Abstract:
A turbine motor for a pneumatic tool, comprising a casing, a rotor and an axis. Compressed air enters the casing through an inlet and is directed towards blades of the rotor in a radial direction, so that torque is exerted on the axis. The blades of the rotors are to a large part hit by compressed air, each for an extended time, so that high effectivity and good efficiency result, allowing for operation at high speed and under high load.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a turbine motor for a pneumatic tool, particularly to a turbine motor which transforms pneumatic energy of air at high pressure into rotational energy, combining high power output of pneumatic tools and high efficiency with simple structure and compact design.  
       DESCRIPTION OF RELATED ART  
       [0002]     Pneumatic tools like air levers generally are driven by turbines that transform pneumatic energy of air at high pressure into rotational energy.  
         [0003]     A turbine motor for an air lever with a regulating device, as shown in  FIG. 6 , has been disclosed in Taiwan patent no. 482075, mainly comprising a pneumatic tool main body a and an adjusting rod b. The pneumatic tool main body a further comprises: a tool case c; an air inlet controlling device d; a rotor e; and a motor body f. A chamber g lies inside the pneumatic tool main body a, with inlet and outlet tubes leading into the chamber g. The motor body f is fixed inside the chamber g. Compressed air is led into the chamber g, driving a rotational movement of the rotor e in the motor body f. A rotating head h is set on the rotor e and is used as a rotating tool. The motor body f has a valve i, which is an integral hollow body, and is placed in the chamber g. The valve i has forward and reverse flow grooves and on a lower side an inlet hole j. The adjusting rod b passes through the valve i. Longitudinal shifting of the adjusting rod b controls flow of air into the valve i by causing air to enter different forward and reverse flow grooves, allowing to control directions of the rotational movement of the rotating head h.  
         [0004]     Referring to  FIG. 7 , U.S. publication no. 2003/0121680 has disclosed a turbine motor for an air lever with a regulating device, as taught in Taiwan patent no. 482075 cited above. In  FIG. 7 , the turbine motor is placed within the dash-dotted circle. Both publications describe similar turbine motors for use in pneumatic tools.  
         [0005]     A conventional turbine motor for pneumatic tools, as described above, has an arrangement of the rotor and the flow grooves that makes it complicated to regulate airflow. Furthermore, air of high pressure entering the rotor from a perpendicular direction hits rotor blades at a certain angle, causing high material stress and reduced efficiency, therefore not allowing for operation under high load and at high speed.  
         [0006]     Considering the shortcomings of conventional art, the present inventor has designed a turbine motor which, following physical laws of conservation of angular momentum and gas dynamics, offers higher effectivity, better efficiency and a simplified passage of air.  
       SUMMARY OF THE INVENTION  
       [0007]     It is the object of the present invention to provide a turbine motor for a pneumatic tool having a rotor hit by air in a radial direction, thus achieving high effectivity, good efficiency and a compact design.  
         [0008]     The present invention can be more fully understood by reference to the following description and accompanying drawings. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0009]     As shown in  FIG. 1 , the turbine motor for a pneumatic tool of the present invention comprises: a casing  10 ; a rotor  20 ; and an axis  30 , on which the rotor  20  is set. The casing  10  is a hollow body surrounding a chamber  11  and having a hole accommodating the axis  30 . An air inlet  12  and an air outlet  13  are attached to the casing  10 . The rotor  20  is placed in the chamber  11 , having an axis body and a plurality of rotor blades  21 . Compressed air entering the chamber  11  through the air inlet  12  drives a rotational movement of the rotor  20 . The axis  30  has a rear end borne by the casing  10  and a front end passing through the hole of the casing  10 , providing torque.  
         [0010]     Operation of the turbine motor for a pneumatic tool of the present invention is as follows: Compressed air enters the chamber  11  through the inlet  12 , flows towards the axis body of the axis  20  and hits the rotor blades  21 , exerting torque on the axis  30 . Since the direction of air flow leaves the rotor blades  21  of the rotor  20  exposed longer and more effective as compared to conventional art, higher output power and better efficiency are attained, making the present invention suitable for high speed and high load.  
         [0011]     Referring to  FIG. 2 , for more effective driving of the rotor  20 , a stator  40  is inserted between the rotor  20  and an inner wall of the casing  10 . The stator  40  has a plurality of stator blades  41  which surround the rotor blades  21  of the rotor  20  and are radially oriented, being placed opposite the inlet  12 . Compressed air entering the chamber  11  through the inlet  12  is deflected by the stator  40  to hit the rotor blades  21  uniformly, increasing efficiency.  
         [0012]     Referring to  FIG. 3 , for regulating forward and reverse directions of the rotating movement, two orientations of the stator blades  41  are adjustable. The stator  40  has a ring body with a plurality of blade supports  42 . The stator blades  41  are turnable on the blade supports  42 , allowing to control in which directions the rotor blades  21  are hit by compressed air, in particular, to regulate forward and reverse directions of the rotating movement. Thus a greatly simplified structure, as compared to conventional art, is achieved.  
         [0013]     Referring to  FIG. 4 , for even higher power output of the rotor  20 , an air whirling device  70  is placed around the stator  40 , reducing turbulence. A shield  60  and an outlet passageway  61  placed in the chamber  11  along airflow to the stator  40  contribute to minimizing power loss.  
         [0014]     Furthermore, a multiple bearing  50  carries the axis  30 , so that the axis  30  and the rotor  20  are disposed within the shield  60 , without friction between the axis  30  and the shield  60  being generated, so that no power is wasted.  
         [0015]     As shown in  FIGS. 5A and 5B , the present invention in another embodiment has a rear casing  80  substituted for the shield  60  and the stator  40 , tightly surrounding the rotor  20  and the rotor blades  21 . A valve  90  allows to switch incoming airflow on and off. An air direction adjusting knob  91 , moving either axially or in an angular direction and directing compressed air from the inlet  12 , allows to control forward and reverse directions of the rotational movement of the rotor  20 .  
         [0016]     As above explanation shows, the present invention, as compared to conventional art, has the following effects: 
        1. By guiding incoming compressed air onto the rotor blades in directions of rotation and having air hit the rotor blades at high speed, the rotor blades are exposed to compressed air for long time intervals and to a large part. In conventional art, rotor blades are hit by compressed air in a perpendicular direction, being exposed shorter times and to a minor part, so that a lower power output and lower speed than in the present invention are achieved.     2. By employing a stator with a variable angular position, the present invention allows to vary the direction of airflow, controlling forward and reverse directions of the rotational movement within a simple structure. Conventional art requires a penetrating, complicated structural part for controlling forward and reverse directions of the rotational movement.     3. The present invention has an air whirling device, directing compressed air to hit all of the rotor blades simultaneously, greatly increasing effectivity. Conventional art allows compressed air only to hit one rotor blade in a given time unit, obviously resulting in lower effectivity than the present invention.     4. Higher output power and greater effectivity make the present invention suitable for high speed and high load.        
 
         [0021]     While the invention has been described with reference to preferred embodiments thereof, it is to be understood that modifications or variations may be easily made without departing from the spirit of this invention which is defined by the appended claims.  
       BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]      FIG. 1  is a sectional side view of the turbine motor for a pneumatic tool of the present invention.  
         [0023]      FIG. 2  is a sectional side view of the turbine motor for a pneumatic tool of the present invention in an embodiment with a stator.  
         [0024]      FIG. 3  is a sectional front view of the stator of the present invention.  
         [0025]      FIG. 4  is a sectional side view of the turbine motor for a pneumatic tool of the present invention in an embodiment with an air whirling device, a shield and an outlet passageway.  
         [0026]      FIGS. 5A and 5B  are sectional views of the turbine motor for a pneumatic tool of the present invention in another embodiment.  
         [0027]      FIG. 6  (prior art) is a perspective view of a conventional turbine motor for a pneumatic tool.  
         [0028]      FIG. 7  (prior art) is a sectional side view of a conventional turbine motor for a pneumatic tool.