Passively retracting pneumatic actuator
A pneumatic actuator and a vehicle using the pneumatic actuator is provided. The pneumatic actuator may be utilized for separating stages of a vehicle, such as a rocket. The pneumatic actuator includes a pushrod channel having a first gas orifice at a first end and a pushrod slidably received within the pushrod channel. The pushrod defines a receiving space and is movable between a retracted position and an extended position. The pneumatic actuator further includes a pintle body received within the pushrod channel. The pintle body is arranged in fluid communication with at least the first gas orifice and the receiving space. A gas inlet valve is provided at the first gas orifice and a gas supply is fluidly coupled with the gas inlet valve. Gas is supplied to the pushrod channel via the first gas orifice according to a timed pneumatic circuit.
1 . A pneumatic actuator configured to deploy during a separation process of a vehicle, the pneumatic actuator defining an axial direction, a radial direction, and a circumferential direction, the pneumatic actuator comprising:
a housing defining a pushrod channel, the housing comprising a first gas orifice at a first end, the first gas orifice being defined through a sidewall of the housing;
a pushrod slidably received within the pushrod channel between a retracted position and an extended position, the pushrod defining a receiving space;
a pintle body received within the pushrod channel, the pintle body being in fluid communication with at least the first gas orifice and the receiving space, wherein the pintle body is fixed to the housing and the first gas orifice is spaced apart from the pintle body;
a gas inlet valve provided at the first gas orifice; and
a gas supply fluidly coupled with the gas inlet valve, the gas supply configured to supply a gas to the pushrod channel according to a timed pneumatic circuit.
2 . The pneumatic actuator of claim 1 , wherein the pushrod comprises:
a main body defining a first end and a second end;
a chamber shell formed at the first end, the chamber shell being at least partially received within the receiving space of the pushrod and defining a chamber receiving space; and
a contact tip provided at the second end.
3 . The pneumatic actuator of claim 2 , wherein at least a portion of the pintle body is received within the chamber receiving space when the pushrod is in the retracted position.
4 . The pneumatic actuator of claim 2 , wherein the pushrod further comprises:
a flange formed at the first end of the pushrod, wherein an outer diameter of the flange is greater than an outer diameter of the main body.
5 . The pneumatic actuator of claim 4 , wherein the flange defines an annular ledge extending along the circumferential direction, the annular ledge being defined between an inner circumferential surface of the housing and an outer circumferential surface of the pushrod.
6 . The pneumatic actuator of claim 5 , further comprising:
a piston ring positioned at the annular ledge, the piston ring being in sliding contact with the housing.
7 . The pneumatic actuator of claim 4 , wherein the pushrod comprises at least one aperture defined along the radial direction through the main body, the at least one aperture allowing fluid communication between the pushrod receiving space and the pushrod channel.
8 . The pneumatic actuator of claim 7 , wherein a distance between the at least one aperture and the flange is between 2% and 5% of a total length of the pushrod.
9 . The pneumatic actuator of claim 8 , wherein the chamber shell comprises:
at least one passageway fluidly coupling the pushrod channel with the receiving space, wherein the at least one passageway has a predetermined cross-sectional area configured to allow a transfer of gas therethrough according to a predetermined rate.
10 . The pneumatic actuator of claim 9 , further comprising:
a check valve positioned within the at least one passageway, the check valve configured to allow gas to pass from the pushrod channel into the receiving space.
11 . The pneumatic actuator of claim 1 , further comprising:
a connection assembly provided at the first end of the housing, the connection assembly configured to connect with a vehicle.
12 . The pneumatic actuator of claim 11 , wherein the connection assembly comprises:
a connector body received within the first end of the housing along the axial direction, the connector body comprising a connector flange;
a latch ring coupled to the connector body; and
a dampening element provided around the connector body along the circumferential direction, the dampening element biasing the connector body against the housing.
13 . The pneumatic actuator of claim 12 , wherein the housing further comprises:
an end cap coupled to the housing at the first end, wherein the dampening element is positioned between the end cap and the connector flange along the axial direction.
14 . The pneumatic actuator of claim 1 , further comprising:
a stabilizer provided around the housing along the circumferential direction, the stabilizer being positioned at a second end of the housing opposite the first end.
15 . The pneumatic actuator of claim 14 , wherein the stabilizer comprises an elastic material.
16 . The pneumatic actuator of claim 1 , further comprising:
a grounding ring provided around the housing along the circumferential direction, the grounding ring positioned at a second end of the housing opposite the first end.
17 . A vehicle comprising:
a first stage, the first stage having a propulsion source and a fuel source;
a second stage operably coupled to the first stage, the second stage being configured to separate from the first stage; and
a pneumatic actuator coupled to the first stage, the pneumatic actuator configured to selectively push the second stage away from the first stage, wherein the pneumatic actuator comprises:
a housing defining a pushrod channel, the housing comprising a first gas orifice at a first end;
a pushrod slidably received within the pushrod channel between a retracted position and an extended position, the pushrod defining a receiving space;
a pintle body received within the pushrod channel, the pintle body being in fluid communication with at least the first gas orifice and the receiving space, wherein the pushrod separates from the pintle body when the pushrod is moved to the extended position;
a gas inlet valve provided at the first gas orifice; and
a gas supply fluidly coupled with the gas inlet valve, the gas supply configured to supply a gas to the pushrod channel according to a timed pneumatic circuit.
18 . The vehicle of claim 17 , wherein the pneumatic actuator is a first pneumatic actuator among a plurality of pneumatic actuators, and wherein each of the plurality of pneumatic actuators is connected with a timed pneumatic circuit such that each pneumatic actuator is activated simultaneously.
19 . The vehicle of claim 17 , wherein the pushrod comprises:
a main body defining a first end and a second end;
a chamber shell formed at the first end, the chamber shell being at least partially received within the receiving space of the pushrod and defining a chamber receiving space; and
a contact tip provided at the second end.
20 . The vehicle of claim 19 , wherein the pushrod comprises at least one aperture defined along the radial direction through the main body, the at least one aperture allowing fluid communication between the pushrod receiving space and the pushrod channel, and wherein the chamber shell comprises at least one passageway fluidly coupling the pushrod channel with the chamber receiving space, wherein the at least one passageway has a predetermined cross-sectional area configured to allow a transfer of gas therethrough according to a predetermined rate.