JP4529815B2 - Pressure generator - Google Patents

Description

  The present invention provides pressurized air to the tire air chamber of a wheel including a pressure generator, for example, a wheel that is supported by a wheel hub of a vehicle and is rotatable and mounted on the wheel to form a tire air chamber. The present invention relates to a pressure (air pressure) generating device that can be supplied.

This type of pressure generating device is disclosed, for example, in Patent Document 1 below. In the pressure generating device (tire pressure compensation device) described in Patent Document 1, a fixed axle is mounted on a wheel of a wheel rotatably supported via a bearing on a non-rotatable fixed axle (axle shaft). A pump unit that reciprocates in the axial direction is disposed, and one end of a piston of the pump unit is brought into contact with a slope of a non-rotating inclined cam integrally assembled with a fixed axle. Therefore, the pump function is obtained by reciprocating the piston of the pump unit as the wheel rotates.
Japanese Patent Laid-Open No. 1-172003

  By the way, in the configuration of the pressure generating device described in Patent Document 1 described above, the axis of the piston in the pump unit is eccentric by a predetermined amount radially outward with respect to the axis of the fixed axle. For this reason, the diameter of the slope of the inclined cam that comes into contact with one end of the piston must be greater than or equal to the amount of radial eccentricity of the axial center of the piston, and it is difficult to reduce the size of the pressure generator. There is difficulty in mounting.

The present invention has been made to cope with the above-described problems. The pressure generating device is a rotating body that is rotatably supported via a bearing on a non-rotatable fixed shaft, and the fixed shaft within the rotating body. A piston which is arranged coaxially with respect to the rotating body or the fixed shaft and is assembled so as to be reciprocable in the axial direction so as to form a pump chamber in the rotating body, provided in the rotating body A motion converting mechanism for converting a rotational motion of the rotating body relative to the fixed shaft into a reciprocating motion of the piston, a suction passage provided in the rotating body and capable of sucking fluid into the pump chamber, and provided in the rotating body. wherein a structure comprising a discharge can discharge passage of fluid from the pump chamber, the motion converting mechanism is a cylindrical portion of the inner circumference and the piston of the outer periphery or between said rotary member of said stationary shaft and the inner circumference of the cylindrical portion of the piston Te The motion conversion mechanism includes a cylindrical cam disposed coaxially with respect to the fixed shaft, and a cam follower that engages with a cam portion of the cylindrical cam. The piston is integrally provided on one of the inner periphery of the cylindrical portion and the outer periphery of the fixed shaft, and the cam follower is integrally provided on the other (invention according to claim 1) , or The cylindrical cam is integrally provided on one of the inner periphery of the rotating body and the outer periphery of the cylindrical portion of the piston, and the cam follower is integrally provided on the other (invention according to claim 2). There is a feature. In this case, the fixed shaft is a fixed shaft integrated with a fixed axle of the vehicle, and the rotating member is disposed coaxially with the fixed axle and rotates integrally with a wheel that is rotatably mounted. (Invention according to claim 3 ) is also possible.

  In the above-described pressure generating device according to the present invention, when the rotating body rotates with respect to the fixed shaft, the rotational motion is converted into the reciprocating motion of the piston by the motion converting mechanism, and the piston is pumped. As a result, the volume of the pump chamber increases and decreases, and the fluid sucked into the pump chamber through the suction passage is discharged from the pump chamber through the discharge passage.

  By the way, in the pressure generating device according to the present invention, the rotating body is rotatably supported by the fixed shaft via the bearing, and the piston is disposed coaxially with respect to the fixed shaft in the rotating body, and the rotating body or the fixed shaft. The pump chamber is formed in the rotating body so that it cannot rotate and can reciprocate in the axial direction. Further, a motion conversion mechanism that converts the rotational motion of the rotating body relative to the fixed shaft into the reciprocating motion of the piston is provided in the rotating body. For this reason, the main part (piston and motion conversion mechanism) of the pressure generating device can be made compact in the rotating body, and the pressure generating device can be downsized.

Also, that before Symbol motion converting mechanism provided between the cylindrical outer circumference of the inner periphery and the piston of the outer periphery or between said rotary member of said stationary shaft and the inner circumference of the cylindrical portion of the piston. For this reason, it is possible to construct a pressure generator that is compact in the radial direction by effectively utilizing the inner circumference of the piston and the outer circumference of the fixed shaft or the inner circumference of the rotating body and the outer circumference of the cylinder of the piston. Is possible.

Also, before Symbol motion converting mechanism is provided with a cam follower that engages with the cylindrical cam are coaxially arranged with respect to the fixed shaft, the cam portion of the cylindrical cam (cam groove or cam projection,), the cylindrical cam is provided integrally to one of the outer circumference of the fixed shaft and the inner circumference of the cylindrical portion of the piston, said cam follower that provided integrally with the other one (the invention according to claim 1), Alternatively, the cylindrical cam is integrally provided on one of the inner periphery of the rotating body and the outer periphery of the cylindrical portion of the piston, and the cam follower is integrally provided on either of the other (according to claim 2). invention). For this reason, it is possible to simply configure the motion conversion mechanism.

In carrying out the present invention, the piston is formed in a cylindrical shape, wherein it is arranged on the outer circumference of the fixed shaft (invention according to claim 4) is also possible. In this case, the bearings may be disposed on both axial sides of the piston (invention according to claim 5 ). In this case, it is possible to secure the support rigidity of the rotating body with both bearings, and it is possible to make the apparatus compact by effectively utilizing the space between both bearings.

In this case, a first seal member and a second seal member for sealing the bearings may be interposed between the rotating body and the fixed shaft (invention according to claim 6 ). In this case, both the bearings can be sealed by the first seal member and the second seal member, and the piston and the motion conversion mechanism can be sealed. The generation device can be made compact and low in cost.

In carrying out the present invention, the fixed shaft can be attached to and detached from a fixed axle of a vehicle, and the rotating body can be attached to and detached from a wheel of a wheel that is rotatably attached to the fixed axle. The invention according to claim 7 is also possible. In this case, it is possible to assemble the pressure generating device integrally with the wheel of the wheel.

In carrying out the present invention, the fixed shaft is integral with a fixed axle of a vehicle, and wheels can be attached to and detached from the rotating body assembled to the fixed axle (invention according to claim 8 ). Is possible. In this case, the pressure generating device can be integrally assembled to the fixed axle of the vehicle.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows a first embodiment of a pressure generating device according to the present invention. The pressure generating device AP1 of the first embodiment is coaxially disposed on a fixed axle (not shown) of a vehicle and integrated therewith. A fixed shaft 10 that is not rotatable, a rotary body 20 that is rotatably supported by the fixed shaft 10 via a bearing 50, and a pump chamber that is assembled in the rotary body 20 The piston 30 which forms Ro is provided.

  Further, the pressure generating device AP1 includes a cam member 41 and a cam follower 42 as a motion conversion mechanism for converting a rotational motion of the rotating body 20 with respect to the fixed shaft 10 into a reciprocating motion of the piston 30, and a ring that supports the cam follower 42 so as to be able to roll. 43.

  The fixed shaft 10 is formed in a stepped columnar shape centered on the axis Lo, and a rotating body 20 is supported on the outer periphery of the fixed shaft 10 via a bearing 50 so as to be rotatable around the axis Lo. The fixed shaft 10 is provided with a spline shaft portion 11 for integrally connecting to a fixed axle (not shown) of the vehicle and a spline shaft portion 12 for integrally connecting to the ring 43.

  The rotating body 20 is coaxially arranged on a wheel (not shown) of a wheel that is coaxially arranged and rotatably mounted on a fixed axle (not shown) of the vehicle, and is connected to be integrally rotatable. A cylinder 21 having a cylindrical shape and having an axial groove 21a on the inner periphery, and a holder 22 assembled in a liquid-tight and integrated manner in the cylinder 21 are provided. The rotating body 20 is provided with a suction passage 20a and a discharge passage 20b.

  The axial groove 21 a is guide means for guiding the protrusion 30 a formed on the outer periphery of the piston 30 in the axial direction, and is formed on the inner periphery of the cylinder 21. The intake passage 20a is for introducing (inhaling) air into the pump chamber Ro, and an intake check valve Vi is interposed therein. The discharge passage 20b is used to lead out (discharge) air from the pump chamber Ro, and a discharge check valve Vo is interposed therein. Note that the pressurized air discharged from the pump chamber Ro can be supplied to a tire air chamber (not shown) of the wheel.

  The piston 30 has a pair of protrusions 30 a on the outer periphery thereof, is hermetically inserted into the cylinder 21 of the rotating body 20 via the annular seal member 31, and is disposed coaxially with the fixed shaft 10. The rotating body 20 is assembled such that it cannot rotate (can rotate integrally) and can reciprocate in the axial direction. Further, the piston 30 is formed in a cup shape, and a cam member 41 is integrally assembled therein (not movable in the axial direction and not rotatable).

  The cam member 41 is a cylindrical cam arranged coaxially with respect to the fixed shaft 10, and is arranged coaxially with respect to the cylindrical portion of the piston 30. The cam member 41 has an annular cam portion 41a that varies in the axial direction, and the cam portion 41a is a cam groove to which a cam follower 42 is fitted. The cam portion 41a has a cam surface that receives an axial load (a vertical load in the drawing) and a radial load (a horizontal load in the drawing) from the cam follower 42, and the cam surface has a V-shaped cross section. It is a shape and is formed with an even number of cycles (for example, two cycles) in the circumferential direction of the fixed shaft 10.

  The cam follower 42 is a ball assembled so as to be able to roll in a recess 43 a formed on the outer periphery of the ring 43, and engages with a cam portion (cam groove) 41 a at a portion protruding from the ring 43. The cam member 41 and the cam follower 42 are rotatable relative to each other. When the cam member 41 rotates about the axis Lo with respect to the cam follower 42, the cam member 41 and the piston 30 are integrated in the cylinder 21 in the axial direction (upper and lower in the figure). Direction). The ring 43 is assembled integrally with the spline shaft portion 12 of the fixed shaft 10 (cannot move and rotate in the axial direction) and is integrated with the fixed shaft 10.

  In the pressure generating device AP1 of the first embodiment configured as described above, when the rotating body 20 rotates around the axis Lo with respect to the fixed shaft 10, the rotational movement of the piston 30 is reciprocated by the cam member 41 and the cam follower 42. Converted to motion, the piston 30 is pumped. As a result, the volume of the pump chamber Ro increases or decreases, and the air sucked into the pump chamber Ro through the suction passage 20a is discharged from the pump chamber Ro through the discharge passage 20b.

  By the way, in this pressure generating device AP1, the rotating body 20 is rotatably supported by the fixed shaft 10 via the bearing 50, and the piston 30 is disposed coaxially with respect to the fixed shaft 10 in the rotating body 20. The pump body Ro is formed in the rotating body 20 so as to be unrotatable with respect to the rotating body 20 and reciprocally movable in the axial direction. Further, the cam member 41 and the cam follower 42 (motion conversion mechanism) are provided coaxially with respect to the fixed shaft 10 in the rotating body 20. For this reason, the main part (piston 30 and motion conversion mechanism) of the pressure generation device AP1 can be configured compactly in the rotating body 20, and the pressure generation device AP1 can be downsized.

  In the pressure generating device AP1, the cam member 41 and the cam follower 42 (motion conversion mechanism) are provided between the inner periphery of the cylindrical portion of the piston 30 and the outer periphery of the fixed shaft 10. For this reason, it is possible to configure a pressure generating device that is compact in the radial direction by effectively utilizing the inner periphery of the cylindrical portion of the piston 30 and the outer periphery of the fixed shaft 10.

  Further, in the pressure generating device AP1, as a motion conversion mechanism for converting the rotational motion of the rotating body 20 relative to the fixed shaft 10 into the reciprocating motion of the piston 30, a cam member 41 assembled to the piston 30 and a ring on the fixed shaft 10 are provided. A motion conversion mechanism including a cam follower 42 assembled through 43 is employed. For this reason, it is possible to simply configure the motion conversion mechanism.

  In the pressure generating device AP1 of the first embodiment described above, when the fixed shaft 10 can be attached to and detached from the fixed axle (not shown) of the vehicle, and the rotating body 20 can be attached and detached together with the wheel of the wheel (not shown). The pressure generating device AP1 can be integrally assembled to a wheel (not shown) of the wheel.

  In the pressure generation device AP1 of the first embodiment described above, the protrusion 30a is provided on the outer periphery of the piston 30, and the axial groove 21a is provided on the inner periphery of the cylinder 21 of the rotating body 20, so Is configured to be fitted in such a manner as to be non-rotatable and reciprocally movable in the axial direction, and by a cam member 41 provided on the inner periphery of the cylindrical portion of the piston 30 and a cam follower 42 integrally assembled on the outer periphery of the fixed shaft 10. The motion conversion mechanism that converts the rotational motion of the rotating body 20 relative to the fixed shaft 10 into the reciprocating motion of the piston 30 is configured and implemented. However, while providing a protrusion on the inner periphery of the piston (30), the fixed shaft (10) An axial groove is provided on the outer periphery, and the piston (30) is configured to be fitted to the fixed shaft (10) so as not to rotate but to reciprocate in the axial direction. ) And a cam follower or cam member provided on the outer periphery of the cylindrical portion and a cam member or cam follower provided on the inner periphery of the rotating body (20) to convert the rotational motion of the rotating body relative to the fixed shaft into the reciprocating motion of the piston. It is also possible to configure and implement.

  Further, in the pressure generating device AP1 of the first embodiment described above, the cam member 41 is provided on the piston 30 and the cam follower 42 is provided on the fixed shaft 10, but the cam follower is provided on the piston (30) and fixed. It is also possible to carry out by providing a cam member on the shaft (10).

  FIG. 2 schematically shows a second embodiment of the pressure generating device according to the present invention. The pressure generating device AP2 of the second embodiment is arranged coaxially on a fixed axle 160 of a vehicle and is connected via a joint 161. A non-rotatable fixed shaft 110 that is integrally assembled to the fixed axle 160, a rotating body 120 that is rotatably supported by the fixed shaft 110 via a bearing 150, and the rotating body 120. A piston 130 that is assembled to form the pump chamber Ro is provided.

  Further, the pressure generating device AP2 includes a cam portion 130b and a cam follower 142 as a motion conversion mechanism for converting a rotational motion of the rotating body 120 with respect to the fixed shaft 110 into a reciprocating motion of the piston 130, and a holder that supports the cam follower 142 so as to be able to roll. 143.

  The fixed shaft 110 is formed in a stepped cylindrical shape with the axis Lo as the center, and a rotating body 120 is assembled to the outer periphery of the fixed shaft 110 via a bearing 150 so as to be rotatable around the axis Lo. Further, the fixed shaft 110 is provided with a spline shaft portion 111 for integrally connecting to the joint 161, and a housing hole 112 for housing the holder 143 and the spring 144. The joint 161 is detachably attached to a fixed axle 160 of the vehicle.

  The rotating body 120 is a rotating member that is coaxially disposed on the wheel 171 of the wheel 170 that is coaxially disposed with respect to the fixed axle 160 of the vehicle and is rotatably mounted, and is coupled so as to be integrally rotatable. It is formed in a bottom cylindrical shape, has a cylinder inner hole 121 that accommodates the piston 130, and an axial groove 122. The rotating body 120 is provided with a suction passage 120a and a discharge passage 120b. As is well known, the wheel 171 of the wheel 170 is detachably attached to an axle hub 180 that is rotatably attached to the fixed axle 160 of the vehicle via bearings 181 and 182.

  The axial groove 122 is guide means for guiding the protrusion 130 a formed on the outer periphery of the piston 130 in the axial direction, and is formed continuously with the cylinder inner hole 121. The intake passage 120a is for introducing (inhaling) air into the pump chamber Ro, and an intake check valve Vi is interposed therein. The discharge passage 120b is for leading out (discharge) air from the pump chamber Ro, and a discharge check valve Vo is interposed therein. The pressurized air discharged from the pump chamber Ro can be supplied to the tire air chamber 173 of the wheel 170 through the discharge passage 120b provided in the rotating body 120 and the supply passage 172 provided in the wheel 171 of the wheel 170.

  The piston 130 has a protrusion 130a on the outer periphery thereof, and is inserted in a cylinder inner hole 121 of the rotating body 120 through a pair of annular seal members 131 and 132 in an airtight and liquidtight manner. It is coaxially arranged with respect to 110, and is assembled so as to be non-rotatable with respect to the rotating body 120 and reciprocating in the axial direction. The piston 130 is formed in a cup shape, and a cam portion 130b is integrally provided on the inner periphery of the cylinder portion.

  The cam portion 130b formed on the inner periphery of the piston 130 is an annular cam groove that varies in the axial direction, and the cam follower 142 is fitted therein. The cam portion 130b has a cam surface that receives an axial load (a vertical load in the drawing) and a radial load (a horizontal load in the drawing) from the cam follower 142, and the cam surface has a cross-sectional shape of V. It is a letter shape and is formed in the circumferential direction of the piston 130 with an even number of cycles (for example, two cycles).

  The cam follower 142 is a ball assembled so as to be able to roll in a recess formed at the end of the holder 143, and is engaged with the cam portion 130 b at a portion protruding from the holder 143. The cam follower 142 and the cam portion 130b are rotatable relative to each other. When the cam portion 130b rotates about the axis line Lo with respect to the cam follower 142, the cam portion 130b and the piston 130 are integrated into the cylinder bore 121 in the axial direction. It can be moved in the vertical direction in the figure. The holder 143 is assembled together with the spring 144 in the accommodation hole 112 of the fixed shaft 110 so as to be movable only in the radial direction.

  Further, in the pressure generating device AP2, a pair of annular seal members 113 and 114 are interposed between the fixed shaft 110 and the piston 130 so as to sandwich the cam follower 142 and the holder 143 in the axial direction. And the piston 130 are liquid-tightly sealed. An annular groove 130 c is formed on the outer periphery of the piston 130.

  The annular groove 130c forms an annular space R1 between the rotating body 120 and the piston 130. The annular space R1 communicates with an annular space R2 formed between the pair of annular seal members 113 and 114 through a communication hole 130d formed in the piston 130. Each of the annular spaces R1 and R2 is an oil chamber that stores a required amount of lubricating oil. The lubricating oil stored in the oil chamber is supplied to the annular seal members 113, 114, 131, and 132, and the cam portion. It is also supplied to the engaging portion of 130b and cam follower 142, the sliding portion of piston 130, and the like.

  In the pressure generation device AP2 of the second embodiment configured as described above, when the rotating body 120 rotates around the axis Lo with respect to the fixed shaft 110 as the wheel 170 rotates with respect to the fixed axle 160. The rotational motion is converted into the reciprocating motion of the piston 130 by the cam portion 130b and the cam follower 142, and the piston 130 is pumped. As a result, the volume of the pump chamber Ro increases or decreases, and the air sucked into the pump chamber Ro through the suction passage 120a is discharged from the pump chamber Ro through the discharge passage 120b and supplied to the tire air chamber 173 of the wheel 170.

  By the way, in this pressure generating device AP2, the rotating body 120 is rotatably supported by the fixed shaft 110 via the bearing 150, and the piston 130 is disposed coaxially with respect to the fixed shaft 110 in the rotating body 120. The pump body Ro is formed in the rotating body 120 so that it cannot rotate with respect to the rotating body 120 and can reciprocate in the axial direction. Further, the cam portion 130 b and the cam follower 142 (motion conversion mechanism) are provided coaxially with respect to the fixed shaft 110 in the rotating body 120. For this reason, the main part (piston 130 and motion conversion mechanism) of the pressure generating device AP2 can be configured compactly in the rotating body 120, and the pressure generating device AP2 can be downsized.

  Further, in this pressure generating device AP2, a cam portion 130b and a cam follower 142 (motion conversion mechanism) are provided between the inner periphery of the cylindrical portion of the piston 130 and the outer periphery of the fixed shaft 110. For this reason, it is possible to configure a pressure generating device that is compact in the radial direction by effectively utilizing the inner periphery of the cylindrical portion of the piston 130 and the outer periphery of the fixed shaft 110.

  Further, in the pressure generating device AP2, a cam portion 130b formed integrally with the piston 130 and a fixed shaft 110 as a motion conversion mechanism that converts the rotational motion of the rotating body 120 relative to the fixed shaft 110 into the reciprocating motion of the piston 130. A motion conversion mechanism including a cam follower 142 assembled to the motor via a holder 143 is employed. For this reason, it is possible to simply configure the motion conversion mechanism.

  Further, in this pressure generating device AP2, the fixed shaft 110 is detachable with respect to the joint 161 that is detachably attached to the fixed axle 160 of the vehicle, and the rotating body 120 is attached to the axle hub 180 together with the wheel 171 of the wheel 170. On the other hand, the pressure generating device AP2 can be integrally assembled to the wheel 171 of the wheel 170 because it is detachable.

  Further, in this pressure generating device AP2, the lubricating oil accommodated in each of the annular spaces R1, R2 is supplied to the seal portions of the annular seal members 113, 114, 131, 132, the engaging portion of the cam portion 130b and the cam follower 142, and the piston 130. Can be supplied to lubricated parts such as sliding parts. For this reason, the lubricity of each lubricated part is ensured, and it is possible to reduce the sliding resistance and improve the durability at each lubricated part.

  FIG. 3 schematically shows a third embodiment of the pressure generating device according to the present invention. The pressure generating device AP3 of the third embodiment is coaxially arranged on the fixed axle 260 of the vehicle and is integrally formed. The fixed shaft 210 that cannot be rotated, the rotating body 220 that is rotatably supported by the fixed shaft 210 via a pair of bearings 251 and 252, and the pump that is mounted in the rotating body 220. A piston 230 that forms the chamber Ro is provided.

  Further, the pressure generating device AP3 includes a cam portion 230b and a cam follower 242 as a motion conversion mechanism for converting a rotational motion of the rotating body 220 with respect to the fixed shaft 210 into a reciprocating motion of the piston 230, and a holder for supporting the cam follower 242 so as to allow rolling. 243.

  The rotating body 220 includes an axle hub member 221 and a cylinder member 222. The axle hub member 221 is formed in a bottomed cylindrical shape centered on the axis line Lo, and can rotate around the axis line Lo. Inside thereof, a pair of bearings 251 and 252 and a pair of annular seal members 253 and 254 are provided. Are accommodated, and a cylinder member 222, a piston 230, and the like are accommodated. The axle hub member 221 is formed with a suction passage 221a, a discharge passage 221b, and a communication passage 221c, and a mounting portion 221d (not shown in detail) of a wheel (not shown).

  The suction passage 221a is for introducing (inhaling) air into the pump chamber Ro formed between the piston 230 and the cylinder member 222 on the outer periphery of the fixed shaft 210, and an intake check valve Vi is interposed therein. It is disguised. The discharge passage 221b is for leading out (discharge) air from the pump chamber Ro, and a discharge check valve Vo is interposed therein. The communication path 221c is for communicating the atmosphere chamber Ra formed between the piston 230 and the cylinder member 222 on the outer periphery of the fixed shaft 210 with the atmosphere, and is located closer to the atmosphere side than the suction check valve Vi of the suction path 221a. Communicate. The pressurized air discharged from the pump chamber Ro can be supplied to a tire air chamber (not shown) of a wheel assembled to the axle hub member 221.

  The cylinder member 222 is formed in a cylindrical shape, and is fitted into the outer periphery of the fixed shaft 210 in the axle hub member 221 through a pair of annular seal members 223 and 224, and the axle hub member 221. It is fitted and fixed in an airtight manner. The cylinder member 222 is coaxially disposed with respect to the fixed shaft 210, and is provided integrally with the axle hub member 221 (not axially movable and non-rotatable). It has a cylinder bore 222a that is accommodated so as to be capable of reciprocating in the axial direction. The cylinder member 222 has a communication hole 222b for communicating the pump chamber Ro with the suction passage 221a and the discharge passage 221b, and a communication hole 222c for communicating the atmospheric chamber Ra with the communication passage 221c. A mounting hole 222d for assembling the cam follower 242 together with the holder 243 and the spring 244 is formed.

  The pair of bearings 251 and 252 are arranged in the axial direction (a direction along the axis Lo) by a predetermined distance, and are interposed between the fixed shaft 210 and the axle hub member 221 so as to sandwich the cylinder member 222 in the axial direction. Thus, the axle hub member 221 and the cylinder member 222, that is, the rotating body 220 are rotatable with respect to the fixed shaft 210. The pair of annular seal members 253 and 254 are disposed at a predetermined distance in the axial direction, and are interposed between the fixed shaft 210 and the axle hub member 221 so as to sandwich the cylinder member 222 and both bearings 251 and 252 in the axial direction. The space between the fixed shaft 210 and the axle hub member 221 is sealed.

  The piston 230 is accommodated in the cylinder member 222 on the outer periphery of the fixed shaft 210, and has an axial groove 230a on the inner periphery and a cam portion 230b on the outer periphery. Further, the piston 230 has a communication hole 230c that extends in the piston radial direction and allows the axial groove 230a and the cam portion 230b to communicate with each other. The piston 230 is fitted to a protrusion 210a formed on the outer periphery of the fixed shaft 210 in an axial groove 230a on the inner periphery so as not to rotate but to reciprocate in the axial direction, and is coaxial with the fixed shaft 210. It is assembled so that it cannot rotate and can reciprocate in the axial direction.

  The piston 230 is fitted to the fixed shaft 210 via a pair of annular seal members 231 and 232 at the inner periphery, and a pair of annular seal members 233 and 233 to the cylinder inner hole 222a of the cylinder member 222 at the outer periphery. The pump chamber Ro is formed in the cylinder member 222 on the outer periphery of the fixed shaft 210, and the atmospheric chamber Ra is formed.

  The pair of annular seal members 231 and 232 are arranged at a predetermined distance in the axial direction, and are interposed between the piston 230 and the fixed shaft 210 at the axial end portion of the piston 230. 210 is hermetically and liquid-tightly sealed. The pair of annular seal members 233 and 234 are disposed at a predetermined distance in the axial direction, and are interposed between the piston 230 and the cylinder member 222 at the axial end of the piston 230. 222 is hermetically and liquid-tightly sealed.

  A cam portion 230b formed on the outer periphery of the piston 230 is an annular cam groove that varies in the axial direction, and a cam follower 242 is fitted therein. The cam portion 230b has a cam surface that receives an axial load (a vertical load in the drawing) and a radial load (a horizontal load in the drawing) from the cam follower 242, and the cam surface has a cross-sectional shape of V. It has a letter shape and is formed in an even period (for example, two periods) in the circumferential direction of the piston 230.

  The cam follower 242 is a ball that is rotatably mounted on a holder 243 that is mounted on the mounting hole 222d of the cylinder member 222, and is urged inward by a spring 244 to the inside of the piston diameter and engages with the cam portion 230b. . The spring 244 is interposed between the cam follower 242 and the axle hub member 221 and urges the cam follower 242 toward the inside of the piston diameter. The holder 243 is formed in a cylindrical shape, and is provided in the mounting hole 222d of the cylinder member 222 so as to be movable in the radial direction.

  In the pressure generating device AP3 of the third embodiment configured as described above, when the rotating body 220 rotates about the axis Lo with respect to the fixed shaft 210, the rotational motion of the piston 230 is reciprocated by the cam portion 230b and the cam follower 242. Converted to motion, the piston 230 is pumped. As a result, the volume of the pump chamber Ro increases or decreases, and the air sucked into the pump chamber Ro through the suction passage 221a is discharged from the pump chamber Ro through the discharge passage 221b.

  By the way, in this pressure generating device AP3, the rotating body 220 is rotatably supported by the fixed shaft 210 via bearings 251 and 252, and the piston 230 is coaxial with the fixed shaft 210 in the rotating body 220. The pump chamber Ro is formed in the cylinder member 222 of the rotating body 220 so as to be non-rotatable relative to the fixed shaft 210 and reciprocally movable in the axial direction. In addition, the cam portion 230 b and the cam follower 242 (motion conversion mechanism) are provided coaxially with respect to the fixed shaft 210 in the rotating body 220. Therefore, the main part (piston 230 and motion conversion mechanism) of the pressure generating device AP3 can be configured compactly in the rotating body 220, and the pressure generating device AP3 can be downsized.

  In the pressure generating device AP3, the cam portion 230b and the cam follower 242 (motion conversion mechanism) are provided between the outer periphery of the piston 230 and the inner periphery of the cylinder member 222. For this reason, it is possible to configure a pressure generating device that is compact in the radial direction by effectively utilizing the space between the outer periphery of the piston 230 and the inner periphery of the cylinder member 222.

  Further, in the pressure generating device AP3, as a motion conversion mechanism for converting the rotational motion of the rotating body 220 with respect to the fixed shaft 210 into the reciprocating motion of the piston 230, the cam portion 230b provided on the piston 230 and the rotating body 220 (cylinder member). 222), a motion conversion mechanism including a cam follower 242 assembled through a holder 242 is employed. For this reason, it is possible to simply configure the motion conversion mechanism.

  Further, in the pressure generating device AP3, the piston 230 is formed in a cylindrical shape and is disposed on the outer periphery of the fixed shaft 210. A pair of bearings 251 and 252 are arranged on both sides of the piston 230 in the axial direction. For this reason, it is possible to secure the support rigidity of the rotating body 220 with respect to the fixed shaft 210 by the pair of bearings 251 and 252 and to effectively utilize the space between the both bearings 251 and 252 to make the device compact. It is possible to configure.

  In the pressure generating device AP3, annular seal members 253 and 254 for sealing the bearings 251 and 252 are interposed between the rotating body 220 and the fixed shaft 210. Therefore, both the bearings 251 and 252 can be sealed by the annular seal members 253 and 254, and the piston 230 and the motion conversion mechanism (the cam portion 230b and the cam follower 242) can be sealed. The pressure generator can be made compact and low in cost by sharing the members.

  Further, in the pressure generating device AP3, the fixed shaft 210 is integral with the fixed axle 260 of the vehicle, and wheels (not shown) can be attached to and detached from the rotating body 220 assembled to the fixed axle 260. For this reason, it is possible to assemble | attach the said pressure production | generation apparatus integrally to the fixed axle 260 of a vehicle.

  In the pressure generating device AP3, a required amount of hydraulic oil is stored in a space sealed by the annular seal members 231 to 234 (a space in which the protrusion 210a of the fixed shaft 210, the cam portion 230b, the cam follower 242 and the like are stored). In this case, the lubricating oil can be supplied to the engaging portion between the cam portion 230b and the cam follower 242, the sliding portion of the piston 230, and the like. For this reason, the lubricity of each sliding part is ensured, and it is possible to reduce sliding resistance and improve durability at each sliding part.

  In the pressure generating device AP3 of the third embodiment described above, the rotary motion of the rotating body 220 relative to the fixed shaft 210 is caused by the cam portion 230b provided on the outer periphery of the piston 230 and the cam follower 242 provided on the inner periphery of the cylinder member 222. Although the motion conversion mechanism for converting the piston 230 into the reciprocating motion is configured, the cam follower 242 provided on the outer periphery of the piston 230 and the cam portion provided on the inner periphery of the cylinder member 222 as in the modified embodiment shown in FIG. It is also possible to configure and implement a motion conversion mechanism that converts the rotational motion of the rotating body 220 relative to the fixed shaft 210 into the reciprocating motion of the piston 230 by 222e.

  In the pressure generating device AP3 of the third embodiment described above, the axial groove 230a is provided on the inner periphery of the piston 230, and the protrusion 210a is provided on the outer periphery of the fixed shaft 210, so that the protrusion 210a (fixed shaft 210) is provided. On the other hand, the axial groove 230a (piston 230) is configured to be fitted so that it cannot rotate and can reciprocate in the axial direction. However, as in the modified embodiment shown in FIG. Protrusions 230d are provided on the periphery, and axial grooves 210b are provided on the outer periphery of the fixed shaft 210. The protrusions 230d (piston 230) are fitted in the axial grooves 210b (fixed shaft 210) so that they cannot rotate but can reciprocate in the axial direction It is also possible to configure and implement them.

  In each of the above-described embodiments, the case where the cam follower of the motion conversion mechanism is a ball and the cam portion engaged with the cam follower is a cam groove has been described, but the shapes of the cam follower and the cam portion can be changed as appropriate. For example, the cam portion can be a cam projection.

1 is a cross-sectional view schematically illustrating a first embodiment of a pressure generating device according to the present invention. It is sectional drawing which showed schematically 2nd Embodiment of the pressure production | generation apparatus by this invention. It is sectional drawing which showed schematically 3rd Embodiment of the pressure generation apparatus by this invention. It is the fragmentary sectional view which showed schematically the deformation | transformation embodiment of 3rd Embodiment shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fixed shaft, 20 ... Rotating body, 20a ... Suction passage, 20b ... Discharge passage, 30 ... Piston, 41 ... Cam member, 42 ... Cam follower, 50 ... Bearing, Vi ... Suction valve, Vo ... Discharge valve, Ro ... Pump Chamber, AP1 ... pressure generating device, 110 ... fixed shaft, 120 ... rotating body, 120a ... suction passage, 120b ... discharge passage, 130 ... piston, 130b ... cam portion, 142 ... cam follower, 150 ... bearing, 160 ... fixed axle, DESCRIPTION OF SYMBOLS 170 ... Wheel, 173 ... Tire air chamber, 180 ... Axle hub, Vi ... Suction valve, Vo ... Discharge valve, Ro ... Pump chamber, AP2 ... Pressure generator, 210 ... Fixed shaft, 220 ... Rotating body, 221a ... Suction passage 221b ... Discharge passage, 230 ... Piston, 230b ... Cam part, 242 ... Cam follower, 251,252 ... Bearing, 260 ... Fixed axle, Vi ... Suction valve, Vo ... Off valve, Ro ... pump chamber, AP3 ... pressure generating device

Claims (8)

A rotating body that is rotatably supported via a bearing on a non-rotatable fixed shaft, and is disposed coaxially with respect to the fixed shaft within the rotating body and cannot rotate with respect to the rotating body or the fixed shaft and is axially And a piston that forms a pump chamber in the rotating body, and a motion conversion mechanism that is provided in the rotating body and converts a rotational motion of the rotating body relative to the fixed shaft into a reciprocating motion of the piston. , inhalable suction passage of fluid into the pump chamber provided in the rotating body, wherein provided on the rotating body provided with a discharge can discharge passage of fluid from the pump chamber, the motion converting mechanism the piston Between the inner periphery of the cylindrical portion and the outer periphery of the fixed shaft, or between the inner periphery of the rotating body and the outer periphery of the cylindrical portion of the piston, and this motion conversion mechanism is arranged coaxially with respect to the fixed shaft. A cylindrical cam and a cam follower that engages with the cam portion of the cylindrical cam are provided, and the cylindrical cam is integrally provided on one of the inner periphery of the cylindrical portion of the piston and the outer periphery of the fixed shaft, and the cam follower is A pressure generating device provided integrally with either one of the two . A rotating body that is rotatably supported via a bearing on a non-rotatable fixed shaft, and is disposed coaxially with respect to the fixed shaft within the rotating body and cannot rotate with respect to the rotating body or the fixed shaft and is axially And a piston that forms a pump chamber in the rotating body, and a motion conversion mechanism that is provided in the rotating body and converts a rotational motion of the rotating body relative to the fixed shaft into a reciprocating motion of the piston. A suction passage provided in the rotating body and capable of sucking fluid into the pump chamber; and a discharge passage provided in the rotating body and capable of discharging fluid from the pump chamber. in peripheral cylindrical portion and the inner periphery of the outer peripheral or between said rotary member of said stationary shaft is provided between the cylindrical outer circumference of the piston, the motion converting mechanism is coaxially arranged with respect to the fixed shaft A cylindrical cam and a cam follower that engages with a cam portion of the cylindrical cam are provided, and the cylindrical cam is integrally provided on either the inner periphery of the rotating body or the outer periphery of the cylindrical portion of the piston, and the cam follower Is a pressure generating device characterized in that it is provided integrally with one of the other. A pressure generating device according to claim 1 or 2, wherein the fixed shaft is fixed axle integral with the fixed shaft of the vehicle, the rotating body is rotatably mounted is disposed coaxially to the fixed axle A pressure generating device that is a rotating member that rotates integrally with a wheel. The pressure generating device according to any one of claims 1 to 3 , wherein the piston is formed in a cylindrical shape and disposed on an outer periphery of the fixed shaft. 5. The pressure generating device according to claim 4 , wherein the bearings are disposed on both axial sides of the piston. 6. 6. The pressure generating device according to claim 5 , wherein a first seal member and a second seal member for sealing the both bearings are interposed between the rotating body and the fixed shaft. Pressure generator. 4. The pressure generating device according to claim 3 , wherein the fixed shaft is detachable with respect to a fixed axle of a vehicle, and the rotating body is detachable together with a wheel of a wheel that is rotatably attached to the fixed axle. There is a pressure generating device. 4. The pressure generating device according to claim 3 , wherein the fixed shaft is integral with a fixed axle of a vehicle, and wheels can be attached to and detached from the rotating body assembled to the fixed axle. apparatus.

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