle along the circumferential direction of the hydrostatic bearing. angle.

Further, the oil inlet hole of the utility model is a capillary restrictor.

Compared with the prior art, the beneficial effects of the utility model are: (1) Since the inner side of the wall of the hydrostatic bearing in the utility model is provided with more than two annular inner oil grooves in the axial direction, the two adjacent annular An axial oil sealing surface structure is formed between the inner oil grooves to avoid the formation of a radial oil sealing surface, thereby preventing turbulent flow caused by cross flow of oil in each annular inner oil groove. In addition, the high-pressure oil formed by the structure of the axial oil sealing surface enables the cylinders of the static pressure exciter of the utility model on the hydraulic vibration table to resist the lateral force generated by mutual influence and protect the The system composed of the oil cylinder and the hydraulic vibration table greatly improves the stability of the system. At the same time, since the static pressure bearing of the utility model can be provided with a plurality of annular inner oil grooves in the axial direction, the number of sets of inner oil grooves can be easily increased in the axial direction, thereby improving the lateral force resistance to the static pressure oil cylinder and realizing the present invention. The utility model relates to the flexible production and processing of the oil cylinder of the static pressure exciter, and the structure of the oil cylinder of the static pressure exciter of the utility model is compact and exquisite. The high-pressure oil formed by the structure of the axial oil sealing surface makes the lubricating oil pumped in between the hydrostatic bearing and the piston separated by a certain gap when the oil cylinder is working normally, so the friction between the hydrostatic bearing and the piston belongs to pure liquid friction. The frictional resistance is extremely small, the power consumption is small, the vibration efficiency is high, the waveform reproduction effect of the hydraulic vibration table, the precision retention is good, and the oil cylinder has a long life. (2) The static pressure bearing in the utility model adopts the structure of "secondary throttling" (i.e. throttling through the oil inlet hole first, and then through the annular outer oil groove of the static pressure bearing), which greatly reduces the oil cylinder of the exciter, especially the The size of the end cover part, and because the floating of the piston is realized by the pressure of external oil, it has a high bearing capacity under various vibration frequencies, and the frequency change has little effect on the stiffness of the oil film. The high-pressure oil formed on the structure of the axial oil sealing surface has good anti-vibration performance and the function of compensating errors, and can reduce the adverse effects of pistons and hydrostatic bearings caused by their own manufacturing errors. (3) The axial oil sealing surface structure of the static pressure bearing of the utility model can make the static pressure bearing meet the requirements of light-load to heavy-load various mechanical equipment in terms of load capacity, oil film stiffness, temperature rise, etc.

Description of drawings

Below in conjunction with accompanying drawing, the utility model is further described.

Fig. 1 is a schematic sectional view of the structure of the utility model static pressure vibration exciter oil cylinder.

Fig. 2 is a schematic diagram of the appearance of the oil cylinder of the static pressure vibration exciter of the utility model.

Fig. 3 is a schematic structural view of the end cap of the present invention.

Fig. 4 is a schematic sectional view of the structure of the end cap in the present invention.

Fig. 5 is a schematic diagram of the appearance of the hydrostatic bearing in the utility model.

Fig. 6 is a schematic cross-sectional view of the structure of the hydrostatic bearing in the present invention.

Fig. 7 is a cross-sectional view along line A-A of Fig. 1 .

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described in detail.

As shown in Figures 1 to 7, the hydraulic cylinder of the static pressure exciter of the present invention includes a cylinder 5 and a piston 2 placed in the inner cavity of the cylinder. Two seals are adopted between the cylinder barrel 5 and the piston 2, which can significantly improve the sealing effect. Both ends of the piston 2 are respectively fixedly connected with a piston rod 11 and a piston rod 12, and the piston rod 11 and the piston rod 12 are respectively fixedly connected with the piston 2 in a threaded manner, and the piston rod 11 and the piston rod 12 extend out of the cylinder 5 respectively. cavity. The hydrostatic bearing 31 is fixedly connected to the end cover 41 through bolts 181 and 182 ; the hydrostatic bearing 32 is fixedly connected to the end cover 42 through bolts 183 and 184 . As shown in Figure 5, the cross sections of the hydrostatic bearing 31 and the hydrostatic bearing 32 are circular, and the outer sides of the walls of the hydrostatic bearing 31 and the hydrostatic bearing 32 are axially provided with four annular outer oil grooves 121, 122, 123, 124, wherein the annular outer oil grooves 121, 123 are oil inlet grooves, and also have the effect of a throttle, thereby greatly reducing the size of the exciter oil cylinder, especially the end caps 41, 42; the annular outer oil grooves 122, 124 are The oil return groove, the annular outer oil groove 122, 124 communicates with the oil outlet holes 171, 172, 175, 176 on the end cover 41, wherein each oil outlet hole is used as an oil return channel. Four annular inner oil grooves 151, 152, 153, 154 are correspondingly arranged on the inner sides of the walls of the hydrostatic bearing 31 and the hydrostatic bearing 32 in the axial direction, thereby forming an axial seal between two adjacent annular inner oil grooves. The oil surface structures 131, 132, 133, 134 avoid the formation of radial oil sealing surfaces, thereby preventing turbulent flow caused by cross flow of oil in each annular inner oil groove. The lubricating oil from the oil inlet holes 71, 72, 75, 76 enters the inner oil grooves 152, 154 through the annular outer oil grooves 122, 124 of the hydrostatic bearing 31 and forms a high-pressure oil film through the oil sealing surface structures 131, 132, 133, 134 , so that the piston rod 11 floats; the lubricating oil from the oil inlet holes 73, 74, 77, 78 enters the inner oil grooves 152, 154 through the annular outer oil grooves 122, 124 of the hydrostatic bearing 32 and passes through the axial oil sealing surface structure 131, 132, 133, 134 form a high-pressure oil film to make the piston rod 12 float. Therefore, the friction between the hydrostatic bearings 41, 42 and the corresponding piston rods 11, 12 belongs to pure liquid friction, and the frictional resistance is extremely small. In addition, as shown in Figures 5 and 6, the annular outer oil groove 121 communicates with the annular inner oil groove 154 through the first through holes 114, 118 provided on the wall of the hydrostatic bearing, and the annular outer oil groove 122 communicates with the annular inner oil groove 153 by setting The first through holes 113, 117 on the wall of the hydrostatic bearing communicate, the annular outer oil groove 123 communicates with the annular inner oil groove 152 through the first through holes 112, 116 arranged on the wall of the hydrostatic bearing, and the annular outer oil groove 124 communicates with the annular inner oil groove 152 The annular inner oil groove 151 communicates through the first through holes 111, 115 arranged on the wall of the hydrostatic bearing, wherein the first through holes 112, 114, 116, 118 are used for oil inlet, and the first through holes 111, 113, 115 , 117 are used for oil return. It should be noted that there may be only one first through hole for communicating each annular outer oil groove with the corresponding annular inner oil groove.

As shown in Figures 1, 3, and 4, the end caps 41, 42 are all provided with a second through hole 10 along the axial direction, and the cross section of the second through hole 10 along the axial direction is stepped, so that the second through hole 10 is from one end to the other. The other end presents the structure of large hole 83 , middle hole 81 and small hole 85 in sequence. The piston rods 11 and 12 respectively pass through the static pressure bearings 31 and 32 and form a clearance fit with the corresponding static pressure bearings, which is the oil film gap 16 formed when the static pressure vibration exciter oil cylinder works normally. The static pressure bearing 31 is fixedly connected to the end cover 41 through bolts 181 , 182 , and the static pressure bearing 32 is fixedly connected to the end cover 42 through bolts 183 , 184 . The static pressure bearing 31 is placed in the inner wall of the small hole 85 of the second through hole 10 of the end cover 41 , and the outer wall of the static pressure bearing 31 forms a transition fit with the inner wall of the small hole 85 . The two ends of the cylinder 5 are respectively placed in the large hole 83 of the second through hole 10 of the end caps 41 , 42 and form a sealing support with the inner wall of the large hole 83 . In addition, a cavity is formed between the piston rod 11 and the middle hole 81 of the second through hole 10 of the end cover 41 so that the piston 2 can move from the inner cavity of the cylinder 5 into the cavity 81 and form a mutual formation with the cavity 81. Clearance fit. The end cover 41 and the end cover 42 are fixedly connected by locking bolts 612, 634, so the structure is compact and the force is uniform.

Oil inlet holes 71, 72, 75, 76 and oil outlet holes 171, 172, 175, 176 are opened on the shell of the end cover 41; oil inlet holes 73, 74, 77, 78 are opened on the shell of the end cover 42 And oil outlet is 173,174,177,178. As shown in Figure 4, the oil inlet hole 72, the oil outlet hole 175, the oil inlet hole 71, and the oil outlet hole 176 on the end cover 41 are distributed sequentially along the axial direction of the end cover 41. Similarly, the oil inlet hole 75, the oil outlet hole 171 , oil inlet holes 76 , and oil outlet holes 172 are sequentially distributed along the axial direction of the end cover 41 , thereby forming a structure in which oil inlet holes and oil outlet holes are distributed alternately. As shown in FIG. 2 , the oil inlet holes 77 , 78 , 73 , 74 on the end cover 42 and the corresponding oil outlet holes 177 , 178 , 173 , 174 also form a staggered distribution structure.

Wherein, as shown in Figure 6, the oil inlet holes 72, 76 communicate with the annular outer oil groove 121 of the hydrostatic bearing, and the oil inlet holes 71, 75 communicate with the annular outer oil groove 123 of the hydrostatic bearing 31; The annular outer oil groove 122 is in communication, and the oil outlet holes 171 , 175 are in communication with the annular outer oil groove 124 . The annular outer oil groove 121 , the annular outer oil groove 122 , the annular outer oil groove 123 , and the annular outer oil groove 124 are adjacent in sequence. In addition, as shown in Fig. 5, there are two first through holes for connecting the annular outer oil groove 121 and the annular inner oil groove 154 of the hydrostatic bearing, which are respectively the first through hole 114 and the first through hole 118, and the first The through holes 114, 118 form an included angle of 90° along the circumferential direction of the hydrostatic bearing. The oil inlet holes of the end cover 41 and the end cover 42 function as capillary restrictors, of course, the oil inlet holes can also be directly replaced by capillary restrictors. The restrictor is an important device in the hydrostatic bearing system. It is just like the resistance element in the circuit system, because it has a certain liquid flow damping, so that the pressure oil from the oil pump produces a pressure drop and acts as a pressure oil. Adjustment function, for constant pressure oil supply hydrostatic bearings, the bearing system must have compensation components, so that the oil pressure in the bearing oil chamber can be adjusted with the change of the external load.

As shown in Figures 1 to 6, the working process of the utility model is as follows: the oil of a certain pressure from the oil pump flows into the annular outer oil grooves 121, 123 of the hydrostatic bearing 31 through the oil inlet holes 71, 72, 75, 76, and passes through the first A through hole 121, 123, 114, 112 enters into the annular inner oil groove 154, 152, and floats the piston rod 11 through the axial oil sealing surface structure 131, 132, 133, 134, and then passes through the annular inner oil groove 151, 153 from the first A through hole 115, 117, 111, 113 flows out to the outer oil tank 122, 124, and finally flows back to the oil tank through the oil outlet holes 171, 172, 175, 176 on the end cover 41, and the pressure is zero now. Since the static pressure bearing only adopts the axial oil sealing surface structure 131, 132, 133, 134 and has no radial oil sealing surface, it can prevent radial oil flow and avoid the phenomenon of turbulent flow, so that the static pressure exciter The oil cylinder has excellent stability. The oil cylinder of the static pressure exciter of the utility model is in the form of double rods, so the two ends of the oil cylinder are respectively arranged with static pressure bearings 41, 42, which greatly enhances the ability of the oil cylinder to resist lateral force.

As shown in Figure 5 and Figure 6, as a preferred embodiment of the present invention, the first through holes 114, 118 form an angle of 90° along the circumferential direction of the hydrostatic bearing, where the first through holes 114, 118 are used as oil; and, the first through holes 113, 117 form an included angle of 90° along the circumferential direction of the hydrostatic bearing, where the first through holes 113, 117 are used for oil outlet. The purpose of the first through holes 114, 118 forming an angle of 90° along the circumferential direction of the hydrostatic bearing and the first through holes 113, 117 forming an angle of 90° along the circumferential direction of the hydrostatic bearing is to increase the oil film establishment speed of the hydrostatic bearing 31, At the same time, by rotating the static pressure bearing 31, the arc lengths of the annular outer oil grooves 121 and 123 that act as throttling are changed, thereby changing the oil inlet liquid resistance and improving the stability of the exciter oil cylinder. At the same time, in order to improve the The oil cylinder resists lateral force, and the number of outer oil grooves, the number of inner oil grooves, and the number of oil inlets and oil outlets corresponding thereto on the end cover can be increased in pairs on the outer walls and inner walls of the hydrostatic bearings 31 and 32. The main purpose of the ring-shaped outer oil grooves 121 and 123 on the outer wall of the hydrostatic bearing is to throttle the oil flowing into the oil chamber, and to cooperate with the oil inlet holes 71, 72, 75, and 76 to regulate pressure. At the same time, because the annular outer oil grooves 121 and 123 play a throttling role, the size of the end cover of the oil cylinder of the vibrator can be greatly reduced. Depending on the condition of the piston of the oil cylinder (such as step load or pulsating cycle load), the number of annular inner oil grooves can be increased on the inner walls of the hydrostatic bearings 31, 32, and the number of annular inner oil grooves can be odd or even. For the multi-degree-of-freedom hydraulic vibration table, the hydrostatic vibration exciter oil cylinder of the utility model is supported by two hydrostatic bearings 31, 32, which can not only meet the needs of system stability and control accuracy, but also make the structure simple and the processing technology Good performance.

As shown in Figure 1, Figure 2, and Figure 7, under the condition of ignoring the self-weight of the piston rod, when the piston rod 11 bears the horizontal leftward applied load W, the piston rod 11 will move along the direction of the load W for a distance of e , if there is a gap 16 between the piston 11 and the hydrostatic bearing 31 when there is no load, then after the load W is applied, the gap 16 on the left side of the oil chamber decreases, while the gap 16 on the right side increases. Where the gap 16 decreases, the oil flow decreases, the resistance increases, and the oil pressure increases; where the gap 16 increases, the oil flow increases, the resistance decreases, and the oil pressure decreases. Assuming that the oil inlet holes 71, 72, 75, and 76 leading to each oil chamber are all the same, that is, the liquid flow damping is the same, and the oil inlet pressure is also the same, then the clearance changes due to the external load make the annular inner oil grooves 154, 152 The pressure of the oil cavity on the left side of the ring increases, so that the pressure of the oil cavity on the right side of the annular inner oil groove 154, 152 decreases. In this way, the force of the pressure difference from left to right generated on the axial oil sealing surfaces 131, 132, 133, 134 on the bearing area is just in balance with the external load W, so the piston 11 is fixed in a new position. According to the working requirements of the piston 11, it is often hoped that the pressure difference generated by the oil pressure on the axial oil sealing surface structures 131, 132, 133, 134 must be able to balance the external load borne, and keep the piston from generating a large pressure difference. displacement. However, in actual situations, constant external loads are rare, especially in vibrators, where external loads mostly change within a certain range. In order to meet the above wishes, this requires that the oil pressure of each annular inner oil groove 152, 154 can change with the change of the external load, so as to ensure that the oil pressure of each oil chamber can change with the change of the external load. Oil grooves 121, 123 play this role exactly. At the same time, the relative positions of the inlets of the oil inlet holes 71, 72, 75, 76 and the annular outer oil grooves 121, 123 of the static pressure bearing 31 can be adjusted by rotating the static pressure bearing 31, so that the arc of the annular outer oil groove that plays a throttling effect can be adjusted. Long length, so as to change the total hydraulic resistance of the oil inlet, the pressure of the oil film can be conveniently adjusted according to the load of the static pressure exciter cylinder, and the dynamic characteristics of the oil film (such as stability, accuracy, and rapidity) can be improved. The oil cylinder of the static pressure vibration exciter of the utility model has strong ability to resist lateral force, and the friction force between the pistons 11, 12 and the static pressure bearings 31, 32 is extremely small, which is convenient for precise control of the multi-degree-of-freedom hydraulic vibration table. At the same time, the hydraulic cylinder of the static pressure vibrator has a simple structure, reduces the difficulty of mechanical processing, and has a compact structure, which can meet the needs of various hydraulic vibration tables.

Claims (3)

1. A hydrostatic vibration exciter oil cylinder, comprising a cylinder barrel (5) and a piston (2) placed in the inner cavity of the cylinder barrel, a piston rod is fixedly connected to both ends of the piston (2), and the Each piston rod extends out of the inner cavity of the cylinder (5), and is characterized in that it also includes locking bolts, a pair of hydrostatic bearings and a pair of end covers, the cross section of the hydrostatic bearings is circular, The outer side of the wall of the static pressure bearing is provided with more than two annular outer oil grooves at intervals along the axial direction, and the inner side of the wall of the hydrostatic bearing is correspondingly arranged with more than two annular inner oil grooves at intervals along the axial direction. The oil groove communicates with an annular inner oil groove correspondingly through the first through hole provided on the wall of the hydrostatic bearing; the end cover is provided with a second through hole (10) in the axial direction, and the second through hole ( 10) The section along the axial direction is stepped; the piston rods respectively pass through one of the hydrostatic bearings and form a clearance fit with each other, and the hydrostatic bearings are respectively fixedly connected with one of the end covers, and the hydrostatic bearings are fixedly connected to each other. The bearings are respectively placed in the small holes of the second through hole (10) of the corresponding end cover and form a transition fit with each other, and the two ends of the cylinder (5) are respectively placed in the second through hole (10) of the corresponding end cover In the large hole and form a sealing support with each other, and a cavity is formed between the piston rod and the middle hole of the second through hole (10) of the corresponding end cover so that the piston (2) can be moved by the cylinder (5) The inner cavity of the inner cavity moves into the cavity and forms a clearance fit with the cavity; the two end covers are fixedly connected by locking bolts; the shells of the end covers are provided with oil inlet holes and corresponding One of the two adjacent annular outer oil grooves communicates with the corresponding oil inlet hole, and the other annular outer oil groove communicates with the corresponding oil outlet hole. 2. The hydrostatic vibration exciter oil cylinder according to claim 1, characterized in that: there are two first through holes for communicating each annular outer oil groove with the corresponding annular inner oil groove, and the two first through holes The through holes form an included angle of 90° along the circumferential direction of the hydrostatic bearing. 3. The hydrostatic vibration exciter cylinder according to claim 1 or 2, characterized in that: the oil inlet hole is a capillary restrictor.

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