TWM589250U - Damper for electric adjustment magnetron - Google Patents

Abstract

A damper with electric adjustment magnetron includes: a force applying unit, a magnet control unit, a driving unit, and a control unit; the force applying unit generates an axial displacement by a transmission rod, and then drives the screw and The rotor with a magnetic ring rotates. The magnetron unit has a fixed seat with linear displacement and permanent magnets. The drive unit has a motor and gear set. The control unit can input the desired damping value and drive accordingly The motor rotates; thereby, the fixed seat will be driven and displaced by the motor and gear set, so that the desired gap between the permanent magnet of the fixed seat and the rotor's magnetic ring, and according to the eddy current load The damping of the rotation of the rotor and the axial displacement of the transmission rod is formed, so that the damper achieves the effect of exercise and fitness.

Description

Electric adjustment magnetic control damper

This creation relates to a damper, especially an electric adjustment magnetron that controls the displacement of the fixed base to achieve the desired gap between the permanent magnet and the magnetic ring, and generates eddy current load to form motion damping. Damper.

Press, in indoor sports or rehabilitation equipment, most of the actuating mechanisms are equipped with damping devices, such as: rowing fitness equipment, muscle training machine, etc.; because sports equipment is limited by space, most of its dampers use hydraulic cylinder structure. The cylinder body of this type of hydraulic cylinder is filled with hydraulic oil, and a piston is provided in the cylinder. A hole is formed in the piston and a piston rod is provided at one end. When the piston rod is linearly displaced in the cylinder body by the axial force, the hydraulic oil will The damping effect is generated by the circulation of the holes on the piston.

The second press is a non-hydraulic damper that converts circular motion with linear displacement and obtains magnetoresistance. As shown in FIG. 1A, the main feature of the creation is: a transmission rod 930 is axially displaced in the cylinder 920, through a The screw sleeve 940 drives a screw 950 to rotate, which in turn drives a ring frame body 960 provided with permanent magnets 963 for circumferential rotation. Since there is a gap between the permanent magnet 963 and the magnetically conductive surface 973 of the cover 970, the gap will generate an eddy current load And form the damping of the displacement movement of the transmission rod 930 accordingly. Although this creation can improve the aforementioned problem of oil leakage from the hydraulic cylinder, the eddy current load formed between the permanent magnet 963 and the magnetic conductive surface 973 will be fixed. In other words, the device can only provide a fixed damping value; however, in reality The inability to change the motion damping will make it difficult to meet the motion needs of different use stages.

Press again, an adjustable damper, as shown in FIG. 1B, is a US Patent No. 14/993,685, which includes a cylinder 820, a transmission rod 830 that can be axially displaced in the cylinder 820, and through the transmission The rod 830 is connected to a threaded sleeve 840 to drive a screw 850 to rotate, thereby driving a ring frame body 860 provided with a permanent magnet 863 to rotate in a circle, and then the ring body 894 of the actuating ring 893 is generated by the rotation of the rotating cap 890 ; Because the inner edge of the ring body 894 is provided with a magnetically conductive surface 895, and the outer peripheral edge of the magnetically conductive surface 895 and the permanent magnet 863 has an annular gap, so the displacement of the ring body 894 will change the permanent magnet 863 and the guide The acting area of the magnetic surface 895 and the eddy current load formed thereby adjust the damping of the displacement movement of the transmission rod 830 accordingly.

The aforementioned adjustable damper can adjust the size of the damper according to the user's needs; however, check that the manually adjusted rotating cap 890 has no setting and feedback mechanism, and the user can only feel the damping by rotating the rotating cap 890 by feeling Because the manually adjusted motion damping device cannot accurately provide the required damping value, it cannot be accepted by the user.

The reason is that the main purpose of this creation is to provide a linear displacement that can be driven by a motor to change the eddy current load generated by the gap between the force unit and the magnet control unit, and then to achieve the electric adjustment of the damping size. Of damper.

Another purpose of this creation is to provide an electric motor that can set the damping value by the control unit and drive the motor so that the gap between the force applying unit and the magnetron unit generates the desired eddy current load, and accordingly achieves the precise control of the damping value. Adjust the magnetron damper.

In order to achieve the above purpose, the technical means adopted in this creation include: a force application unit, a magnetron control unit, a drive unit, and a control unit; wherein the force application unit has a cylinder body in its first axial passage A transmission rod and a screw sleeve are inserted through and interlocked with the transmission rod. A screw is screwed with the screw sleeve, and the axial displacement of the screw sleeve will drive the screw to rotate. A rotor The magnet is sleeved on the outer periphery of the screw rod; the magnetron unit has a fixed seat and is provided with an arc-shaped permanent magnet, which is arranged on the side of the magnetizer ring adjacent to the rotor, so that A gap is formed between the two and an eddy current load is generated accordingly. The shaft hole of the fixing seat is sleeved on the outer edge of a nut, the nut is screwed with a rotating shaft, and the end of the rotating shaft is connected to a Passive gear, so that the passive gear can drive the rotating shaft to rotate, and then drive the fixed seat to produce linear displacement through the nut; the drive unit has a motor and a gear set connected thereto, and makes the passive gear system in the magnetic control unit It meshes with the gear set so that the rotating shaft in the magnetic control unit can be driven and rotated by the motor; the control unit has an input interface and a controller that can drive the motor to rotate.

Thereby, when the force applying unit receives an axial force, the transmission rod is in the first axial channel The shaft is axially displaced, and the screw is driven to rotate through the screw sleeve, which drives the rotor and the magnetic ring to rotate in a circle; then a damping value is set by the input interface of the control unit, then the controller of the control unit will According to the set damping value, the motor of the drive unit is driven to rotate; the gear set of the drive unit is connected with the passive gear to drive the rotation of the rotating shaft and produce a linear displacement of the fixed seat of the magnetic control unit, then The desired gap will be formed between the permanent magnet and the magnetic ring, and the eddy current load generated by the gap will form the force applying unit to damp the axial force accordingly.

According to the aforementioned features, the control unit further includes a variable resistor with an input Shaft, the input shaft is connected to the gear set so that it can be driven and rotated by the motor, and a signal of a displacement value is fed back to the controller.

According to the aforementioned feature, the permanent magnet can be composed of a plurality of rubidium magnets; and the magnetic ring can be composed of a ring-shaped magnetic conductive member fixed on the periphery of the rotor.

According to the aforementioned features, the first pivotal portion includes an oil-containing bearing or a circular tube; and the second pivotal portion also includes an oil-containing bearing or a circular tube.

With the help of the aforementioned features, the electric damper with electric adjustment has the following benefits: (1) This creation converts the linear displacement of the transmission rod into the circular rotary motion of the rotor and the magnetic ring, and drives the displacement of the fixed seat by the motor to form between the permanent magnet of the fixed seat and the magnetic ring of the rotor The gap, and the eddy current load generated by the gap will form the damping of the rotation of the rotor and the linear displacement of the transmission rod; because this creation replaces the traditional hydraulic cylinder structure with magnetic resistance, it has no oil leakage and the movement force can be quickly The effect of the reaction; at the same time, this creation is driven by the displacement of the fixed seat by the motor, the user does not need to manually adjust the motion damping, so it also has the benefits of automation and labor saving. (2) The control unit of this creation includes an input interface for the user to set the desired damping value, a variable resistor driven by the motor and feedback the displacement value, and a motor that can receive the feedback information and calculate the motor The controller of the parameter value; then the fixed seat displacement is driven by the motor to obtain the desired gap between the permanent magnet and the magnetic ring, and the eddy current load generated by the gap will form the axial force of the force applying unit As the damping of this creation is through the control unit to control the displacement of the fixed seat to obtain the desired clearance, the effect of accurately controlling the damping value can be achieved accordingly.

First of all, please refer to FIGS. 2 to 3 and FIG. 4A, which is a mechanism for electrically adjusting the magnetron damper 100 for this creation; it includes: a force applying unit 10 with a cylinder body 11 and a first axial direction on the inner edge The channel 111 is provided with a first through hole 112 and a second through hole 113 at both ends thereof; a transmission rod 12 is penetrated through the first axial channel 111 and protrudes outside the first through hole 112 , And a first pivot portion 121 is provided on the outer end thereof, and the first pivot portion 121 is composed of an oil bearing or a round tube; a screw sleeve 13 is nested outside the inner end of the transmission rod 12 Edge, so that it can be linked with the transmission rod 12 in the first axial channel 111 in the axial displacement of the linkage; a screw 14 has a shaft section 141 and a threaded section 142 can be screwed with the threaded sleeve 13, And the axial displacement of the screw sleeve 13 will make the screw 14 show a rotatable state; a rotor 15 is sleeved on the shaft section 141 of the screw 14, and a magnetic ring 151 is provided on the outer periphery of the screw The magnetic conductive ring 151 can be formed by an annular magnetic conductive member fixed on the periphery of the rotor 15; a first housing 16 is provided with a first accommodating space 161 for accommodating the rotor 15, and a lower cover 162 for fixing The second through-hole end 113 of the cylinder 11 and an upper cover 163 are used to connect a second pivotal portion 164, and the second pivotal portion 164 is composed of an oil-containing bearing or a round tube; In the force unit 10, the first pivoting portion 121 and the second pivoting portion 164 are respectively connected to the force applying rod and the fixing portion (not shown) of the fitness equipment. The user can operate the force applying rod to enable the transmission rod 12 produces an axial displacement, which in turn causes the rotor 15 of the force applying unit 10 to rotate and interlock.

A magnetron unit 20 (please refer to FIG. 4B further) has a fixed seat 21, which is disposed in the first accommodating space 161, and is provided with a circular arc-shaped permanent magnet 22, which is adjacent to the rotor 15 The side of the magnetic ring 151, and a gap G is formed between the permanent magnet 22 and the rotating magnetic conductive ring 151, and an eddy current load is generated accordingly; this load is formed by the eddy current resistance formed by the magnetic field fluctuation to form The damping required for fitness exercise; the basic principle is that the conductor is placed in the variable magnetic flux, a back electromotive force is formed on the locally closed circuit in the conductor, and a so-called eddy current (eddy current) is generated, which is established by the flow direction of this eddy current. The magnetic action must be opposite to the direction of the original magnetic flux that generated the current; Max-well's Eq knows that the magnitude of the magnetic force is proportional to the square of the magnetic flux density, and the magnetic force can provide what is needed for sports equipment. Damping. Furthermore, the permanent magnet 22 of the magnetron unit 20 is composed of a plurality of rubidium magnets, and the fixing base 21 is provided with a shaft hole 211, which is sleeved on the outer edge of a nut 25, and a rotating shaft 23 is provided with a The screw section 231 is screwed with the nut 25, and the rotating shaft 23 protrudes outside the first housing 16, and the end of the screw shaft 23 is connected to a driven gear 24, so that the driven gear 24 can drive the rotating shaft 23 Rotate, and then drive the fixed seat 21 to produce linear displacement in the XX axis through the nut 25; because the passive gear 24 can be controlled to perform forward and reverse steering and control the number of rotations, the displacement of the fixed seat 21 The direction and the displacement distance are also controlled; in other words, the rotation of the passive gear 24 can be controlled by the author to displace the fixed base 21 and achieve the required gap G value between the permanent magnet 22 and the magnetic ring 151 And then use it to generate the eddy current load to get the load damping required for fitness exercise.

A driving unit 30 (please also refer to FIGS. 5 to 6), has a motor 31 and a driving gear 32 connected thereto; a second housing 33 is provided with a second accommodating space 331 for accommodating the The motor 31, a gear chamber 332 are used to install the gear set 34 required for deceleration and transmission, a top plate 35 is used to fix the first housing 16, and an inner plate 36 is used to cover the second accommodating space 331 To protect the motor 31 and an outer plate 37 to cover the gear chamber 332 to protect the gear set 34 from exposure; the gear set 34 includes first, second, and third transmission gears 341/342/343 and a plurality of An intermediate gear 344, which is inserted into the shaft seat 346 through several gear shafts 345 to make it rotate; and the driving gear 32 extends into the gear chamber 332 to mesh with the first transmission gear 341, so through the gear set The connection of a plurality of intermediate gears 344 in 34 will reduce the speed of the motor 31 and be transmitted to the second and third transmission gears 342/343 via the first transmission gear 341, respectively, and the passive gear in the magnetic control unit 20 24 is meshed with the second transmission gear 342, so the rotating shaft 23 in the magnetron unit 20 can be driven and rotated by the motor 31.

A control unit 40 (please refer to FIG. 2 and FIG. 5), has an input interface 41 for the user to set a desired damping value, is installed on the wall surface of the second housing 33; a variable The resistor 42 is set in the second accommodating space 331 and has an input shaft 43 that extends into the gear chamber 332 and is connected to the third transmission gear 343. Therefore, the input shaft 43 is affected by the motor 31 Drive and rotate; a controller (not shown) electrically connects the motor 31 and the variable resistor 42 so that the controller can drive the motor 31 according to the desired damping value and accept the The displacement value signal fed back by the variable resistor 42 is used to adjust the rotation of the motor 31.

Thereby, the user can operate the force bar of the fitness equipment to make the transmission rod 12 in the first Axial displacement is generated in the axial channel 111, and the screw 14 is driven to rotate through the threaded sleeve 13, thereby driving the rotor 15 and the magnetic ring 151 to rotate in a circle; the user then uses the input interface 41 of the control unit 40 If a damping value is set, the controller of the control unit 40 will drive the motor 31 of the driving unit 30 to rotate according to the set damping value; the second transmission gear 342 of the gear set 34 is meshed via the passive gear 24, Drive the rotating shaft 23 to rotate and make the fixed seat 21 of the magnetic control unit 20 produce linear displacement; at the same time, the input shaft 43 of the variable resistor 42 is connected to the third transmission gear 343 and driven by the motor 31 to rotate, the The variable resistor 42 sends a feedback displacement signal to the controller to adjust the rotation of the motor 31, then the fixed base 21 of the magnetic control unit 20 is further displaced by the feedback signal of the variable resistor 42, and finally The desired gap between the permanent magnet 22 and the magnetic ring 151 is achieved, and the eddy current load generated by the gap will form the damping of the rotation of the rotor 15 and the axial displacement of the transmission rod 12.

Please refer to FIG. 7 to FIG. 8 for the displacement pattern of the fixed base 21 in the magnetic control unit 20; according to this, the fixed base 21 is provided with an arc-shaped permanent magnet 22 which is adjacent to the outer periphery of the rotor 15 On the side of the magnetic conductive ring 151 provided on the edge, the shaft hole 211 of the fixing seat 21 is sleeved on the outer edge of a nut 25, the nut 25 is screwed with the rotating shaft 23, and the rotating shaft 23 protrudes A passive gear 24 is connected to the outside of the first housing 16, so that the passive gear 24 can drive the rotating shaft 23 to rotate, and the driving of the nut 25 will cause the fixed seat 21 to produce linear displacement, the fixed seat 21 is displaced As a result, the gap between the permanent magnet 22 and the magnetic ring 151 will be changed; where, as shown in FIG. 7, the fixed base 21 is moved to the state closest to the rotor 15, at this time, the permanent magnet 22 and the magnetic ring 151 The minimum gap value G1 is formed between them, and the magnetic flux density generated by the minimum gap value G1 is the highest, that is, the motion damping will be the largest; Figure 8 shows that the fixed base 21 is displaced to the state farthest away from the rotor 15, at this time the permanent magnet A maximum gap value G2 is formed between 22 and the magnetic ring 151, and the maximum gap value G2 generates the lowest magnetic flux density, that is, the motion damping will be the smallest.

9 is a block diagram of the operation steps of the control unit 40 between its components; first, the desired motion damping value is set by the user using the input interface 41, then the controller 44 will refer to the damping value to calculate the permanent magnet 22 and The gap between the magnetic ring 151 and the parameter value required to rotate the motor 31 of the drive unit 30 is estimated and given an actuation command, then the motor 31 rotates and is respectively transmitted to the second transmission gear 342 via the gear set 34 to drive The passive gear 24 causes the fixed seat 21 of the magnetic control unit 20 to generate a linear displacement, and transmits to the third transmission gear 343 to drive the input shaft 43 so that the variable resistor 42 returns a displacement value signal to the controller 44 , The controller 44 then calculates the compensation value required for the rotation of the motor 31, so that the desired gap value G can be achieved between the permanent magnet 22 and the magnetic ring 151, and then the desired gap value G is generated The eddy current load is the damping torque T1, and the user needs to apply force to the force applying unit 10 to axially displace the transmission rod 12 to drive the rotor 15 to rotate is the force applying torque T2, because the force applying torque T2 must be greater than the damping torque T1 can only drive the displacement of the transmission rod 12 and the rotation of the rotor 15, so the creative device of this creation will provide users with the effect of exercise and fitness.

Since this creation converts the linear displacement of the transmission rod 12 into the circular rotating motion of the magnetic ring 151, and drives the fixed base 21 to be displaced by the motor 31, the eddy current load formed by the gap between the permanent magnet 22 and the magnetic ring 151, It can be used as the damping of the rotation of the rotor 15 and the linear displacement of the transmission rod 12; because this creation replaces the traditional hydraulic cylinder structure with magnetic resistance, it has the effect of no oil leakage and rapid response of motion force; at the same time, this creation By driving the displacement of the fixed base 21 by the motor 31, the user does not need to laboriously adjust the motion damping, so it also has the benefits of automation and labor saving. Furthermore, the control unit 40 of the present invention includes an input interface 41 for the user to set the desired damping value, a variable resistor 42 driven by the motor 31 and capable of feeding back the displacement value, and a feedback receiving The controller 44 uses the information and estimates the parameter values of the motor 31; the motor 31 drives the fixed base 21 to displace, so that the permanent magnet 22 and the magnetic ring 151 get the desired gap G, and the eddy current generated by the gap The load will be used to form the force applying unit 10 to damp the axial force. Since the original control system controls the displacement of the fixed base 21 through the control unit 40 to obtain the desired gap G, the damping value can be accurately controlled accordingly effect.

In summary, the structure disclosed in this creation is unprecedented, and it can indeed achieve the improvement of efficiency, and it can be used by the industry. It is fully in line with the requirements of new patents. Pray that the Office will grant patents to encourage innovation , No sense of virtue.

However, the diagrams and descriptions disclosed above are only the preferred embodiments of this creation. Anyone who is familiar with this skill, and the modifications or equivalent changes made in accordance with the spirit of this case, should still be included in the scope of the patent application in this case.

10‧‧‧Force unit 11‧‧‧Cylinder 111‧‧‧ First axial channel 112‧‧‧First through hole 113‧‧‧Second through hole 12‧‧‧ Transmission rod 121‧‧‧First pivot 13‧‧‧Sleeve 14‧‧‧screw 141‧‧‧Shaft section 142‧‧‧Thread section 15‧‧‧Rotor 151‧‧‧Magnetic ring 16‧‧‧First shell 161‧‧‧ First accommodation space 162‧‧‧ Lower cover 163‧‧‧Cover 164‧‧‧Second pivot 20‧‧‧Magnetic control unit 21‧‧‧Fixed seat 211‧‧‧shaft hole 22‧‧‧Permanent magnet 23‧‧‧spindle 231‧‧‧Thread section 24‧‧‧Passive gear 25‧‧‧ Nut 30‧‧‧Drive unit 31‧‧‧Motor 32‧‧‧Drive gear 33‧‧‧Second shell 331‧‧‧Second accommodating space 332‧‧‧Gear room 34‧‧‧Gear set 341‧‧‧ First transmission gear 342‧‧‧Second transmission gear 343‧‧‧ Third transmission gear 344‧‧‧Intermediate gear 345‧‧‧ gear shaft 346‧‧‧Shaft seat 35‧‧‧Top board 36‧‧‧Inboard 37‧‧‧Outboard 40‧‧‧Control unit 41‧‧‧ input interface 42‧‧‧Variable resistor 43‧‧‧ input shaft 44‧‧‧Controller 100‧‧‧Electromagnetic adjustment damper G‧‧‧Gap/desired gap value G1‧‧‧Minimum gap value G2‧‧‧Maximum gap value T1‧‧‧Damping torque T2‧‧‧Forcing torque

Figure 1A: This is a cross-sectional view of the structure of the first case of this creation. Figure 1B: This is a structural cross-sectional view of the second case before the creation. Figure 2: The combined perspective view of this creation. Figure 3: The exploded perspective view of this creation. Figure 4A: This is a combined cross-sectional view of this creation. Figure 4B: Partial sectional view of the creation. Figure 5: Exploded perspective view of the creative drive unit. Figure 6: Schematic diagram of the gear set of this creative drive unit. Figure 7: Schematic diagram of the displacement of the magnetic base of the magnetic control unit of this creation. Figure 8: Schematic diagram of the displacement of the magnetic base of the magnetic control unit of this creation. Figure 9: A block diagram of the operation steps of the creative control unit.

10‧‧‧Force unit

11‧‧‧Cylinder

111‧‧‧ First axial channel

112‧‧‧First through hole

113‧‧‧Second through hole

12‧‧‧ Transmission rod

121‧‧‧First pivot

13‧‧‧Sleeve

14‧‧‧screw

15‧‧‧Rotor

151‧‧‧Magnetic ring

16‧‧‧First shell

161‧‧‧ First accommodation space

162‧‧‧ Lower cover

163‧‧‧Cover

164‧‧‧Second pivot

20‧‧‧Magnetic control unit

21‧‧‧Fixed seat

22‧‧‧Permanent magnet

23‧‧‧spindle

231‧‧‧Thread section

24‧‧‧Passive gear

25‧‧‧ Nut

30‧‧‧Drive unit

33‧‧‧Second shell

35‧‧‧Top board

36‧‧‧Inboard

37‧‧‧Outboard

40‧‧‧Control unit

41‧‧‧ input interface

100‧‧‧Electromagnetic adjustment damper

Claims (6)

An electric adjustment magnetic control damper, including: A force-applying unit has a cylinder with a first axial channel at its inner edge and a first through hole at one end; a transmission rod is inserted through the first axial channel and protrudes from the first The outside of a through hole, and the outer end of the through hole is provided with a first pivoting portion; a screw sleeve is nested on the outer edge of the inner end of the transmission rod, so that it can appear with the transmission rod in the first axial channel Linked axial displacement; a screw with a shaft section and a threaded section that can be screwed with the threaded sleeve, and axial displacement of the threaded sleeve will make the screw rotatable; a rotor, set A magnetic conducting ring is arranged on the shaft section and the outer periphery of the shaft section; a first housing is provided with a first accommodating space for accommodating the rotor, a lower cover for fixing the cylinder body, and an upper cover To connect a second pivotal portion; A magnetic control unit with a fixed seat is arranged in the first accommodating space, which is provided with a circle The arc-shaped permanent magnet is close to the side of the rotor's magnetic ring to form a gap and be produced accordingly Eddy current load; the fixed seat is provided with a shaft hole, the sleeve is set on the outer edge of a nut, and a rotating shaft is provided with A threaded section and screwed with the nut, and the rotating shaft protrudes outside the first shell, and the end Part is connected to a passive gear, so that the passive gear can drive the rotating shaft to rotate, and then driven by the nut The fixed seat produces linear displacement; A drive unit with a motor and a gear set; a second housing with a second housing empty To accommodate the motor and a gear chamber to accommodate the gear set; and to make the passive in the magnetic control unit The gear train meshes with the gear set so that the rotating shaft in the magnetic control unit can be driven and rotated by the motor; A control unit is installed on the wall surface of the second casing and has an input interface for setting A damping value, and a controller can drive the rotation of the motor according to the set damping value; In this way, when the force applying unit receives an axial force, the transmission rod is axially displaced in the first axial channel, and the screw is driven to rotate through the screw sleeve, thereby driving the rotor and the magnetic ring to rotate in a circle Movement; by setting the damping value, the control unit will drive the motor of the drive unit to rotate, and the gear set is connected with the passive gear to drive the rotation of the shaft and make the fixed seat of the magnetic control unit linear Displacement will form the desired gap between the permanent magnet and the magnetic ring, and the eddy current load generated by the gap will form the damping of the axial force of the force applying unit accordingly. The electronically-adjustable magnetically controlled damper as described in item 1 of the patent scope, where, The control unit further includes a variable resistor, which is disposed in the second accommodating space, the variable The resistor includes an input shaft that is connected to the gear set so that the input shaft can be driven by the motor Rotate and feed back a displacement signal to the controller. The electrically-adjustable magnetically controlled damper as described in item 1 or 2 of the patent application, wherein the permanent magnet can be composed of a plurality of rubidium magnets. The electrically-adjustable magnetically controlled damper as described in item 1 or 2 of the patent application range, wherein the magnetically conductive ring system can be formed by an annular magnetically conductive member fixed on the periphery of the rotor. The electrically-adjustable magnetically controlled damper as described in item 1 or 2 of the patent application scope, wherein the first pivot portion is composed of an oil-containing bearing or a round tube. The electrically adjustable magnetically controlled damper as described in item 1 or 2 of the patent application scope, wherein the second pivotal portion is composed of an oil-containing bearing or a round tube.

Images